gwf international Stormwater Management (Vorschau)

S1 / 2013 

Volume 154 

INTERNATIONAL 

The leading specialist journal 

for water and wastewater 

DIV Deutscher Industrieverlag GmbH 

www.gwf-wasser-abwasser.de 

ISSN 0016-3651 

B 5399 

© Rainer Sturm, pixelio.de 

Key Issue: 

STORMWATER MANAGEMENT 

Experts from Science and Practice about the State of Knowledge

gwfWasser 

Abwasser 

S1 / 2012 

Volume 153 

gwf 

Oldenbourg Industrieverlag München 


INTERNATIONAL 

The leading specialist journal 

for water and wastewater 

ISSN 0016-3651 

B 5399 

The leading Knowledge Platform in 

Water and Wastewater Business 

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Titel GWF.indd 1 18.10.2012 10:19:10 Uhr 

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KNOWLEDGE FOR THE FUTURE

POINT OF VIEW 

Stormwater Management – a Task which has to Rely 

on Local, Regional and National Cooperation 

The Situation in Dresden 

August 2002: With an Elbe water level of 9.40 m, a 

hundred year flood leaves a dramatic damage. 

Flooding, destruction of the equipment or sewer 

collapses caused damages of more than 50 millions of € 

at the Stadtentwässerung Dresden (SEDD) alone. No 

one had expected such an extreme weather event, the 

cooperation of major stakeholders of civil protection 

was rusty, and precautionary measures were only of 

limited use or non-existent. Climate change as one of 

the possible causes moved into the focus of the Dresdeners 

with a bang. Since then much has happened. 

June 2013: The June 2013 flood on the Elbe was that 

with the highest runoff volume, the third highest level 

and in addition accompanied by heavy precipitation. 

That the damages for Dresden, e.g. for the SEDD, with 

approx. € 2 million were rather limited is a considerable 

success. 

Together with local and state politics, together with 

science, together with relevant neighbours along the 

Elbe catchment area as well as together with the direct 

stakeholders, from construction and water authorities 

to the state dam administration to the drinking water 

and sewage companies, we struggle to find a balance in 

dealing with extreme weather events. We work together 

on a sustainable stormwater management that puts 

prevention and protection measures in a practical relation 

to technical, social and financial resources. 

Promoting the nature-orientated use of 

rainwater 

A nature-orientated use of rainwater within the meaning 

of § 55 (2) of the Water Resources Act (WHG) is practiced 

in Dresden since two decades now. A key tool for 

this purpose is the split precipitation fee introduced in 

1999. It provides incentives to seep away rainwater on 

the land or to use it. Wherever possible, in new construction 

areas largely unpolluted rainwater is released a 

short way back into nature. An estimation of the ratio of 

the surface areas connected to the sewer system in the 

early 90s to the surface areas of today – with respect to 

the city of Dresden - leads to the conclusion that the 

sum of the area disconnections must have approximately 

the magnitude of the outflow effective new soil 

sealing. This relation, to be considered mainly in urban 

planning, turns out to be hydrologically and economically 

reasonable. 

Investments in prevention and protection 

measures are an integral part of an overall 

strategy 

Every extreme weather event and especially the individually 

caused damage almost reflexively provokes the 

call for higher ramparts. Apart from the insight that 

there is neither the absolute protection, nor a return to 

supposedly comforting ancient times via drastic unsealing 

programs, the realization grows that many small, 

accurate and above all intertwined steps can make a 

difference. The Dresden example shows this. 

Since 2002, the SEDD invested more than € 26 million 

in sewage pumping stations and sewage treatment 

plants that are better adapted to high water. Furthermore, 

there is a powerful channel network with flood 

pumping stations for rain water and mixed water drainage, 

which has also been expanded in recent years. In 

addition to its actual usable storage volume, it is used in 

case of emergancy for the discharge of excess water 

when the stormwater management boundaries are 

reached, the groundwater levels no longer allow any 

seepage and extreme weather events occur simultaneously 

with large amounts of precipitation. 

A professional coordination of the actors of civil protection, 

the direct facility security by water barrier elements 

or disassembling of by now flexibly installed system 

components as well as the dedicated and unexcited 

effort of employees also considerably contributed to 

the minimisation of the damages during the flood event 

in 2013. Dealing with extreme weather events is also a 

learning process. 

Defuse local hotspots 

Less relaxed than in the districts of Dresden equipped 

with the mixed systems is the situation in the separation 

system areas without stormwater sewers. After the 

Wende exclusively the construction of wastewater networks 

was subsidised and responsibility for a professional 

development of stormwater management was 

transferred to the property owners. A standard sentence 

in many planning permissions is for many years: “The 

rain water is to be seeped away on the property.” 

Depending on the hydrogeologic conditions, the expertise 

and the financial budget, this works more or less 

well. All stormwater management facilities have in common 

that they are designed for a specific load case and 

International Issue 2013 

gwf-Wasser Abwasser 1

POINT OF VIEW 

High water in 

August 2002 

flooded the 

Schillergarten 

in Dresden. 

© Stefan Malsch, 

wikipedia.de 

that the distance of the groundwater to the seepage 

facilities is sufficiently large. If this is not the case, there 

are massive choke drains or overflow events. Both phenomena 

can lead to local flooding and contamination of 

the existing sewer or waters in which they end. If there is 

only one waste water system, the results are hydraulic 

overloading of the pumping stations and sewage treatment 

plants as well as water pollution and sometimes 

backwater for hours or even days. This leads to significant 

restrictions on the drainage comfort to citizens. 

Because these issues are on the frontier of the protection 

by criminal penalties, it can be assumed that not all 

subterraneous problems properly reach the surface. 

However, the operating experience of Stadtentwässerung 

Dresden regarding to the heavy rain and flood 

events in recent years as well as the findings from the 

research project “REGKLAM”, which deals with the effects 

of climate change, show that parts of our settlement 

areas are at latent risk. The risk of system overload 

increases due to the cumulation of extreme weather 

events involved with climate change. Therefore, such a 

kind of scenarios should be thought through in advance. 

It is not enough just to measure equipments and to 

approve additional impoundment frequencies. DIN 

1986-100 provides for the development of such scenarios 

for larger plots already today. Potential flood areas 

are to be kept free of construction, memory spaces and 

emergency waterways are to be created and precautions 

are to be taken in certain areas against rising 

groundwater levels. New and existing stormwater management 

systems should be planned, evaluated and, if 

necessary, adjusted in terms of their sustainability. 

„Fight climate change“ and „develop 

adaptation strategies“ belong together 

In long-living, capital-intensive infrastructure sectors 

such as water management rapid changes are almost 

impossible. It is not enough to develop adaptation strategies. 

Fighting the causes and the integration of climate 

or demographic change related adaptation strategies 

belong together. 

Since Dresden is one of the lucky cities in Germany 

that are not exposed to the consequences of demographic 

change, the SEDD in recent years could massively 

attend with very specific contributions to climate 

protection. With a new state-of-the-art digestion plant, 

photovoltaic, heat from the sewer, geothermal energy, 

and hydropower in the final effluent, an almost 60 % 

CO 2 -neutral power generation could be achieved with a 

consistent efficiency strategy and renewable energy. 

However, all this requires collaboration - locally, regionally 

and nationally. 

Gunda Röstel 

Managing Director 

Stadtentwässerung Dresden GmbH 


2 gwf-Wasser Abwasser

© JenaFoto24.de_pixelio.de

CONTENT 

Key Issue: 

Stormwater Management 

Experts from Science and Practice about the State of Knowledge 

Science 

Urban Stormwater Management 

20 J. Marsalek 

Fifty Years of Innovation in 

Urban Stormwater Management: 

Past Achievements and Current 

Challenges 


32 B.J. D’Arcy 

Managing Stormwater: 

From Aspirations 

to Routine Business 

39 G.D. Geldorf, P. Regoort and H. Bothof 

Stormwater Change in 

Existing Urban Areas 

Stormwater-runoff-management 

46 M. Kaiser 

Rainwater Management at Logistic 

and Commercial Estates with Large 

Paved Surfaces 

Rehabilitation Management 

50 F. Tscheikner-Gratl et. al. 

Integrated Rehabilitation 

Management for Different 

Infrastructure Sectors 

Emerging Pollutants 

57 J.B. Ellis, D.M. Revitt and L. Lundy 

The Treatability of Emerging 

Pollutants in Urban Stormwater 

Best Management Practice (BMP) 

Drainage Systems 

Water Management 

66 M. Suchanek et. al. 

Drainage Area Study of the City 

of Hradec Kralove, Czech Republic, 

and its Utilization for Urban 

Planning 

72 M. Lafforgue, V. Lenouvel and C. Chevauché 

The Syracuse Project – A Global 

Approach to the Management of 

Water Uses in an Urban Ecosystem 

79 J. Hoyer and J. Ziegler 

Water Sensitive Urban Design as 

a Role Model for Water 

Management in Germany? – 

Lessons learned from Australia 

Integrated Water Resources Management 

(IWRM) 

84 K. Yang, Y.P. Lü, Z.Y. Shang and Y. Che 

Stormwater Pollution and 

Management Initiatives in Shanghai 



CONTENT 

Point of View 

1 G. Röstel 

Stormwater Management – a Task which 

has to Rely on Local, Regional and National 

Cooperation – The Situation in Dresden 

Topical Subject 

6 K.W. König 

A Great Climate Thanks to Vertical Forest – 

Apartment Build in Milan: Shrubs on 

Balcony Support Technology in Building 

12 Urban Farming – the Swiss Way 

14 M. Raab 

A Building with Power 

Research Activities 

16 Quick Test Kit Detects Phenolic Compounds 

in Drinking Water 

16 How Legionella Subverts to Survive 

17 Sheltering Rising Population from 

Storm Water 

18 Extreme Weather Events Fuel Climate 

Change 

Practice 

90 SimTejo Implements Real-time Integrated 

System to Accurately Predict Sewer 

Overflows in Lisbon’s Water Network 

93 Distributed Storm Water Treatment Devices: 

Increasing Importance and Efficiency 

98 Modern Stormwater Management 

“Am Stadtpark” in Baunatal 

100 Water Treatment Plants Using Large 

Stainless Steel Filters: New Perspectives 

102 Beverage Water Treatment – Clarification 

of Surface Water with Microsand 

105 PS&S Deploys Bentley Software to Design 

BMW’s U.S. Headquarters Expansion 

Products + Solutions 

107 EVERS e. K. Receives Major Order from 

Turkey 

108 ABEL EM 100, the Perfect Solution 

to Improve Reliability and Greatly Reduce 

Maintenance Costs 

(Nampa WWTP, Idaho, USA) 

109 Merck Millipore Launches Spectroquant® 

Move 100 Mobile Colorimeter for Faster, 

More Reliable Water Analysis 

110 Top Class Stormwater Treatment 

111 BIRCO Channel Systems draining London’s 

Museum Mile 

112 RAUSIKKO Stormwater Solution 

114 Innovation and Efficiency – Connected 

Information 

116 Edition Notice 



TOPICAL SUBJECT 

A hectare of vertical forest 

(Bosco Verticale) in the centre 

of Milan. © Boeri Studio 

A Great Climate Thanks to Vertical Forest 

Apartment Build in Milan: Shrubs on Balcony Support Technology in Building 

Klaus W. König 

Designing building services according to what plants need. This is what is done in the greenhouses of every 

botanical garden. The plants are on the inside, protected by the building. But using the opportunities provided 

by the plant world first and considering the building services as a nice addition second has now been accomplished 

with as yet unprecedented consistency, at least with regard to skyscrapers. Here the plants are on the 

outside protecting the building and its residents – even up on the 20th floor. We’re talking about two residential 

buildings one 80, the other 112 metres high and the greenery covering the buildings’ facades makes up an area 

equivalent to a hectare of forest. This vertical forest (Bosco Verticale) is supplied with process water. 

Air-conditioning is only used in 

this ambitious project in the 

summer if the shade caused by the 

trees and evaporative cooling 

capacity of the plants on the facade 

is not sufficient. Forestation here 

consists of 480 large and mediumsized 

trees, 250 small trees, 5,000 

shrubs and 11,000 ground covers 

and hanging plants. 

Background and preparation 

The idea behind Bosco Verticale 

comes from Stefano Boeri. As an 

architect he looks for ways and 

means of realising urban development 

in an ecological and sustainable 

fashion. As a professor at universities 

in Milan, Genoa and Venice, he 

teaches how construction should 

and can be an interplay of human 

beings, animals and plants. In 2006- 

2008, the planning team, Boeri Studio, 

developed the design and technology 

that is used today in the project 

with the fine-sounding name of 

Porta Nuova Isola. It’s located in an 

inner-city area, north of Milan’s centre. 

Up until 60 years ago, this was 

the site of several large industrial 

plants with direct rail access to Porta 




Garibaldi station. Following its restoration, 

a metro line was taken 

through the area, which, together 

with a new road concept, further 

improves access, both to the city 

and to the outskirts of the culturally 

and economically strong metropolis, 

which Milan, as capital of the 

Lombardy Region, has always been. 

The 65-million euro project, 

Porta Nuova Isola, is now in the construction 

phase, which was scheduled 

to start in 2008 and finish by 

2013. While the final floors are still 

being built, the trees have already 

“moved in” to their tubs on the 

lower floors. Dr. Laura Gatti and 

Emanuela Borio are responsible for 

selecting the plants. For years, these 

two specialists have examined trees 

and shrubs for their suitability for 

the particular requirements of this 

experiment. Wind pressure and 

wind suction, temperature and 

humidity, the supply of water and 

nutrients as well as how the roots 

would hold (in plant tubs which 

contain their typically light substrate) 

are the critical issues. To be 

on the safe side and for reasons of 

building liability insurance, windtunnel 

tests were carried out on 

original construction components 

at a university in Florida, USA. Fully 

mature, the trees will later reach 

heights of up to 9 metres. Although 

the height of the substrate in the 

plant tubs is only 1 metre, the 

length is variable; therefore the biggest 

trees can grow in 4-5 m³ of this 

specially designed substrate. As a 

safety measure, each tree will have 

two or three attachment points, 

depending on its expected height, 

connecting it to a vertical cable, 

which is fixed to the balcony above. 

This prevents the tree from bending 

excessively, but still gives it the flexibility 

to move in the wind. “Another 

precautionary measure has involved 

growing the trees in a special nursery”, 

Laura Gatti says, “to ensure that 

right from the start they grow 

according to the special conditions 

they will be exposed to when they 

are planted on the facade”. 

The content of the tubs does not 

become the property and responsibility 

of the residents upon purchase 

of an apartment. This is part 

of the “climate system facade” and 

will therefore be tended by a special 

horticultural team in compliance 

with a maintenance agreement. The 

team will be lowered down in a basket 

from above, similar to window 

cleaners, by a crane that moves 

along the ridge of the roof. 

Process water concept and 

geothermal energy 

All the plant tubs are connected to 

an automatic watering system. This 

is designed to be supplied with processed 

grey water from the apartments. 

The process water system is, 

in turn, supplied with groundwater. 

In the course of examinations of the 

building site grounds it was discovered 

that groundwater is available 

at a depth of about 20 m, which was 

formerly used by the factories that 

were located on this site. Since the 

industrial era came to an end a few 

decades ago here, it has been discovered 

on the one hand that the 

quality of groundwater reservoirs is 

deteriorating and, on the other, that 

the water level is steadily rising. This 

has motivated the city council to 

recommend the use of treated 

groundwater in building techniques. 

And they offer removal 

thereof at the lowest, legally permitted 

fees. 

Several wells were drilled at the 

Porta Nuova Isola site. The water is 

treated and pumped into the process-water 

network, which subsequently 

supplies the water to the 

plant tubs on the outer walls of the 

apartment blocks. It is additionally 

treated by heat exchangers, making 

use of the geothermal properties of 

the groundwater for heating and 

cooling systems. As this is available 

all year round, the heat that is 

gained can also be used for the provision 

of hot water, which is also 

required throughout the year. A 

total of 4 heat pumps are installed 

in an underground technology 

 

Vertical section of the residential tower Porta Nuova 

Isola with its vertical forest (Bosco Verticale) in the 

centre of Milan. © Boeri Studio 

Two residential towers, 80 and 112 m high under 

construction in February 2013. Large trees and 

shrubs have already been planted on the lower 

floors. Bushes and ground-cover plants will also 

be planted. © König 




One of the heat 

exchangers in 

the underground 

technology 

centre. 

Geothermal 

energy from 

groundwater is 

used to provide 

warm 

water. © König 

The lower floors of one of the two residential towers, 

Porta Nuova Isola, with their vertical forest (Bosco 

Verticale), February 2013. © König 

Plant tub as balcony balustrade on the 14th floor before being planted. 

© König 

One of the 4 pumps in the underground technology 

centre. Geothermal energy from groundwater is used 

to provide warm water. © König 

Plant tub as balcony balustrade on the 14th floor, 

connected to automatic water system supplied by 

process water from the treated groundwater. © König 




centre next to the heat exchangers. 

Ring pipe systems supply the two 

towers and a further three lower 

houses in the area with warm water, 

hot water, drinking water, etc. A 

separate transfer station underneath 

each of the buildings takes 

care of further distribution. 

Excess groundwater is conveyed 

back into the earth via soakaways 

once the heat has been removed; in 

the winter a little cooler than when 

it was removed and in summer a little 

warmer, as the building’s climate 

technology gives off its waste heat 

to the soakaway water. All in all, less 

groundwater is returned than is 

removed. The difference comes 

from the watering of the facade 

plants where evaporation is utilised 

for cooling purposes slightly raising 

air humidity levels in the surrounding 

area. “We carefully calculated 

the yearly water consumption for 

each tower, façade and floor. It’s 

equal to the annual consumption of 

around 60 people,” Laura Gatti 

explains. “We assume that the plants 

will need to be watered from March 

to October, but we could even continue 

watering during the winter if 

the weather is particularly warm, 

which sometimes happens. The system 

does not use potable water; the 

water comes from the watertable 

and has been used for heating/airconditioning 

before.” 

Air-conditioning and 

certification of the building 

The shade provided by the leafy 

trees in the summer months and 

the respective evaporative cooling 

is taken into account on a flat-rate 

basis when measuring the cooling 

performance inside rooms. The 

engineer has not provided specific 

data. However, the plan is to use 

data gathered during the initial few 

years in order to adjust the technology 

retrospectively. An evaluation 

of water consumption with regard 

to groundwater and drinking water 

will also be conducted; the respective 

water metres are said to have 

been installed. The project developer, 

Hines, is putting forward the 

project for certification in accordance 

with LEED (Leadership in 

Energy and Environmental Design) 

and hopes to receive a Gold award. 

“Two points for using groundwater 

for watering the grounds are already 

guaranteed,” says the relevant LEED 

advisor, Mattia Mariani, and adds: 

“The water-saving fixtures in bathrooms 

and kitchens have also been 

taken into consideration. And 

points have also been gained for 

grassing the property in order to 

avoid urban heating.” Just how 

many points can be awarded for the 

hectare of forest in front of the 

building’s facade as a means to provide 

shade cannot be ascertained 

from the certification lists. Compari 

 

Project data: Bosco Verticale / Porta Nuova Isola 

Location 

Total area of Porta Nuova 

Isola site 

Tower D 

Tower E 

Plant tub area on facades 

of the towers D and E 

Milan /Italia, between Via de 

Castillia and Via Con falonieri 

40,000 m² 

height 80 m, 18 storeys, 

40 apartments 

height 112 m, 26 storeys, 

73 apartments 

10,000 m² 

Construction phase 2008–2013 

Costs 

Architectural design 

Landscape consultants 

Building contractor, general 

contractor and project 

developer 

€ 65 million 

Boeristudio (Stefano Boeri, 

Gianandrea Barreca, 

Giovanni La Varra) 

Emanuela Borio, Laura Gatti 

Hines Italia 

Leed consultant, MEP design Deerns Italia 

Structural design 

Precipitation in Milan 

Process water from ground 

water, required daily for 

watering (seasonal) 

Tower D annual 

(March – October) 

Tower E annual 

(March – October) 

Arup Italia 

980 mm 

max. 19–21 m³ 

min. 1855 / med. 1778 / 

max. 1975 m³ 

min. 3490 / med. 3343 / 

max. 3708 m³ 

The tree as a natural form of air conditioning 

Every plant and tree transpires, thus acting as a natural type of air 

conditioning. Aloys Bernatzky, old master of German dendrology, 

described the functional value of a 100-year-old free-standing beech 

when exposed to the best ecological conditions in his book “Baumchirurgie 

und Baumpflege” in 1978. This 25 m high tree with a crown 

spanning 14 m, a crown volume of 2,700 m³ and an inner-cellular leaf 

area of 160,000 m² absorbs 2,352 g of CO 2 and 960 g of water every 

hour. It evaporates 10 m³ of water every year at a thermal energy consumption 

of a total of 8 x 106 kcal. At 1 cubic metre that corresponds 

to 8 x 105 or 800,000 kcal per year. In physics, the energy required to 

evaporate a cubic metre of water is given as 680 kWh. This figure 

refers to evaporation at 30 °C. At 100 °C it is only 630 kWh. 

Plant tub as balcony balustrade on the 14th floor 

being planted in February 2013. Shrubs and groundcover 

plants will also be planted. © König 



Via Jacopo dal Verme 


sons have been looked for with 

awnings and then improvised. 

Outlook 

In order to avoid conflicts of interest, 

Stefano Boeri has had himself 

released from his duties at the University 

Politechnico di Milano since 

he took over the appointment of 

mayor of Milan for culture, design 

and fashion in June 2011. His planning 

office, Stefano Boeri Architetti, 

has not recruited any new assignments 

since then. It can be expected 

of such a consistent and pragmatic 

visionary that his belief of the necessity 

to transform the town into an 

ecologically healthy organism and 

its architecture into works of art that 

enable energy and space to be 

saved will be carried forward in local 

politics. 

Milan as a “playground” for this 

purpose is perfect as in the not all 

too distant future EXPO 2015 will be 

held here, with the motto: Feeding 

the planets; energy for life. 

Together with partners and students, 

the Stefano Boeri Architetti 

office has been developing feasible 

models to gradually transform 

Milan’s sealed and petrified cityscape 

into an organic Milan for 

years. Recommissioning of the 26 

closed-down agricultural enterprises 

(agriculture and horticulture) 

alone could trigger the change, supported 

by the international trend 

towards urban farming, i.e. self-supply 

of city dwellers with garden 

Via Luigi Galvani 

Via Federico Confalonieri 

Bosco Verticale 

Via Gaetano de Castillia 

Milano Porta Garibaldi 

Gioia 

Garibaldi 

Viale Don Luigi Sturzo 

Via Melchiorre Gioia 

The lower floors of one of the two residential towers, 

Porta Nuova Isola, with their vertical forest (Bosco 

Verticale), May 2013. © Mann 

Site diagram showing the Bosco Verticale Project, the new residential 

district Porta Nuova Isola in the northern part of the city of Milan. 

© Lukas König 

The trees are grown in a special nursery to ensure that they grow according to the special conditions they will be exposed to 

when they are planted on the façade. © Laura Gatti 




products by greening court yards, 

roofs and facades. Maybe EXPO 

2015 will not only see the vertical 

forest of the Bosco Verticale residential 

towers on the Porta Nuova 

Isola site, but also further utopias of 

a “metropolis with biodiversity”. This 

abstract-seeming term is the subtitle 

of the book “biomilano” bound in 

a suitably green cover. The respective 

models can be found illustrated 

in its over 150 pages. Author: Stefano 

Boeri, published 2011 by Corraini 

Edizioni, price € 26.00, 

ISBN 9 788875 703028. 

Contact: 

Klaus W. König, 

Jakob-Kessenring-Straße 38, 

D-88662 Überlingen, 

Phone +49 (0) 7551-61305, 

E-Mail: kwkoenig@koenig-regenwasser.de, 

www.klauswkoenig.com 

Evaporation mitigates the urban heat island effect 

Non-permeable surfaces such as roofs, facades and roads impair the microclimate by 

disturbing the radiation and energy balance of areas. In city centres solar radiation is 

turned into perceptible heat and long-wave radiation instead of evaporating into water, 

causing the urban heat island effect. That is why buildings need to be cooled more in the 

summer. When conventionally generated electricity is used, in terms of the entire process 

in which energy is converted more heat is produced than cold, which intensifies the 

problem of global warming. One measure that can be taken to avoid this is to plant greenery 

on buildings, with the aim of providing shade and cooling through evaporation. This 

saves energy in air conditioning systems for buildings, improves the microclimate, binds 

dust and insulates noise. 

Evaporation, a fascinating, globally-effective phenomenon, keeps our weather on the 

move. Your need for warmth is supplied worldwide by heat from the sun, which also 

causes humidity. This cools down the surrounding area. Vice versa, when humid air 

meets cooler layers in the atmosphere, clouds of very fine, condensed water are created. 

In turn, when this process continues, the clouds turn into rain and the bound-up energy 

is re-released. In this manner water and heat are continually transported from one place 

to another all around the globe. We also experience the change of the aggregate state from 

liquid to gas in our own bodies when we sweat. The heat required for evaporation is 

provided in this case by the environment and also by our bodies. Evaporation brings 

about the cool-down we need. 

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Urban Farming – the Swiss Way 

Smoked trout and crispy salad vegetables sourced directly from a producer just around the corner – nothing 

new for country dwellers but an entirely novel experience for their city cousins. This is precisely what is happening 

in the city of Basel thanks to Zurich-based company “UrbanFarmers”. The founders Roman Gaus and 

Andreas Graber have developed a system that combines traditional urban agricultural methods with aquaponics 

technology. The idea took shape during their time at the Zurich University of Applied Sciences in 

Wädenswil. 

All is not quite 

what it 

seems… The 

“LokDepot” 

rooftop farm, 

Dreispitz, 

Basel. © Urban 

Farmers.com 

Roman Gaus and Andreas Graber 

may now be serious businessmen 

but they have lost none of the 

youthful enthusiasm and drive they 

showed during their student days. 

Together they founded the spin-off 

“UrbanFarmers”, which has its headquarters 

in Zurich. Their mission is 

to transform urban wastelands (incl. 

flat roofs) from a concrete jungle 

into small-scale agricultural oases. 

Although urban farming and urban 

gardening have been around for 

quite some time (the US, in particular, 

has a sizeable urban farming 

community), what makes this project 

unique and unmistakably Swiss 

is the marriage of age-old techniques 

with cutting-edge technology 

(aquaponics). In Switzerland 

the names of Gaus and Grauber are 

on everyone’s lips thanks to their 

ingenious idea. 

Fish and vegetables from 

a Basel rooftop 

In summer 2012 Swiss UrbanFarmers 

opened Europe’s first-ever rooftop 

farm in Basel. The site for this 

pilot facility is the top of a former 

engine shed (“LokDepot”) in the 

city’s Dreispitz quarter. Here, the 

natural symbiotic relationship 

between fish and plants is exploited 

to the maximum, yielding up to five 

tonnes of vegetables and 800 kilos 

of fish. 

How aquaponics works 

The rooftop farm in Basel, which 

was set up by Swiss UrbanFarmers, 

is built around the system of aqua 

City-grown tomatoes and lettuces are particularly 

popular. In Wädenswil, researchers are looking into 

the possibility of using this system to grow exotic 

fruits as well as lemongrass. © UrbanFarmers.com 

Aquaponics – naturally simple. Vegetables and fish grow in a closed 

system developed by Zurich University of Applied Sciences in 

Wädenswil. © UrbanFarmers.com 




ponics. The fish farm at the rear of 

the greenhouse provides the other 

sections with water and natural fertilisers. 

This means that the plants 

can be grown without humus and 

with 80 % to 90 % less water than 

traditional agricultural methods. 

This system is therefore a combination 

of two classic production methods: 

“aquaculture” (breeding fish 

and growing plants in water) and 

“hydroponics” (growing plants in 

water rather than in the soil). 

The advantage of this closed 

loop system is that it does away 

with chemical fertilisers, pesticides 

or fungicides. In addition, the fish 

farm is antibiotics-free because 

population numbers are kept low 

and only fresh water is used. 

Since 1994 the Institute of Natural 

Resource Sciences (IUNR) of the 

Zurich University of Applied Sciences 

Wädenswil (ZHAW) has been 

involved in pioneering research 

into aquaponics. Today, co-founder 

of the UrbanFarmerscompany, 

Andreas Graber, lectures in aquaponics 

at his alma mater and is considered 

a leading expert in the field. 

In a Nutshell 

Locally farmed fish on the 

menu in local restaurants 

The Dreispitz rooftop farm is the 

first of its kind in the world. With 

financial support from the Baselbased 

ChristophMerian Foundation 

and the Federal Commission for 

Technology and Innovation (CTI), 

UrbanFarmers were able to plough 

a total of CHF 800,000 into this 

ground-breaking project. 

As a “proof of concept” facility, 

the “LokDepot” farm should demonstrate 

the commercial and scientific 

feasibility of producing fish and 

vegetables in a closed water cycle. 

Roman Gaus, lic.oec.HSG, Founder & Chief Executive Officer of 

UrbanFarmers 

Before starting UrbanFarmers, Roman was a rebel in the industrial 

and consumer goods industries. He noticed the urban agriculture 

trend, and learned about breakthrough technology that could make it 

more reliable and sustainable. Then one day while flying back into the 

city, he noticed the thousands of empty rooftops, and connected the 

dots. UrbanFarmers was born. 

Short Q&A with UrbanFarmer Roman Gaus: 

What contribution do you think the project has made to technological developments in 

general (green tech and cleantech)? 

“In my opinion, this approach to urban food production is not only highly integrated, but 

also scalable and commercial.” 

“I think that the urban environment offers a great many synergies which are ripe for 

exploitation, such as the recovery of low-temperature waste heat and greenhouses powered 

by solar energy.” 

How do you see its commercial future? 

“Commercial food producers and retail chains could integrate and sell UrbanFarmers’ 

produce in their own product cycles.” 

In the future, new urban agriculture 

projects will be able to benefit from 

the experience and know-how generated 

by this pioneering farm. 

The farm supplies fish and vegetables 

to local restaurants. True to its 

green credentials, the farm delivers 

its produce by electric bike. 

Further Information: 

http://urbanfarmers.com/ 

Wasseraufbereitung water treatment GmbH 

Grasstraße 11 • 45356 Essen • Germany 

Phone Telefon +49 (02201 01) 8 61 48-60 

Fax Telefax +49 (02201 01) 8 61 48-48 

www.aquadosil.de 

Unbenannt-2 1 04.08.2009 09:37:31 

Network Analysis 

F I SCHER- UHRI G E N GINEERING BERLIN 

Import Network Graph and Data (Text, 

CSV, XML, ODBC, ArcView, Mapinfo, 

many GIS / CAD Systems), Import 

Background Images (DXF, BMP, TIFF 

etc.), Show Maps and Elevation Data 

from Internet or intranet resources 

(WMS, OSM and others) 

STANET Network Simulation 

Gas, Water, District Heating, 

Steam, Waste Water, Electricity 

Stationary and Dynamic Simulation, 

Consumption Modeling based on Time, 

Temperature, Measurements and 

Consumption Billing, Events/Rules 

(PLC-Simulation), Mixtures of Qualities 

& Substances, Fire Flow Simulation, 

District Heating Simulation including 

Low Load and Condensation, Diameter 

Optimization, Height Interpolation, 

Routing and Capacity Analysis, Time 

Charts and Spatial Charts, Reports, 

Scenario Comparison 

Complete Help System, fast and scalable (more than 1 Mio Pipes) 

FISCHER-UHRIG ENGINEERING • BERLIN • GERMANY 

web: www.stafu.de email: info@stafu.de 

TEL.: +49 30 300 993 90 FAX: +49 30 308 24 212 




The power of photosynthesis: Microalgae enable the house to supply its own energy. 

A Building with Power 

Martin Raab, Endress+Hauser, Reinach 

Now, when he has developed bioreactor facades, Martin Kerner wants them to generate energy on the spot: 

on buildings in the middle of the city. Endress+Hauser is throwing its weight behind the pioneer. 

Dr. Martin Kerner has a vision: 

generating energy from algae. 

The 57-year-old was so captivated 

by the idea that he promptly took 

matters into his own hands after his 

customer suddenly lost interest in 

the project several years ago. 

With the six employees of his 

advisory service, Strategic Science 

Consult (SSC), and in cooperation 

with universities and industry he 

worked on the concept for five years 

and developed the necessary bio 

process technology. Following an 

open-field pilot installation, now 

the first building has been furnished 

with an entire facade made from 

bioreactors. Called BIQ, the building 

is one of the flagship projects of the 

International Building Exhibition in 

Hamburg. 

Why algae? For Kerner, who holds 

a PhD in hydrobiology and is qualified 

as a professor, the advantages of 

the tiny microscopic organisms are 

obvious. “Microalgae double their 

biomass every day,” he explains. 

“They grow five to ten times faster 

than conventional energy crops and 

do not compete with agriculture.” 

Built from the ground up 

Nonetheless, the entrepreneur was 

caught off guard by the phone call 

from the architecture firm. Why not 

turn the facade into a power plant, 

asked the planners. Kerner recalls 

initially thinking, “For heaven’s sake! 

We have enough problems to solve 

with the open-field installation. But 

I became increasingly fascinated 

with the idea.” Not least because 

facades are unsuitable for photovoltaic 

technology, which leaves 

enormous swathes of unused area 

on the exterior walls. 

It was soon obvious to Kerner 

that the plastic reactors developed 

for the open-field application would 

not work as building cladding. “A 

facade serves many purposes,” he 

ex-plains. It protects, insulates and 

shades the building and must satisfy 

functional as well as aesthetic 

demands. For this reason, an engineering 

company and a plant 

builder brought additional knowhow 

to the table. 

It also became evident that 

extensive automation technology 

would be required to integrate and 

operate such a system in a building. 

At this juncture, Endress+Hauser 

stepped in as project partner and 

sponsor for measurement and control 

engineering. “Endress+Hauser 

demonstrated its pioneer spirit and 

a sense of adventure,” says Kerner. 

Ingenious technology 

Apart from the instrumentation, 

Endress+Hauser also supplied the 

control engineering through its alliance 

partner Rockwell Automation 

and developed the control software 

for the highly complex system. The 

shimmering green algae solution is 

pumped through the glass reactor 

elements in a continuous cycle. The 

organisms are fed with carbon dioxide 

and nutrients to keep them alive 

and to promote growth and photosynthesis. 

The measurement technology 

monitors all of the parameters that 

are important for the well-being of 

the algae cultures and the functionality 

of the system. Endress+Hauser 

devices measure the reactors’ volume 

flow and level, determine the 

solution’s temperature, turbidity, pH 




value, conductivity and the nitrate 

and oxygen contents. “We know 

exactly what is needed to produce 

optimum conditions,” says Kerner. 

The algae harvesting is fully automated 

while the biomass will be 

processed to biogas at another 

location. 

Martin Kerner wants to use the 

first large-scale project in Hamburg 

as a stepping stone to expand the 

concept elsewhere. The innovative 

bioreactor facade is already generating 

interest. The managing director 

of SSC emphasizes that the technology 

is not suitable for singlefamily 

dwellings. “But it makes a lot 

of sense for large office and apartment 

buildings or shopping centers.” 

When the bioreactors are finally 

produced in high volume and when 

the engineering and process control 

solutions can be simply reproduced, 

“then the costs will sink to 

levels comparable to photovoltaic 

or solar-thermal elements.” 

Threefold benefit 

Kerner is looking even further 

ahead. The reactors already combine 

the use of biomass and solarthermal 

energy. “Algae require only 

a small part of the light spectrum in 

order to grow,” explains the entrepreneur. 

“That’s why we are thinking 

about equipping the reactors with 

thin-layer photovoltaic modules.” 

This could potentially increase the 

yield to nearly 60 percent of the 

light energy. 

The joint effort with Endress+ 

Hauser has evolved into a close 

partnership. Endress+Hauser plans 

to enhance the automation technology 

for future installations. 

Martin Kerner: “Our goal is to 

increase the biomass and heat production 

even further and drastically 

reduce maintenance efforts.” 

Martin Kerner, photobioreactor 

developer: “Endress+Hauser demonstrated 

its pioneer spirit and a 

sense of adventure.” 

Apart from the instrumentation, Endress+Hauser also 

supplied the control engineering through its alliance 

partner Rockwell Automation and developed the control 

software for the highly complex system. 

Model for the future 

The 2013 International Building 

Exhibition (IBA) in the heart of Hamburg 

is a quest for solutions to 

address urban living, lifestyle and 

work issues of the future. The BIQ, 

which is one of 60 model projects, is 

a five-story apartment block with a 

unique energy concept. The southeast 

and southwest facades contain 

129 photobioreactors that generate 

biomass and collect solar energy. 

The thermal energy is used to heat 

the building while the biomass created 

from the algae cultures is converted 

into biogas at another location. 

A geothermal system ensures a 

year-round hot water supply and 

stores the excess energy from the 

bioreactors. The green building with 

the bioreactor facade can be visited 

throughout IBA2013. 

Contact: 

Endress+Hauser, 

Messtechnik GmbH+Co. KG, 

Colmarer Strasse 6, 

D-79576 Weil am Rhein, 

Phone +49 (0) 7621 9 75 01, 

Fax +49 (0) 7621 97 55 55, 

E-Mail: info@de.endress.com, 

www.de.endress.com 


gwf-Wasser Abwasser 15 

The algae 

within the 

southwest and 

southeast 

façades produce 

biomass 

for renewable 

energy.

RESEARCH ACTIVITIES 

Quick Test Kit Detects Phenolic Compounds 

in Drinking Water 

Clean drinking water is a diminishing natural resource in developing nations and in many industrialised 

countries. VTT Technical Research Centre of Finland has developed a simple and inexpensive test kit that 

detects phenolic compounds in water. Sources of phenolic compounds found in drinking water include industrial 

wastewaters, drug residues and pipes. Certain phenolic compounds are toxic and some may even cause 

cancer. 

The indicator 

turns red to 

indicate that 

the sample 

contains phenol. 

Credit: VTT 

The method developed by VTT is 

based on a chemical reaction. A 

small test stick determines whether 

or not a water sample contains 

harmful phenolic compounds. If so, 

the stick will change colour within a 

few minutes. No quick, easy and 

inexpensive water quality test has 

been available until now. VTT’s test 

will be launched in 2 to 3 years. 

High levels of phenolic compounds 

in water are a problem particularly 

in industrialised countries, 

where an inexpensive test kit has 

market potential not only in the 

industrial and agricultural sectors, 

but in use by health inspectors, 

water utilities, and possibly even 

consumers. 

Markets for water quality test 

kits are also increasing in the developing 

countries. Dwindling water 

resources, increasing water prices, 

inadequate sewer systems and long 

distances between sample sites and 

laboratories increase the demand 

for simple and inexpensive test 

methods which can be applied on 

site. 

Non-degradable, toxic and ecologically 

unsafe phenolic compounds 

in industrial wastewaters 

are among the most harmful. Chlorophenols, 

for example, are carcinogenic 

and affect hepatic and renal 

function. In industrial wastewaters, 

the concentration of phenolic compounds 

may be as high as several 

hundreds of milligrams per litre. The 

cut-off value in VTT’s test is currently 

0.1 mg/l, but development of 

test precision continues. 

Phenolic compounds are used as 

raw material in chemical industries 

for producing polymers, phenolic 

resins, explosives, pigments and 

drugs. Phenols can be found in the 

wastewaters of oil refineries and 

petrochemical, wood processing, 

plastics, rubber, textile, coating and 

leather industries. 

VTT and the University of Helsinki 

have developed water quality 

test kits in collaboration with their 

industrial partners. 

Further information: 

www.vtt.fi 

How Legionella Subverts to Survive 

Bacteria of the genus Legionella have evolved a sophisticated system to replicate in the phagocytic cells 

of their hosts. LMU researchers have now identified a novel component of this system. 

In humans, Legionella is responsible 

for the so-called Legionnaires’ 

disease, a form of bacterial pneumonia 

that is often lethal. The bacteria 

can also cause Pontiac fever, a 

flu-like condition characterized by 

coughing and vomiting. Most 

Legionella-associated illnesses in 

humans are caused by Legionella 

pneumophila. 

These microorganisms are found 

in soil, lakes and rivers, and can enter 

our water supply via the groundwater. 

The greatest risk of human infection 

arises when the bacteria colonize 

air-conditioning ducts or piping 

used to transport warm water. Persons 

can be infected when they 

inhale contaminated aerosols – in 

the shower, for instance. 

The research group led by 

Hubert Hilbi, Professor of Medical 

Microbiology at LMU, studies how 

these intracellular parasites survive 




and replicate in phagocytic cells of 

their eukaryotic hosts or in the environment. 

For instance, the pathogen 

can grow and proliferate in the 

amoeba Dictyostelium, which normally 

preys on soil bacteria, engulfing 

and digesting them. But 

Legionella turns the tables, resists 

degradation and continues to grow 

in the amoeba until it is so full of 

bacteria that it bursts. 

Legionella sabotages the 

immune system 

When L. pneumophila cells infect 

the human lung, essentially the 

same thing happens. The bacteria 

are taken up by white blood cells 

called macrophages, which normally 

clear bacterial pathogens 

from the circulation. But instead of 

being consumed, the bacteria replicate 

in the macrophages and ultimately 

destroy them. Robbed of its 

first line of defense, the immune 

system has difficulty coping with 

the infection, and a life-threatening 

pneumonia may develop. 

The biochemical processes that 

enable the parasites to outwit their 

temporary hosts are highly complex. 

Thus, L. pneumophila secretes 

around 300 proteins into the 

infected cell, which is forced to redirect 

its resources for the bacterium’s 

benefit. 

Hilbi and his colleagues have 

now characterized one of these 

proteins and describe its mode of 

action for the first time. This factor, 

called RidL, disrupts an intracellular 

transport system that is necessary 

for the elimination of ingested bacteria. 

RidL binds to the so-called retromer 

complex, which is needed 

for the continued recycling of re 

ceptors, which deliver degradative 

enzymes to phagosomes containing 

bacteria destined for digestion. 

“We demonstrate that Legionella 

blocks the retromer-dependent 

transport route, thus promoting its 

own survival in the cell,” Hilbi 

explains. This function is unique. 

“Proteins that act in this way are 

otherwise unknown in the bacterial 

The picture shows a Legionella-containing vacuole 

(0.002 mm in diameter) isolated from an infected 

Dictyostelium amoeba. The vacuole is fluorescently 

labeled with the Dictyostelium protein calnexin 

(green) and the membrane lipid phosphatidylinositol-4-phosphate 

(blue), and encloses a single Legionella 

bacterium (red). 

world, and are not found in higher 

organisms either,” he adds. 


Ludwig-Maximilians-Universität München 

(LMU), 

Geschwister-Scholl-Platz 1, 

D-80539 München, 

www.uni-muenchen.de 

Sheltering Rising Population from Storm Water 

Conventional solutions to the challenges in urban storm water need to be adjusted to deal with rising 

populations and diminishing space in cities at all stages of development. 

Storm water is a critical consideration 

in managing urban water, 

as it influences the risks of flooding. 

Unfortunately, a global rise in urban 

population means that water management 

in urban areas is now 

under strain. Indeed, in the first decade 

of the XXI century, the global 

urban population grew to exceed 

the rural for the first time. It is estimated 

that urban living will be a 

reality for 60 % of the global population 

by 2030. 

To facilitate the necessary 

change in the approach to urban 

water management, it is essential to 

look at new management options 

at urban and river basin levels. This 

was precisely the objective of the 

SWITCH project, funded by the EU 

and completed in 2011. It adopted a 

novel approach by considering 

storm water as both a hazard and a 

potential resource for urban landscaping 

and urban recreational and 

open space. 

The management practices recommendations 

stemming from the 

project were implemented in four 

case study areas: in Lodz, Poland, in 

Birmingham, UK, in Emscher, Germany 

and Belo Horizonte, Brazil. 

“[The project] helped implement 

real and practical results in cities like 

Lodz, Poland, where buried streams 

were restored and their capacity for 

drainage improved,” says Peter van 

der Steen, a lecturer in waste water 

treatment at the UNESCO IHE Institute 

for Water Education, located in 

Delft, the Netherlands. He is also the 

coordinator of the project’s central 

management unit. 

The project created several databases 

identifying city-specific 

threats and outlining the impacts of 

specific control practices on storm 

water. It also led to basic best practice 

guidelines for storm water management. 

What makes this project 

stand out is its emphasis on dis 




© Alex Buirds, wikipedia.de 

semination of its findings, for use in 

future projects. 

Van der Steen sees these databases 

being used today in many 

projects he comes across. For example, 

“projects like the recent Blue 

Green Dream (BGD) project are 

using outputs from our work, even 

though there are no direct daughter 

projects of SWITCH,” he tells youris. 

com. BGD brings together urban 

planners, landscape architects and 

water experts to build better cities, 

bring down costs and make urban 

areas more attractive. 

The question is how applicable 

will be the project’s storm water 

management solutions in the coming 

decades? “Integration of urban 

stormwater management systems is 

one of the most pressing issues that 

the sector will continue to face,” says 

Philip Binning, associate professor 

of environmental modelling at the 

Technical University of Denmark, in 

Lyngby. He believes having a single 

platform is a small step in that direction. 

However, “there is still much to 

be understood about stormwater 

management and how it relates to 

the overall water cycle in cities,” he 

tells youris.com. 

Other experts believe there is a 

need to broaden the databases’ 

scope. “Most of what is presented in 

the findings seems to have in mind 

the scenarios of Northern America, 

Europe and other countries with 

sanitation infrastructures and an 

administrative system with some 

level of organisation,” says Ana Estela 

Barbosa, research officer in the 

water resources and hydraulic structures 

section at the Nation Laboratory 

for Civil Engineering in Lisbon, 

Portugal. “It should now be possible 

to make specific recommendations 

for stormwater management in 

countries where cities have few or 

no sanitation infrastructures.” 

Extreme Weather Events Fuel Climate Change 

In 2003, Central and Southern Europe sweltered in a heatwave that set alarm bells ringing for researchers. It 

was one of the first large-scale extreme weather events which scientists were able to use to document in detail 

how heat and drought affected the carbon cycle (the exchange of carbon dioxide between the terrestrial ecosystems 

and the atmosphere). Measurements indicated that the extreme weather events had a much greater 

impact on the carbon balance than had previously been assumed. It is possible that droughts, heat waves and 

storms weaken the buffer effect exerted by terrestrial ecosystems on the climate system. In the past 50 years, 

plants and the soil have absorbed up to 30 % of the carbon dioxide that humans have set free, primarily from 

fossil fuels. 

The indications that the part 

played by extreme weather 

events in the carbon balance had 

been underestimated prompted scientists 

from eight countries to 

launch the CARBO-Extreme Project. 

For the first time, the consequences 

of various extreme climate events on 

forests, bogs, grass landscapes and 

arable areas throughout the world 

underwent systematic scrutiny. 

Satellites and recording 

stations document extreme 

events 

The researchers working with 

Markus Reichstein took different 

approaches to their study from the 

ecosystem perspective. Satellite 

images from 1982 to 2011 revealed 

how much light plants in an area 

absorb so that they can perform 

photosynthesis. From this, they 

were able to determine how much 

biomass the ecosystem in question 

accumulates during or after an 

extreme weather event. The 

researchers also used data from a 

global network of 500 recording 

stations, some in operation for more 

than 15 years, which record carbon 

dioxide concentrations and air currents 

in the atmosphere a few 

meters above ground or in forest 

canopies. Calculations from these 

values indicate how much carbon 

an ecosystem absorbs and releases 

in the form of carbon dioxide. 

The team then fed the various 

readings into complex computer 

models to calculate the global effect 

of extreme weather on the carbon 

balance. The models showed that 

the effect is indeed extreme: on 

average, vegetation absorbs 11 billion 

fewer tonnes of carbon dioxide 

than it would in a climate that does 

not experience extremes. “That is 

roughly equivalent to the amount 

of carbon sequestered in terrestrial 

environments every year,” says 




Markus Reichstein. “It is therefore by 

no means negligible.” 

Droughts hit vegetation 

particularly hard 

Droughts, heat waves, storms and 

heavy rain have not yet become 

more frequent and pronounced as a 

consequence of anthropogenic climate 

change. However, many climate 

researchers expect that they 

will in the future. This would mean 

more carbon dioxide in the atmosphere 

as a result of extreme weather 

conditions. 

Periods of extreme drought in 

particular reduce the amount of carbon 

absorbed by forests, meadows 

and agricultural land significantly. 

“We have found that it is not 

extremes of heat that cause the 

most problems for the carbon balance, 

but drought,” explains Markus 

Reichstein. He and his colleagues 

expect extreme weather events to 

have particularly pronounced, varied 

and long-term effects on forest 

ecosystems. Drought can not only 

cause immediate damage to trees; it 

can also make them less resistant to 

pests and fire. It is also the case that 

a forest recovers much more slowly 

from fire or storm damage than 

other ecosystems do; indeed, grasslands 

are completely unaffected by 

high winds. 

The researchers also discovered 

that serious failures to absorb carbon 

are distributed according to a 

so-called power law, like avalanches, 

earthquakes and other catastrophic 

events. This means that a few major 

events dominate the global overall 

effect, while the more frequent 

smaller events occurring throughout 

the world play a much less significant 

part. 

One extreme after another: Long periods of drought, such as that shown here in Greece, 

have the effect that the ecosystem absorbs considerably less carbon than under normal climate 

conditions. © Marcel van Oijen 

Weather extremes are still 

very rare, but more research 

is needed 

The researchers are planning more 

studies to improve their understanding 

of the consequences of 

extreme events. For example, they 

want to investigate the way the different 

ecosystems respond in laboratory 

and field experiments. “These 

experiments have already been carried 

out, but mostly they only look 

at extreme events which occur once 

in a 100 years,” explains Michael 

Bahn, a project partner from the 

University of Innsbruck. “We should 

also take account of events which 

so far have only happened once in 

1,000 or even 10,000 years, because 

they are likely to become much 

more frequent towards the end of 

this century.” The researchers are 

also suggesting that, in a drought or 

a storm, satellites be directed at the 

area in question as quickly as possible 

so that the immediate effect can 

be recorded along with the longterm 

impact. 

The investigations of the current 

study, however, show that the consequences 

of weather extremes can 

be far-reaching. “As extreme climate 

events reduce the amount of carbon 

that the terrestrial ecosystems 

absorb and the carbon dioxide in 

the atmosphere therefore continues 

to increase, more extreme 

weather could result,” explains 

Markus Reichstein. “It would be a 

self-reinforcing effect.” 

Journal Reference 

Markus Reichstein, Michael Bahn, Philippe 

Ciais, Dorothea Frank, Miguel D. 

Mahecha, Sonia I. Seneviratne, Jakob 

Zscheischler, Christian Beer, Nina 

Buchmann, David C. Frank, Dario 

Papale, Anja Rammig, Pete Smith, 

Kirsten Thonicke, Marijn van der 

Velde, Sara Vicca, Ariane Walz, Martin 

Wattenbach: Climate extremes and 

the carbon cycle. Nature, 2013; 500 

(7462): 287 DOI: 10.1038/ 

nature12350 

Contact: 

Dr. Markus Reichstein, 

Phone +49 (0) 3641 57-6273, 

E-Mail: mreichstein@bgc-jena.mpg.de, 

www.bgc-jena.mpg.de 



SCIENCE Urban Stormwater Management 

Fifty Years of Innovation in Urban 

Stormwater Management: Past 

Achievements and Current Challenges 

Innovation, stormwater characterization, stormwater treatment, stormwater impacts on 

receiving waters, urban stormwater research 

Jiri Marsalek 

The past 50 years brought great progress in the management of urban stormwater, characterized by the development 

of understanding of generation of stormwater runoff and its quality and impacts on receiving waters, 

and the computer modelling of such processes. This knowledge was used to develop best management practices 

(BMPs) for impact mitigation. The future research and innovation is likely to follow financial incentives 

for assessing emerging pollutants and their source controls, stormwater treatment technologies, tools for planning, 

design and operation of urban drainage systems, and methods for estimating responses of stormwater 

management systems to a changing climate. As urban drainage and stormwater management issues keep 

evolving, there will be continuing demands for research targeting such needs. 

1. Introduction 

Rapid urban development after the Second World War 

contributed to fast urbanization in many regions of the 

world. To provide drainage of such areas, urban drainage 

systems (UDSs) were greatly extended or new ones 

built. Yet these efforts and expenditures did not eliminate 

urban flooding or water pollution, but just transposed 

these problems to downstream areas, and in this 

process, often created new impacts of even greater 

magnitude. In response to such problems, water managers 

and researchers in many regions of the world 

started to examine urban stormwater runoff and the 

means of mitigation of its impacts. By the mid 1960s, 

publications on this topic started to appear regularly in 

the literature and addressed mostly the characterization 

of urban stormwater and the associated impacts [1]. 

Currently, the process of urbanization is continuing 

on the global scale, with more than one half of the 

global population living in urban areas, and the trend 

towards urbanization is continuing, particularly in less 

developed countries [2]. Thus, urban drainage continues 

to attract attention world-wide. In general, the 

issues of urban drainage can be examined using a systems-analysis 

approach, whose principal objective is to 

define the system needs so that it will serve the needs of 

end-users. In specific terms, this process starts with 

problem definition, followed by the search for alternative 

solutions, evaluating such solutions (including their 

cost vs. effectiveness), interpreting these evaluations, 

and finally adapting a mix of solution measures and 

taking action through their implementation. In this context, 

the major innovation milestones in urban drainage 

and stormwater management can be described in the 

following chronological order: 

a) Problem definition – recognition of unsustainable 

growth of UDSs (i. e. unsustainable environmentally 

and economically; growth – reflecting the size of 

individual elements as well as the spatial extent of 

the system), increasing risk of flooding, stream erosion, 

stormwater pollution, and other environmental 

impacts, with concomitant reduction in services provided, 

b) Development of computer-based tools for evaluating 

urban drainage problems (i. e., urban rainfall/ 

runoff models), 

c) Development of problem solutions by stormwater 

management, including BMPs (best management 

practices), 

d) Evaluation of stormwater management measures 

with respect to solving drainage problems and the 

cost of such measures, often conducted by application 

of models simulating the performance of stormwater 

management measures, and 

e) Implementation of the best solutions through master 

drainage plans, municipal bylaws and government 

policies. 

While system analysis of urban drainage may seem 

readily tractable, it suffers from some limitations, 

imposed by such facts as: 




SCIENCE 

a) UDSs may be well-defined hydrologically, but not 

with respect to chemical inputs and interactions 

with other urban infrastructures, 

b) the nature of UDS problems keeps evolving in time, 

which somewhat contradicts the long-life expectancies 

of traditional infrastructure elements (80–100 

years for concrete sewers) contributing to technological 

lock-in [3], and 

c) UDS and drainage services involve many stakeholders 

whose participation increases the complexity of 

the implementation process. In this context, technological 

lock-in was defined as a process in which 

macro-level forces create systematic obstacles to the 

adoption of new technologies [3]. 

Thus, systems analysis of urban drainage requires periodic 

updating, of which feasibility may be impeded by 

other competing urban priorities and fluctuating levels 

of interest of the political decision makers as well as of 

end-users. 

The main objective of the paper that follows is to 

provide an overview of past achievements in stormwater 

management (SWM) and offer a cursory analysis of 

future technical challenges in this field. 

2. Past achievements 

Description of past achievements in the management 

of urban stormwater follows the path of systems analysis, 

starting with the problem definition, including the 

assessment of stormwater impacts on receiving waters, 

tools for assessing UDS problems, stormwater management 

measures, and framework for stormwater management 

implementation. 

2.1 Problem definition: stormwater quantity and 

quality 

Urban drainage impacts on the living environment represent 

a sub-group of broader environmental impacts 

of urbanization on the atmosphere, surface waters, wetlands, 

soil, groundwater and biota [2]. In discussions of 

UDSs, the problem is usually viewed more narrowly and 

encompasses the issues of surface runoff and flooding, 

stream erosion, water pollution caused by chemicals, 

solids, microbiological organisms, and discharges of 

waste heat, and the associated impairment of beneficial 

uses and impacts on biota, in the form of loss of abundance 

and biodiversity. Combined physical impacts of 

urban developments, on both surface waters and 

groundwater, were described by Leopold [4] and more 

recently by Chocat [5] who noted that urban development 

leads to increased ground imperviousness, higher 

runoff volumes and peaks, reduced groundwater 

recharge, increased soil erosion and sediment yields, 

and increased flood frequency. More recently, elevated 

temperatures of urban runoff and their effects on the 

receiving waters were also reported [6]. Reduced 

Urban stormwater management pond in a transportation corridor, 

Burlington, Canada. © Jiri Marsalek 

groundwater recharge then leads to lower baseflows 

and depressed water tables. In both cases, there is a loss 

of beneficial water uses and decrease in biodiversity [2]. 

There has not been much research done on physical 

impacts lately; they are considered as relatively well 

understood and readily addressed using the available 

models [7]. On the other hand, the issues of stormwater 

quality have attracted and continue to attract much 

more attention. 

Since the mid 1960s papers on urban stormwater 

quality have started to appear regularly in the literature 

and reported concentrations of such constituents as 

TSS, COD, BOD, TP, PO4-P, TN, TKN, trace metals (typically 

Cd, Cu, Cr, Hg, Ni, Pb and Zn), older organochlorine pesticides 

(e. g., endrin, methoxychlor, lindane), PCBs, and 

faecal indicator bacteria (faecal coliform, E. coli, streptococci) 

[8]. 

More efforts followed the initial “discovery” period in 

the form of numerous investigations of urban stormwater 

quality in a number of countries during the 1970s 

and early 1980s, with the objective of advancing the 

understanding of stormwater quality impacts on the 

receiving environments. The most extensive among 

these efforts was the US NURP (Nationwide Urban Runoff 

Program) program summarizing data from 81 sites 

monitored in 28 projects located across the USA [9]. 

NURP findings confirmed concerns about runoff quantity 

contributing to flooding and erosion/sedimentation, 

but the main effort focused on stormwater quality 

issues manifested by the impairment of beneficial uses, 

violations of water criteria, and local public perception, 

and general means of remediation. Similar but less 

extensive activities were conducted in other countries 

as well, e.g., France [10], Germany [11], and UK [12]. In 

1999, Duncan [13] referred to more than 600 references 

in a statistical overview of worldwide urban stormwater 

quality data. Some of the work related to the earlier or 




new databases on stormwater quality continued, e. g. in 

the USA, as reported by Smullen and Cave [14] (a follow 

up on the NURP) and a new database from the stormwater 

NPDES program (National Pollutant Discharge Elimination) 

[15]. In general, the worldwide efforts in 

researching stormwater quality can be credited with 

producing a general understanding of stormwater quality 

with respect to conventional and some priority pollutants 

(e. g., inorganics), and thereby producing arguments 

for conducting research on stormwater pollution 

assessment and its mitigation by control measures. 

Priority pollutants were also monitored in a number 

of studies, but in view of low concentrations (environmentally 

significant in some cases) and high analytical 

costs, such efforts were much less extensive and conclusive. 

The NURP addressed the occurrence of US EPA Priority 

pollutants and reported generally high frequencies 

of detection of inorganics (Pb, Zn, Cu, Cr, As, Cd and 

Ni; detected in more than 43 % of samples), and among 

the 106 organics on the list, 63 were detected, particularly 

the plasticiser Bis(2-ethylhexyl) phthalate (22 %) 

and an older pesticide, a-Hexachlorocyclohexane (20 %). 

There were additional 12 organics (mostly pesticides 

and PAHs) occurring in more than 10 % of samples. 

Recent studies confirmed the earlier findings with 

respect to trace metals and PAHs [16] and produced 

new information concerning phthalates, nonylphenols, 

more recently introduced pesticides, PCBs, and plasticisers 

[17, 18, 19, 20, 21, 22]. As discussed in current challenges, 

the process of stormwater characterization with 

respect to chemical pollutants will never be complete as 

long as new chemicals are released into the environment 

and the analytical methods are refined to measure 

such releases at exceptionally low, though potentially 

significant, concentrations. 

Control of urban creek grade by drop structures. © Jiri Marsalek 

2.2 Assessment of stormwater environmental 

impacts on receiving waters 

In general terms, stormwater impacts on many aspects 

of receiving waters and needs to be examined in this 

context. Depending on local legislation and policies, the 

point of focus may be the impairment or denial of beneficial 

uses, violation of water quality criteria, or local 

public perception. Impairment of beneficial uses was 

defined in the Great Lakes region [23] as a change in 

environmental conditions (chemical, physical or biological 

integrity) causing restrictions on fish and wildlife 

consumption, tainting of fish and wildlife flavour, degradation 

of fish and wildlife populations, fish tumours or 

other deformities, bird or animal deformities or reproduction 

problems, degradation of benthos, restriction 

of dredging activities, eutrophication or undesirable 

algae, restrictions on drinking waters consumption, or 

taste and odour problems, beach closings, degradation 

of aesthetics, added costs to agriculture or industry, 

degradation of phytoplankton and zooplankton, and, 

loss of fish and wildlife habitat [24]. 

Stormwater impacts on aquatic life were addressed 

for various types of biological communities, including 

algal communities, benthos and fish. Stormwater disturbs 

algal community richness and evenness by the 

presence of algal toxins (e. g., heavy metals) and interference 

with the supply of nutrients [25]. The issues 

concerning fish populations may be addressed by 

assessing the fish community performance, which 

depends on such factors as the flow regime, physical 

habitat structure, biotic interactions, energy (food) 

sources, and chemical variables (pollution) [26]. Recognizing 

the difficulties in working with fish communities, 

a simpler, but more practical analysis is usually performed 

by focusing on benthos (a source of food for 

fish) and applying sediment triads, which combine field 

sampling of the sediment chemistry and the benthic 

community composition, and laboratory testing of sediment 

toxicity [27]. In general, the above approaches are 

best applicable when examining stormwater ponds and 

constructed wetlands, or receiving waters with dominant 

impacts of stormwater. In other water bodies, 

urban drainage may still dominate the flow regime, but 

with respect to pollution, there may be too much interference 

from other polluted discharges, including agricultural 

flows, and municipal wastewater and industrial 

effluents [24]. In those cases, the emphasis is placed on 

integrated monitoring and contributions of stormwater 

to the integrated effects may be hard to discern. 

At the second level, water quality criteria violations 

and the resulting risks to human health and aquatic life 

may be assessed. Examples of such approaches were 

presented in [28 and 29]. Finally, the third level (public 

perception) represents public complains about receiving 

water colour, odour, or general aesthetic appearance 

[9]. 




SCIENCE 

2.3 Development of computer models for rainfall/ 

runoff/drainage systems/receiving waters 

Problem recognition contributed to the needs to 

address urban runoff computations for large hydrologically 

connected areas, with high volumes of physiographic 

and sewer system data. The only practical way 

of accomplishing such a task was to use computerized 

procedures, which would take into account the knowledge 

of hydrology, large diversity of the catchment 

cover, sizeable sewer systems with thousands of pipes, 

nodes and appurtenances, exposed to design hyetographs 

or historical rainfall data, and these procedures 

had to process the input information at short time steps, 

reflecting the fast hydrological response of the drainage 

system. The predecessors of the hydrologic modules of 

these models were the hydrograph methods, which 

were developed in Los Angeles [30] and Chicago during 

the 1940s. The period from the early 1960s to the early 

1980s was ‘a golden era’ of the development of urban 

rainfall/runoff models, with more than 30 models 

appearing in the literature. In the following years, there 

has been a quick consolidation in this field, with vast 

majority of urban rainfall / runoff / runoff control modelling 

being currently accomplished with several leading 

modelling packages, listed alphabetically as DHI MOUSE 

[31], Innovyze Infoworks SD CS [32], and US EPA SWMM 

[33], notwithstanding some specialty models used for 

the planning and design of BMP and LID (low impact 

development) measures [34, 35] and the modelling of 

receiving waters. This consolidation resulted from the 

fact that the leading models are robust, offer numerous 

features, and have been continuously supported and 

refined. Furthermore, the processing of physiographic 

data has been simplified by using GIS support. Further 

model development can be expected, as new research 

produces new knowledge suitable for implementation 

in models and the improvements in computer hardware 

produce ever-decreasing computing times, thus allowing 

a greater complexity models. Undoubtedly, the 

introduction of computer models into urban stormwater 

analysis was one of the most significant breakthroughs 

in this field, which facilitated the use of better 

methods in runoff computation and sewer design, and 

allowed addressing more comprehensively the complex 

issues of runoff generation and transport, stormwater 

management, and mitigation of impacts on receiving 

waters, while maintaining high levels of productivity. 

For an in-depth review of urban hydrology processes, 

and their modelling and implications for receiving 

waters, see [7]. 

2.4 Stormwater management measures: Best 

Management Practices (BMPs) and Low Impact 

Development (LID) 

A theoretical basis for stormwater quantity management 

(i. e., reduction and control of flow volumes and 

Source: berwis/pixelio.de 

rates) is relatively simple and has been known in catchment 

hydrology for quite some time. It is based on two 

concepts: the hydrological equation (describing the 

attenuation of inflows by storage) and manipulation of 

rainfall abstractions. The former concept has been used 

in dam reservoir design for flood management, but in 

the urban environment, storage may assume many 

shapes and forms, ranging from roof storage (e.g., on 

green roofs), to street surface storage (enhanced by 

inlet flow restrictors), to classical stormwater ponds. 

Typical rainfall abstractions in urban areas include surface 

depression storage, infiltration on pervious parts of 

the catchment (into soils – natural or engineered, pervious 

and permeable pavements), and evapotranspiration 

which is characterized by relatively slow process 

rates compared to the other abstractions [36]. In actual 

applications, both concepts are applied, but generally 

not to the same extent. Storage by itself redistributes 

flows, but generally does not affect flow volumes and 

distribution of runoff into various water balance compartments 

[37], as further discussed below [38]. 

Stormwater quality control measures are more complex 

than those for quantity control only and are still 

evolving. Firstly, quality controls need to be considered 

as closely related to quantity controls. Indeed, if stormwater 

volumes and flows are reduced by quantity controls, 

then the corresponding fluxes of stormwater pollutants 

are prevented, which is one of the fundamental 

axioms of modern stormwater management – preventing 

problems and exerting control as close to the source 

as possible [39, 36]. The early stormwater quality controls 

focused on passive treatment in stormwater management 

facilities, with emphasis on settling or filtration 

of total suspended solids (TSS), the next generation of 

BMPs also included some forms of biological treatment 

and targeted not just TSS, but also other pollutants, 




Source: 

Carola Langen/ 

pixelio.de 

including trace metals, nutrients, and faecal indicator 

bacteria. Conventional BMPs included stormwater management 

ponds (dry or wet), various forms of storage 

(roofs, super pipes), infiltration trenches and basins, 

porous pavement, water quality inlets, constructed wetlands, 

grassed swales or grassed filter strips, and sand 

filters [6]. To large extent, the treatment oriented BMPs 

were adopted with modifications from other fields, particularly 

wastewater treatment, in which various forms 

of settling (plain, or with lamellas, or chemically aided, 

or ballasted), treatment by infiltration into the soil, sand 

filtration, and treatment wetlands have been used for 

long time [40]. In that sense, these older methods can 

be seen as “low hanging fruit” options that were readily 

available to the early adopters. The process of searching 

for innovative stormwater management and/or treatment 

is still continuing [41], but some of the innovative 

approaches (technological devices) may be becoming 

too expensive to gain broad municipal acceptance. 

Stormwater environmental technologies represent 

devices or structures which provide stormwater treatment 

by application of various unit processes. This is a 

fairly dynamic evolving field driven largely by the competition 

to serve a potentially large market for such 

devices. However, this field is not without its own challenges, 

largely caused by the ever-increasing complexity 

of these technologies, resulting in increasing costs, 

including the heavy demands on maintenance (some of 

these devices, e.g., inserts into catch basin, may require 

weekly maintenance). Furthermore, there is confusion 

about the actual life-cycle costs and benefits of these 

devices, which is partly attributable to ambiguous information 

on their performance in treating stormwater 

(e.g., not specifying the characteristics of the treated 

medium and presenting treatment performance for fine 

sand, rather than clay and silt encountered in the field). 

Finally, with the increasing complexity of stormwater 

treatment devices, the requirements on their maintenance 

greatly increase. This aspect of stormwater management 

is still somewhat being neglected, partly 

because of maintenance underfunding. Capital investments 

into the municipal infrastructure produce much 

higher visibility than sewer or BMP maintenance. 

In recent literature, a distinction has been drawn 

between the conventional BMPs and the measures promoted 

more recently under such headings as LID (low 

impact development), SUDS (sustainable urban drainage 

systems), WSUD (water sensitive urban design), and 

others [38]. When drawing a distinction between these 

new approaches and the “conventional” BMPs, the BMPs 

were sometimes presented as more or less end-of-the 

pipe measures, but this perception may be biased. 

Some of this criticism may apply to the older facilities 

(from the 1960s and 1970s), which were primarily 

designed for reducing post-development runoff peaks. 

More recently, the stormwater management objectives 

were expanded to include preservation of groundwater 

and baseflow characteristics, prevention of undesirable 

and costly geomorphic changes in watercourses, prevention 

of flood risk potential, protection of water quality, 

and maintenance of appropriate abundance and 

diversity of aquatic life and opportunities for human 

beneficial uses [42]. Beneficial uses represent the most 

recent addition to the list of objectives and include a 

broad range of aspects, including visual and recreational 

amenity of stormwater facilities [39], rainwater 

harvesting and use [43, 44], and ecological services [45]. 

Thus, the difference between BMP and LID applications 

consist more in the design approach taken, i.e., the 

design criteria followed, rather than the measures themselves. 

Furthermore, the BMPs have never been meant 

to represent “the structural measures” only, but rather all 

the measures including non-structural measures focusing 

on such source controls as land use planning and 

development [46]. 

LID and similar approaches follow a goal of pursuing 

a comprehensive, landscape-based approach to sustainable 

urban development encompassing strategies 

to maintain existing natural systems, hydrology and 

ecology [47]. In that respect, they are similar McHarg’s 

“design with nature”, which was introduced more than 

40 years ago [48]. LID source controls target runoff generation 

and the associated pollution generation, good 

stewardship with respect to pollution sources and their 

exposure to rainwater, but without limitations on the 

nature of treatment processes. The modelling of LID 

measures creates special requirements on modelling 

urban catchment processes, with more importance 

assigned to groundwater/baseflow components and 




SCIENCE 

exfiltration from LID facilities. Elliott and Trowsdale [34] 

reviewed 10 models used in LID modelling and noted 

that several leading models provided practically all the 

features required for successful LID design. 

2.5 Framework for stormwater management 

implementation 

The understanding of technical-scientific issues of 

urban stormwater management and their verbalization 

has greatly advanced during the last two decades. Various 

stakeholders can describe rainfall/runoff processes, 

stormwater management and impacts on receiving 

waters exceptionally well, but generally within the limits 

of their experience and without a deeper understanding 

of quantitative aspects of such processes, or other 

limitations. In this process, there is a tendency for propagation 

of “idola fori”, false notions or fallacies arising 

from the imperfections and the abuse of language (Sir 

Francis Bacon (1561-1626) in Novum Organum, cited in 

Wikipedia [49]. Such notions may include thoughts that 

“pavements should be peeled off” from urban areas (i.e., 

ignoring the need to provide ground support for traffic 

and the fact that one can design pervious pavements 

with reduced runoff), all stormwater is a “resource” 

under all circumstances (this would include catastrophic 

rainfalls, e. g. the 2005 Mumbai rain event that recorded 

944 mm of rainfall in 24 h), exaggerated performance of 

some environmental technologies, and so on. These 

notions need to be corrected through public education 

and scientific studies. 

At the same time, there is a realization that the city’s 

performance in meeting end-users needs, including 

drainage, does not depend just on hard infrastructure 

(roads, sewers, treatment plants), but also on the availability 

and quality of knowledge communication and 

social infrastructure, where the latter infrastructure 

includes information and communication technologies 

and contributes to urban competitiveness. These concepts 

were introduced into urban planning as “smart” or 

“intelligent” cities, or “livable” cities, and do bear some 

consequences for urban drainage development (socioeconomic 

factors). Furthermore, livable cities feature 

attractive built and natural environments. It is of interest 

to note how these concepts are viewed by the economists. 

The Economist magazine (2013) suggested that 

these concepts (exemplified by “smart cities”) follow a 

“hype cycle” (coined by Gartner, Inc., Wikipedia, http:en. 

wikipedia.org/wiki/Hype_cycle; visited March 13, 2013) 

characterized by a period of “inflated expectations”, 

reaching some peak, followed by rapidly reduced visibility 

leading to the “trough of disillusionment”, and then 

following a slope of enlightenment to some “plateau of 

productivity”. Naturally this is just a discussion model, 

which is based on past stories of technology triggers, 

and their eventual stabilization at some plateau of productivity, 

which is hard to predict. The Economist magazine 

suggested that perhaps later this year (2013), or 

next year (2014), some benefits of the smart cities concept 

may start appearing. 

While various explanations for different rates of 

uptake of modern stormwater management have been 

offered [3], the author is of the opinion that economic 

aspects dominate in: (a) “green-field” developments, 

where such stormwater management may be required 

by regulations, mostly because the funds and space are 

available, and (b) high-value retrofits, where again funding 

is available, and the drainage design may be motivated 

by the need to meet the drainage restrictions 

placed on the land, or marketing considerations. In the 

former case, the level of uptake of modern stormwater 

management depends on the rate of growth of the city; 

e.g., in Calgary (Alberta, Canada), where the sustained 

growth has been 12 % annually, within 6 years, half of 

the city would have modern drainage, but in the case of 

a city with a negative growth (e. g., Windsor, Ontario; 

–1 %), the gains will be minimal. In the former case, it is 

relatively easy to work with principal stakeholders and 

ensure the implementation of modern drainage. Other 

factors include the local precipitation regime, and geological 

and terrain conditions. 

3. Current challenges 

Developing a comprehensive list of current and future 

challenges in such a broad field as urban drainage is a 

daunting task, particularly for a single author. Thus, the 

list of ideas compiled here is recognized as incomplete, 

and mostly reflecting the author’s experience in the 

field, with emphasis on physical aspects of UDS, rather 

than social sciences. Nevertheless, it could serve as a 

starting point for initiating discussions on this topic and 

eventually developing a much broader outlook on the 

future of urban drainage, effectively updating the earlier 

outlook provided by Chocat et al. [50]. With these 

qualifications, the author would like to address here 

future innovations, evaluation of urban drainage problem 

definition (sources of pollution, priority pollutants 

and climate change impacts), BMP research issues 

(models vs. prototype, generalization of results from 

single facilities, and study duration), and measuring the 

research accomplishments. 

3.1 Future innovations 

As cities continue to grow, there is a pressure on political 

decision makers and managers to provide water services, 

including drainage, to a growing population and 

generally at higher levels of service, certainly in the 

environmental context [2]. This is a daunting task which 

can be fully accomplished only by adopting innovative 

approaches over expanding urban areas. However, in 

urban drainage the diffusion of innovation may be 

somewhat constrained by technological lock-in, attributable 

to such factors as monopolistic provision of ser 




vices, long design lives of drainage elements, and lack of 

funding. On the other hand, it is also recognized that 

new innovations can be spurred by incentives, as noted 

in the case of the private sector (The Economist, 2013). 

If one examines the past innovation in urban stormwater 

management, much of it was the result of adopting 

and/or adapting relatively well-known processes 

from catchment hydrology (i.e., in controlling stormwater 

quantity) and wastewater management (in controlling 

stormwater quality). This leads to a question, how 

much innovation in urban drainage can be expected in 

the near future and where will this innovation come 

from. The answer to this question will differ depending 

on who is posing the question – the end-user (i.e., an 

urban dweller), the UDS operator (a municipality or utility), 

technology vendor, designer (a consulting company), 

or researcher. The issue of concerns about future 

innovation is by no means unique to urban drainage; it 

has been addressed in many fields, including computer 

processing, and in that case the Economist magazine 

(2013) questioned whether the past pace of innovation 

can be sustained. 

The author would like to suggest that with respect to 

innovation in urban drainage, there may be a nearfuture 

period during which the innovation concerning 

the basic drainage elements (i. e., sewer infrastructure 

with appurtenances, traditional BMPs) will change 

rather slowly (limited incentives), but other aspects of 

UDSs, including those involving the private enterprise 

and requiring research (e.g., UDS problem definition 

updating, software for planning, design and operation 

of UDSs, environmental technologies) will keep evolving, 

because of the inherent incentives. Such a tendency 

seems particularly clear in the case of environmental 

technologies, where there has been proliferation of 

devices and structures serving to treat stormwater, or to 

protect or enhance its quality [41]. However, the complexity 

of innovative products and their total costs (i.e., 

the initial investment plus the operating costs) keep 

increasing, which is sometimes overlooked. For example, 

inserts into sewer inlets/catch basins for improving 

stormwater quality have been proposed, but require 

weekly maintenance. The costs of such innovations may 

become rather high because of the servicing costs, and 

the environmental and economic efficiency of such 

measures (i.e., measured in dollars per kg of solids, or 

litter removed) needs to be questioned and assessed. 

Furthermore, the associated maintenance costs could 

overwhelm the existing public works departments and 

their typical allocations of resources. 

Finally, a further concern in the diffusion of innovation 

in stormwater management is the ambiguous terminology 

(i. e., terminology which is either doubtful or 

uncertain, or capable of being understood in more than 

one sense). This concern has been voiced during the last 

decade, but there is no improvement in sight. The current 

state reflects the process of evolution of stormwater 

treatment in many jurisdictions, without any consolidation 

of terminology, and as pointed out by Minton 

[51], this ambiguity led to different design methods 

developed for essentially identical processes/devices. In 

spite of recognition of this situation and a general 

agreement among stormwater professionals that the 

situation should be corrected, it is not happening, partly 

because the experts may be able to navigate among 

these ambiguous terms, and partly that this ambiguity 

was introduced by the proponents of stormwater management 

designs or technologies, who wished to distinguish 

their products / approaches from those already on 

the market and in that process wished to imply some 

superior features of their approaches. A substantive 

contribution to introducing a clear terminology has 

been made by Minton [51], who proposed to group SW 

treatment systems into the following five families: 

Basins, swales, filters, infiltrators and screens, and subdivided 

each family into sub-families, unit operations, and 

systems representing specific products or facilities. 

3.2 Evolution of urban drainage problem 

definition 

While the understanding of common impacts of urbanization 

on various environmental compartments is at a 

fairly advanced level, several specific issues are currently 

of concern and will stimulate further research: 

a) Building materials as in-situ sources of pollutants, 

b) Priority pollutants from local or remote sources, and 

c) Future precipitation regimes and their potential 

modifications by climate change, with implications 

for quantity and quality of urban stormwater. 

3.2.1 Building materials as an in-situ source 

of pollution 

Building materials have been identified as sources of 

pollutants in urban stormwater more than 30 years ago, 

certainly in the case of trace metals released by metal 

roofing materials [52]. The past 15–20 years brought 

about a greatly expanded research on this topic [53], 

with the list of pollutants identified expanding from 

metals to such chemicals, as plasticizers or biocides 

used in industrial paints on building facades (e. g., 

DCMU, Terbutryn and Carbendazim). There are continuing 

concerns about this in-situ source of stormwater 

pollution and the limited control options available to 

the municipal drainage professionals to address it, particularly 

for the existing buildings [54]. Building or road 

pavement materials may also exert positive effects on 

runoff (washoff), as documented by the use of selfcleaning 

concrete with embedded TiO 2 particles, e. g. for 

pervious concrete [55]. This photocatalyst, oxidizes air 

pollutants, including nitrogen oxide and volatile organic 

compounds, and thereby removes pollutants at street 

level. 




SCIENCE 

3.2.2 Priority pollutants 

A high number of priority pollutants have been identified 

by various international and national environmental 

agencies, starting with the US EPA list of 129 Priority 

Pollutants studied in the NURP program [9] and followed 

recently in a number of studies initiated under 

the EU Water Framework Directive [19, 56]. Experience 

from NURP shows that such data are generally used for 

assessing the pathways and fate of priority pollutants, 

but it is highly unlikely that their control would be 

added to the mandate of municipal or drainage engineers; 

it is more probable that such pollutants will be 

controlled by policy instruments (source controls), as 

was the case of phasing lead out of gasoline [57]. In a 

related example from urban drainage, this action was 

equivalent to across-the-board removal of 97 % of Pb 

from highway runoff [58]. Furthermore, municipal “ownership” 

of the priority pollutants problem would create 

municipal liabilities – i. e., responsibility for deposition 

and storage of priority pollutants in municipal stormwater 

management facilities, and the exceptionally high 

costs of their removal and disposal. The latter problem 

has been noted for stormwater pond sediment disposal 

and would apply to other BMPs as well. While the marginally 

polluted stormwater sediments can be disposed 

of for as little as CAD $ 20/m 3 (i. e., the sediment of quality 

allowing on-land disposal at a public site, located 

about 7 km from the pond), for severely contaminated 

sediments disposal costs at special containment facilities 

may be up to two orders of magnitude higher [59]. 

Controls of priority pollutants are likely to arise from 

international action at high level, as was the case of 

phasing lead out of gasoline through a series of international 

agreements. 

3.2.3 Climate change impacts on urban drainage 

Climate change impacts on urban drainage have been 

addressed during the past decade in many publications 

and much of that effort has been synthesized in [60]. In 

spite of this progress, the problem of producing quantitative 

assessments of climate change impacts on urban 

drainage remains to be challenging and further complicated 

by the dynamic nature of urban catchments, 

which keep changing as well. In projecting climate 

changes, the main challenges arise from the fact that 

global or regional climate model outputs need to be 

downscaled to scales of few kilometres and time resolution 

in minutes. Under such circumstances, the downscaled 

results may be highly uncertain and dependent 

on the downscaling process itself [60]. In this uncertain 

environment, the infrastructure managers need to make 

decisions with consequences projected 80–100 years 

into the future. Perhaps the first important step would 

be to develop uniform procedures which municipalities 

could apply, while maintaining design flexibility allowing 

further adjustments in the future. So far, most of 

the attention focused on flooding aspects, but the 

assessment of performance of the stormwater quality 

infrastructure in a changing climate is also of interest 

[61]. This performance will be impacted by the anticipated 

changes in stormwater quantity and quality 

regimes, and likely changes in pollution sources and 

their controls. 

3.3 Stormwater management measures: research 

challenges 

Achievements in developing stormwater quantity and 

quality management measures are indisputable. However, 

there are some limitations of the current research 

which will require further study. Among those, one 

could list strong reliance on laboratory rather than field 

studies, focus on small installations, relatively short 

durations of studies (ignoring issues of performance 

deterioration in time and the need for maintenance), 

and a “case study” nature of research work. Further discussion 

follows. 

3.3.1 Model vs. prototype studies 

Researchers who have worked in the field fully appreciate 

the challenges of such a work, including the difficulties 

in controlling experimental conditions and coping 

with the risk of vandalism. On the other hand, laboratory 

studies (typically on small elements of the prototype) 

eliminate practically all such challenges. However, 

Source: 

Maren Beßler/ 

pixelio.de 




to produce realistic results, lab studies on small elements 

(or even field studies on such elements) have to 

mimic fully the actual field conditions. Essential needs 

are establishing the mass balance of water, chemicals 

and solids in such tests, and mimicking fully the boundary 

conditions. The mass balance determines the ultimate 

fate of mass entering the facility (particularly the 

chemicals) and boundary conditions (e.g., outflow from 

filters into water or soils, rather than into free atmosphere) 

change the unit area treatment rates and possibly 

even the chemical reactions. Furthermore, field 

facilities (permeable/porous facilities) are prone to the 

development of macro-pores (or soil cracks) which 

greatly affect the infiltration/percolation rates, development 

of preferential flows, and also suffer from deficiencies 

occurring during construction. This has been noted 

for research facilities, and there is no reason why the 

same problem would not apply to common field installations. 

Compared to the lab studies, the field installations 

are exposed to different atmospheric, chemical and biological 

influences, such as the nature of rainfall events 

providing hydraulic loads of the test facility (distribution 

of rainfall depth and intensities, and rainwater quality), 

atmospheric deposition of chemicals or chemical applications 

or influx in field installations (e. g., chloride input 

in cold climate), solids input (e.g., from applications of 

sand and grit in winter road maintenance, subject to 

grinding by vehicle tires), and naturally occurring bioturbation 

of soils or benthic sediments by biota. In 

would be desirable to demonstrate that the results from 

small element (lab) studies describe adequately the performance 

of full-scale facilities. 

3.3.2 Spatial scaling: A single facility vs. catchment 

Spatial issues are perceived here as resulting from studying 

a single facility vs. the whole catchment. The literature 

on BMP and LID measures contains numerous studies 

essentially investigating mass balance of specific 

singular facilities and indicating inflows and outflows of 

water, chemicals and solids. Such studies have been 

most useful in developing a basic understanding of 

operation of such facilities. However, from the water 

management point of view, the interest is much broader 

– how a set of such measures (often including various 

types of measures) protects the entire catchment and 

its water resources [62]. The issue is more complex than 

a simple assumption of additive properties of these 

facilities, because the control measures within catchments 

should be designed as integrated systems, rather 

than individual dispersed measures. Thus, looking for 

evidence that urban BMPs/LID provide water protection 

at the catchment level is a legitimate question, even 

though highly challenging (i. e., to find comparable 

watersheds with different uptakes of stormwater management). 

A closely related issue concerns the fact that most 

field studies of urban stormwater BMPs are done at a 

single facility, generally because of the costs or lack of 

choices. While such studies may offer insight into field 

processes, there are usually so many experimental variables 

that often these studies represent case studies, 

rather than research studies. Thus, there is a need to 

look at larger groups (samples) of BMP facilities and 

attempt to develop more general findings [45]. While 

compilation of databases of BMP facilities performance 

is most helpful [63], such efforts may be impaired by 

challenges in undertaking QA/QC on the data submitted. 

Formation of task groups mining such databases 

and addressing specific BMPs with the objective of 

developing robust criteria for their design in various 

conditions would be most useful. 

3.3.3 Study duration 

One of the neglected points in the UDSs research is 

studying BMP performance over sufficiently long time 

periods, which would cover gradual deterioration of 

performance due to deposition of sediment, reduction 

in filtration capacity by clogging [64, 65] and reduction 

of sorption spaces, recognizing that there may be even 

changes in the rainfall regime due to a changing climate. 

Recognizing high costs of facility monitoring, it 

may be impractical to monitor such facilities (or sites) 

continuously, but in that case periodic revisiting of the 

facility would be desirable. The other factor which may 

speak against this approach is the dynamic nature of 

the urban areas (and the climate), but still the author 

believes that it would be a worthwhile activity. Alternatively, 

we need quick, inexpensive procedures for 

assessing the performance and maintenance needs status 

of BMPs, and procedures for triggering the maintenance 

action [66]. Such procedures should reach 

beyond the cost-benefit analysis, by including environmental 

risks associated with accumulations of contaminants 

in stormwater management facilities. 

3.3.4 Pollutant source control by policy 

instruments 

There are examples of environmental research which 

resulted in adoption of policies that contributed to the 

successful development of source control policies. Primary 

examples of such success stories include phasing 

lead out of gasoline and substitution of low copper content 

materials in automobile brake pads. There are 

opportunities for more advances in this field, by focusing 

on the pollution source management process. This 

requires collaboration between the researchers and 

science policy communities, by identifying sources of 

contaminants in urban stormwater, assessing the 

associated environmental risks, engaging in advocacy 

and argument in support of source controls, adopting 

source control decisions and actions, and finally, provid 




SCIENCE 

ing feedback and revision of environmental regulations. 

When dealing with low-level diffuse contaminants, 

source control policies are the most cost-effective management 

control tools deserving further promotion and 

development [58]. 

3.4 Measuring the research accomplishments 

Research accomplishments can be measured by the 

performance indicators of drainage systems, or in the 

case of academic researchers, by publications. In the 

former case, the performance criteria may include full or 

partial preservation of predevelopment water balance; 

reduction of directly connected imperviousness; compliance 

with water quality criteria; return of critical species 

(fish, birds) into the receiving waters ecosystems; 

and, benthic community performance with respect to 

biodiversity and abundance. For researchers, one of the 

main criteria are publications in refereed journals and 

citations. The volume of peer reviewed journal publications 

identifying with urban drainage research has been 

steadily growing for some time, but the rate of growth 

has greatly increased during the last decade. This is 

partly caused by the continuing interest in the urban 

environment and the resulting availability of funding, 

and partly by the pressure on researchers to publish, 

preferably in journals with high impact factors, and 

obtain citations for such publications. While this 

approach may work well for natural sciences and be 

appropriate for some aspects of urban drainage, its usefulness 

for assessing the benefits to the end-users (i.e., 

urban dwellers) can be questioned. For many publications, 

it may be challenging to identify how they serve 

the end-users and their needs. The review process generally 

does not ask about the real or perceived applicability 

of the paper findings, but simply the adherence to 

the scientific method, and other formal requirements, 

including high probability of securing paper citations 

for the journal. The widening gap between the end 

users (e.g., municipal engineers) and authors of journal 

papers has increased to the point, where some research 

programs institute “knowledge translation” projects, 

which provide a communication bridge between the 

science producers (usually university professors, whose 

scientific performance is measured by publications) and 

the end users of the produced knowledge, representing 

urban drainage professionals working for government 

agencies, or the private sector (consultants, utilities). 

Furthermore, the papers with lower citation potential 

(e.g., addressing specific climate regions) are less welcome 

in publication media. 

The business model of publication of peer reviewed 

journal papers is unusual in the fact that in the process 

of publication of research results, which may represent a 

costly product (i. e., the funds required to produce the 

research results), the quality control (i.e., the review process) 

relies greatly on help of volunteers, some of whom 

are even competitors (i. e., colleagues working in the 

same field) striving to publish in the same journal. There 

are no obvious and immediate solutions to this problem; 

the publication process can not afford the additional 

costs of “professional” reviewers, but the potential 

bias in the system should be reduced by a careful selection 

of reviewers, who understand and accept their 

responsibility for unbiased quality control. Furthermore, 

some prolific authors ‘do not have time’ for reviewing 

papers of others [67], which reduces the quality of the 

reviewer population. Additional challenges to this publication 

process are likely to be caused by proliferating 

on-line journals, which offer free access to papers by the 

general public, but are also in a conflict of interests, 

because their operation depends directly on the publication 

fees paid by the authors. In time, these on-line 

journals may provide real competition for traditional 

journals. 

4. Conclusions 

In spite of the remarkable progress in the development 

of urban drainage and stormwater management during 

the past 50 years, demands on innovation and research 

will continue in the near future, because of the dynamic 

nature of urban areas and their inhabitants. Requirements 

on urban drainage systems and stormwater management 

are continually changing, as a result of the 

dynamic nature of urban areas, changes in precipitation 

and temperature over urban areas due to climate 

change, changing releases of pollutants, and changing 

objectives for operation of urban drainage systems, 

resulting from changing expectations of the urban population. 

Acknowledgements 

This paper is based on the keynote lecture with the same title delivered by 

the author at, and included in electronic proceedings of, the 8th Int. Conf. on 

Planning & Technologies for Sustainable Urban Water Management (NOVA- 

TECH), organized by GRAIE in Lyon, June 23–27, 2013. 

References 

[1] Porcella, D.B. and Sorensen, D.L.: Characteristics of nonpoint 

source urban runoff and its effects on stream ecosystems. 

U.S. EPA, Report EPA-600/3-80-032, Corvalis, OR, 1980. 

[2] Marsalek, J., Jimenez-Cisneros, B., Karamouz, M., Malmqvist, 

P.-A., Goldenfum, J. and Chocat, B.: Urban water cycle processes 

and interactions. Taylor & Francis, Leiden, The Netherlands, 

2008. 

[3] Patouillard, C. and Forest, J.: The spread of sustainable urban 

drainage systems for managing urban stormwater: A multilevel 

perspective analysis. J. of Innovation Economics, 8 

(2011), p. 141–161. 

[4] Leopold, L.: Hydrology for urban land planning – A guidebook 

on the hydrologic effects of urban land use. U.S. Geological 

Survey Circular 554, Govt. Printing Office, Washington, 

D.C., 1968. 




[5] Chocat, B. (ed.): Encyclopedie de l’hydrologie urbaine et de 

l’assainissement (in French: Encyclopaedia of urban hydrology 

and sanitation), Paris, Lavosier Tec and Doc., 1997. 

[6] Schueler, T.: Controlling urban runoff: A practical manual for 

planning and designing urban BMPs. Metropolitan Washington 

Council of Governments, D.C., 1987. 

[7] Fletcher, T.D., Andrieu, H. and Hamel, P.: Understanding, management 

and modelling of urban hydrology and its consequences 

for receiving waters: A state of the art. Adv. in Water 

Resources, 51, p. 261–279. 

[8] Shaheen, D.G.: Contributions of urban roadway usage to 

water pollution. U.S. EPA, Report 600/2-75-004, Washington, 

D.C., 1975. 

[9] U.S. Environmental Protection Agency (EPA): Results of the 

Nationwide Urban Runoff Program Volume I – Final Report. 

Water Planning Division, U.S.EPA, Washington, DC., 1983. 

[10] Hemain, J.C., Bachoc, A., Kovacs. Y. and Breuil, B.: The current 

position in France as regards urban stormwater quality data: 

The need for a data base. In: Proc. 5 th Int. Conf. on Urban 

Storm Drainage, Osaka, Japan, July 23–27 (1980), 

p. 351–356. 

[11] Brombach, H., Weiss, G. and Fuchs, S.: A new database on 

urban runoff pollution: comparison of separate and combined 

sewer systems. Wat. Sci. Tech. 51 (2005) No. 2, 

p. 119–128. 

[12] Ellis, J.B.: Urban runoff quality in the UK: problems, prospects 

and procedures. Applied Geography 11 (1991), p. 187–200. 

[13] Duncan, H.P.: Urban stormwater quality: a statistical overview. 

Cooperative Research Centre for Catchment Hydrology, 

Melbourne, Australia, Report 99/3, 1999. 

[14] Smullen, J.T. and Cave, K.A.: National stormwater runoff pollution 

database. In: Wet-Weather Flow in the Urban Watershed, 

edited by R. Field and D. Sullivan. Lewis Publishers. Boca 

Raton (2002), p. 67–78. 

[15] Pitt, R. Maestre, A. and Morquecho: The National Stormwater 

Quality Database (NSQD, version 1.1). Dept. Civil and Env. 

Engng, University of Alabama, Tuscaloosa, AL, 2004. Available 

at: http://rpitt.eng.ua.edu/Research/ms4/Paper/Mainms 

4paper.html 

[16] Zgheib, S., Moilleron, R. and Chebbo, G.: Priority pollutants in 

urban stormwater: Part 1 – Case of separate storm sewers. 

Wat. Res. 46 (2012) No. 20, p. 6683–6692. 

[17] Rossi, L., de Alencastro, L., Kupper, T. and Tarradellas, J.: Urban 

stormwater contamination by polychlorinated biphenyls 

(PCBs) and its importance for urban water systems in Switzerland. 

Sci. of Tot. Environ. 322 (2004) No. 1–3, p. 179–189. 

[18] Eriksson, E., Baun, A.,Scholes, L., Ledin, A., Ahlman, S., Revitt, M., 

Noutsopoulos, C. and Mikkelsen, P.S.: Selected stormwater 

priority pollutants – An European perspective. The Sci. Tot. 

Environ. 383 (2007) No. 1–3, p. 41–51. 

[19] Bertrand-Krajewski, J.-L., Becouze, C., Dembele, A., Coquery, M., 

Cren-Olive, C., Barillon, B., Daunthuille, P., Chapgier, J., Grenier- 

Loustalot, M.-F. and Marin, P.: Priority pollutants in stormwater: 

the ESPRIT project. In: CD-ROM Proc. 11 th Int. Conf. on 

Urban Drainage, Edinburgh, UK, 2008. 

[20] Bressy, A., Gromaire, M.C., Lorgeoux, C. and Chebbo, G.: Alkylphenols 

in atmospheric deposition and urban runoff. Wat. 

Sci. Tech. 63 (2011) No. 4, p. 671–679. 

[21] Zgheib, S., Moilleron, R. and Chebbo, G.: Influence of the land 

use pattern on the concentrations and fluxes of priority pollutants 

in urban stormwater. Wat. Sci. Tech. 64 (2011) No. 7, p. 

450–1458. 

[22] Bjorklund, K., Cousins, A.P., Stromvall, A.-M. and Malmqvist, 

P.-A.: Phthalates and nonylphenols in urban runoff: occurrence, 

distribution and area emission factors. Sci. of Tot. 

Environ. 407 (2009), p. 4665–4672. 

[23] International Joint Commission United States and Canada: 

Revised Great Lakes Water Quality Agreement of 1978, as 

Amended by Protocol Signed Nov. 18, 1987. IJC, Windsor, 

Canada, 1988. 

[24] Novotny, V., Bartosova, A.A., O’Reilly, N. and Ehkinger, T.: 

Unlocking the relationship of biotic integrity of impaired 

waters to anthropogenic stresses. Wat. Res. 39 (2005), 

p. 184–198. 

[25] Olding, D.D.: Algal communities as a biological indicator of 

stormwater management pond performance and function. 

Water Qual. Res. J. Canada 35 (2000) No. 3, p. 489–503. 

[26] Yoder, C.: The development and use of biocriteria for Ohio 

surface waters. In: G.H. Flock (ed.), Proc. Nat. Conf. on Water 

Quality Standards for the 21 st century, U.S. EPA, Office of 

Water, Washington, D.C., 1989, p. 139–146. 

[27] Long, E.R. and Chapman, P.M.: A sediment quality triad: measures 

of sediment contamination, toxicity and infaunal community 

composition in Puget Sound. Mar. Poll. Bull. 16 

(1985), p. 405–415. 

[28] Eriksson, E., Baun, A., Mikkelsen, P.S. and Ledin, A.: Chemical 

hazard identification and assessment tool for evaluation of 

stormwater priority pollutants. Wat. Sci. Tech. 51 (2005), 

p. 47–55. 

[29] Lundy, L., Ellis, J.B. and Revitt, D.M.: Risk prioritisation of 

stormwater pollutant sources. Wat. Res. 46 (2012), p. 6589– 

6600. 

[30] Hicks, W.J.: A method of computing urban runoff. Trans. of 

the American Soc. of Civil Engrs (ASCE) 109 (1944), p. 1217– 

1253. 

[31] DHI water and Environment: MOUSE pipe flow: Reference 

manual. DHI Water & Environment, Hørsholm, Denmark, 

2004. 

[32] Innovyze: InfoWorks CS Technical Review Collection Systems 

(CS). Available on line, 2011, http://www.innovyze.com/ 

products/infoworks_cs/, visited on March 5, 2013. 

[33] Rossman, Lewis A.: Storm Water Management Model User’s 

Manual. EPA/600/R-05/040, U.S. Environmental Protection 

Agency, Cincinnati, OH, 2009. 

[34] Elliott, A.H. and Trowsdale, S.A.: A review of models for low 

impact urban stormwater drainage. Environmental modelling 

and Software 22 (2007), p. 394–405. 

[35] Gironas, J., Roesner, L. and Davis, J.: Stormwater Management 

Model, Applications Manual. US EPA, Report EPA/600/R-09/ 

077, EPA, 2009. 

[36] Water Environment Federation (WEF) and American Society 

of Civil Engineers (ASCE): Urban runoff quality management. 

WEF Manual of Practice No. 23, ASCE Manual and Report on 

Engineering Practice No. 87, Alexandria and Reston, VA, 

1998. 

[37] Sieker, H.: Generelle Planung der Regenwasserbewirtschaftung 

in Siedlungsgebieten (In German: General planning of 

stormwater management in urban areas). Doctoral thesis, 

Tech. University of Darmstadt, Germany, 1999. 

[38] Burns, M.J., Fletcher, T.D., Walsh, C.J., Ladson, A.R. and Hatt, 

B.E.: Hydrologic shortcomings of conventional urban stormwater 

management and opportunities for reform. Landscape 

and Urban Planning 105 (2012), p. 230–240. 




SCIENCE 

[39] Geiger, W. and Dreiseitl, H.: Neue Wege für das Regenwasser 

(In German: New path for rainwater). R. Oldenbourg Verlag 

GmbH, Munich, 1995. 

[40] Metcalf and Eddy, Inc.: Wastewater engineering: treatment 

and reuse. 4 th ed., McGraw Hill, Toronto, 2003. 

[41] Clark, S.E. and Pitt, R.: Targeting treatment technologies to 

address specific stormwater pollutants and numeric discharge 

limits. Wat. Res. 46 (2012) No. 20, p. 6715–6730. 

[42] Ministry of the Environment (MOE): Stormwater management 

planning and design manual. MOE, Toronto, 2003. 

[43] Schuetze, T.: Rainwater Harvesting and Management – Policy 

and Regulations in Germany. Wat. Sci. Tech.: Water Supply, 

Vol. 13 (2013) No. 2, p. 376–385. 

[44] Ward,. S., Barr, S., Memon, F. and Butler, D.: Rainwater harvesting 

in the UK: exploring water-user perceptions. Urban 

Water 10 (2013) No. 2, p. 112–126. 

[45] Moore, T. L.C. and Hunt, W.F.: Ecosystem service provision by 

stormwater wetlands and ponds – A means for evaluation? 

Wat. Res. 46 (2012) No. 20, p. 6811–6823. 

[46] Field, R., Tafuri, A.N. and Masters, H.E.: Urban runoff pollution 

control technology overview. US Environmental Protection 

Agency, Report EPA-600/2-77-047, Washington, D.C., 1977. 

[47] Davis, A.P., Hunt, W.F., Traver, R.G. and Clar, M.E.: Bioretention 

Technology: An Overview of Current Practice and Future 

Needs. J. Environ. Engng, 135 (2009) No. 3, p. 109–117. 

[48] McHarg, I.L.: Design with nature. Natural History Press, Garden 

City, NJ., 1969. 

[49] Wikipaedia (2013): http://en.wikipedia.org/wiki/Idola_fori 

(visited on Feb.18, 2013). 

[50] Chocat,. B., Ashley, R., Marsalek, J., Matos, M.R., Rauch, W., 

Schilling, W. and Urbonas, B.: Towards the sustainable management 

of urban storm-water. Indoor and Built Environment 

16 (2007) No. 3, p. 73–285. 

[51] Minton, G.R.: A tower of Babel: A proposed framework for 

treatment terminology. Stormwater 8 (2007) No. 2, p. 48. 

[52] Malmquist, P.-A. and Svensson, G.: Urban storm water pollutant 

sources. In: Proc. Int. Symp. on the effects of urbanization 

and industrialization on the hydrological regime and on 

water quality, IAHS Publication No. 123, IAHS Press, Wallingford, 

UK, 31–38, 1978. 

[53] Foerster, J.: Variability of roof runoff quality. Wat. Sci. Tech. 39 

(1999) No. 5, p. 137–144. 

[54] Burkhardt, M., Zuleeg, S., Vonbank, R., Bester, K., Boller, M., Carmeliet, 

J. and Wangler, T.: Leaching of biocides from façades 

under natural weather conditions. Env. Sci. Tech. 46 2012) 

No. 10, p. 5497–5503. 

[55] Burton, M.C.: Pervious concrete with titanium oxide as a photocatalyst 

compound for a greener urban road environment. 

M.Sc. thesis, Dept. of Civil and Environ. Engng, Washington 

State University, Pullman, WA, 2011. 

[56] Birch, H.: Monitoring of priority pollutants in dynamic stormwater 

discharges from urban areas. PhD Thesis. Dept. of Env. 

Engng, Technical University of Denmark, Lyngby, 2012. 

[57] Organisation for Economic Co-Operation and Development 

(OECD) and United Nations Environmental Programme 

(UNEP). Phasing lead out of gasoline. OECD, Paris, France, 

1999. 

[58] Marsalek, J. and Viklander, M.: Controlling contaminants in 

stormwater: Linking environmental science and policy. In: J. 

Lundqvist (ed.), On the Waterfront, Vol. 2, Selections from 

the 2010 Water Week in Stockholm, Stockholm International 

Water Institute, Stockholm, Sweden, 2011. 

[59] Karlsson, K., German, J. and Viklander, M.: Stormwater pond 

sediments: temporal trends in heavy metal concentrations 

and sediment removal. Soil & Sediment Contamination 19 

(2010) No. 2, p. 2178–230. 

[60] Willems, P., Olsson, J., Arnbjerg-Nielsen, K., Beecham, S., Pathirana, 

A., Bulow Gregersen, I., Madsen, H. and Nguyen, V.T.V.: 

Impacts of climate change on rainfall extremes and urban 

drainage systems. IWA Publishing, London-New York, 2012. 

[61] Borris, M., Viklander, M., Gustafsson, A.-M. and Marsalek, J.: 

Modelling the effects of changes in rainfall event characteristics 

on TSS loads in urban runoff. Hydrological Processes 

DOI: 10.1002/hyp.9729), 2013. 

[62] Roy, A., Wenger, S., Fletcher, T., Walsh, C. Ladson, A., Shuster, W., 

Thurston, H. and Brown, R.: Impediments and solutions to 

sustainable, watershed-scale urban stormwater management: 

lessons from Australia and the United States. Environ. 

Management 42 (2008) No. 2, p. 344–359. 

[63] International Stormwater BMP Database (2013). Available 

on-line; www.bmpdatabase.org (visited March 15, 2013). 

[64] Le Coustumer, S., Fletcher, T.D., Deletic, A., Barraud, S. and 

Poelsma, P.: The influence of design parameters on clogging 

of stormwater biofilters: A large scale column study. Wat. 

Res. 46 (2012) No. 20, p. 6743–6752. 

[65] Sansalone, J., Kuang, X., Ying, G. and Ranieri, V.: Filtration and 

clogging of permeable pavement loaded by urban drainage. 

Wat. Res. 46 (2012) No. 20, p. 6763–6774. 

[66] Yong, C.F., MacCarthy, D.T. and Deletic, A.: Predicting physical 

clogging of porous and permeable pavements. J. Hydrology 

481 (2013), p. 48–55. 

[67] Dixon, D. and van Loosdrecht, M.: Two sides of the coin (an 

editorial). Wat. Res. 46 (2012) No. 20, Editorial page. 

Author 

Prof. Dr. Jiri Marsalek 

E-Mail: jiri.marsalek@ec.gc.ca | 

Water Science and Technology Directorate | 

Environment Canada, 867 Lakeshore Rd | 

Burlington, ON, Canada L7R 4A6 

and 

Urban Water | 

Luleå University of Technology | 

S-971 87 Luleå (Sweden) 



SCIENCE Stormwater Management 

Managing Stormwater: 

From Aspirations to Routine Business 

Stormwater, urban diffuse pollution, SUDS, environmental regulation, BMPs 

Brian J. D’Arcy 

Stormwater management is a requirement for all urban areas, associated with the high degree of imperviousness 

of cities, towns and industrial/commercial developments. The origins of innovations are a combination of 

the need to address serious problems (pollution and flooding) allied with a desire to use rainwater as a 

resource. Resource use includes amenity and allowing nature a place in the urban environment by creating 

functional green space. Aspirations are easy, realising them is challenging. The SUDS concept in the UK developed 

from combining urban BMPs techniques with the need to creatively address pluvial flooding risks, with 

the overall aim of trying to mimic natural hydrology. A combination of innovative environmental regulation, 

together with partnership working and education including technical guidance has resulted in SUDS being 

routine business in Scotland, contrasting with the situation elsewhere in the UK and much of Europe. But this 

widespread application of the technology is novel; there are still many challenges to achieving effective, attractive 

and fit for purpose features where they are needed, including retrofits. 

1. From Problems to Aspirations 

Urban stormwater in this context is taken to refer to 

rainfall driven surface water runoff, whether it drains to 

surface water sewers, to combined sewers, enters a 

watercourse directly as surface runoff, or infiltrates into 

soil and groundwater (Ellis et al 2004). The origins of 

innovative approaches to managing stormwater in the 

built environment in the UK are threefold: 

1. Water quality issues 

2. Groundwater recharge and water shortages 

3. Pluvial flooding associated with more intensive 

rainfall in constrained drainage catchments. 

Initially, three different organisations in the UK were 

involved, at first working independently to explore 

more intelligent techniques to manage stormwater in 

relation to the above issues. 

The Forth River Purification Board (FRPB), a statutory 

catchment based water pollution control authority in 

Scotland until 1996, initiated a review of remaining 

water pollution control issues in 1993, in anticipation of 

the 1996 formation of SEPA, the Scottish Environment 

Protection Agency. One of the findings of the review 

was that diffuse sources were a hitherto unrecognised 

but very significant problem for water quality in the 

Forth catchment. One of the diffuse source categories 

was urban drainage, which was a significant cause of 

poor water quality (FRPB 1995). Figure 1 shows the 

sources of unsatisfactory quality as determined by 

chemical and ecological data interpreted using expert 

knowledge of each sub-catchment in relation to discharges 

and pollution sources. 

The evidence was more compelling when the worst 

case impacts were examined (classes 3–4), where 19 % 

and 24 % respectively of the class 3 and class 4 polluted 

reaches were associated with urban drainage. Intensive 

efforts to control urban pollution prior to the FRPB 

review had focused on oil spills and on the variety of 

pollution that characterised contaminated drainage 

from industrial estates (D’Arcy and Bayes 1995). Generally, 

the most important pollutants were thought to be 

oil, PAHs and toxic metals, (subsequently investigated in 

a national Scottish stream sediments survey, Wilson et al 

2005). There was also a growing recognition in parts of 

the UK that foul-into-surface-water wrong connections 

were an important issue. Unpublished surveys in Merseyside 

showed that sewage discharges from surface 

water drains was a ubiquitous feature of the drainage 

network, and similar subsequent investigations in Scotland 

found chronic and new problems too. 

The recognition of diffuse pollution as an issue, led 

to understanding that there was a need for stormwater 

management infrastructure that could accept an unavoidable 

level of contamination in surface water drainage 

and capture problem pollutants; specifically to capture 

suspended matter with adsorbed persistent pollutants, 

and to allow degradation of hydrocarbons. That 

FRPB review thus provided the environmental evidence 

that a new approach was required to manage urban diffuse 

pollution, including urban drainage, and the pollu 




SCIENCE 

Table 1. Problem driven Stormwater aspirations in UK, mid-1990s. 

Drivers 

Water Quality 

a) Address existing intractable, 

chronic pollution 

Water quality 

b) Prevent new problems 

Water Quantity 

a) Address urban flood risks 

Water quantity 

b) Address groundwater 

recharge 

Geographic 

Focus 

Scotland 

Scotland 

England 

England 

Example Issues 

Separately sewered Industrial 

estates, especially in New Towns 

such as Cumbernauld & Glenrothes 

Major roads and housing developments 

Imperviousness a major issue for 

pluvial flood risks 

Loss of natural hydrology – imperviousness 

Loss of natural hydrology UK Implicated in mobilisation of diffuse 

pollutants as well as flooding & 

groundwater recharge 

Environmental Regulator 

Forth River Purification Board, FRPB, 

then from 1996 Scottish Environment 

Protection Agency, SEPA 

FRPB then SEPA 

National Rivers Authority, NRA, then 

environment Agency, EA (England 

and Wales) 

NRA then EA from 1996 

The key to an integrated philosophy 

for managing stormwater in UK 

tion evidence base was extended nationally for Scotland 

in 1996 and subsequently (SEPA 1996, 1999, Wilson 

et al 2005). 

Initially independently of the water quality investigations 

noted above, the then NRA (National Rivers 

Authority) in SE England was concerned about the need 

to recharge groundwater, allied with interest in reducing 

flood risks exacerbated by urbanisation of catchments 

(Gardiner et al 1994). In parallel, investigations at 

Coventry University into permeability in the built en 

vironment at that time led to interest in permeable 

pavements (Pratt 1989, 1995), as well as soft engineering 

technology for stormwater management. The result 

of those interests in stormwater quantity issues and 

water resources led to a guidance document from the 

Construction Industry Research and Information Association, 

(CIRIA 1992). Thus by the early-mid 1990’s in UK, 

the following aspirations for stormwater management 

were recognised: 

"" 

Attenuate peak flows prior to discharge to the water 

environment by encouraging infiltration 

"" 

Capture diffuse sources of pollutants as close 

to source as possible 

"" 

Favour drainage techniques that allow for degradation 

as well as capture of pollutants 

"" 

Encourage drainage infrastructure that minimizes 

opportunities for wrong connections of foul into 

surface water drains 

"" 

In providing drainage for the built environment seek 

to replicate the natural hydrology of the area. 

The detailed considerations behind those aspirations, 

(driving policies and actions in the UK), are set out in 

table 1. 

Figure 1. Causes of unsatisfactory river water quality in the Forth 

Catchment, with reference to a four category classification scheme 

whereby 1 is the best and four the poorest (FRPB, 1994) 

2. BMPs and developing the infrastructure 

aspirations 

Best Management Practices or BMPs are defined as 

techniques that an agency may require to address diffuse 

sources of pollution (Novotny 2003), and may be 

procedures or physical structures. From table 1 it is 

clear why the BMPs concept was recognised in Scotland 

but not seen as such a key idea elsewhere in UK. Typical 

urban BMPs include grass swales and filter strips, 

extended detention basins, detention and retention 

ponds, permeable surfaces, bioswales and rain gardens 

(see Schueler 1987, Schuler et al 1992). One of the ideas 




Figure 2. 

MDCIA exemplified 

for (a) 

housing in Berlin 

and (b) 

Seattle: roof 

runoff discharges 

onto 

front lawn. 

Foul connections 

are not 

an option. 

that emerged from USA as an element in the application 

of BMPs for managing stormwater was MDCIA, minimising 

directly connected impervious area (Urbonas 1999). 

That was advocated as a basic strategic approach to 

reduce runoff rates and delivery of pollutants to the 

water environment, by favouring grass/soil infrastructure 

or permeable surfaces for groundwater recharge or 

at least slowing runoff and allowing sedimentation/filtration, 

wherever possible. For the UK aspirations above 

it became clear that MDCIA would also eliminate the 

insidious problem of foul into surface water drains. Thus 

if the stormwater passed through a grass filter strip prior 

to connecting with a public drainage network, any foul 

drain contamination would surely be noticed and 

resolved very quickly by the householder/occupier of 

the premises (see figure 2 (a), example of surface runoff 

from domestic house discharging onto front lawn in 

Berlin, Germany and (b) example from Seattle, USA) 

BMPs were therefore recognised for their primary 

purpose of addressing diffuse pollution issues, but also 

the more specific concerns in the aspirations noted 

above for UK urban drainage. The potential of such techniques 

for allowing recharge of groundwater and more 

natural drainage patterns was also recognised for many 

of the close to source techniques, which were advocated 

for that reason and also for perceived benefits as 

part of a flood risk management strategy for urban 

development; these techniques were advocated in the 

UK as source controls (CIRIA 1992a and b). 

1992 was of course the year of the Rio summit and 

emergence of the sustainable development concept as 

an idea to be worked into practical actions. Accordingly 

the above ideas for trying to achieve more natural 

hydrological patterns for drainage from urban areas 

were seen as more sustainable than conventional techniques 

because of the aspirations for reduced environmental 

impacts. The relative lack of concrete in many of 

the soft engineering techniques was also seen as a step 

in the direction of practical sustainable development. It 

was a feature of many arguments about BMPs that they 

can have additional environmental benefits such as 

enhancing urban wildlife interest (biodiversity in the 

post-Rio vernacular) and can add to amenity value of 

urban landscapes (IAWQ 1996, D’Arcy and Frost 2001, 

Stahre 2006). To the problem solving aspirations were 

therefore added desirables, as set out in table 2. 

For source control techniques at least, there was a 

good fit with water quality drivers for BMPs and for the 

groundwater recharge/flow attenuation at source aspirations 

for urban drainage infrastructure. Even end of 

pipe techniques such as ponds and basins could also be 

adapted to achieve both functions if considered at the 

outset. Rainwater harvesting was added as an aspiration 

for stormwater management by WSUD (Welsh SUDS 

working party) also as part of the wider post-Rio 

approach to managing stormwater in the UK, and as 

first action in that direction, many UK water utilities provided 

water butts (rain barrels) to their customers. 

3. From BMPS to SUDS 

The problem driven aspirations to address quality and 

quantity issues, together with the amenity and biodiversity 

elements of table 2, were encapsulated in the simple 

concept of the sustainable drainage triangle (D’Arcy 

1998) illustrated in figure 3 below. The two qualitatively 

different sets of drivers in tables 1 and 2 were reflected 

in the term used for urban BMPs in relation to the paper 

that introduced the idea: sustainable urban drainage. 

Despite widespread uptake of that term in the UK 

subsequently, initial UK guidance (e.g. CIRIA 2000) did 

not seek to set out an integrated approach to stormwater 

management, on the basis that it was the water quality 

aims of urban BMPs that were new to the UK, and 

flood risk measures were already well known. Nonethe 




SCIENCE 

Table 2. UK sustainability aspirations for stormwater management infrastructure that were desirable but not directly 

problem-driven. 

Aspirations Perceived benefit Examples Comments 

Soft engineering 

Passive treatment 

Biodiversity 

Less concrete, less CO 2 in production 

No pumping, reduced CO2 

emissions 

Enhancing wildlife interest in 

urban environment 

Swales, ponds, grass filter strips 

BMPs as above, & permeable 

pavement 

LBAP spp. colonised BMP 

ponds, e.g. great crested newts, 

reed buntings, water voles 

Social engagement Enrich quality of urban life Dry feet on permeable surfaces, 

pleasant green landscapes 

Education 

Economics 

Water as a resource 

Raise awareness of wider environmental 

issues 

Potential for cost savings on 

new developments 

Reduce demand on centralised 

network 

Community engagement projects 

Demonstrated at DEX, Scotland 

and at M-way services in England 

Rainwater harvesting, waterbutts 

Fit sought within green landscaping 

requirements 

Regulator cannot require passive 

treatment 

Guidance published, but often 

not heeded 

Public more interested in dry 

feet than flow attenuation? 

signs and trails, features in 

schools 

Not achievable if an add-on 

rather than alternative 

Impact limited so far 

less, the new term “SUDS” (sustainable urban drainage) 

came into use in preference to “urban BMPs” and the 

difference between the terms should be the multiple 

benefits and sustainability aspirations at the heart of the 

SUDS idea. 

4. Implementing the technology 

Initially, the BMP technology was simply advocated by 

presentations from US and Swedish leaders in the field, 

invited to a series of conferences in the UK in the mid 

1990s, and featured in the diffuse pollution video 

Nature’s Way (IAWQ 1996). Excellent technical guidance 

was freely available in USA, and published in text books 

and academic literature (e.g. Schueler, 1987, Schueler et 

al, 1992). Resistance to change is more complex however 

than merely being invited to consider facts, experiences 

and opportunities. Three inter-related aspects of 

persuasion can be recognised Education, Regulation 

and the Economic environment. They are not mutually 

exclusive and are not alternatives, but the relative proportions 

are a function of specific circumstances and 

opportunities (Campbell et al 2004). Where economic 

environment can be aligned with regulatory requirements 

and educational effort, then clearly the costs of 

the latter will be less than if there is no statutory requirement, 

only asking and explaining and advocating. 

In Scotland, a regulatory approach was taken by the 

FRPB for the water quality aspects of stormwater management, 

winning an appeal to the Scottish Executive 

by housebuilders in connection with an FRPB enforced 

requirement for treatment of surface water drainage. 

That ground-breaking regulatory action was followed 

by policies for stormwater management in FRPB and 

Figure 3. The Sustainable drainage triangle concept for multiple 

benefits of stormwater management (D’Arcy 1998). 

later in the Scottish Environment Protection Agency, 

SEPA which became the single regulatory body for Scotland 

from 1996. The SEPA policy required use of SUDS 

technology for new developments, with detailed prescriptive 

advice on requirements for various land-use 

categories such as industrial estates (3 levels of treatment 

required) and motorways and trunk roads (2 levels 

of treatment). That clear regulatory drive quickly led to a 

reaction from developers and other stakeholders and in 

1997 a stakeholder group, chaired by SEPA, was formed: 

SUDSWP, the Sustainable Urban Drainage Scottish 

Working Party. The working party was therefore available 

almost from the outset to co-develop a strategy for 

implementation of the technology, including co-pro 




Assess 

Effectiveness 

Figure 4. Stakeholder engagement. 

Regulation to require 

SUDS technology 

Establishment 

of a 

Market for the 

technology 

Environmental 

Problem 

Socioeconomic 

considerations 

Co-promote 

solutions with 

target sector 

Technical & policy 

Guidance (Planning, 

Roads, Water 

Utility, EPA, 

Building Standards) 

Consistent uptake 

of technology 

Affordable, widespread uptake 

of technology 

Definition and 

Characterisation 

Co – develop with 

target sector ideas 

for resolution of 

problem 

Economic 

environment 

Figure 5. The relationship between statutory requirements and 

guidance and economic factors. 

Score 

25 

20 

15 

10 

5 

0 

Construction inspect'n & Guidance 

Road Runoff 

Source Control 

Planning 

Sewers for Scotland 2 

Guidance & best practice 

Biodiversity 

Industrial estates 

Assessment of SUDS proposals 

Manual, DA and S4S2 consistency 

Land Take by SUDS 

Filter/infiltration systems 

New/alternative SUDS 

Greater landscape arch't involvem't 

Alternatives, 

not add-on 

costs 

Reductions 

In water 

charges 

Educating Public 

Adoption & Maintenance 

Figure 6. SUDSWP stakeholder group poll on priorities for future 

work in 2010. 

ducing technical guidance for Scottish circumstances. 

SUDSWP then influenced regulation applied to establish 

public sector responsibilities for SUDS and for managing 

diffuse pollution. Figure 4 illustrates the iterative 

process for taking SUDS technology forward in partnership 

with stakeholders, whereby an environmental 

problem is identified, and solutions are co-explored 

with those who need to be part of the answer. Once 

consensus is agreed, then it is delivered with the positive 

support of the regulated sector. 

Figure 4 illustrates the primary role of an environmental 

problem in driving the technology forward. That 

is because regulatory actions are focused on addressing 

problems (table 1), rather than addressing less pressing 

aspirations such as those in table 2. Nevertheless, the 

wider aspects of sustainable drainage aspirations were 

addressed in dialogue with developers and seen as 

important in gaining support from stakeholders. Two 

example sectors are briefly considered below. 

Housebuilders 

The power of the amenity/wildlife interest for house 

sales was exemplified by advertisements for new houses 

in front of a SUDS pond, which quoted the view of the 

“wildlife pond” ahead of mentioning such conventional 

sales positives as en suite master bedroom, fitted 

kitchen etc. Maxwell (1999) set out a housebuilder’s perspective 

on the application of SUDS technology in a 

major development in Scotland. The need for performance 

evidence was recognised and the developers of 

the 5km 2 DEX site in Dunfermline (see Campbell et al 

2004) jointly funded a medium term monitoring programme, 

particularly focused on maintenance requirements 

and costs (Jefferies et al 2002). 

Ecologists 

The wildlife value of SUDS was evaluated by Pond 

Action for SEPA, together with a succession of student 

projects led by the University of Stirling, plus contract 

work at the University of Edinburgh. Surprisingly positive 

results in terms of taxa present and the habitat 

value were recorded, including LBAP species (local biodiversity 

action plan, CoSLA, 1997) and some national 

biodiversity action plan species too such as water vole, 

Arvicola terrestris. Problems with invasive species were 

also identified however, associated with contaminated 

soils from commercial garden centres supplying plants 

such as water lilies for the developers. Biodiversity is not 

enhanced by over-specifying plant species, and herbicide 

applications to control “weeds” (c.f. FAWB 2009). 

Considerable cost savings can accrue from wildlife 

focused maintenance regimes (by savings on grass cutting 

and pesticides). Whilst what is attractive in an urban 

landscape is a personal matter and opinions differ 

widely, increasingly in the UK at least, beauty is in the 

eye of the budget holder. 




SCIENCE 

5. Environmental Regulation 

Figure 5 shows the importance of environmental regulation. 

Once statutory requirements are in place all the 

other sectors must align their own technical guidance 

to comply with that legislation, notably highways 

authorities, planning and development control and others. 

The reason why Scotland has progressed so far 

ahead of England is the regulatory stance taken by SEPA 

at the outset in 1996, in contrast to the policy of the 

equivalent agency for England and Wales (The Environment 

Agency). That dichotomy is also perhaps a function 

of the pre-requisite establishment of a water quality 

evidence base in Scotland (FRPB 1994, SEPA 1996, 

1999). Only in 2012 are clear policy requirements being 

established for SUDS in England and Wales, and driven 

by the same water quantity priority issues as in the aspirations 

in table 1. 

6. Continuing Challenges 

In 2010, the SUDSWP group carried out a poll of members 

to evaluate priorities for continuing work after 

agreement had been reached on the strategic questions 

concerning public sector responsibilities for SUDS features. 

Construction and inspection was recognised by 

all as a primary challenge; to produce fit for purpose 

features (figure 6). An inspection regime and training 

for builders are both still required. The major application 

issue was the relative lack of source control. 

It’s a new technology: 2014 will be the centenary celebration 

of the invention of the activated sludge process 

for sewage treatment. No-one could say it has not 

been a successful technology, even though even now it 

is not difficult to find failing works and examples of poor 

maintenance or operations. By comparison with sewage 

treatment technology, the current innovative approaches 

to sustainable urban drainage have barely begun, 

and the fact that poor examples can be found should 

not imply that the technology as a whole is a failure. 

Brand names and market positioning 

BMPs, LID, SUDS, SuDS, integrated drainage, WSUD; a 

proliferation of jargon has a justification if it allows the 

technology to be accepted and established in an increasing 

number of countries. It can also lead to innovation 

and positive developments, not just confusion, imitation 

masquerading as innovation, or commercial advantage. 

But each new innovation or evidence for improved 

design should be part of the internationally recognised 

move towards more sustainable drainage technology for 

stormwater management, of necessity integrated with 

landscape and social needs too. It’s not another new 

name or term that’s the primary need! 

Developing the technology 

Five areas for innovation can readily be identified in 

Scotland at least: 

1. The fate of pollutants – it’s not enough to simply 

consider how to optimise pollutant capture, it is 

equally important to be focused on optimising biodegradation 

of pollutants within the SUDS features 

(Napier et al 2009). 

2. Landscape integration – more creativity and 

rewards/awards for all levels of professional and 

trade contractors developing sites and installing 

SUDS features. In the UK landscape architects and 

ecologists are still often not sufficiently engaged 

with the positive aspects of the technology (there 

are notable exceptions). 

3. Modular units for the hard pressed uninterested 

developer and consulting engineer/architect, especially 

applied on a unit plot SUDS basis may be the 

best means of establishing fit for purpose features 

on a routine basis for all developments. 

4. Source control measures able to accept all local 

stormwater runoff flows, rather than notional first 

flushes (see Zhang et al, 2012). 

5. Unit plot SUDS combines (3) and (4) and offers an 

economic driver for source control by saving housebuilders 

money if it is used, and also reduces exposure 

to problems for the water utility or other public 

bodies (D’Arcy and Campbell 2012). 

Finally, as technology moves into routine business, it is 

useful to review the original aspirations and assess progress 

in meeting them, and whether regulatory or adoption 

procedures are allowing realisation of all aspirations 

or are some being lost as businesses focus narrowly 

on their perceived needs and priorities? 

Regulatory regimes need to allow for creativity as well 

as require basic measures, and put in place an inspection 

regime to produce fit for purpose facilities. 

Acknowledgement 

This paper is based on the paper presented at Stormwater2012 in 

Melbourne, in October 2012, and the support of Melbourne Water 

and feedback from delegates there to improve the paper, is gratefully 

acknowledged. 

Thanks also to Sue Charlesworth and Heiko Sieker for comments on 

the draft. 

References 

Campbell, N., Berry, C., Ross, H. and Hutton, R.: Working together – 

implementing the DEX Drainage Master Plan. In Pratt, C. 

(Ed.) Standing Conference on Stormwater Source Control, 

vol. XXVI, Coventry University, Coventry, 2004. 

Campbell, N., D’Arcy, B., Frost, A., Novotny, V. and Sansom, A.: Diffuse 

Pollution: An Introduction to the Problems and Solutions. 

IWA Publishing, London, 2004. ISBN: 1 900222 53 1. 

CIRIA: Scope for control of urban runoff. Report 123, Construction 

industry research and information association, London, 

1992. 

CIRIA: Sustainable Urban Drainage Systems – a design manual for 

Scotland and Northern Ireland. CIRIA Report C521, CIRIA, 

London, 2000, 114 pp. 




CoSLA: Local Biodiversity Action Plans – A Manual. The convention 

of Scottish Local Authorities and The Scottish Office, Edinburgh, 

1997. 

D’Arcy, B.J.: A New Scottish Approach to Urban Drainage in the 

Developments at Dunfermline. Proceedings of the Standing 

Conference on Stormwater Source Control. Vol. XV. The 

School of the Built Environment, Coventry University, Coventry, 

1998. 

D’Arcy, B.J. and Bayes, C.D.: Industrial Estates: A Problem. In C Pratt 

(ed.) Proceedings of the Tenth Meeting of the Standing Conference 

on Stormwater Source Control. School of The Built 

Environment, Coventry University, Coventry, 1995. ISBN 0 

905949 33 1 

D’Arcy, B.J. and Campbell, N.S.: Managing stormwater at source: 

bringing new techniques into practice. IWA Water Climate 

Energy nexus conference, Dublin, May 2012. 

D’Arcy, B. and Frost, A.: The Role of Best Management Practices in 

Alleviating Water Quality Problems Associated with Diffuse 

Pollution. The Science of The Total Environment 265 (2001), 

pp. 359-367, Elsevier. 

Ellis, B., Chocat, B., Fujita, A., Rauch, W. and Marsalek, J.: Urban Drainage. 

A multilingual glossary. IWAPublishing, London, 2004. 

ISBN: 1 900222 06 X 

FAWB: Adoption Guidelines for Stormwater Biofiltration Systems, 

Facility for Advancing Water filtration, Monash University 

,Melbourne, June 2009, 2004. ISBN 978-0-9805831-1-3. 

FRPB: A Clear Future for Our Waters. Report and video of the Forth 

River Purification Board, Edinburgh, UK, 1994. 

Gardiner, J., Thomson, K. and Newson, M.: Integrated watershed/ 

river catchment planning and management: a comparison 

of selected Canadian and United Kingdom experiences. 

Journal of Environmental Planning and Management Vol. 37 

(1994) No. 1, pp. 53-67. 

IAWQ: Nature’s Way. Video film from the International Association 

on Water Quality (now International Water Association, IWA), 

London, 1996. Now in Campbell et al 2004. 

Jefferies, C., Heal, K., Spitzer, A., McBennet, D. and Duffy, A.: MUD 

WADE Report January-December 2001. University of Abertay 

Dundee, 2002. 

Maxwell, J.: Scotland’s first best management practice surface 

water treatment – the developer’s perspective. In AC 

Rowney, P Stahre and LA Roesner (eds.) Sustaining urban 

water resources in the 21 st century. ASCE, Virginia, 1999. 

ISBN 0-7844-0424-0 

Napier, F., Jefferies, C., Heal, K.V., Fogg, P., D’Arcy, B.J. and Clarke, R.: 

Evidence of traffic-related pollutant control in soil-based 

Sustainable Urban Drainage Systems (SUDS) Water Science 

and Technology, Vol. 60 (2009) No. 1, pp. 221-30. 

Novotny, V.: Water Quality: Diffuse Pollution and Watershed management. 

John Wiley & Sons, inc New York, 2003. ISBN 0 471 

39633 8. 

Pratt, C.J.: Urban stormwater reduction and quality improvement 

through the use of permeable pavement. Water Sci Technol. 

21 (1989), pp.769-778. 

Pratt, C.J.: UK research into the performance of permeable pavement, 

reservoir structures in controlling stormwater discharge 

quantity and quality. Proceedings of the Standing 

Conference on Stormwater Source control, Coventry University, 

Coventry, 1995. ISBN 0 905949 51 X. 

Schueler, T.R.: Controlling Urban Runoff: A Practical Manual for 

Planning and Designing Urban BMPs. Metropolitan Council 

of Governments, Washington, DC, 1987. 

Schueler, T.R., Kumble, P.A. and Heraty, M.A.: A current assessment of 

Urban Best Management Practices. Metropolitan Council of 

Governments, Washington, DC 

SEPA: State of the Environment Report, 1996. Scottish Environment 

Protection Agency, Stirling, 1992. 

SEPA: Improving Scotland’s Water Environment - SEPA State of the 

Environment Report, Scottish Environment Protection 

Agency, Stirling, 1999. 

Stahre, P.: Sustainability in urban storm drainage – Planning and 

examples. Svenskt-Vatten, Stockholm, 2006. ISBN 91-85159- 

20-4 

UNCED: Agenda 21, United Nations Conference on Environment 

and Development, New York, 1992. 

Urbonas, B.: Design & Selection Guidance for Structural BMPs. In AC 

Rowney, P Stahre and LA Roesner (eds.) Sustaining urban 

water resources in the 21 st century. ASCE, Virginia, 1999. 

ISBN 0-7844-0424-0. 

Wilson, C., Clarke, R., D’Arcy, B.J., Heal, K.V. and Wright, P.W.: Persistent 

Pollutants Urban Rivers Sediment Survey: Implications for 

Pollution Control. Water Science & Technology. Vol. 51 

(2005), No. 3-4, pp. 217-224. 

Zhang, W., Che, W., Liu, D.K., Gan, Y.P. and Lv, F.F.: Characterisation of 

runoff from various urban catchments at different scales in 

Beijing, China. Water Science and Technology 66 (2012) No1, 

pp. 21-27. 

Author 

Dr. BJ D’Arcy 

E-Mail: b.darcy@btinternet.com | 

Research Fellow | 

University of Abertay Dundee | 

Dundee, Scotland UK 

www.wassertermine.de 




SCIENCE 

Stormwater Change in Existing 

Urban Areas 

KWW Strategy, social innovation, stormwater management, tacit knowledge, uncertainties, 

the water coalition 

Govert D. Geldof , Peter Regoort and Heleen Bothof 

In the Netherlands, most new built urban areas have sustainable water systems where stormwater is separated 

from wastewater and utilised in the urban environment. For existing areas it is more difficult. There are good 

examples where (1) an intensive public participation process has been set up, (2) other problems in the living 

area have been tackled, (3) a vision has been set up in one day and (4) uncertainties have been coped with in 

a process of learning by doing. Still, most of the projects are too expensive. A significant social innovation is 

needed to come up with plans that are acceptable both socially and financially. Based on the experiences, the 

KWW Strategy has been set up, in which a learning process is organised around the uncertainties that stormwater 

projects in the existing urban environment reveal and Tacit Knowledge is put into play. The Water Coalition 

shows that it might be possible to lower the costs significantly, but people involved have to learn to play a 

new role. This change – social innovation – needs time. 


This paper is focussing on experiences with stormwater 

issues in the Netherlands. Since mid 80’s a lot has been 

changed. Until mid 80’s urban water management was 

more or less equivalent to sewer management, where 

70 % of the systems are combined, and stormwater was 

regarded as ’waste’ that has to be discharged to rivers 

and sea as quickly as possible. Nowadays, stormwater is 

a resource - according the new Dutch Water Law - and 

stormwater, sewers, surface water quantity, surface 

water quality, groundwater, ecology and urban design 

are approached in an integrated way, especially in new 

residential areas. In every new plan integrated urban 

water management is fully implemented and many 

urban areas have something called “a sustainable water 

system”. However, in existing urban areas it is still difficult. 

There are many successful examples of disconnecting 

impervious from sewers and stormwater infiltration, 

but to conclude: most of the projects are too expensive. 

Implementing sustainable water solutions in existing 

urban areas is really costly. Without a change in 

approach, pilot projects will not evolve into large scale 

change. This paper advocates two important factors. 

Firstly, solving urban water problems always has to be 

combined with other urban problems, or stated in a 

more extreme way: “if you want to solve water problems, 

do not solve water problems!” Secondly: social 

innovation is crucial. Applying new stormwater techniques 

in existing areas with the same mind set and 

procedures as in new urban areas will result in inertia. 

This paper especially focuses on this social innovation 

needed. 

Example 1: De Vliert, Den Bosch 

One of the first larger projects of stormwater management 

change in the Netherlands concerns the residential 

area De Vliert in the Municipality of Den Bosch, in 

the south of the Netherlands (figure 1). This area is 

developed in the 30’s and 50’s of the 20 st Century. During 

the replacement of the sewer system in the mid 90’s, 

the stormwater and wastewater were separated. Normally, 

for replacing an old sewer, the road surface is 

opened, the old sewers are removed, the new sewers 

are put into place and the road surface is closed again. 

The original situation is approached as accurate as possible. 

In Den Bosch people at the sewer department 

asked themselves the next question: „Why should we 

bring back the original situation when we invest a lot of 

money and have the opportunity to improve the liveability 

in the area?“ In cooperation with other departments 

they started an intensive public participation 

process, starting with a meeting in the local community 

centre. It became clear that water problems are a minor 

issue for the residents, compared to traffic safety, social 

safety, litter, etc. So, in a process of several years, the 

sewer system has been replaced, a new stormwater system 

has been implemented and several other aspects of 

the living environment have been improved. On the 

question „are you satisfied about the new water system?“ 

one of the residents answered: „yes, now we do 

not have any problems with rat-run traffic anymore.“ 

Example 2: Nijmegen 

In the Municipality of Nijmegen the process of making 

an Integrated Water Plan started in 1997. At 11 June 




Figure 1. One 

of the many 

examples of 

stormwater 

discharge at 

private property 

in 

Nijmegen. 

Figure 2. 

Twelve water 

values. 

1997 people from several disciplines and governmental 

organisations made a Water Vision in one day. The heart 

of the vision is about going from an end-of-pipe control 

to stormwater source control. The vision shows some 

broad sketches. After 11 June eight city project leaders 

were asked whether they are willing to include the 

vision’s ideas in their projects or not. They all agreed. 

Since then, hundreds of projects have been realised in 

Nijmegen, both on private property and in public space. 

The process in Nijmegen has been described in detail by 

Geldof [1]. 

2. Need for social innovation, 

one step further 

The examples in Den Bosch and Nijmegen show some 

social innovation characteristics. In Den Bosch (1) an 

intensive public participation process has been set up 

and (2) other problems in the living area have been 

tackled, like the rat-run traffic. In Nijmegen (1) a vision 

has been set up in one day, instead of ongoing research 

for many years, and (2) uncertainties have been coped 

with in a process of learning by doing. Still, it is not 

enough. In spite of the many combinations that have 

been made, the costs of taking measures in the urban 

environment are too high. Somehow, the social innovation 

has to be pushed one step further. The next chapters 

describe the search for finding a way in the existing 

urban environment in which sustainable stormwater 

management will be applied in practice in a social and 

economic accepted way. Key elements are uncertainties 

and Tacit Knowledge (figure 2). 

3. Three challenges 

When stormwater measures in the existing urban area 

are separated from other urban life issues, they will be 

too expensive. The urban tissue shows a huge variety of 

shapes, functions and dynamics and it is really difficult 

to fit in new structures. Some people conclude that it is 

impossible to implement urban water structures in the 

existing urban environment, especially because residents 

have no real interest in water. All people have different 

ideas and opinions, so it is impossible to find 

consensus about the optimal solution. However, experiences 

like in Den Bosch and Nijmegen show that when 

you do not regard residents as “people that have to be 

convinced of the brilliancy of our optimised plan”, but as 

knowledge resources, good opportunities emerge. Listening 

to the stories that citizens tell enriches the outcome 

space. For reducing the costs, there are at least 

three challenges: 

1. Maintenance. From the beginning to the end, maintenance 

has to be taken fully into account. There are 

too many urban stormwater facilities that are 

clogged within a few years or even impossible to 

maintain. In many municipalities people making the 

designs work at different departments than the people 

that are responsible for maintenance. In the 

interaction with citizens in community centres, 

maintenance issues often dominate. In Groningen, 

one of the residents stated it in a clear way: “You do 

not have to show us how it will be, but how it will 

stay.” In the Netherlands rational maintenance systems 

were introduced in the 80’s. The experience is 

that these systems do not allow people from technical 

departments to interact with residents. Now, we 

make the step to adaptive maintenance, in which 

rational information from models and measurements 

are combined with residents’ observations. 

2. Widening the scope of values. Figure 2 shows twelve 

values, based on Dooyeweerd [2]. These values are 

ranked from high (moral) to low (physical). Experiences 

with stormwater projects in the Netherlands 




SCIENCE 

show that most attention is given to the lower values 

(physical and chemical), which makes sense from an 

engineer’s and scientist’s point of view. However, 

many actors in the urban environment have other 

interests. They observe urban dynamics in a different 

way and value other aspects and issues. As told, residents 

are interested in traffic safety, social safety, litter, 

etc. The challenge is to make connections that 

fulfil the “the whole is more than the sum of its parts” 

principle. Instead of “people have to engage themselves 

to our technical stormwater solutions”, the 

approach is “by solving problems that residents are 

suffering from in a day to day situation - like traffic 

safety, social safety and litter - we add values by combining 

solutions for these problems with stormwater 

facilities.” This is quite fundamental, like “the sun is 

not going around the earth, but the other way 

around.” 

3. Including other urban water cycle elements. Figure 3 

gives an idea about how the transition of urban 

water systems could look like in the next coming 

decades. The word ’waste water’ is slowly disappearing 

and replaced by ’resources’. New techniques arise 

for making combinations with energy production, 

nutrients recovery from urine and urban agriculture. 

In the Netherlands a group of people from several 

organisations and disciplines have developed a long 

term vision on the urban water cycle [3]. In this 

vision, stormwater will be handled completely separated. 

It can be used for making the urban environment 

more attractive and to cool down paved areas 

to avoid the so-called heat island effect. 

4. Complexity and uncertainty 

Facing all these challenges, we meet complexity. The 

heart of the social innovation needed is that complexity 

should not be regarded as a nuisance, something that 

has to be suppressed, but as a fact of life [1]. Life is complex 

by nature and by suppressing it we also suppress 

life characteristics. For many people this statement is 

contra intuitive. So it is not easy to apply it in practice, 

especially due to the fact that complex processes show 

many uncertainties. Coping with uncertainty is probably 

the most essential thread running through the three 

challenges. 

Figure 4 shows a classification into the different levels 

of uncertainty [2]. The first two are coupled to working 

with models. Statistical uncertainty manifests itself 

when models are calibrated and verified using measuring 

sequences. Statistical uncertainty in stormwater 

projects concern quantity and quality aspects. What is 

the urban run-off? How often can we expect an urban 

flood? Will the subsoil be contaminated? There is scenario 

uncertainty when various development trends are 

possible, for instance in relation to the climate. What will 

be the increase in rain volume due to climate change? Is 

it possible to utilise stormwater for cooling down cities 

during hot summers? It is a matter of recognised ignorance 

when it is a known fact that knowledge is lacking 

or hard to transfer. Especially the three challenges introduce 

many questions at the level of recognised uncertainty. 

Will adaptive maintenance be a success? What 

will the political landscape look like in ten years? What 

will be the developments in the economy in the coming 

years? Do we still need energy from the urban water 

cycle after twenty years? How will food policy develop 

itself? With total ignorance, we do not know what we do 

not know. 

Characteristic for traditional stormwater approaches 

is that attention is mainly aimed at the first two forms of 

uncertainty. The state space which can be described 

with some accuracy by means of deterministic models is 

heavily relied on. The uncertainties are kept as small as 

possible. Stirling [5] studied about three hundred projects 

in the UK and observed that experts often perceive 

uncertainty as risk, and risks have to be reduced and 

controlled. One might say that all risks introduce uncertainty, 

but not all uncertainties are risks. Risk has two 

dimensions: a hazard and vulnerability. It is about things 

that might go wrong, so it is negative. Uncertainties, 

Figure 3. Schematic representation of the urban water transition in the 

next coming decades. 



Figure 4. Four 

levels of uncertainty 

[4].


however, can also be positive and challenging. Technological 

innovation, discovering new ways for dealing 

with stormwater, and coping in social processes in a 

tense political and economic context can be exiting, 

although not for everyone. There has to be a balance in 

uncertainties that has to be dealt with. 

In complex processes, it is best to set out a course 

between too much and too little uncertainty. If no 

uncertainties are accepted, nothing will change. It is an 

attitude of rather doing something wrong and being 

certain about it than doing something that might actually 

be right. On the other hand, it is also important that 

there are not too many uncertainties at play because 

processes will then predictably go wrong. 

This intermediate course is presented in a schematic 

way at Figure 5. The horizontal axis shows uncertainties 

accepted in the desired change process and the vertical 

axis shows the complexity of the process. If no uncertainties 

were accepted in the process, this would reflect a 

working method that is not very complex. Maximum 

certainty is obtained when everything is done as it is 

always done. Nothing really changes. However, when 

too many uncertainties are accepted – ignoring them as 

it were – this also does not reflect a complex working 

method. So many changes are made simultaneously 

that something predictably goes wrong. Probably the 

project fails and it is decided to continue as before: “We 

tried it and it was no success”. It is the trick to find the 

middle path, introducing innovation without ending up 

in a situation in which the uncertainties have become 

unmanageable. This situation is characterised by maximum 

complexity. Figure 5 uses Aristotle’s terminology. 

In his book Ethics, he advocates bravery, which he sees 

as the middle path between recklessness and cowardice. 

Figure 5. Three domains for coping with uncertainty [7]. 

The middle path is not calculated, but it emerges by 

making plans with both many and few uncertainties, 

relating to all three challenges. Iteratively, structural 

adaptations are determined. On the middle path, the 

parties involved feel that uncertainties are manageable 

and that there are enough opportunities to reduce 

uncertainties through further investigation. It stipulates 

the learning dimension. The middle path is the most 

complex because choices have to be made. Not everything 

that is possible is also carried out directly. Choices 

will anchor the process. If no choices are made, too 

many balls are being juggled at the same time. If the 

focus is too restricted, contact with context is lost. It is a 

question of constantly observing and consciously 

weighing whether to intervene or not. It becomes clear 

in this process that continually investigating how to 

reduce the statistical uncertainty and scenario uncertainty 

results in stagnation. The middle path says something 

about the uncertainties of ’the whole’ and a 

healthy balance between the different forms of uncertainty 

is a condition for this. The middle path is continuously 

evolving in a learning process. Measures that have 

been assessed as reckless ten years ago might be brave 

in the present situation. 

5. Tacit Knowledge and learning 

In 2006 a research programme started in the Netherlands 

on the relationship between knowledge, learning 

and complexity [7]. This research especially focussed on 

the importance of Tacit Knowledge: implicit knowledge 

that people acquire when they get experienced. It was 

introduced by the philosopher Polanyi [8]. Tacit knowledge 

is person-specific, difficult to reproduce or quantify, 

with no specific focus, but available for a range of 

(unexpected) situations. At the beginning of the 

research three propositions were postulated: (1) the 

complexity of water management increases, (2) for coping 

with such complexity Tacit Knowledge is crucial and 

(3) attention given to Tacit Knowledge in water management 

decreases; therefore, Tacit Knowledge becomes 

marginalised. The research results confirm these propositions 

and introduce a direction for improvement: New 

Craftsmanship. It is interesting to see that in the time of 

the Medieval Guilds craftsmen applied two main principles 

for learning [9]: 

1. Acting repetitively; 

2. Story telling. 

By doing procedures over and over again, people learn, 

and by telling stories they exchange knowledge, both 

implicit (Tacit) and explicit. For several hundreds of 

years this way of learning was very successful. Only in 

the last decades there has been a shift to modern ways 

of learning, with modelling, measurement programmes, 

studies, meetings, etc. The data from the research on 

Tacit Knowledge [7] illustrates that nowadays some 




SCIENCE 

experts attend meetings for more than 50 % of their 

working time. 

6. The KWW Strategy 

Based on all experiences until now, the awareness of 

increasing complexity due to the three challenges, the 

need for a brave approach between cowardice and recklessness 

and the ideas about introducing New Craftsmanship, 

the KWW Strategy emerged. KWW stands for 

“Kiek’n wat ut wordt” which is Dutch dialect for “look 

what will happen.” 

Figure 6 shows a schematic representation of a traditional 

approach for a stormwater project. There are 

three phases: (1) plan process, (2) implementation and 

(3) maintenance. In these phases different people are 

active. In the plan process planners, engineers, decision 

makers and many others make a plan or a design. In 

principle, they tackle all uncertainties in this phase. 

When the plan is ready and the specifications have been 

developed, the work will go to a contractor. After completion, 

the project is finished, the standards are met 

and the objects constructed (assets) will be handed 

over to the people that maintain. 

This traditional approach suffices when complexity is 

relatively low and uncertainties will be restricted to the 

levels of statistical and scenario uncertainty. However, 

when embracing the three challenges, complexity 

increases. Then it is impossible to tackle all uncertainties 

in the phase of the planning process. Recognised ignorance 

comes into play. Then a KWW Strategy is preferred 

(figure 7). 

The KWW Strategy reflects a process of learning by 

doing. It offers a modern version of how Medieval 

Guilds organised the learning process. The main difference 

to the traditional approach is that it is harder to 

distinguish the three phases. In fact, the maintenance 

people are involved in the process from the beginning 

and not all measures are taken at once. Traditionally the 

governmental organisations will pay for all construction 

works, but in the KWW Strategy the implementation is 

restricted to a first ’slap’, where costs are shared by several 

actors, both private and public. After the first slap 

the process continues and for the water experts there is 

an ongoing dialogue with the water system, the external 

people (e.g. the citizens and companies) and the 

people within the own organisation. In these dialogues 

the middle path of bravery evolves. Essential in the 

KWW Strategy is that besides an exchange of explicit 

knowledge – reports, emails, model results, measurements, 

etc. – there is a constant flow of Tacit Knowledge. 

People share experiences by telling stories. 

Table 1 shows some other characteristics of the 

KWW Strategy. These will not all be discussed in this 

paper. Quite essential is the last row. Aristotle stated 

that we have to search for phronesis, which stands for 

practical wisdom. He showed that for phronesis there 

Figure 6. Some characteristics of a traditional process. 

Figure 7. Some characteristics of a KWW Strategy. 

Table 1. Two approaches for coping with stormwater projects. 

Traditional Approach 

Meetings, workshops, studies, etc. 

Integrated, complete and complicated 

Communication about a project 

Discussions, negotiations 

Focus on Logos 

KWW Strategy 

Werkplaatsen (Workshops) 

Small, local and concrete 

Communication within a project 

Narrative approach (story telling), 

building up a common story 

are three building blocks: Logos, Ethos and Pathos. 

Roughly, Logos is about logic and rationality, Ethos 

about attitude and Pathos about feelings, empathy. 

Nowadays, the focus in stormwater projects is on Logos. 

Models are used to calculate the optimal solution. In the 

KWW Strategy Logos is still important, but extra attention 

is given to Ethos and Pathos. The research on Tacit 

Knowledge [7] shows that in many complex water projects 

especially Ethos is the Achilles heel. The KWW 

Strategy results in a significant social innovation. 

Focus on Logos, Ethos and Pathos 




7. The Water Coalition 

One of the processes in the Netherlands that is applying 

a KWW Strategy concerns the Water Coalition. Not only 

waterboards and municipalities are aware that water 

challenges have to be approached differently, but also 

people at ministries at national level. Traditional top 

down approaches have to be combined with bottom up 

strategies. Recently, several Dutch water organisations 

signed the National Administrative Water Agreement 

2011-2015, in which they formulated goals for reducing 

costs, both by innovation and optimising the existing 

water systems. The Water Coalition is an initiative from 

the Ministry of Infrastructure and Environment that 

brings the ideas formulated in the water agreement a 

step further. The idea is to form networks of citizens, 

companies, governmental organisations and non-governmental 

organisations, in order to make clever combinations, 

related to all three before-mentioned challenges. 

In these networks, the national government 

operates as a facilitator and a stimulator, and not as the 

actor that only makes laws and regulations. So, for the 

Figure 8. Playing cards for interaction with citizens, societal midfield 

and companies in Delft. 

Figure 9. Dialogue between water experts, citizens and companies at 

the community centre in Delft. 

people of the ministry this is a new role. The goal is: “better 

results with less effort.” 

The Water Coalition at this stage focuses on (1) coping 

with stormwater in and around the house and (2) 

the self-sufficient house of the future (see Figure 3). 

One of the projects is in Delft, the Wippolder residential 

area, built in the 50’s and the 60’s. In this area groundwater 

levels are high, which results in moisture problems in 

houses, and during intensive showers the stormwater 

storage is insufficient, so in some parts people suffer 

from local urban floods. Besides that, residents indicate 

a need for more public green and there are also some 

problems with litter, traffic and maintenance. Local 

groups took the initiative for urban agriculture projects. 

Traditionally, the municipality and the water board 

would make a plan together, based on policy goals and 

public participation outcome. This plan would be implemented 

and fully financed by these local governmental 

authorities. However, due to the present economic conditions, 

the possibilities to finance this kind of initiatives 

are limited. So the Municipality of Delft joint the Water 

Coalition, together with the water board of Delfland, to 

develop a new way for increasing to liveability in the 

area in close cooperation with citizens, non-governmental 

organisations and companies. Accordingly, a 

KWW Strategy would be very realistic here. The municipality’s 

attitude is clear: “We will facilitate the process 

and finance it partially, but initiatives have to be taken 

by other parties.” For everybody this is new. Both residents 

and companies are used to their reactive role and 

now they have to be proactive. This kind of change 

needs time. 

The process in Delft has started with discussions 

with local actors. All actors have been asked what their 

ideas are for improving the Wippolder area and what 

they think their contributions might be. Out of these 

discussions came ideas that were put on playing cards 

(see Figure 8). After that, two meetings have been 

organised in the local community centre where the parties 

involved met each other and could have a dialogue 

about the brave balance between the desired, possible 

and probable situation in the area (see Figure 9). Bit by 

bit coalitions emerge. It is still not clear whether the 

process will succeed or not – the process shows many 

uncertainties – but people are aware that when it does 

not succeed, the liveability will decrease in the next 

coming years. Five small, local and concrete activities 

have been selected for the first slap. 

8. Conclusion 

Adapting stormwater systems in the existing urban 

areas is more complex than in new built residential 

areas. It is possible to introduce sustainable water measures, 

but within the present paradigm of (1) implementing 

the optimal plan at once and (2) financing projects 

by governmental organisations, it is too expensive. A 



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SCIENCE 

significant social innovation is needed to cope with the 

complexity and the related uncertainties. The KWW 

Strategy offers good possibilities. Experiences with the 

Water Coalitions illustrate that it might work: “better 

results with less effort.” Future will tell. 

References 

[1] Geldof, G.D.: Coping with complexity in integrated Water 

Management, On the road to Interactive Implementation, 

2005. Adapted PhD thesis. Download from: http://www.geldofcs.nl/pdf/Boekje/Coping_with_complexity_in_integrated_water_management.pdf 

[2] Dooyeweerd, H.: Wijsbegeerte der Wetsidee (translated into 

English in 1953: A New Critique of Theoretical Though). 

[3] Interconnecting Water: A long term vision for the urban 

water cycle. Download from: http://samenwerkenaanwater. 

nl/bronnen/doc/verbindend_water_LT_Visie_Engels_DEF_ 

LR.pdf 

[4] Walker, W.E., Harremoës, P., Rotmans, J., Sluijs, J.P. van der, 

Asselt, M.B.A. van, Janssen, P. and Von Kraus, M.P.: Defining 

Uncertainty. A Conceptual Basis for Uncertainty Management 

in Model-Based Decision Support. Integrated Assessment, 

Vol. 4 (2003) No. 1, pp. 5-17. 

[5] Stirling, A.: Keep it Complex. Nature, Vol. 468 (2010), pp. 

1029-1031. 

[6] Geldof, G.D.: Coping with uncertainties within integrated 

urban water management. Water Science and Technology, 

Vol. 36 (1997), No. 8-9, pp. 265-269. 

[7] Geldof, G.D., Heijden, C.M.G van der, Cath, A.G. and Valkman, 

R.: The Importance of Tacit Knowledge for Urban Water Management. 

Proceedings 12th International Conference on 

Urban Drainage, Porto Alegre/Brazil, 11-16 September 2011. 

[8] Polanyi, M.: The Tacit Dimension. First published by Doubleday 

& Co., 1966. 

[9] Sennett, R.: The Craftsman. New Haven & London: Yale University 

Press, 2008. 

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Ministry of Infrastructure 

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WASTE WATER Solutions 



SCIENCE Stormwater-runoff-management 

Rainwater Management at Logistic and 

Commercial Estates with Large Paved 

Surfaces 

Stormwater-runoff-management, Logistic centre, Commercial estates, flooding protection, 

cost cutting, water balance 

Mathias Kaiser 

As a result of the development of the single European market, a dynamic increase of extensive industry and 

logistics areas occurs. The essential locational factors are an advantageous connection to the trunk road 

system, extremely short periods concerning the settlement and the startup, and low costs of the location. 

On the one hand, managing the rainwater drain in a decentral way relieves the public infrastructure (no 

hydraulical overcharge), on the other hand, it allows to realize basic interests, like a prompt startup, cost 

saving construction and cost-saving operating (rainwater charge is not applicable). 

Spitzenabfluss [l/s] 

1200 

1000 

800 

600 

400 

200 

0 

vor Bebauung 

konvent. Entwässerung 

Fläche in Hektar 

Dorsten Dortmund Salzgitter München Kerpen Leverkusen Bremen Mittelwert 

71 

570 

4,7 

137 

978 

9,16 

250 

1842,5 

19,25 

121 

835 

8,1 

97 

862 

8,6 

137 

879 

9,8 

Figure 1. Peak loads of logistic and industrial estates, before 

construction works and with conventional drainage systems. 

Source: own presentation 

103,19869 

915 

9,7 

130,9 

983,0 

9,9 

Challenges 

As a result of strong increase and a tightened competition, 

the actors demand an especially quick project 

development and constructional realisation of the new 

extensive industry and logistics areas. 

The majority of these are still being constructed on 

idle land, which is well connected to public infrastructure. 

The new built and large industrial estates (halls and 

roads) cause stormwater-runoff. In most cases, the land 

was used for agriculture before. Now, the amount of 

incidental rainwater in case of a storm has multiplied. 

During the short period between settlement and 

startup, it is – in some cases – impossible to augment 

the capacity of the public drainage infrastructure. In 

other cases, this can only be achieved by high investments. 

Furthermore, the settlement of extensive industry 

and logistic estates has a negative impact on the 

ecological balance of the area. The yearly local water 

balance is modified, as there is more drain and less infiltration 

and evaporation. A decreasing groundwater 

level and negative influences on the microclimate can 

be the results. 

The two involved parties, on the one hand the settling 

corporation, on the other hand the municipality, follow at 

first sight very similar fields of interest, namely a 

"" 

fast and 

"" 

cost saving 

allocation of the needed infrastructure. 

A closer examination of the fields of interest clarifies 

that they are in fact diametrically opposed to each 

other. The corporations are in search of a simple and 

cost-saving construction on their ground. The required 

risk prevention is diverted to the public infrastructure. 

As the municipality has to provide this infrastructure, it 

is often the situation that a required modification of the 

wastewater system cannot be realized during the short 

time frame the corporation has scheduled for settlement. 

In addition, the required modifications sometimes 

are too expensive. These factors endanger the 

target settlement in extreme cases. The municipalities’ 

competition for the settlement of corporations often 

leads to a solution that does not respect the vital interests 

of both parties. 

The experience in the planning of numerous logistic 

centres has revealed the main cost-factor and main 

problem concerning the site development: the 

extremely high amount of incidental rainwater. As the 

paved estates often have a size of 10 to 40 ha, the man 




SCIENCE 

agement of the incidental rainwater is essential for a 

successful settlement and a sustainable operation. 

New estate-based approach 

Synergetic solutions for the problems mentioned above 

have been elaborated during the past years. 

The public wastewater system is no longer used in 

order to manage the peak loads of the new paved 

estates. Trying to manage the rainwater – decentral –, in 

contra, means that it is managed on the logistic estate 

itself. 

The effective norms for building sewer in Germany 

[1] advise not to use floor gravity drainage systems 

underneath the building. Concerning extensive industry 

and logistic estates, this generally results today in 

the formation of underpressure or open channel sewage 

under the roofing, in the roof frame. In the area of 

the exterior wall, these pipes can be conducted downwards 

and then – through opened or closed trenches – 

towards the installed basins. This anticipates a drop 

below ground level, which normally is – using gravity 

drainage systems – not preventable. Therewith, a feed 

into surficial basins is possible. In case the basins are 

situated higher than the paved area next to the building, 

it is usefull to install pipe bridges coming from the 

roof area. 

Basic planning principles concerning the differences 

of altitude and the drainages on ground-level estates 

are: 

Figure 2. Logistics centre with docking-station and starting range. 

Source: own presentation 

Figure 3. Conduction of roof runoffs into high situated vegetated 

surfaces via pipe bridges. Source: own presentation 



Figure 4. 

Local plan of a 

logistics centre 

with surrounding 

infiltrationbasins 

(light 

green) and 

planted areas 

(dark green). 

Source: 

own presentation

SCIENCE Stormwater-runoff-management 

60 

50 

40 

30 

20 

10 

0 

Zu entwässernde Niederschlagshöhen in mm (Höxter) 

6 mm 

Entwässerung 

18 mm 

Überflutungsschutz 

Freiflächen 

50 mm 

Überflutungsschutz 

abflusslose Senken 

Figure 5. Amount of stormwater, which has to be discharged or 

detained normally (2 year event) and in case of flooding (20 year, or 

100 year event), Source: own presentation 

Figure 6. Normal detention of stormwater (profile above) and also 

protection by a higher basin skirt in case of flooding (profile below). 

Figure 7. Calculated accumulation of stormwater in truck parking 

and routing area after flooding. 

"" 

open, on or above the ground level installed delivery 

pipes; 

"" 

discharge of rainwater into – preferably – open, vegetated 

basins; 

"" 

flood detention, treatment (conducting water 

through vegetated soil in order to clean it), infiltration 

(where possible) and (where requiered) a curbed 

discharge of rainwater. 

The paved surfaces surrounding the building are normally 

shaped with a transversal slope (2.5 % to 0.5 %). 

They dewater diffusely (over the shoulder) into the 

basins, which are situated on the brink of the surface. In 

order to assimilate this system to varying territorial conditions, 

pipe bridges, gutter and depression areas can 

be installed. 

With the consequent use of transversal slopes in 

direction to the basins, the installation of dewatering 

trenches can be avoided completely. Cost savings of 

two digit percentages can be achieved. 

According to the Federal Land Utilisation (in Germany 

Baunutzungsverordnung), relevant plot areas in 

highly concentrated industrial estates have to be revegetated. 

Precise ordinances for the revegetation are often 

indicated in the local plan. Detention and infiltration 

basins can be installed within, or rather on the verge of 

these revegetated areas. The banks of the basins and 

their border area can be used for the realisation of ordinances 

concerning woods or bushes. 

Combination of rainwatermanagement 

and flooding protection 

In recent years, heavy and long local storms have 

occurred frequently. DIN 1986-100, which was reformulated 

in 2008, meets this trend: extensive estates (more 

than 800 sq. m of paved surface) need a flood protection 

certificate. This has completely changed the way of 

planning and measuring local drain systems. Until 

recently, it had to be proofed that the detention and 

drainage system is designed for the management of the 

two year (five minute) storm event. The reformulation of 

DIN 1986-100 has tightened the requirements for the 

certificate. Depending on the local conditions, the 

detention and drain system has to be designed at least 

for the 20 year event, in endangered places for the 

100 year event. 

The amount of rainwater relevant for the flooding 

protection varies from 18mm to 50mm. The required 

capacities of the local drain system have clearly 

increased. 

DIN 1986-100 follows the philosophy of decentral 

rainwater management. The discharging rainwater shall 

(in case of the 20, or 100 year event) be detained and 

managed on the origin place, so to say: decentrally. 

For the planning of the local drainage system this 

results in the arrangement of large detention capacities 




SCIENCE 

on the estate. Connected with the estate-based rainwater 

management (conducting via slopes, detention 

and infiltration in vegetated basins), this can be realized 

in an easy and cost-saving way. 

In contra to the standard measurement (5 year event 

concerning infiltration systems), a higher skirt of the 

detention and infiltration basins is – in most cases – satisfactory. 

In case of floodings, this allows an accumulation 

of water, which is – compared to the standardmeasured 

event – several decimetres higher in the area 

of the basins and surrounding surface. 

Normally, this puts the additional necessary 

detention capacities in practice 

A temporary accumulation on paved surfaces (parking, 

routeing and loading areas) can be tolerated in order to 

activate auxiliary or alternative detention capacities. 

The maximum accumulation level has to be considered. 

It depends on the terms of use of the different areas (car 

parking areas, truck parking and loading areas 8–12 cm 

higher where applicable). 

The introduction of DIN 1986-100 as a generally 

approved norm obligatorily integrated the planning 

and the calculative analysis of flooding protection into 

the estate-based planning of drain systems. Experience 

has shown that to this day deficits concerning the 

enforcement of the norm exist. The extra-costs of a conventional 

underground construction (detention-pipes 

etc.) are not attractive and can not be communicated 

with the settling corporation. 

The result is that even today building projects which 

do not meet the flood protection standard are not realized. 

In case of flooding, this can result in damages on 

the concerned estate or on lower situated estates and 

infrastructure. These damages are not covered by the 

liability law. 

But the damages will only be compensated by insurances 

if the installed flooding protection meets the 

standard norm. Precise liability risks for the persons in 

charge (planners, executors, property owners and operators) 

can be the results in case of failure. 

Recapitulation of the results, evaluation 

and outlook 

The de-central rainwater management has been implemented 

over the last 20 years and it is now a proofed 

alternative for the conventional discharge of rainwater 

on extensive logistic and industry estates. 

The installed constructions have also shown their 

sustainable functionality and capacity in changing basic 

conditions. 

Questions for ageing behaviour, inevitable maintenance 

and repair measures and cycles of modernization 

are gaining importance over the course of operation 

time. Scientific investigations, analysis of the hitherto 

existing experiences and the collocation of general 

guidelines are necessary at this point. 

Confronting new standard norms, like the flooding 

protection, decentral rainwater management shows a 

high flexibility and adaptability in the construction of 

extensive logistic and industry estates. 

Compared to underground constructional solutions, 

not only the construction costs can be economized, but 

also (depending on the local soil and charge rate) relevant 

operational costs can be saved. New standard 

norms (flooding protection, detention of the 

20–100 year event on the estate) can be integrated and 

realized almost self-financing. At the same time it reliefs 

the public de-watering infrastructure from additional 

peak loads. 

Range and chronological sequence of site development 

measures taken by the municipality in order to 

valorise the industrial area can be reduced without losing 

attractiveness for settling corporations. In addition, 

the local water-balance before construction works can 

be preserved more easily. While conventional drain 

infrastructure increases the amount of surface-discharge 

and reduces the peculation rate, this alternative 

approach enhances it. 

Further potential for the preservation of the waterbalance 

combined with energy-saving strategies exists. 

The stormwater can be used for cooling towers, adiabatic 

vaporisation systems, or for the passive cooling of 

sun-exposed building elements (e.g. flat roof) during 

summer. 

This allows a reduction of the potable water supply 

and an increase of the (yearly) vaporisation rate. Such 

further changes in estate-based stormwater management 

have been developed during the past years. They 

have been implemented in numerous projects and are 

available today in a broad range. 

References 

[1] DIN 1986-100: Drainage systems on private ground – 

Part 100: Specifications in relation to DIN EN 752 and 

DIN EN 12056. 

Author 

Dr.-Ing. Mathias Kaiser 

E-Mail: mkaiser@kaiseringenieure.de | 

KaiserIngenieure | 

Gutenbergstraße 34 | 

D-44139 Dortmund 



SCIENCE Rehabilitation Management 

Integrated Rehabilitation Management 

for Different Infrastructure Sectors 

Rehabilitation Management, Deterioration Model, Priority Model 

Franz Tscheikner-Gratl, Christian Mikovits, Michael Möderl, Max Hammerer, Wolfgang Rauch und 

Manfred Kleidorfer 

In Europe, our water distribution and wastewater collection networks are near the end of their assumed lifespan 

or will be in the coming years. Therefore, the main focus of urban water management is shifting from 

construction to rehabilitation. For state of the art rehabilitation management lots of different models to simulate 

the deterioration process are in use. These models depend strongly on the quality accuracy of the available 

data. Data is seldom available in high quality due to the only recently started information management of the 

operating companies. Therefore, a good data validation and reconstruction of the available data is essential 

for rehabilitation planning. Beside the deterioration also the interaction between the different infrastructure 

(gas, wastewater, water distribution, electric grids and road network) has to be taken into account as well as the 

changes in environmental factors (climate, population, etc.). These influences are integrated into a priority 

model to identify the “hot spots” for rehabilitation in the different networks. 


Urban areas and their development strongly depend on 

the two key tasks of urban water management: supply 

of high quality potable water and disposal of wastewater 

and stormwater. These services are central for the 

human wellbeing as well as for the economic development 

of urban settlements [1]. 

In the last decades the main focus of water supply 

and sewer management has moved from construction 

of new sewer and water supply networks to rehabilitation 

and adaptation of the existing infrastructure. Rehabilitation 

is the term for either repairing, renovating or 

for replacement of pipes. The main goal is to maintain or 

even improve the existing service level of the networks 

in the most efficient way. This is required for drainage 

and sewer systems and regulated in (inter)national 

guidelines and technical rules as for example in EN 752 

[2]. However, the present rate of system rehabilitation 

does not keep pace with these requirements [3]. 

Lots of models have been developed to aid the process 

of asset management and decision making for sustainable 

rehabilitation planning. Most of these tools are 

statistical models (for an overview for water supply systems 

see for example Kleiner and Rajani [4] or Osman 

and Bainbridge [5]; for waste water collection networks 

for example Ana and Bauwens [6]), but also physical 

models exist [7]. These models usually focus only on a 

specific infrastructure network, i.e. either on water supply 

or drainage networks (stormwater and wastewater 

collection). This separated view cannot cope with the 

complex situation. Future Tasks demand an integrated 

management approach across the different sectors [8]. 

Furthermore, in the majority of cases not only these 

two networks have to be considered for management 

and rehabilitation of urban infrastructure assets. Other 

infrastructure facilities like gas supply, district heating, 

electrical and telecommunication grids and of course 

traffic facilities overlap with water infrastructure since 

the layout of all these networks is driven by the street 

network. Mair, et al. [9] show that 78 % of all roads are 

containing 81 % and 86 % of the water supply and sewer 

network, respectively. An efficient planning of rehabilitation 

measures has to take into account different networks 

to take advantage of the synergies and coherences 

[10] that a combined approch can provide (e.g. to 

reduce e. g. the duration of construction or road closures). 

Additionally integrated planning can benefit 

from data availability and data reconstruction methods 

of related networks. 

Also the changing environment and its challenges 

influence rehabilitation management due to its high 

impact on the costs of future delivery of water services 

[11]. To improve a prospective design of rehabilitation 

and adaptation measures of urban water infrastructure 

a novel concept was developed by the authors [1]. 

Therein deterioration models are combined with projections 

for future development of the city (new development 

areas, growing population) as well as with climate 

change projections. 

2. Concept 

With the influences of an anticipated future (climate 

change, population change) and an economic model 

for the different rehabilitation techniques (repair, reno 




SCIENCE 

vation, replacement) the boundaries for the decision 

support system of the rehabilitation management are 

set. 

The project consists of following modules (shown in 

figure 1): 

"" 

Deterioration model to predict the aging of the infrastructure 

networks and the need for rehabilitation 

"" 

Analysis of vulnerability to predict the effects of 

possible failures 

"" 

Priority Model to pinpoint the most urgent areas 

for rehabilitation 

This concept is based on the experience and data of 

three municipalities in Austria and Germany. They were 

used as case studies for this paper. 

Table 1 shows an overview of the networks from 

these municipalities. Data is available for all three water 

distribution networks and the corresponding failure statistics. 

For case study 1 we have the longest duration of 

failure statistics (since 1976), but unfortunately no data 

about the house connections. For the other two case 

studies we have these data, but the failure statistics has 

been implemented later (1983 and 2002). Noteworthy is 

the high share of house connections (43.30 %) to the 

overall network in case study 3. For the sewer system we 

have data for two cities, whereas the data of case 

study 1 is of better quality (63 %). For Gas distribution 

networks we have only data from one municipality – 

case study 3. 

3. Data issues 

The models used for this concept depend on the quality 

and availability of the network data. The data collection 

of all possible influencing factors is a time consuming, 

difficult task, which is nearly impossible to be accomplished 

in complete detail. 

For this project the first step was to determine the 

optimal dataset for rehabilitation planning (shown in 

Figure 1. Concept. 

Table 1. Case studies. 

Data Case Study 1 Case Study 2 Case Study 3 

Population (2012) 121,329 94,882 13,107 

Water distribution netwrk 225.94 km 851.27 km 207.70 km 

Transportation pipes 11.50 % 7.40 % 5.40 % 

Distribution pipes 88.50 % 61.00 % 51.30 % 

House connections – 31.60 % 43.30 % 

Sewer network 234.43 km – 92.29 km 

Condition states 63.00 % – 46.00 % 

Gas dristibution network – – 207.70 km 

Transportation pipes – – 10.50 % 

Distribution pipes – – 51.90 % 

House connections – – 23.60 % 

table 2 and 3 [12]), which because of the above reasons 

was not completely obtainable. Thus, the real dataset 

was of fluctuating quality and differed both for the case 

studies and the type of infrastructure network. 

Table 2. Optimal dataset regarding the networks [12]. 

Wastewater collection Water distribution Gas distribution 

Dimension Dimension Dimension 

Pipe shape Material Material 

Material Position (Coordinates) of the Pipes Position (Coordinates) of the Pipes 

Pipe length Material of pipe bed Material of pipe bed 

Material of pipe bed Type of pipe connection Type of pipe connection 

Type of pipe connection Failure statistics Failure statistics 

Hydrodynamic Model of the network Hydraulic Model of the network Time interval between onsite inspections 

Time interval between onsite inspections and the 

derived condition state 

Time interval between onsite inspections 

Year of construction 

Depth of coverage Year of construction Depth of coverage 

Year of construction 

Type of wastewater 

Depth of coverage 




Table 3. Optimal dataset regarding surrounding areas [12]. 

Transport infrastructure Position important objects Environment 

Routes of railway, tramway, etc. Archives Weather conditions (Temperature, etc.) 

Traffic Volume Museums Soil conditions 

Road construction Hospitals Seismic 

Importance of roads 

Schools, Universities, etc. 

Sports infrastructure 

Infrastructural buildings 

Government buildings 

Other sensible objects 

Ground-water level 

Land use 

Populations density 

Vegetation 

A good example for the fluctuating data quality is 

the nature of the failure statistics of the water distribution 

network (for case study 3 shown in figure 2). These 

statistics were mostly quite sound regarding the properties 

of the affected pipe, but lacked details of the 

failure type and the age of the affected pipe. 

Figure 2. Example of data quality: Water distribution network failure 

statistics of a case study. 

Figure 3. Construction years of a water distribution network. 

4. Deterioration model 

For deterioration modelling we chose the approach of a 

cohort survival model (as proposed by Herz and Krug 

[13]) as this approach has been proven to be appropriate 

for calculating the need for future rehabilitation for 

entire networks [6]. For the water supply networks as 

well as for the sewer networks these calculations have 

been performed and result in the percentage of the network 

in need of rehabilitation, which will subsequently 

be chosen by the priority model. 

4.1 Water and gas supply 

For the water supply network at first the existing network 

(case study 2) was examined and classified by 

the construction year (done separately for distribution 

pipes and household connections). Figure 3 shows the 

age distribution of the network. In this case we had a 

very good data-set in which the construction year is 

available for 91 % of the pipe length. The missing 9 % 

were proportionally distributed among the existing 

data. Further, the data was classified into the different 

pipe materials used (Asbestos Cement, Cast Iron, Lead, 

Polyvinylchloride, Ductile Iron, Steel and Polyethylene). 

For each material a normal distributed life expectancy 

with the means and standard deviations of Baur 

[14] was assumed and the length of failing pipes per 

year was calculated (shown in figure 4). We presumed 

that all the failing pipes are replaced by a material with a 

higher life expectancy. Further, we expected that all 

lead pipes are replaced immediately due to health regulations. 

The main focus of this kind of models has been 

the main water distribution pipes although in average 

the number of damages in the connection pipes to 

households is higher. From the data of our case studies 

we see that we have in average a failure rate of 0.067 failures 

per kilometre and year for distribution pipes. For 

house connection conduits this rate is 4 times higher, 

but due to the smaller length this rate is not very significant. 

More informative is the failure rate per house connection 

and year which was estimated from the existing 

data of the three case studies. In average 0.6 % of all 

house connection pipes have failures per year. Accordingly, 

a distinction has to be made here (compare 




SCIENCE 

figure 3, figure 4 and figure 5) between network and 

house connections. 

The lower life expectancy of the older pipes constructed 

before 1965 would demand a high rehabilitation 

rate in the coming years. Regarding a total length 

of the water supply network of 851 km, a rehabilitation 

rate of almost 3 % in the next years would be required. 

This rate decreases to 1.2 % until 2060 and then rises 

again (with taking into account that the replaced pipes 

are aging as well). Due to the large amount of replaced 

pipes the mean network age would stabilize until 2040 

and then slowly increase until 2080 to around 50 years 

(due to the higher life expectancy of the replaced 

pipes). At this time the age of the network would be 

more than 2 times higher if no rehabilitation measures 

are taken. 

The chosen life expectancy has a major influence on 

these calculations; therefore, choosing them should be 

one of the main focuses. For example, the change of 

the mean life expectancy of all distribution pipes to 

100 years and all house connection pipes to 50 years 

changes the picture completely (shown in figure 5). A 

much lower rehabilitation rate of around 0.6 % in the 

next years would be sufficient. Then this rate would 

increase to 1.4 % in 2080. Due to the small amount of 

replaced pipes in the next years, the mean age of the 

network is only marginally lower as it would be without 

rehabilitation. The mean age would stabilize in 2060 to 

around 50 years. The gap to the scenario without rehabilitation 

would only be 25 years. 

Therefore, the estimation of plausible and usable life 

expectancies of the already constructed pipes [14] as 

well as for the new pipes which will replace the failing 

ones has to be done with care. It either can be derived 

by statistical models or by expert knowledge from the 

operating company. 

Because of similarities between the gas and water 

distribution system, the estimation for gas pipes will be 

carried out like the method described above, but with 

different life expectancies. 

4.2 Wastewater collection 

For the sewer systems the data of case study 1 were 

used for detailed simulations. The diameters of the 

pipes in this case study range between 250 and 600 

mm. The most frequently used material was concrete 

and to a smaller proportion clay and polypropylene. The 

estimation of the condition states was carried out following 

ISYBAU [15] distinguishing 5 states from immediate 

action necessary (CS5) to no action necessary 

(CS0). This rating was reduced to 2 states: acceptable 

(CS3 or better) and unacceptable (CS4 and CS5) [12]. The 

transition function between these two conditions is 

approximated by the Gompertz relation (shown in 

Equation 1), parameters are determined using the 

method of least squares. 

Figure 4. Length of failing pipes per year with life expectancy from Baur 

[14] and the influence of the rehabilitation rate on the network age. 

Figure 5. Length of failing pipes per year with a mean life expectancy 

of 100 years for distribution pipes and 50 for house connection pipes. 

R (x) = A · e –e B–C · x (1) 

R (x) … Percentage of sewers which stay in 

acceptable condition (Condition state 

3 or better) after x years 

A, B, C … Empirical parameters 

Figure 6 shows that with this function a mean life time 

for this sewer network of 125 years is predicted. One of 

the problems of this prediction is the lack of data for 

sewers older than 120 years, which results from the fact 

that the sewer system of the case study currently has no 




older pipes and if pipe replacement took place it was 

not recorded in the data-set. 

This example was calculated for the entire network, 

but was also estimated for different groups of pipes 

classified into Dimension, Material, etc. as shown by 

Herz and Krug [13]). With these functions the rehabilitation 

rate and the length of the necessary rehabilitation 

for the network can be predicted similarly to the water 

supply system. 

Figure 6. Transition curve between acceptable and unacceptable sewer 

condition [12]. 

Figure 7. Output of Deterioration Model (Condition states of sewer 

network) and the vulnerability of the same network to the collapse of 

a pipe [1]. 

5. Priority model 

The deterioration models for rehabilitation define a 

strategy on the network scale, but for detailed choosing 

of rehabilitation areas a priority model is needed. 

With having the yearly rehabilitation length acquired 

by the deterioration model or with the given rehabilitation 

rate of the operating company (which is mostly less, 

because of budget considerations) we still have not 

decided which parts of the network in particular have to 

be rehabilitated. But it gives us the boundaries for the 

priority model. The aim is now to define the areas with 

the most pressing problems or where through interaction 

of different networks (gas, water, wastewater, 

streets, etc.) rehabilitation appears to be economically 

coherent. 

The priority model therefore consists of six parts: 

"" 

Results of the deterioration model, like the different 

aging behaviours of different materials 

"" 

Environmental influences like groundwater level, etc. 

"" 

Interactions between neighbouring networks to 

accomplish an economic and integrated rehabilitation 

management 

"" 

Passive Rehabilitation driven by land use changes, 

street or railway construction and repairs, etc. 

"" 

The importance of the areas and buildings supplied 

by the examined network 

"" 

Already observed failure rate in the examined area 

"" 

The importance of the observed part of the network 

– estimated by the vulnerability as shown for example 

by Möderl, et al. [16] (see also figure 7) 

These parts are weighted and incorporated into an integrated 

planning model to optimize the rehabilitation 

management. Some of the parameters are valid for the 

whole network (for example the parameters from the 

deterioration models) and others have to be examined 

individually for different areas. In this project the networks 

are divided into street strands and their individual 

properties are estimated (for example the varying failure 

statistics for the streets with the highest failure rates 

shown in figure 8). 

Figure 8. Failure/Street statistics for a water distribution network. 

6. Prediction of future influences 

Considering stormwater and wastewater collection, the 

most influencing factors of future development are climatic 

change and land use change. The water supply 




SCIENCE 

system on the other hand is driven by the demand and 

is therefore mainly influenced by urbanization (population 

increase or decrease). For this system case, impact 

of climate change is specifically ranging from severe 

pressure to water resources management in some areas 

to insignificant effects in other parts of the world. It can 

also have an impact on the water consumption [17]. 

Climate change can influence urban drainage system 

performance due to changing temperature, changing 

rain intensities and duration or changes in the 

evaporation (i. e. impact on rainfall runoff behaviors). In 

particular, the changes of the rain intensities and duration 

have major effects on the sewer system [18]. Further 

increase of sedimentation or the production of 

hydrogen sulfide could be consequences of longer dry 

periods. The hydrogen sulfide could also affect the pipe 

material [19] and consequently the rehabilitation needs. 

Land use change means changing population and 

changing ground sealing. For the Austrian example 

Hanika [20] predicts an increase of the overall population, 

but additionally great variations between different 

regions. The conurbations and their surroundings will 

have increasing population, while rural areas will 

decrease. The development of the population in one of 

our case studies is shown in figure 9. It shows that the 

city after a phase of stagnation from 1970 until 2000 

starts to grow again and is predicted to continue. This 

effect is also observable for the surrounding areas (0–15 

or 15–30 min by car from the city). Another factor is the 

change of the population structure from bigger groups 

to single households. 

By considering these changes, future scenarios can 

be created and implemented into an integrated rehabilitation 

planning. Figure 12 shows an area in one of 

our case studies in its present state. 

For modelling the future condition of the network in 

this area we assumed that the area will be used as housing 

area (with a runoff coefficient of 0.5). Further, an 

increase of the rainfall intensity by a factor of 1.2 [21] 

because of climate change is applied. Figure 11 shows 

the results of a hydrodynamic calculation (using 

PCSWMM) considering these future conditions for the 

scenario of a collapsing pipe because of the lack of rehabilitation. 

The resulting high flooding volume shows the 

importance of pipe integrity in this place. 

7. Conclusion and outlook 

The example shown here is only one of many possible 

future scenarios which have to be taken into account. To 

prevent mistakes and future deadlocks in planning the 

consideration of a wide variety of future scenarios is 

recommendable. 

Also we will have to regard the interactive effects 

between the different kinds of infrastructure. Only with 

an integrated approach all the different requirements of 

maintaining the high standard of our infrastructure can 

Figure 9. Population development of a case study in the city itself, 

0–15 min driving time from the city, 15–30 min from the city; 

Number of single households [18]. 

Figure 10. Case study scenario – present; visualized with Google 

Earth. 

Figure 11. Case study scenario – possible future; visualized with 

Google Earth [12]. 




be met. This could decrease planning and construction 

costs of rehabilitation measures by exploiting synergies 

between the different infrastructural sectors, by pinpointing 

the best time for rehabilitating several infrastructures 

in one area rather than replacing them one by one. For 

this a better coordination between the different operators 

of networks is viable. Also regarding the risks of pipe 

failure (with the implementation of house connections as 

well into the models) and the importance of the infrastructure 

for the entire network this method offers an 

interdisciplinary platform for different operating companies 

to apply these methods. This is gaining more and 

more importance, because better data management 

results in better rehabilitation management. In times of 

low budgets, where a foresighted asset management 

should be able to keep the balance between rehabilitation, 

maintenance and low risks at the same time, this 

cannot be emphasized enough. 

Acknowledgments 

This work was funded by the Austrian Research Promotion Agency FFG in the 

project “REHAB – Integrated planning of rehabilitation strategies of urban 

infrastructure systems” (FFG project number 832148). This work was presented 

at the CEOCOR Conference 2013 in Florence. 

This work is part of the project “DynAlp - Dynamic Adaptation of Urban Water 

Infrastructure for Sustainable City Development in an Alpine Environment” 

funded by the Austrian Climate and Energy Fund as part of the Austrian Climate 

Research Program (project number KR11AC0K00206). 

References 

[1] Kleidorfer, M., Möderl, M., Tscheikner-Gratl, F., Hammerer, M., 

Kinzel, H. and Rauch, W.: Integrated planning of rehabilitation 

strategies for sewers. Water Science & Technology 68 (2013) 

No. 1, p. 8. 

[2] EN 752: Drain and sewer systems outside buildings. Ed. E.C.f. 

Standardization, 2008. 

[3] Selvakumar, A. and Tafuri, A.: Rehabilitation of Aging Water 

Infrastructure Systems: Key Challenges and Issues. Journal of 

Infrastructure Systems 18 (2012) No. 3, p. 202–209. 

[4] Kleiner, Y. and Rajani, B.: Comprehensive review of structural 

deterioration of water mains: statistical models. Urban Water 

3 (2001) No. 3, p. 131–150. 

[5] Osman, H. and Bainbridge, K.: Comparison of Statistical Deterioration 

Models for Water Distribution Networks. Journal of 

Performance of Constructed Facilities 25 (2011) No. 3, 

p. 259–266. 

[6] Ana, E.V. and Bauwens, W.: Modeling the structural deterioration 

of urban drainage pipes: the state-of-the-art in statistical 

methods. Urban Water Journal 7 (2010) No. 1, p. 47–59. 

[7] Rajani, B. and Kleiner, Y.: Comprehensive review of structural 

deterioration of water mains: physically based models. 

Urban Water 3 (2001) No. 3, p. 151–164. 

[8] Ashley, R. and Hopkinson, P.: Sewer systems and performance 

indicators – into the 21 st century. Urban Water 4 (2002) No. 2, 

p. 123–135. 

[9] Mair, M., Sitzenfrei, R., Möderl, M. and Rauch, W.: Identifying 

multi utility network similarities. In World Environmental 

And Water Resources Congress, 2012. Albuquerque, New 

Mexico, United States: American Society of Civil Engineers. 

[10] Sitzenfrei, R. and Rauch, W.: From water networks to a “Digital 

City” – a shift of Paradigm in Assessment of Urban Water 

Systems. In 12 th International Conference on Urban Drainage, 

2011. Porto Alegre/Brazil. 

[11] Cashman, A. and Ashley, R.: Costing the long-term demand for 

water sector infrastructure. foresight 10 (2008) No. 3, p. 9–26. 

[12] Tscheikner-Gratl, F., Mikovits, C., Hammerer, M., Rauch, W. and 

Kleidorfer, M.: Chancen und Herausforderungen für eine ganzheitliche 

Sanierungsplanung von Kanalisationen. Wiener 

Mitteilungen 229 (2013), p. C1–26. 

[13] Herz, R. and Krug, R.: Sanierungsbedarf und Sanierungsstrategien 

für Abwassernetze. In 11. Leipziger Bau-Seminar – 

Thema: öffentliche und industrielle Wasserwirtschaft im 

Umbruch. Leipzig, 2000. 

[14] Baur, R.: Einsatz von Zustandsbewertungsprogrammen für 

Gas- und Wasserversorgungsnetze – KANEW. Technische 

Universität Dresden, 2004. 

[15] BmVBS: Arbeitshilfen Abwasser – Planung, Bau und Betrieb 

von abwassertechnischen Anlagen in Liegenschaften des 

Bundes. Berlin: Bundesministerium für Verkehr, Bau und 

Stadtentwicklung, 2012. 

[16] Möderl, M., Kleidorfer, M., Sitzenfrei, R. and Rauch, W.: Identifying 

weak points of urban drainage systems by means of Vul 

NetUD. Water Sci Technol. 60 (2009) No. 10, p. 2507–13. 

[17] Ruth, M., Bernier, C., Jollands, N. and Golubiewski, N.: Adaptation 

of urban water supply infrastructure to impacts from 

climate and socioeconomic changes: The case of Hamilton, 

New Zealand. Water Resources Management 21 (2007) No. 6, 

p. 1031–1045. 

[18] Mikovits, C., Tscheikner-Gratl, F., Rauch, W. and Kleidorfer, M.: 

Integrierte Betrachtung von Anpassungsmaßnahmen und 

Rehabilitierung. in ÖWAV – Sanierung und Anpassung von 

Entwässerungssystemen: Alternde Infrastruktur, Landnutzungsänderungen 

und Klimawandel. Innsbruck: ÖWAV, 2013. 

[19] Mack, A., Müller, K. and Siekmann, T.: Klimaanpassungsstrategien 

für Entwässerungssysteme. In Dynaklim. Aachen, 2011. 

[20] Hanika, A.: Kleinräumige Bevölkerungsprognose für Österreich 

2010–2030 mit Ausblick bis 2050 („ÖROK-Prognosen“). 

Österreichische Raumordnungskonferenz: Wien, 2010. 

[21] Gregersen, I.B., Madsen, H. and Arnbjerg-Nielsen, K.: Estimation 

of climate factors for future extreme rainfall: Comparing 

observations and RCM simulations. in 12 th International 

Conference on Urban Drainage. Porto Alegre/Brazil, 2011. 

Authors 

Dipl. Ing. Franz Tscheikner-Gratl 

E-Mail: franz.tscheikner-gratl@uibk.ac.at | 

Dipl.-Ing. Christian Mikovits | 

Dipl.-Ing. Dr. techn. Michael Möderl | 

Univ.-Prof. Dipl.-Ing. Dr. techn. Wolfgang Rauch | 

Ass.-Prof. Dipl.-Ing. Dr. techn. Manfred Kleidorfer | 

Institute for Infrastructure Engineering | 

Unit for Environmental Engineering | 

Department of Civil Engineering Sciences | 

University of Innsbruck | 

Technikerstrasse 13 | 

A-6020 Innsbruck/Austria 

Max Hammerer 

hammerer-system-messtechnik | 

Golgathaweg 1 | 

A-9020 Klagenfurt am Wörthersee/Austria 




SCIENCE 

The Treatability of Emerging Pollutants 

in Urban Stormwater Best Management 

Practice (BMP) Drainage Systems 

Emerging pollutants, Urban runoff, Stormwater BMPs, Unit operating processes 

J. Bryan Ellis, D. Michael Revitt and Lian Lundy 

A range of emerging pollutants (EPs) are now being considered for regulatory designation as potentially 

hazardous or as priority substances. These EPs occur ubiquitously in urban receiving waters and have both 

point and non-point sources. The occurrence and likely sources of four selected EPs (diclofenac, PFOS, HBCD 

and DDVP) found in urban surface water discharges are discussed. A unit operating process (UoP) methodology 

is utilised to evaluate primary BMP removal processes based on physico-biochemical properties and the 

susceptibility of the individual EPs to be removed by these processes. True source control approaches such as 

direct infiltration, green roofs, rain gardens and porous paving would appear to the most effective management 

measures. 


Concern about the sources, fate and impacts of emerging 

pollutants (EP) has substantially increased over the 

past decade largely driven by research-based programmes 

and networks developed in the United States 

by the USGS [1] and USEPA (www.water.epa.gov; www. 

creec.net) as well as similar European networks such 

as KNAPPE (www.ecologic.eu), POSEIDON, (www.euposeidon.com), 

NORMAN (www.norman-network.net), 

PHARMAS (www.pharmas-eu.org) etc. This concern is 

underlined by the recent addition of three pharmaceutical 

compounds to the EU priority substance list [2]. 

These newly designated substances and their environmental 

quality standards (EQS) will need to be taken 

into account in the establishment of individual member 

state supplementary monitoring programmes and preliminary 

programmes of measures (PoMs) to be submitted 

under the EU Water Framework Directive (WFD) by 

the end of 2018. However, the large majority of the current 

research effort to date has focussed on a limited 

number of endocrine disruptor chemicals (EDCs), pharmaceutical 

and personal care products (PPCPs) and 

persistent organic pollutants (POPs). The USGS studies 

detected over 100 contender EPs in some 80 % of urban 

receiving water samples [3] and similar evidence for EP 

occurence in both urban surface waters and groundwater 

have been reported for continental Europe [4, 5, 6] 

and the UK [7]. In the latter UK study, metabolites were 

found at higher concentrations than the parent compounds 

for 60 % of all samples with urban groundwater 

concentrations correlating with wet weather recharge. 

However it should be noted that relatively few of the 

samples analysed in these various studies exceeded any 

regulatory guidelines where these exist, mainly occurring 

at low levels below 0.1 µg l –1 , although as many as 

30–40 EPs were found as complex mixtures in any single 

sample. In order to address the environmental concerns 

regarding potential contamination of receiving waterbodies 

with pharmaceutical residues, the European 

Commission is intending to undertake risk assessment 

studies to provide a baseline analysis to support the relevance 

and effectiveness of any strategic approaches to 

guiding future legislative amendment or extension. 

The principal focus of the EP research effort to date 

has been on diffuse agricultural runoff [8], whilst in 

terms of urban drainage, the research has almost exclusively 

addressed wastewater effluents and drinking 

water with relatively little regard for urban runoff 

sources and discharges [9]. Figure 1 shows the principal 

EP sources, pathways and sinks in urban areas and 

underscores the complexity of EP entry, conveyance, 

transformation and bioaccumulation mechanisms that 

can occur within urban drainage networks. Figure 1 

and the supporting literature emphasise that there are 

still fundamental and major gaps in both data and 

understanding of the occurrence, character and behaviour 

of most EPs within this urban cycle which make the 

management and control of their potential toxicity 

impacts a very challenging issue [10]. 

It is certainly clear that the traditional individual substance 

approach for evaluating environmental risks will 

not be sustainable in the future given that little environ 



SCIENCE Emerging Pollutants 

Figure 1. 

Urban sources, 

pathways and 

sinks of 

emerging 

pollutants 

(EPs). 

URBAN 

DRAINAGE 

DOMESTIC 

INDUSTRY 

COMMERCIAL/RETAIL 

HOSPITALS/CARE HOMES etc 

AGRICULTURE 

Road & Impervious 

Surface Runoff 

Disposal 

Product 

Disposal 

Biosolids 

WASTEWATER 

TREATMENT 

Sludge 

Landfill 

Soil 

CSOs 

Effluent 

SURFACE WATER 

& SEDIMENT 

Runoff 

Infiltration 

Leachate 

Infiltration 

Runoff 

Groundwater 

NOTE : Shaded boxes denote 

both EP and metabolite 

occurrence ; urban 

contributions identified by 

dashed enclosure 

Bioavailability 

Bioaccumulation 

Receiving 

Water 

Ecology 

Drinking 

Water 

mental or toxicological data is available for the large 

majority of EPs. This view is confirmed by the growing 

realisation of the critical importance of multi-generational, 

simultaneous ecological exposure to individual 

trace levels of multitudes of chemical stressors [11]. This 

is particularly true for urban stormwater runoff pollutants 

which essentially comprise a complex mixture 

“cocktail” which renders risk assessment of both individual 

and multi-generational compounds a highly 

speculative business in terms of both science and regulation 

[12]. This urban stormwater runoff “cocktail” is 

derived from a variety of sources and thus there is some 

concern about the potential interactive effects of EP 

mixtures and how this might be dealt with in the current 

individual compound legislation and definition of 

standards. At ultra-trace levels it may no longer be possible 

to deconvolute imposed EP effects from their incidence 

as ambient background and it will be difficult to 

determine the source apportionment of EP risk in terms 

of overall environmental and aquatic concerns. 

Given the apparent ubiquitous occurrence of EPs in 

urban receiving waters as evidenced by the various US 

and European studies mentioned previously, there are 

continuing concerns over their modes of entry into the 

aquatic environment as well as about the characteristics 

which render them potentially hazardous to the receiving 

water ecology. In addition, there is an open question 

as to whether any of the various source control sustainable 

drainage options provide effective treatment efficiency 

for EPs in urban runoff, particularly given their 

low-level concentrations. The purpose of this paper is to 

explore the characteristics and sources of some typical 

EPs found in urban stormwater runoff and to examine 

their removal potential under the prevailing physicobiochemical 

processes operating within typical source 

control best management practice (BMP) treatment 

systems. 

2. Emerging pollutants 

2.1 Definitions 

A widely used definition for EPs is that they are not currently 

included in routine monitoring programmes but 

could pose a significant risk requiring (future) regulation, 

depending on their potential eco-toxicological and 

health effects and their levels as found in the aquatic 

environment. Xenobiotic substances which conform to 




SCIENCE 

this definition may be new-to-market “designer” substances 

(e. g. herbal supplements, non-prescription 

medicines) or may have for a number of years entered 

urban receiving waterbodies from both natural and 

anthropogenic sources, but may now be considered 

“emerging” due to recent awareness of their potential 

toxicological and human health impacts. They may not 

have been subject to regulatory checks when first produced 

and may not be subject to current regulatory 

receiving water environmental quality standards (EQS). 

This serves to differentiate them from priority hazardous 

substances (PHSs) which for example, within the 

European Community are covered in Article 16 of the 

Water Framework Directive (WFD; 2000/60/EC) and the 

associated Priority Substances Directive (2008/105/EC) 

and Groundwater Daughter Directive (2006/118/EC). 

Such substances would be covered under the equivalent 

Contaminant Candidate List (CCL) and Toxic Substance 

Control Act (Section 6, TSCA) of the Clean Water 

Act in the US. This means that there is overlap between 

the EP and PS contaminant suites with current EP 

organic compounds such as bisphenol A and oestradiol 

being under review as future designated PSs or PHSs 

within the Drinking Water Directive (98/83/EC) and having 

proposed limit values of 0.1 µg l –1 and 0.01 µg l –1 

respectively. The EP triclosan represents an antimicrobial 

agent which is also under review for future designation 

as a PS under the EC Priority Substance Directive. As 

such these EPs can be considered to represent “stealth” 

pollutants which have eluded attention to date because 

they may have been masked, indiscernible, surreptitiously 

introduced into the environment, difficult or 

cryptic to detect clearly or may have just previously 

remained undetected. 

2.2 Sources 

The presence of POPs in both treated wastewater effluent, 

combined sewer overflows (CSOs) and urban runoff 

is well known comprising a mix of polyaromatic hydrocarbons 

(PAHs), EDCs, PPCPs, solvents as well as plasticisers, 

surfactant breakdown products etc. [9]. In general 

terms, assuming a 2 % overflow frequency and a 

50 % dilution, could imply a long term EP substance loss 

amounting on average to 1 % of the total CSO discharge 

load. As indicated in figure 1, to this mix could be added 

landfill leachate (e. g. phthalates, sterols etc) as well as 

exotic surface-derived substances found in urban 

stormwater runoff such as caffeine, nicotine, cocaine 

etc. [13]. Major potential urban sources include industrial/commercial 

and wastewater discharges as well as 

untreated combined sewer overflows (CSOs) and urban 

surface water or stormwater outfalls (SWOs). SWO discharges 

constitute a major secondary source and derive 

EPs from a variety of origins: 

## 

Illegal sewer misconnections which allow untreated 

sewage and greywater to enter and mix with the 

surface stormwater system. One estimate suggests 

that between 300,000 to 400,000 such wrong connections 

(0.6 % to 2 % of domestic households) exist 

in England and Wales alone [14]. Clearly sanitary 

wastewater and greywater misconnections to the 

separate surface water sewer can constitute principal 

EP sources to urban receiving waters. 

## 

It is estimated that some 1 % to 3 % of combined sewers 

(especially in older inner city areas) are subject to 

exfiltration which could lead to a sewage leakage loss 

of anything between 26 and 260 m 3 km –1 year –1 in 

European cities [15]. A major source of such leakage 

is believed to be via house connections which are 

often in a poor structural state [9], but unfortunately 

there are very few studies available to fully confirm 

this source attribution. The large majority of exfiltration 

loss will be to urban groundwater but the shallow 

depth of most surface water pipes means that 

there will inevitably be some EP return (even if in 

diluted form) as groundwater or infiltration inflow to 

urban surface waters as well as resul ting from trrench 

seepage into damaged surface water sewers. 

## 

The flushing of EP substances from impervious urban 

surfaces during wet weather conditions may also be 

an important source given the variety of potential 

everyday materials that contain or sequester xenobiotic 

pollutants e.g solvents in wood preservatives, 

foam retardents, rainfall-runoff flushing of garage 

service forecourts and industrial yards, discarded 

recreational drugs, drug syringes and medicants, 

phthalates leaching from weathered plastic materials 

etc. [13, 16]. 

## 

A range of emerging organic pollutants (EOPs) are 

also associated with wet weather urban runoff from 

parks, open spaces, gardens, golf courses as well as 

leachates from local and transport authority applications 

e.g pesticides such as glyphosate used for 

weed control. 

## 

Leachate seepage from decommissioned landfill 

sites which yield a range of pharmaceuticals, solvents, 

pesticides etc. 

## 

Domestic disposal of medications and drugs as well 

as other abuses of the surface water sewer system 

e.g direct disposal to surface water drains of used oil, 

waste bin washings, unwanted and outdated pesticides/biocides/insecticides, 

solvents and paints etc. 

[17]. 

2.3 Classification and Occurrence 

As the definition of EPs covers a wide range of compounds, 

they are often grouped into classes depending 

on their chemical characteristics or by their mode of 

action. Table 1 categorises EPs based essentially on their 

application together with examples of compounds and 

the concentration ranges of representative compounds 

discussed in this paper (and highlighted in bold) as con 




sistently detected in urban runoff discharges and receiving 

waters. Algal toxins and antifouling compounds have 

been omitted from this list as they have rarely been 

reported in urban waters. Whilst the median values 

noted in the table for the four named EP compounds 

generally confirm that the large majority of EPs are 

detected at trace levels, one feature is the common 

occurrence of high magnitude outliers as indicated by 

the maximum values. One explanation for these might 

be related to the impact on urban receiving waters of 

untreated CSO discharges. Some EPs such as PAHs and 

bisphenol A can be effectively removed during secondary 

biological treatment but can substantially increase in 

concentration within the receiving water during CSO wet 

weather events as the lack of treatment becomes more 

important than any in-stream dilution effect. By comparison, 

POPs and other EPs which are not well removed in 

STW treatment e.g. carbmazepine and caffeine can be 

expected to be found at decreasing concentrations due 

to storm runoff dilution. Fono and Sedlack [18] have 

demonstrated a persistent 75 % – 90 % attenuation of 

PPCP species such as the PPCP beta-blocker propranolol 

below CSO discharges and which is not explicable by 

photodegradation or biotransformation mechanisms. 

Such patterns have been consistently found in many 

urban receiving water source studies [16, 19]. Some EP 

species such as the insecticide cypermethrin, have very 

low solubilities and bind strongly to suspended solids 

and are therefore likely to accumulate within receiving 

water sediments adjacent to outfalls. Previous work on 

PPCPs in urban receiving waters has noted this potential 

for sediment accumulation as well as possibilities for the 

development of antimicrobial resistance [20]. 

3. BMP control EP stormwater discharges 

3.1 Selecting EPs for analysis 

The adoption of BMP drainage options for the control 

and management of urban stormwater runoff has 

become an integral principle for sustainable urban 

drainage infrastructure provision. Such BMP devices are 

seen as providing effective water quality treatment in 

addition to their primary function of flood control and 

previous work has shown that the physical, chemical 

and biological processes operating within such control 

structures can provide a reliable basis for the assessment 

of their relative capabilities to remove a variety of 

micropollutants [21]. However, is it feasible to apply a 

unit operating process methodology to evaluate the 

removal potential of EPs within BMPs? To explore this 

question further, a limited number of EP compounds 

representative of the classes listed in table 1 have been 

selected for analysis and which have been highlighted 

in bold in the table. 

## 

Diclofenac; is a non-steroidal anti-inflammatory 

PPCP used throughout the world and available as 

both a prescription and “over-the-counter” drug, 

with an estimated 151 tonnes per annum used in the 

UK [22] and over 80 tonnes per annum in Germany 

[23]. Diclofenac occurs in urban runoff and receiving 

waters mainly as a result of direct CSO discharges, 

sewer misconnections and illicit domestic disposal. It 

has been estimated that up to 50 % – 60 % of the 

total observed surface water loads are derived 

from the two latter sources [21]. Surveys in UK surface 

waters indicate a concentration range of 

10–76.3 ng l –1 with a median value of 12.6 ng l –1 . 

Maximum concentrations appear principally associated 

with wet weather winter periods [21]. Previous 

work on urbanised tributaries of the River Thames in 

metropolitan London has indicated receiving water 

concentrations between10.5 and 85 ng l –1 with an 

average concentration of 51 ng l –1 being recorded 

for the River Seine at Orly in metropolitan Paris and 

100 ng l –1 in Berlin surface waters [20]. In the cited 

UK studies, sewage treatment plant discharges of 

diclofenac were substantially diluted by endogenous 

concentrations derived from upstream sources 

primarily fed from diffuse urban inflows. It is known 

that diclofenac is subject to photolysis and biodegradation 

with the latter processes having a half-life of 

about 8 days, although the degradation metabolite 

products are frequently 5–6 times more toxic than 

the parent compound. It is now a designated PS with 

an EQS value of 0.1 µg l –1 . 

## 

Perfluoro-octane sulphonic acid (PFOS); this is a surfactant 

widely used as a stain repellent and in fire 

fighting foams as well as in metal plating and photographic 

processes. PFOS is very resistent to hydrolysis, 

photolysis and biodegradation and is an exceptionally 

stable and persistent compound. It is characterised 

by abundant congeners, all of which are 

accumulatively adsorbed into internal organs of the 

receiving water ecology. PFOS became of particular 

interest in the UK following a major oil terminal fire 

in Hertfordshire north of London in December 2005 

when receiving waters of the Ver and Colne in the 

urban areas downstream of the fire location recorded 

PFOS levels between 4.6 and 5.9 µg l –1 [24]. Levels of 

between 8 and 28 µg l –1 have also been recorded in 

surface waters adjacent to airports following fire 

fighting practice and breakthroughs above 1.0 µg l –1 

have also been noted in CSO discharges [24]. These 

reported levels are well in exceedance of the normal 

quartile range and median values as identified in 

table 1 as they represent extreme conditions following 

exceptional releases. PFOS became partly regulated 

in 2010 and a 0.2–0.3 µg l –1 ecosystem threshold 

risk level has become widely accepted; the compound 

is now a designated PHS with an EQS value of 

0.00065 µg l –1 . 

## 

Hexabromocyclododecane (HBCD); this compound 

is widely used in polystyrene foam insulation board 




SCIENCE 

Table 1. Classification and examples of EPs in urban receiving waters and typical concentration ranges. 

CLASS Compound Examples Concentration Range 

(ng l –1 ) 

PPCPs/ Fragrances Diclofenac, Ibuprofen, Carbamazepine, Diazipane; Camphor, Musk, Parabens 10–(12.6)–85 [1002] 

EDCs; Steroid Hormones 

Antimicrobials/Virals 

Plasticisers 

Oestradiol, Coprostanol 

Triclosan, Osaltamivir 

Bisphenol A, Phthalates, Methanone 

Surfactants/ Detergents Perfluoro-octane sulphonic acid (PFOS), Nonylphenols, APEs 1.3–(3.4)–21.0 [195] 

Addictive Drugs 

Nanoparticles 

Cocaine, Heroin, Morphine 

Silica, Aluminium fibre, Gypsum, Cellulose 

Flame Retardents Hexabromochloracyclododecane (HBCD), Tri (2-chloroethyl) phosphate, PBDEs 1.0–(2.9)–13.0 [137] 

Solvents 

Other POPs 

(Aromatics, Pesticides, Biocides, 

Perfluoroalkylated substances etc.) 

Para-Cresol, DNP 

Dichlorvos (DDVP), PAHs(Indenopyrene, anthracene, benzofluoranthene etc.) 

Pesticides (Diuron, DEHP, Endosulfan, Glyphosate , Diazinon), Cypermethrin, 

Perfluoroalkylated Substance Trichloromethane 

NOTE: Concentration range shown as: 25 th ‰ – (Median) – 75 th ‰ – [Maximum] values 

1.4–(17.8)–40.7 [1552] 

ing and textile coatings as a brominated flame 

retardant. It is estimated that some 19 kg year –1 of 

HBCD are released into the UK environment of which 

some 30 % is discharged into surface waters [25]. It is 

a persistent, lipophilic organic pollutant having a 

poor water solubility and low volatility. It becomes 

strongly adsorbed to suspended solids and sediment 

and has a low leaching potential [26]. There is 

evidence for trophic magnification particularly in livers 

of smelt and trout, with a fish to sediment bioconcentration 

factor of 15 : 1 [25]. HBCD sediment 

accumulations in the range of 199–1680 ng kg –1 

have been recorded at locations downstream of 

both CSOs and SWOs in urban receiving waters of N 

England which could pose long term chronic ecosystem 

effects. HBCD is now a designated PHS with an 

annual average EQS value of 0.0016 µg l –1 . 

## 

Dichlorvos (DDVP); this is a widely used organophosphorous 

insecticide and weed killer, which because 

of its solubility in water possesses a high acute toxicity 

potential. It has a recommended freshwater EQS 

of 0.00061 µg l –1 and a maximum 0.02 µg l –1 drinking 

water threshold set by the WHO. DDVP is subject to a 

combination of volatilisation, hydrolysis and microbial 

degradation. Few concerns to date have been 

expressed about its occurrence in urban surface 

waters and surveys of European rivers have suggested 

PFOS levels to be generally near the detection 

limit with a NOEC ecosystem threshold of 

around 3.4 µg l –1 . DDVP has now been designated a 

PS. 

3.2 BMP unit operating processes (UoPs) for EPs 

Field data on the different environmental behaviours 

and fates of many of the generic stormwater micro-pollutants 

within structural BMPs are scarce. In an attempt 

to overcome this deficiency, a systematic methodology 

based on unit operating processes (UoPs) to provide a 

comparative assessment of pollutant removal potentials 

has been developed [21]. Table 2 shows the primary 

unit operating processes considered in the methodology 

and which directly or indirectly control pollutant 

removal potential within a BMP device; the process 

unit measurements are also shown in the table. The 

methodology is based on a quantitative consideration 

of these primary removal processes (biological, chemical 

and physical) associated with the different identified 

BMP. The susceptibility of individual pollutant species to 

be influenced by the UoPs is then considered separately 

on a largely empirical and qualitative basis. The two sets 

of data are then combined to derive an overall value for 

the removal potential of each BMP option for each considered 

pollutant enabling pollutant specific ranked 

orders of preference to be generated. Full details of the 

methodological approach and its application can be 

found elsewhere [21] and which also demonstrates 

comparability with recorded literature values and field 

case studies. In this paper green roofs have been added 

to the previous list of 15 different BMPs. An additional 

modification is that in order to ensure that the potential 

removal characteristics of the EPs are fully considered, 

the susceptibility to hydrolysis processes has been 

included and incorporated together with photolysis in a 

category identified as abiotic degradation. This is allocated 

an equal weighting to the other potential mechanisms 

for pollutant removal during BMP treatment 

(Table 3).The methodology to date has been applied to 

generic pollutants commonly included in the large 

majority of urban runoff investigations and which occur 

in readily detectable concentrations as reflected in the 




event mean concentration (EMC) distributions recorded 

in the US EPA national stormwater BMP database (www. 

bmpdatabase.org). EPs on the other hand generally 

occur at low or ultra-low concentrations and have a 

minimal evidence database. Whilst ultra-trace concentrations 

may imply that EP transformation is unlikely to 

contribute much to microbial growth, enzyme degradation 

might well make substantial contributions to cometabolism 

functions rendering them potentially ecologically 

hazardous. 

Table 3 illustrates both quantitative and qualitative 

process values for each of the four selected EP compounds 

which form the basis for evaluating their overall 

removal potentials to the UoPs. Experimental data has 

been used where this is available but is often subject to 

wide variations as demonstrated by the ranges of Koc 

values for PFOS and Kh values for diclofenac and HBCD. 

However, this has a limited impact on the applied 

methodological approach as the EP removal potentials 

are broadly categorised as low, low/medium, medium, 

medium/high and high as shown in table 3. Thus HBCD 

can be seen to be highly susceptible to removal by 

adsorption to substrat settling/filtration, microbial 

degradation and plant uptake but it is resistant to abiotic 

degradation processes. In contrast, DDVP although 

biodegradable, is less readily removed by adsorption 

and precipitation mechanisms and is not susceptible to 

plant uptake. It is the only one of the four investigated 

EPs to demonstrate a potential to undergo abiotic degradation. 

The qualitative assessments for the removal 

potentials have been converted to numerical values and 

by combining the values for removal of a specific pollutant 

by a BMP removal process with the values representing 

the importance of the primary removal mechanisms 

within each BMP, the relative rankings for the removal of 

different EPs within the different BMPs has been established 

as shown in figure 2. 

4. BMP removal potentials 

The ranking orders displayed in figure 2 demonstrate 

identical behaviours by the selected EPs for the two 

most highly ranked treatment systems (infiltration 

basins and sub-surface flow constructed wetlands) and 

for the five least efficient treatment systems (filter drains, 

filter strips, lagoons, porous asphalt and sedimentation 

tanks). Although green roofs are mainly employed for 

water volume retention purposes, the results of this 

theoretical approach indicate their ability to perform 

consistently well with regard to the removal of the four 

EPs. Between the identified extremes of the treatment 

performance rankings there is evidence of discrimination 

in how the individual pollutants respond to different 

BMPs. The greatest variation in performance rankings 

across the four pollutants occurs for porous paving 

and retention pond treatment systems. Porous paving 

has an average ranking of 6 but performs best for perfluorosulphonic 

acid (ranking 4) due to the combined 

susceptibility of this pollutant for removal by adsorption 

and filtration, which are both important removal mechanisms 

in porous paving systems, particularly where an 

Figure 2. 

Predicted order 

of preference 

for BMPs to 

remove 

Diclofenac, 

PFOS, HBCD 

and DDVP. 

Ranked order of preference 

diclofenac 

perfluorooctane sulphonic acid 

hexabromocyclododecane 

dichlorvos 

BMP 

IB = infiltration basin; CWSSF = sub-surface flow constructed wetland; GR = green roof; CWSF = surface flow constructed wetland; 

EDB = extended detention basin; PP = porous paving; RP = retention pond; DB = detention basin; SW = swale; SO = soakaway; 

IT = infiltration trench; FD = filter drain; FS = filter strip; LA = lagoon; PA = porous asphalt; ST = sedimentation tank. 




SCIENCE 

Table 2. Indirect and direct removal processes in BMP systems. 

Removal Process 

Indirect removal process Adsorption to suspended solids K oc (L/g). 

Precipitation 

Direct removal processes Settling 

Adsorption to substrate 

Microbial degradation 

Filtration 

Volatilisation 

Photolysis 

Hydrolysis 

Plant uptake 

Relevant measurements and units 

Water solubility (mg/L) 

Settling velocity (m/s) 

K oc (L/g) 

Rate of aerobic and anaerobic biodegradation (½ life in days) 

Function of K oc (L/g) and precipitation (mg/L) 

K h (atm-m 3 /mole) 

Rate of photodegradation (½life in days) 

Susceptibility to hydrolysis under neutral conditions based on functional 

groups present 

K ow ; bioaccumulation concentration factor (BCF) 

Key: K oc = organic carbon adsorption coefficient = partitioning of a substance between the solid and dissolved phases at equilibrium expressed on an organic 

carbon basis 

K h = Henry’s Law constant (based on the relationship that at a constant temperature the mass of gas dissolved in a liquid at equilibrium is proportional to 

the partial pressure of the gas) 

K ow = octanol-water partition coefficient = a measure of the potential for organic compounds to accumulate in lipids = ratio of the concentration of a pollutant 

in octanol to that in water at equilibrium 

Table 3. Removal processes within BMPs together with their potentials to occur for four emerging pollutants. 

UoPs Properties Diclofenac Perfluorosulphonic 

acid 

(PFOS) 

Hexabromocyclododecane 

(HBCD) 

Dichlorvos 

(DDVP) 

Adsorption K oc values 405–830 2,562–71,680 1.76–5.2 × 106 27.5–151 

Potential for removal Low/Medium Medium/High High Low 

Precipitation Solubility (mg/L) * 2.37–4.52 0.104 0.034-0.086 2,044–8,000 

Settling & filtration 

Aerobic 

biodegradation 

Anaerobic 


Overall 


Potential for removal High High High Medium 

Potential resulting 

from adsorption & 

precipitation potentials 

Susceptibility or half 

life (days) 

Susceptibility or half 

life (days) 

Medium High High Low/Medium 

37–170d 

Negligible; Low 

No experimental evidence 

for aerobic or 

anaerobic degradation 

1–32; Medium/High < 1; High 

Negligible; Low 1.1–6.9; High 3.5; High 

Potential for removal Low Low High High 

Volatilisation K h values 4.7 × 10 –12 – 5.3 × 10 –9 9.34 × 10 –7 1.7 × 10 –6 – 1.2 × 10 –4 5.7–8.6 × 10 –7 

Potential for removal Low Low/Medium Medium Low/Medium 

Photolysis Half-life (hours) 192 hours; Low Resistant to photolysis; 

Low 

Hydrolysis 

Susceptibility Low Resistant to hydrolysis; 

Low 

Potential for abiotic 

degradation 

Resistant to 

photolysis; Low 

Resistant to 

hydrolysis; Low 

Low Low Low Medium 

Some susceptibility to 

photolysis; Medium 

Half life of 2.5–4.0 days 

at pH7; Medium 

Plant uptake K ow 10,471–32,359; Medium 30,900; Medium 5.5 × 107; High 3.98–26.9; Low 

Potential for bioaccumulation; 

BCF value 

3.162; Low 56; Medium 8,800–18,000; High 0.6–3.13; Low 

Potential for removal Low/Medium Medium High Low 




underlying substrate is present. Dichlorvos possesses 

the lowest ranking (8) for porous paving, as a relatively 

low Koc value and an increased solubility compared to 

the other pollutants do not facilitate ready removal by 

adsorption and filtration. The behaviour of dichlorvos 

reverses for retention ponds where it demonstrates the 

highest removal potential (ranking 5 compared to an 

average ranking of ~ 8) due to its susceptibility to both 

aerobic and anaerobic biodegradation in retained water 

systems. Hexabromocyclododecane behaves least well 

in retention ponds as two of its major removal mechanisms, 

adsorption and filtration, do not have high 

importance in this type of treatment system. The same 

factors influence the preferential pollutant removal patterns 

in extended detention basins (average ranking 

between 4 and 5) and to a lesser extent in detention 

basins (average ranking ~ 8) where sedimentation is less 

important due to the time available for this process. 

Sub-surface flow constructed wetlands consistently 

perform more efficiently than the corresponding surface 

flow systems due to the greater potential in the 

former for adsorption, filtration and microbial degradation 

to occur in both aerobic and anaerobic conditions. 

Both systems are vegetated but the sub-surface flow 

version will provide increased contact time between the 

pollutant and the plant roots as well as an increased 

possibility of algal uptake. Hexabromocyclododecane is 

removed most efficiently in those vegetated systems 

which exhibit discrimination (surface flow constructed 

wetlands and swales) because of high Kow and BCF values. 

In contrast, dichlorvos has low values for both these 

parameters and so tends to perform least well in vegetated 

systems, as represented by surface flow constructed 

wetlands and swales. The same characteristics 

properties also account for dichlorvos performing least 

well in green roofs. 


A UoP methodological approach to evaluate the potential 

performance efficiency of BMP control structures to 

remove EPs provides a feasible theoretical framework. 

The methodology appears to retain discriminatory 

power for individual compounds even when they are 

known to occur together as multi-generational complex 

mixtures as their physic-chemical properties are individually 

distinctive. This is supported by the prevailing 

low-level concentrations which limit compound interactions 

that could affect their characteristic behaviours. 

Nevertheless, there is considerable variability in the 

data values reported for many of the UoP processes 

noted in table 3 which inevitably introduces uncertainty 

into the methodology. This implies that the relative BMP 

removal rankings illustrated in figure 2 should be 

regarded as providing a first-order screening function. 

Nevertheless, it is apparent that true source controls 

such as direct infiltration, rain gardens (pocket-wetlands), 

green roofs and porous paving offer the most 

appropriate and effective EP treatment for urban stormwater 

runoff management. 

References 

[1] USGS: Toxic Substance Hydrology Program (2011). http:// 

toxics.usgs.gov/regional/emc. (Accessed 03/11/13) 

[2] EU: Proposed Amendment 34 to EU Directives 2000/60/EC 

and 2008/105/EC. European Commission, Brussels (2013). 

[3] Kolpin, D.W., Furlong, E.T., Mayer, M.T., Thurson, E.M., Zaugg, 

S.D., Barber, L.B. and Buxton, H.T.: Pharmaceuticals, hormones 

and other organic wastewater contaminants in US streams 

1999–2000; A national reconnaissance. Environ. Sci. Tech. 36 

(2002) No. 6, p. 1202–1211. 

[4] Houtman, C.J.: Emerging contaminants in surface waters and 

their relevance for the production of drinking water in 

Europe. Journ. Integrative Environ. Sci. 7 (2010) No. 4, p. 271– 

295. 

[5] Loos, R., Gawlik, B.M., Lecoro, G., Rimaviciute, E., Contini, S. and 

Ridoglio, G.: EU-wide survey of polar organic persistent pollutants 

in European river water. Environ. Poll. 157 (2009), 

p. 561–568. 

[6] Musolff, A., Leschik. S., Moder, M., Strauch, G., Reinstorf, F. and 

Schirmer, M.: Temporal and spatial patterns of micropollutants 

in urban receiving waters. Environ. Poll. 157 (2009), 

p. 3069–3077. 

[7] Stuart, M.E., Manamsa, K., Talbot, J.C. and Crane, E J.: Emerging 

Contaminants in Groundwater. Report OR/11/013. 

Groundwater Science Programme. British Geological Survey 

(BGS), Keyworth, Nottingham, UK (2011). 

[8] Pal, A., Gin, K.Y.H., Lin, A.Y.C. and Reinhard, M.: Impact of 

emerging organic contaminants on freshwater resources: 

Review of recent occurrence, sources, fate and effects. Sci. 

Total Environ. 408 (234), (2010), p. 6062–6069. 

[9] Ternes, T. and Joss, A. (Edits): Human Pharmaceuticals, Hormones 

and Fragrances: The Challenge of Micropollutants in 

Urban Water Management. IWA Publishing. London. UK. 

(2007), ISBN 9781843390930. 

[10] Trembley, L.A., Stewart, M., Peake, B.M., Gadd, J.B. and Northcott, 

G.: Review of the Risks of Emerging Organic Contaminants 

and Potential Impacts. Report No. 1973. Prepared for 

Hawkes Bay Regional Council. Cawthron Institute, Nelson. 

New Zealand (2011). 

[11] Dietrich, S., Ploessi, F., Bracher, F. and Lafousch: Single and 

combined toxicity of pharmaceuticals at environmentally 

relevant concentrations in Daphnia magnia: A multi-generational 

study. Chemosphere 79 (2010) No. 1, p. 60–66. 

[12] Ellis, J.B.: Antiviral pandemic risk assessment for urban 

receiving waters. Water Sci. Tech. 61 (2010) No. 4, p. 879–884. 

[13] Rieckermann, J.: Occurrence of illicit substances in sewers. 

53–72 in Frost, N and Griffiths, P. (Edits): Assessing Illicit 

Drugs in Wastewater. Insight Series No. 9, European Monitoring 

Center for Drugs and Drug Addiction, Lisbon. Portugal 

(2008), ISBN 9789291683178. 

[14] Defra: Draft Flood & Water Management Bill. Cm 7582. Dept 

Environment, Food & Agriculture (Defra). London. UK., 

(2009). 

[15] Ellis, J.B. and Bertrand-Krajewski, J-L. (Edits): Assessing Infiltration 

and Exfiltration on the Performance of Urban Sewer 

Systems (APUSS). IWA Publishing, London. UK. (2010), ISBN 

9781843391494. 

[16] Ellis, J.B.: Assessing sources and impacts of priority PPCP 

compounds in urban receiving waters. (2008). Proc. 11th Int. 




SCIENCE 

Conf. Urban Drainage (ICUD11). August 2008. Edinburgh, 

Scotland. CD-ROM, IWA Publishing, London, UK. (2008), ISBN 

9781899796212. 

[17] Daughton, C.G. and Ruhoy, I.S.: Environmental footprint of 

pharmaceuticals; The significance of factors beyond direct 

excretion to sewers. Environ.Toxicology & Chem. 28 (2009) 

No. 12, p. 2495–2521. 

[18] Fono, L.J. and Sedlack, D.L.: Use of the chiral pharmaceutical 

propranolol to identify sewage discharge into surface 

waters. Environ.Sci.& Tech. 39 (2005) No. 23, p. 9244–9252. 

[19] Phillips, P. and Chalmers, A.: Wastewater effluent, CSOs and 

other sources of organic compounds to Lake Champlain. 

Journ. Amer.Water Works Assoc. 45 (2009) No. 1, p. 45–57. 

[20] Ellis, J.B.: Pharmaceutical and Personal Care Products (PPCPs) 

in urban receiving waters. Environ. Poll. 144 (2006), p. 184– 

189. 

[21] Scholes, L., Revitt, D.M. and Ellis, J.B.: A systematic approach 

for the comparative assessment of stormwater removal 

potentials. Journ. Envir. Managt. 88 (2008) No. 3, p. 467–478. 

[22] Boxall, A.B.A., Monteiro, S.C., Fussell, R., Williams, R.J., Bruemer, 

T., Greenwood, R. and Bersuder, P.: Targeted Monitoring for 

Human Pharmaceuticals in Vulnerable Source and Final 

Waters. Report WD 0805; DWI 70/2/231). UK Drinking Water 

Inspectorate, London. UK. (2011). 

[23] Herberer, T., Schmidt-Baumler, K. and Stan, H.J.: Occurrence 

and distribution of organic contaminants in the aquatic system 

in Berlin. Acta Hydrochem. Hydrobiology. 26 (1998), 

p. 271–278. 

[24] Atkinson, C., Blake, S., Hall, T., Karda, R. and Rumsby, P.: Survey 

of the prevelance of perfluoracetone sulphonate (PFOS), 

perfluoro-octonic acid (PFOA) and related compounds in 

drinking water and their sources. Defra (Department of Environment 

Food & Rural Affairs) Report 14612-0. Water 

Research Centre (WRc). Swindon, Wilts. UK. (2008). 

[25] Brooke, D.N., Burns,J., Crookes, M.J. and Dungey, S.M.: Environmental 

Risk Evaluation Report: Decabromodiphenyl ether. 

Environment Agency, Bristol, UK. (2009) ISBN 

9781849111126. 

[26] Kohler, M., Schmid, P., Hartman, P.C., Stumm, M., Heeb, N.V., 

Zenreg, M., Esesbe, A.C., Gujer, E., Kohler, H. and Giger, W.: 

Occurrence and temporal trends of HBCD in Swiss lake sediments. 

Proc. 16 th Annual Meeting SETAC-Europe. The Hague. 

7–11 May 2006 (2006). 

Authors 

Prof. Dr. J. Bryan Ellis 

(Corresponding author) 

E-Mail: B.Ellis@mdx.ac.uk | 

D. Michael Revitt | 

Lian Lundy | 

Urban Pollution Research Centre | 

Middlesex University | 

The Burroughs, Hendon | 

London. NW4 4BT. UK 

Tiefbaumesse InfraTech 

15. - 17. Januar 2014 

Messe Essen, Nordrhein-Westfalen 

adv-IFTDuitsland_176x123mm_bezoekers-DUI-drukklaar.indd 1 

10/10/2013 2:11:19 PM 



SCIENCE Water Management 

Drainage Area Study of the City of 

Hradec Kralove, Czech Republic, and its 

Utilization for Urban Planning 

Stormwater management; sustainable development; urban drainage; urban planning 

Milan Suchanek, Jiri Vitek, David Stransky, Ivana Kabelkova and Pavla Finfrlova 

Drainage Area Study of the City of Hradec Kralove, Czech Republic, was a large water management project 

defining concept of stormwater management in the region in accordance with the sustainability principles. 

The goal of the study was to link rules and criteria of sustainable stormwater management with urban planning. 

In the framework of the study a complex assessment of the current status of water management including 

the risk of flooding was performed, potential of the existing development to approach pre-urbanization runoff 

behavior was evaluated and conditions of the sustainable stormwater management in the planned development 

were specified. 


The process of sustainable stormwater management 

implementation in the Czech Republic was delayed 

compared to the most developed countries. Until 2009, 

virtually no sustainable urban drainage systems were 

applied with exception of individual projects of environmental 

enthusiasts and EU financed projects (e.g. INTER 

Figure 1. Regulation plan of Hradec Kralove created by Josef Gocar in 

1928. 

REG IIIB CADSES project RainDROP). Since 2009, after 

the revision of Water Act and regulations to the Building 

Act, the attitude towards stormwater management has 

started to change towards sustainability. Priorities of 

stormwater management were given (table 1). 

In this paper, a pioneer Drainage Area Study of the 

City of Hradec Kralove [1] focusing on sustainable 

stormwater management in relation to urban planning 

is presented, where these priorities were respected. 

The Drainage Area Study was a large project comprising 

many goals. The most important goals in the 

area of water management were to set a long-term conception 

of the city stormwater drainage respecting sustainability 

principles, to link stormwater management 

within the region with the new City Development Plan 

and to provide decision support for city authorities. It 

comprised the following tasks: 

"" 

Assessment of current status of the stormwater management 

in the area and identification of regions of 

high flood risk both in open channels and in the 

sewer system, 

"" 

Analysis of the potential of the existing development 

to approach pre-urbanization runoff behavior, 

"" 

Definition of rules and criteria of sustainable stormwater 

management in the planned development, 

"" 

Design of measures in the in the catchment, sewer 

system and open channels. 

2. Methods 

2.1 Pilot catchment 

The city of Hradec Kralove is situated at the confluence 

of the rivers Elbe and Orlice having 7 smaller tributaries. 




SCIENCE 

Hradec Kralove (96,000 inhabitants in 2010) was planned 

as a green city before the Second World War by architect 

Josef Gocar (figure 1). Today, it is still an excellent example 

of clever urban planning. Stormwater drainage was 

solved as a first priority before starting planning the 

urbanization itself. Gocar designed a system combining 

natural water bodies and open vegetated channels. 

Moreover, infiltration systems were created in some 

areas. However, in the past few decades, Hradec Kralove 

has suffered from massive urbanization resulting in overloading 

of the system of natural and artificial water bodies 

as well as of the sewer system. 

The area of interest of the Drainage Area Study comprised 

the region of 243 km 2 with about 332 km of rivers, 

streams and channels (figure 2). 

2.2 Assessment of current status of stormwater 

management 

The Drainage Area Study incorporated extensive monitoring 

and surveys (rainfall, water levels, discharges, 

water quality parameters, ecological status of streams, 

catchment hydrogeology and infiltration potential etc.). 

The complex network of open channels and streams 

was mapped and documented for the first time. 

Hydrodynamic modeling of the sewer system, water 

bodies, artificial open channels, underground waters 

and elements of stormwater management was performed 

(MIKE Urban, MIKE11) and hydraulic capacity of 

the individual parts of the system as well as flooding 

frequency was assessed based on a 10-years rainfall 

data series and design storm events. CSOs impacts were 

assessed with REBEKAII. Paralelly, a groundwater flow 

model was created by Jacobs Consultancy. 

2.3 Analysis of the BMPs potential of the existing 

development 

The analysis of the BMPs (best management practices) 

potential of the existing development focused on the 

determination of the impervious areas, which can be 

potentially disconnected from the combined sewer system 

by applying BMPs of stormwater drainage. The 

analysis contained four steps: 

1. Analysis of the City Plan from the point of view of 

BMPs application, 

2. Field survey of the potential of the area to infiltrate 

or to delay stormwater runoff (e.g. sufficient green 

areas), 

3. Evaluation of the technical and available BMPs 

potential in different areas (based on the enhancement 

of the field survey for hydrogeology, slopes, 

ecological burdens, character of the development, 

ownership of the buildings and grounds), 

4. Determination of the total BMPs potential of the 

existing development. 

Figure 2. The area of interest. 

Figure 3. Example of evaluation of the frequency of overloading of 

open channels (number of events per year in categories 0-5; 2-10; 

10-20; >20 events presented by graded shades of blue from light to 

dark blue). 

Table 1. Priorities of stormwater management (if no other utilization of 

stormwater is planned) in the regulation to the Building Act [2]. 

Priority 1 

Priority 2 

Priority 3 

Infiltration, in the case of polluted runoff, pre-treatment is 

needed. If not possible, then: 

Retention and regulated discharge to the receiving waters 

(directly or by a separate sewer system), pre-treatment if 

needed. If not possible, then: 

Retention and regulated discharge to the combined sewer 

system 




2.4 Water management rules and criteria for the 

planned development 

For the purposes of the future city planning, rules and 

criteria for the areas to be urbanized had to be specified: 

1. Analysis of the water regime was performed and 

water management criteria distinguishing areas suitable 

and unsuitable for the future urbanization were 

set, 

2. Possibilities of stormwater management (the selection 

of the stormwater recipient) in areas suitable for 

urbanization were evaluated respecting priorities set 

in table 1, 

3. Requirements regarding maximum specific regulated 

discharge from individual building plots and 

supplementary assessments were specified. 

Figure 4. Potential of introduction of BMPs in the existing development 

(available – dark green, conditionally available – light green, not available 

– orange, none – red). 

3. Results and discussion 

3.1 Current status of the stormwater management 

Streams and open channels were ranked according to 

the reaching of a certain relative water depth during 

rain events (the categories were set as 100 % of filling). The limiting value designated 

as flooding was considered to be 80 % of the 

channel filling (due to model uncertainties). Sewers 

were classified based on their overloading defined as 

the pressure line level above the top of the pipe and a 

level below the surface. Water levels higher than 10 cm 

above the top of the pipe for 10 minutes were considered 

to cause flooding. The capacity of the whole system 

was presented in thematic maps showing the frequencies 

of overloading as number of events per year in 

categories 0–5; 2–10; 10–20; >20 events (figure 3). 

Areas of flood risk were identified. 

The overloading of the system in urbanized areas 

begins with the frequency between 2 and 5 years (the 

sewer system was designed for a 2-years storm originally). 

Thus, it is apparent that the hydraulic capacity 

limits the further development of the city as the reserves 

are small. 

3.2 BMPs potential of the existing development 

In total 92 evaluation sheets were elaborated for existing 

development giving an overview on the possibilities and 

restrictions of the introduction of BMPs instead of the 

conventional drainage system (table 2). Grounds with 

areas suitable for stormwater infiltration and prevailing 

surface slope less than 3 % were marked as having technical 

BMPs potential. Only grounds under city ownership 

were considered to have an available BMPs potential. 

Similar evaluation sheets were elaborated for streets and 

roads within the urban area. The BMPs potential was 

ranked as available, conditionally available, not available 

or none (figure 4). The evaluation of the total BMPs 

potential showed that the city can disconnect 43 ha of 

impervious surfaces connected to the combined sewer 

system, and thus reduce the connected impervious area 

by 15 %. In this way, free hydraulic capacity in the sewer 

system can be gradually created. 

3.3 Incorporation of water management criteria in 

urban planning 

Due to water management restrictions, urbanization is 

limited in following areas: 

"" 

Areas of natural water retention (due to a high underground 

water level; less than 1 m bellow surface) 

"" 

Areas of flood risk 

"" 

Areas that can be used for the accumulation of surface 

waters in case of flooding 

Figure 5. Detail of the map with water management limitations to the 

city development (area of flood risk – blue, area for surface water accumulation 

– green, area of natural water retention – grey). 

These areas were determined in the catchment and 

incorporated into the new City Development Plan processing 

(figure 5). 




SCIENCE 

Table 2. Example of the BMPs evaluation sheet for existing development. 

Streets 

Borders of area 

Pod Zameckem, Milady Horakove, Prostejovska, Fricova, 

Urxova 

Local part 

Trebes 

Acreage 

35 ha 

Hydrological catchment No. 1-03-01-002 

Trunk sewer 

C 

Criteria 

Information on the development 

Technical 

potential of 

infiltration 

Available 

potential of 

infiltration 

Prevailing development 

Ecological burdens 

Stormwater infiltration 

Presence of areas suitable for stormwater infiltration 

Prevailing slope of surface 

Owner of buildings 

Classification 

city centre 5 % 

multi-storey dwellings 95 % 

low-storey dwellings 

industrial area 

traffic infrastructure 

Yes 

No 

• 

no limitations 10 % 

conditionally suitable 

difficult 90 % 

impossible 

Yes 

No 

< 3% • 

≥ 3% 

City 

other 

Owner of adjacent areas suitable for stormwater infiltration City • 

other 

• 

• 

In addition, decision support and rules for the city 

authorities and the building politics in terms of sustainable 

stormwater management were provided: 

1. Local possibilities of stormwater management for 

individual planned development areas were evaluated. 

In total 24 development areas of 10-60 ha were 

assessed in 80 sheets (table 3). 

2. Design criteria and rules for the planned development 

were specified as follows: 

"" 

For individual (scattered) developments, the 

maximum specific regulated discharge from the 

ground plot was set as 3 L/(s.ha), the return 

period for the design of a retention volume as 

5 years, 

"" 

Extensive individual developments or large 

development projects are in addition under the 

obligation to recalculate the effects on the water 

regime in terms of the hydraulic capacity of the 




Table 3. Example of the stormwater management evaluation sheet for planned development. 

Development area No. 3 ZA METELKOU, DRTINOVA STREET 

Borders of area 

Identification of areas Acreage of areas Functional type 

6-9/6, 7-9/14, 7-9/30, 6-9/4 18 013 m 2 suburban low-storey development 

6-9/7 5 487 m 2 multi-storey dwellings 

Studies and regulation plans 

Areas of special water regime 

Natural water retention area 

Flood risk area 

Inundation area 

Adjacent recipients 

Groundwater 

groundwater level 

No 

No 

No 

No 

hydraulic conductivity 

ecological burden 

Available surface receiving waters / storm sewers 

Available combined sewers / foul sewers 

Drainage concept for stormwaters 

Groundwater 

Surface receiving water / storm sewer 

Combined sewer – 

Drainage concept for foul waters 

Combined sewer system, sewers B, B18 or B19 

Comments 

– 

2 to 5 m below surface 

≥ 1 x 10-6 m/s 

No 

no limitations for infiltration 

Melounka Brook (Identification No.10101505, Hydrological catchment 

No. 1-03-01-005) 

combined sewer B (DN 500) – Petra Jilemnického Street 

combined sewer B 18 (DN 300) – U Drevony Street 

combined sewer B 19 (DN 300) – Predmericka Street 

Decentralized infiltration devices recommended 

(detailed hydrogeological survey necessary) 

Melounka Brook recommended for overflows from infiltration 

devices 

sewer system, water bodies and artificial channels, 

and of groundwater level changes. 

3.4 Measures 

Measures designed to achieve sustainable stormwater 

management in the city in the long-term comprised not 

only the above mentioned non-structural measures for 

both existing and planned development (3.2 and 3.3), 

but also a range of technical measures such as measures 

aiming at the reduction of the impervious area of 

the existing development by 15 % within the next 30 

years: 

"" 

Removal or sinking of existing curbs, 

"" 

Lowering or adjustment of the surface, 

"" 

Transfer of stormwater from the area of street inlets 

to decentralized devices, 

"" 

Taking apart gutters and street inlets within green 

areas. 




SCIENCE 

Technical measures in the planned development aim at 

approaching pre-urbanization runoff conditions (similar 

hydrograph volume and shape). Four functional types 

of stormwater management structures were recommended 

in dependence on the bedrock and ground 

water level. However, it is beyond the scope of this 

paper to discuss all measures in detail. 


The study demonstrates the necessity of integrating 

stormwater management into urban planning. On contrary 

to past times when Urban Drainage Masterplans 

were elaborated independently of City Development 

Plans Authors, the approach applied shows the important 

role of water management engineers already during 

the first phases of urban planning. The water management 

engineers impose limits on urbanization for 

urban planning as well as specify technical rules for 

constructions. Water management criteria incorporated 

in the City Development Plans guarantee sustainable 

development of the city. 

Urban planning is a complicated process going from 

general tools such as the City Development Plan down 

to the approval of individual buildings in terms of their 

technical functionality. Moreover, a large number of 

actors is involved in this process, which must be coordinated 

(in the case of Hradec Kralove it was the city council, 

four city commissions and departments, two departments 

of the state administration, six different surface 

waters administrators and a sewer system administrator). 

Thus, it is necessary to prepare transparent step-bystep 

guidelines specifying activities and responsibilities 

at each level of urban planning from the stormwater 

management point of view and provide actors with a 

decision support system containing consistent data 

about water issues in the city. 

The project presented went beyond the current 

Czech legislation and serves as a good example for similar 

studies. For the city of Hradec Kralove, the project 

represents a reconnection to its origins and timeless 

urban planning by Josef Gocar. 


This work was supported by the project of Czech Ministry of Education, 

Youth and Sport No. MSM6840770002. 

References 

[1] DHI and JVPROJEKTVH: Drainage Area Study of the city of 

Hradec Kralove. Technical Report (in Czech), 2011. 

[2] Act 183/2009 Coll., on town and country planning and building 

code (the Building Act). 

Authors 

Ing. Milan Suchanek 

(corresponding author) | 

E-Mail: m.suchanek@dhi.cz | 

DHI a.s., Na Vrsich 1490/5 | 

100 00 Praha 10, Czech Republic 

Ing. Jiri Vitek 

E-Mail: vitek@jvprojektvh.cz | 

JV PROJEKT VH s.r.o. | 

Kosmakova 1050/49 | 

615 00 Brno, Czech Republic 

Ing. David Stransky, PhD. 

E-Mail: stransky@fsv.cvut.cz | 

Dr. Ing. Ivana Kabelkova 

E-Mail: kabelkova@fsv.cvut.cz | 

Czech Technical University | 

Faculty of Civil Engineering | 

Department of Sanitary and 

Ecological Engineering | 

Thakurova 7 | 

166 29 Praha 6, Czech Republic 

Ing. Pavla Finfrlova 

E-Mail: finpav1@tiscali.cz 

Magistrat mesta Hradce Kralove | 

Ceskoslovenske armady 408 | 

502 00 Hradec Kralove, Czech Republic 

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contact the editorial office 

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EAZ Netzwerk 2 engl.indd 1 15.10.2013 17:57:06 




The Syracuse Project – A Global 

Approach to the Management of Water 

Uses in an Urban Ecosystem 

Alternative technologies, decentralised management, energy, solid wastes, waters 

Michel Lafforgue, Vincent Lenouvel und Catherine Chevauché 

The centralised management of the water cycle in the urban environment that has prevailed since the 19 th century 

has today reached its limits, and in an increasingly water-stressed and contaminated environment it is now 

necessary to assess the benefits to be derived from adopting a new approach. It is the aim of the Syracuse 

research project to answer that question. This paper explains the methodology used in Syracuse, with particular 

reference to the urban water cycle. 

After reviewing the state of the knowledge of existing or potential options in connection with the water, energy 

and waste cycles in the urban environment, the project will attempt to evaluate small-loop configurations and 

the synergies that can be achieved between and within these loops. The aim will be to assess the benefits to be 

derived, more specially in terms of environmental impacts, in comparison with a centralised, single-sector scenario. 

This will make it possible to identify requirements governing their implementation, operation and maintenance. 

For that purpose, the Syracuse project will involve ten real-life applications that will be examined in 2013 

and 2014. These cases will be selected to reflect a variety of contexts (climate, water, urban, institutional, etc.). 


Just as urbanisation continues to increase worldwide, so 

will the water demand of the world’s population, too. 

The rise is likely to be such that between 2010 and 

2025–2030 the amount of water withdrawn for domestic 

and municipal purposes is expected to increase by 30 to 

50 percent [1; 2]. Over the same period, the effects of climate 

change will lead to greater vulnerability of water 

resources in most catchments, with water availability 

declining and rainfall events potentially increasing in 

intensity. With demand expected to increase in sectors 

such as irrigation and industry [1; 2], all signs point to 

increasing water scarcity going forward. Therefore, there 

will be a need to store more water, to optimize abstraction 

(which, by extension, will involve greater reuse of 

water, the reduction of water losses and more waterefficient 

agricultural practices and industrial processes) 

and to optimize the management of extreme events. 

At the same time, energy and raw materials will also 

be affected by scarcity as they come under growing 

pressures from expanding populations, too. A new paradigm 

– in this case an integrated systems-based 

approach – will be part of the answer how to find solutions 

to the problem of water scarcity. Such a paradigm 

change will involve: i) considering the water cycle globally, 

and ii) considering its interactions with energy and 

solid wastes cycles. The result will be the improved 

management of all of these resources. 

That water systems – and by extension other ecosystems 

– will be affected by growing environmental pressures 

is all but inevitable. Against this backdrop, EU regulations 

in the form of the Water Framework Directive 

(WFD) require Member States to take action to achieve 

the good ecological status of their water bodies by 

2015. In spite of the exemptions that have been granted 

(and in particular extension of the deadline beyond 

2015), the WFD objective will in all likelihood only be 

achieved if strong and rapid measures are taken to 

reduce the impact of human activity on resources. Cities, 

which in Europe account for 16 percent of all water 

withdrawals [3] and whose stormwater and wastewater 

discharges have a significant impact on the quality of 

water systems, are one type of ecosystem for which 

solutions must be developed. 

Combining an analytical and case studies approach, 

the Syracuse research project 1 is based on an interdisciplinary 

assessment of water, energy and waste cycles in 

the urban environment, the aim being to explore possi 

1 The Syracuse project brings together social science research 

centres LATTS (an in-house lab of the French scientific research 

centre, CNRS) and Centre for European Studies of Sciences Po 

Paris, the water and waste research centre, CIRSEE, the companies 

SAFEGE and EXPLICIT and the Plaine de France Urban 

Development Corporation, within a multidisciplinary consortium. 

The project is financed by the French National Research 

Agency and accredited by the Advancity competiveness cluster. 




SCIENCE 

ble interactions and synergies between cycles, make 

them more sustainable and reduce their environmental 

impacts. The project will encompass the technical, regulatory, 

institutional and socio-economic issues involved, 

all of which will impact the implementation of possible 

combinations of technical options. After reviewing the 

current state of the knowledge on the relevant technologies, 

the project will explore how these may be combined 

at different spatial scales (ranging from the building 

level to the citywide level) and in different types of 

urban environment (shrinking or growing cities, concentrated 

or dispersed development, flat or rugged 

topography, arid or temperate climates, etc.), so as to 

adapt possible solutions to multiple contexts. Commencing 

in 2012 and scheduled for completion by 

2016, the project will culminate in the development of a 

decision-support tool for use by planners, developers, 

local authorities and service providers. 

This paper presents the key features of the adopted 

approach, with a specific focus on the water cycle and 

its management in the urban environment. In a subsequent 

stage, real-life applications will be examined and 

the outcomes to date presented. 

2. Rethinking the water cycle in the 

urban environment 

2.1 Dynamics of the urban water cycle 

The principles underpinning the structure of the urban 

water cycle are as follows: 

"" 

Groundwater is generally preferred over surface water 

as a supply source, since it offers certain advantages 

such as the quality of the abstracted water. The decision 

as to which type of resources is used will depend 

on the water-related environment, the structure of 

the demand (can the supply source meet population 

needs throughout the duration of the season?), the 

constraints associated with transport (in particular 

the distance between the supply source and end 

users) and the intrinsic quality of the supply source. 

"" 

Except in the case where groundwater is separated 

from contaminants by an impermeable stratum, 

most aquifers located beneath urban conurbations 

are polluted. When an impermeable substratum 

exists, the aquifer is fed by less contaminated sources 

originating upstream of the city. 

"" 

The water distributed to users is generally of drinking 

water quality. Accordingly, it is treated centrally 

before distribution. In most cases there is only one 

distribution system. Cities like Paris with a dual system 

are the exception, and in such cases it is rare, for 

sanitary reasons, that both systems are used for 

domestic needs (the second system is usually dedicated 

to uses such as street cleaning, sewer flushing, 

irrigation of green spaces and industrial purposes). 

"" 

Wastewater and stormwater are collected in separate 

or combined systems (in the latter case wastewater 

and stormwater are collected in the same pipe 

and overflow weirs and storage basins are provided 

to regulate flow and ensure that sewer and treatment 

plant capacities are not exceeded). Treatment 

is centralised in one or more wastewater treatment 

plants depending on the city’s topography, and the 

treated effluent is discharged to a river or stream 

which is usually located nearby, but which is always 

located downstream of the city so as to prevent 

contamination of drinking water supply sources 

upstream of intake structures. 

"" 

The urban environment is characterised by extensive 

impervious surface cover, hence the requirement 

for a system to collect stormwater and send it 

either to a treatment plant (in the case of low-intensity 

rainfall events) or to the nearest river or stream 

(where and when flows exceed the capacity of the 

sewer system or treatment plant). This principle 

results in heavier flows in heavy rainfall events and 

spikes in pollution at the start of the rainfall event 

(as a result of contaminant wash-off from impervious 

surfaces such as roads, pavements, parking lots 

and rooftops). Ongoing global climate change will 

lead to more extreme rainfall events and so greater 

flows and loads. 

2.2 Limitations of centralised wastewater and 

stormwater management systems 

These centralised, artificial systems have a number of 

undesirable consequences: 

"" 

No differentiation between water uses: All water supplied 

is of drinking water quality. Treating water to 

such standards has a high monetary and environmental 

cost, insofar as lower-quality water is perfectly 

adequate for uses such as toilet flushing, garden 

watering and cleaning. 

"" 

Mixing together of all wastewater, however, polluted: 

All domestic wastewater is sent to the sewer system, 

regardless of what the water was originally used for 

and the quality of the wastewater. As a result, sewer 

systems and wastewater treatment plants are oversized, 

and wastewater streams of varying quantity 

and quality are handled in a single, combined system 

and by a single set of treatment processes. 

"" 

Insufficient groundwater recharge: As Shanahan and 

Jacobs show [4], the impact of urbanisation on 

groundwater depends on the level of development 

of the city. Natural groundwater recharge is significantly 

reduced by impervious cover as a result of 

direct discharge into rivers and streams. This process, 

coupled with higher levels of groundwater abstraction, 

frequently results in a decline in the water table 

[5], which in turn can sometimes lead to differential 

settlement or subsidence [6]. A textbook example of 

this phenomenon is Mexico City, where subsidence 

rates can reach 30 cm/year [7]. Moreover, infiltration 




in an urban setting often affects the quality of 

groundwater in shallow aquifers. 

"" 

Destruction of aquatic ecosystems: The pollutant 

loads and water fluxes associated with rainfall events 

tend to concentrate over time, leading to a cascade 

of impacts on processes in receiving waters [8]. These 

imbalances can result in erosion, deterioration of 

water quality and loss of biodiversity, which in turn 

can diminish the beneficial uses of the water body 

downstream from discharge points [9]. 

One can see very well that these centralized, artificial 

systems – once justified by a public-health-focused 

approach, and currently the norm in the cities of the 

wealthy nations, while being adopted by the vast majority 

of cities in the less developed world – are a nonoptimal 

solution, both from a cost and environmental 

perspective. This is particularly true when it comes to 

stormwater management. It is therefore necessary to 

find a new paradigm. 

2.3 Towards a paradigm change in the urban 

water cycle 

Since the early 2000s a new approach has emerged – 

one that is based on the concepts of urban symbiosis 

and the principle of small-loop systems as a route to 

resource efficiency and lower environmental impacts 

[10; 11; 12; 13]. 

The Syracuse project digs deeper into these ideas, in 

particular with respect to the management of the urban 

water cycle. Some of the principles explored are as follows: 

"" 

Differentiation between different water uses: Households 

use water for different purposes: drinking, 

cooking, laundry and dishes, bathing and showering, 

toilet flushing, watering the garden, washing the car, 

and so on. The quality of the water required is not 

the same in each case. It follows that water uses may 

be grouped together according to the quality of the 

water required (from a sanitary, regulatory, societal 

acceptability or other standpoint), and that supply 

sources may be separated accordingly. Such is the 

so-called Fit-for-Purpose idea, whereby the quality of 

the water is adapted to the need [12]. Here, the aim is 

to explore the potential for differentiating between 

quality standards for domestic uses as shown in 

Table 1. The table, which has been developed under 

the Syracuse project, provides an example of how 

different domestic water needs can be broken down. 

The table 1 example of separation of needs by use is 

based on recent French statistics [14]. This approach 

can be adapted to any country. The idea is to classify 

needs not only according to regulatory standards 

(which are specific to each country) as is generally 

the rule, but also according to the requisite sanitary 

quality (e.g. certain parameters, which may not be 

addressed in the regulatory standards, may downgrade 

the water when it comes to the sanitary quality 

required for a particular use, pending the introduction 

of regulations governing the parameter in 

question). Moreover, the notion of societal acceptability 

is to be included here, this parameter being 

highly variable from country to country and a consequence 

of the population’s lifestyle. Reusing treated 

wastewater will or will not be acceptable, for example, 

depending on how this practice is perceived by 

the population. And this factor will affect the choice 

of an appropriate solution. 

"" 

This innovative schematic developed for the purposes 

of the Syracuse project is necessarily based 

on the most restrictive standards, which leads us, 

in the table 1 example, to retain only two different 

qualities of water, one for toilet flushing, 

watering gardens and car washing and the other 

for drinking purposes. Based on the separation of 

inputs by quality requirements and the community 

within the loop concerned, overall daily 

requirements in terms of water fluxes of a given 

Table 1. Example of the separation of water uses as a function of flow and quality requirements from a sanitary, regulatory, societal and cultural 

standpoint in France. 

Water use 

Water consumption ratio 

(l/day/inhabitant) 

Sanitary required quality 

Regulatory required quality 

Societal and cultural 

acceptable quality 

Toilet flushing 30 quality 1 quality 2 quality 2 

Watering the garden, 

washing the car 

9 quality 1 quality 2 quality 2 

Laundry 18 quality 2 quality 4 quality 4 

Bathing and showering 58.5 quality 3 quality 4 quality 4 

Various domestic uses 9 quality 3 quality 4 quality 4 

Dishes 15 quality 4 quality 4 quality 4 

Cooking 9 quality 4 quality 4 quality 4 

Drinking 1.5 quality 4 quality 4 quality 4 




SCIENCE 

Figure 1. A 

first examination 

of urban 

water fluxes 

(SAFEGE). 

quality are determined, and used as a basis for 

identifying appropriate technologies and supply 

sources. 

"" 

This use-based analysis should then be compared 

to an analysis of the capital flows involved so that 

financially viable solutions can be developed. 

"" 

This application of the “Fit-for-Purpose” concept 

opens up possibilities for optimisation and for 

achieving water savings through a small-loop 

approach. The reuse of grey water in parts of 

Japan, like the district of Shinjuku in Tokyo, is a 

typical example [5]. 

"" 

Rainwater harvesting in the urban environment: Rainwater 

hitting rooftops and impervious services will 

vary in quantity according to housing type (apartment 

blocks or houses) and can potentially be used 

as a supply source, which is non-potable but which 

can be used (after appropriate treatment) for some 

of the purposes mentioned above (toilet flushing, 

irrigation of green spaces and enhancement of 

aquatic ecosystem functions) [13; 15]. 

"" 

Groundwater recharge as a means of filtering out contaminants 

and improving the water cycle: One possible 

option is to capture the rainwater and feed it 

back into the aquifer as a means of reducing surface 

runoff and pollutant loads and by extension the 

impact on the receiving water body. The design of 

the recharge process will need to be such as to filter 

out contaminants. In this case, the aim is not only to 

assess the impact of alternative stormwater management 

practices on the availability and quality of supply 

sources, but also on processes in the centralised 

sewer system and associated treatment facilities. This 

concept may be broadened to include the in-ground 

disposal of treated wastewater, which will then serve 

both as an additional purification process and as a 

means of replenishing the aquifer [16]. 

"" 

Purification processes that are adapted to supply 

sources and the intended uses: Wastewater may be 

reused either after the source separation of grey 

water, black water and/or yellow water [17; 12; 18], or 

after a wastewater treatment process. The treatment 

process will depend on the quality of the influent 

and the intended use of the treated effluent. This will 

involve assessing wastewater treatment systems in 

these specific contexts, and the potential for reusing 

treated wastewater at different scales. 

No configuration will be ruled out under the Syracuse 

project. In this way multiple closed-loop systems may 

be envisaged, whether in terms of the characteristics of 

the wastewater used, or the treatment, storage, transport 

and reuse of the wastewater. Figure 1 shows the 

urban water cycle and possible scales at which solutions 




might be implemented as well as possible linkages 

between sectors (wastewater, energy, waste, etc.). It will 

provide the basis for exploring combinations of decentralised 

technologies and practices. 

How viable and how virtuous the different loops will 

be, will depend on a number of factors, including the 

size of the loop. Syracuse explores possibilities with 

respect to three different scales: the building loop, the 

district loop and the city loop. Some configurations may 

be feasible on one scale but not relevant or viable on 

the other two. The following are some examples: 

"" 

The costs and operating constraints associated with 

some wastewater treatment processes may make 

them optimal for a medium-sized loop but not advisable 

at the scale of the building. These processes 

may be justified by the raw wastewater quality and 

treated wastewater quality required for a given use 

(see table 1 above), and will therefore be associated 

with a loop of a particular size. 

"" 

The harvesting and reuse of water from rooftops is 

only of benefit if the rainwater is used in small-loop 

configurations (at the scale of the building or neighbourhood), 

albeit at a citywide level. 

"" 

The separation of urine from the wastewater flow is 

only feasible at the scale of the individual home. 

Large-scale systems for the circulation of urine are 

impracticable on account of the operating constraints. 

"" 

In some cases there are no obvious constraints arguing 

in favour of a particular scale. But some scales 

may emerge as more appropriate following the cost 

assessment and/or review of the financing possibilities. 

Should the green-roof option be applied only to 

individual buildings or on a neighbourhood-wide 

scale, for example? 

Moreover, as Speers points out [11], it is important that 

these alternative water management practices are successfully 

integrated into the communities that they are 

to serve. In testing the viability of different combinations, 

the social and cultural aspects must also be 

addressed, since these will determine the acceptability 

of certain options to the communities involved, which 

in turn will determine whether and/or how they will be 

implemented. By way of example, the reuse of treated 

wastewater - albeit after an advanced tertiary treatment 

and treatment to drinking water standards by means of 

membrane technologies reputed for their ability to 

remove all contaminants - may not secure public acceptance 

because of lack of confidence or as a matter of 

principle. 

2.4 Synergies between water, energy and waste 

Another area explored in the Syracuse project is that of 

synergies. As Goen points out [18], there are possibilities 

for optimisation through linkage of different types of 

urban infrastructure. In the Syracuse project, the aim is 

to determine how connections between water, energy 

and waste can be used to optimise and reuse these different 

cycles locally and in a manner that reduces the 

environmental impacts and optimises costs. 

Various technologies lie at the interface between 

these different cycles, some of which are described 

below: 

"" 

Increasingly efforts are being devoted to reducing 

energy consumption within wastewater treatment 

plants. We now talk in terms of net energy positive 

wastewater treatment plants, or at least net energy 

neutral plants. 

"" 

The possibility of using energy contained in water or 

wastewater in the form of heat (recovery of heat 

from wastewater as exemplified in the Blue Degrees 

process [19]) or pressure (micro-hydro turbines) has 

spawned technologies to recover this energy for 

localised uses (or to be fed back to centralised systems 

such as the electricity grid and district heating 

systems). Examples of localised uses in France are 

the Levallois swimming pool heating system which 

is based on the recovery of heat from wastewater, 

and the Valenciennes city hall heating system. 

"" 

Renewable energy sources can be used for seawater 

desalination and vapour condensation purposes, 

and self-sufficient processes (membrane filters, fog 

harvesting and solar water disinfection) are emerging 

and can be used in less developed countries [20]. 

"" 

Sink-mounted waste disposal units, which are very 

common in the USA and in some European countries, 

are a technology where water meets waste and 

whose potential needs to be assessed (lower waste 

collection costs, on the one hand, higher treatment 

costs and risk of deposits in the sewer system, on the 

other hand). 

"" 

Organic waste (food waste, sewage sludge, etc.) and 

source-separated urine, black water and/or treatment 

plant phosphorus can be used as fertilizers for 

urban kitchen gardens and crops, as well as for the 

production of energy in the form of biogas, electricity 

or heat. By 2015, the Swedish city of Gothenburg 

is aiming to recycle 60 percent of the phosphorus 

from wastewater treatment plants for application on 

arable land [21]. 

2.5 Economic and institutional aspects 

Clearly, economic viability is a key parameter to be 

addressed in this approach: those persons, organisations, 

companies or institutions financing such projects 

must be convinced of their merits. The small-loop projects 

envisaged must enable savings to be achieved, 

whether in terms of the network and infrastructure 

requirements and/or the operating costs. In addition to 

this Capital Expenditure/Operational Expenditure 

approach, the positive and negative knock-on effects 




SCIENCE 

must be explored, quantifiable or otherwise (e.g. quality 

of life, environmental impacts, development of the 

social fabric, etc.). One of the externalities to be assessed 

is the impact of decentralisation on the financing of the 

service. In an OECD report [22], Leflaive stresses that 

decentralised water services could preclude financial 

solidarity between users and may result in differences in 

service quality and monitoring practices. To counter 

these effects, new cross-subsidisation mechanisms 

must be developed. 

The deployment of urban services will be contingent 

on the formal and informal institutions (regulatory and 

socio-cultural frameworks) specific to the national and 

local contexts [23]. If they are to be supported, the 

technologies must be compatible with these institutions. 

Following on from the public-health-focused 

approach which saw the emergence of centralised sewerage 

systems in Europe at the beginning in the 19 th 

century, a water-focused approach has emerged, and 

more recently an environment-focused approach [24]. 

While these conceptual developments have resulted in 

new regulations (DERU, etc.) being introduced, the legislation 

has often been an obstacle to the adoption of 

innovative technologies [18]. This is true in the United 

States where the somewhat rigid approach of the U.S. 

Environmental Protection Agency has hindered the 

development of innovative systems for improving water 

quality [25; 26]. It is also true in France, where it has only 

been possible to reuse rainwater for non-potable uses 

since 2008, 2 and where these uses are still restricted and 

accompanied by safeguards (such as a two-pipe system 

in private part of houses and buildings, and inclusion of 

non return valves to prevent backflow to potable water 

supplies). 

Moreover, as mentioned previously, informal institutions 

are a key factor affecting the acceptability of the 

configurations envisaged, and need to be factored into 

the project preparation phase to ensure that the project 

is viable. Socio-cultural factors will therefore need to be 

addressed in tandem with possible processes and technologies. 

3. Conclusion and prospects 

The work presented above reflects progress to date on 

the Syracuse project, with specific reference to the field 

of water. It identifies the synergies that are possible with 

other flows (energy and waste) and the impacts of the 

loops and scopes adopted on possible options. 

After a first step of reviewing the current state of the 

knowledge (technical and cost-related) on possible 

technologies, the project aims to assess the synergy 

loops created and determine their suitability – and the 

2 

Decree of 21 August 2008 governing rainwater harvesting and 

use inside and outside 

environmental benefits they offer in particular – as compared 

to a centralised, single-sector scenario. At the 

same time it will attempt to identify their societal merits 

and shortcomings, as well as the requirements for 

their development, implementation, maintenance and 

renewal. 

To that end, during 2013 and 2014 the project will 

involve the analysis and modelling of ten real-life applications 

of the principles explored. These cases have 

been selected to cover a broad range of contexts (in 

terms of climate, water context, urban and institutional 

setting, etc.) and as such include more specially study 

cases in Europe (such as Stockholm and Geneva) and 

Asia (such as Singapore and Suzhou in China). 

A good example of an initiative challenging the 

existing urban water management paradigm is the ecovillage 

of Flintenbreite in Lübeck. It features: 

"" 

The decentralised management of rainwater by a 

system of swales. 

"" 

The decentralised management of grey water by 

vertical flow reed bed treatment systems with discharge 

to the river. 

"" 

Water savings through the use of vacuum toilets. 

"" 

The decentralised production of energy and heat by 

means of anaerobic digestion of black water and 

biodegradable waste. 

The analysis of this case has contributed to: i) the development 

and validation of the project methodology 

ahead of the various case studies; and ii) the evaluation 

of these different technologies in the context of the 

shrinking city as is commonplace in the former East Germany 

and the once flourishing industrial and mining 

heartlands of western Europe, North America (Flint, 

Detroit) and Japan [27]. In these contexts it is important 

to examine the knock-on effects of decentralised projects 

of this kind on the financial viability of the existing 

centralised systems. 

The Syracuse project has already shown that the 

technical, institutional and socio-cultural aspects cannot 

be considered in isolation when it comes to assessing 

the suitability and viability of any given decentralised 

solution. And already, the differences between new 

schemes (new-build neighbourhoods or buildings) and 

redevelopment projects (rehabilitation schemes, shift to 

more resource-efficient and sustainable systems) are 

becoming apparent, the latter involving many more 

constraints than new projects. 

The eco-cities or cities of the future should enable 

significant reductions in water and energy usage as well 

as in the quantities of pollutants released into the environment 

and the volumes of waste disposed of. Zero 

greenhouse gas emissions may even be a reality one 

day [28]. The use of small reuse loops and synergies 

between different types of infrastructure should be part 

of the answer how to reduce resource consumption. 




References 

[1] Shiklomanov, I.A.: World Water Resources And Their Use, St 

Petersburg: State Hydrological Institute/UNESCO (1999). 

[2] 2030 Water resources group: Charting our water future. Economic 

frameworks to inform decision making. 198 pages 

(2009). 

[3] FAO: AQUASTAT database (2010). 

http://www.fao.org/nr/aquastat 

[4] Shanahan, P. and Jacobs, B.L.: Ground water and cities. In Cities 

of the future - Towards integrated sustainable water and 

landscape management, V. Novotny and P. Brown (eds), IWA 

publishing (2007), p. 122-140. 

[5] Furumai, H.: Reclaimed stormwater and wastewater and factors 

affecting their use. In Cities of the future - Towards integrated 

sustainable water and landscape management, V. No 

votny and P. Brown (eds), IWA publishing (2007), p. 218-235. 

[6] Poland, J.F.: Guidebook to studies of land subsidence due to 

ground-water withdrawal. UNESCO. PHI Working Group 8.4. 

(1984), p. 1-305. 

[7] Rivera A., Ledoux, E. and de Marsily, G.: Nonlinear Modeling of 

Groundwater Flow and Total Subsidence of the Mexico City 

Aquifer-Aquitard System. Land Subsidence (Proceedings of 

the Fourth International Symposium on Land Subsidence). 

IAHS 200, 45-58 (1991). 

[8] Novotny, V.: Effluent dominated water bodies, their reclamation 

and reuse to achieve sustainability. In Cities of the 

future - Towards integrated sustainable water and landscape 

management, V. Novotny and P. Brown (eds), IWA publishing 

(2007), p. 191-215. 

[9] Bledsoe, B.P.: Framework for risk-based assessment of stream 

response to urbanization. In Cities of the future Towards integrated 



[10] Brown, P.R.: AICP. The importance of water infrastructure and 

the environment in tomorrow’s cities. In : Cities of the future 

– Towards integrated sustainable water and landscape management, 

V. Novotny and P. Brown (eds), IWA publishing, 2-7 

(2007). 

[11] Speers, A.: Water and cities – overcoming inertia and achieving 

a sustainable future. In : Cities of the future – Towards integrated 



[12] Daigger G.: Integrating water and resource management for 

improved sustainability. In Cities of the future – Water infrastructure 

for sustainable communities, X. Hao, V. Novotny 

and V. Nelson (eds), IWA publishing (2010), p. 11-21. 

[13] Lucey, W.P., Barraclough, C.L. and Buchanan S.E.: Closed loop 

water and energy systems: implementing nature’s design in 

cities of the future. In Cities of the future – Water infrastructure 

for sustainable communities, X. Hao, V. Novotny and 

V. Nelson (eds), IWA publishing (2010), p. 59-70. 

[14] Demoulière, R., Schemba, J.B., Berger, J., Aït Kaci, A. and Rougier, 

F.: Public water supply and sanitation services in France. 

Economic, social and environmental data. BIPE editor, 86 

pages (2012). 

[15] Furumaï, H.: Evaluation of community-owned water 

resources based on water quality labelling system. In Cities 

of the future – Water infrastructure for sustainable communities, 

X. Hao, V. Novotny and V. Nelson (eds), IWA publishing 

(2010), p. 89-116. 

[16] Le Corre, K., Aharoni, A., Cauwenberghs, J., Chavez, A., Cikurel, 

H., Ayuso Gabella, M.N., Genthe, B., Gibson, R., Jefferson, B., Jeffrey, 

P., Jimenez, B., Kazner, C., Masciopinto, C., Page, D., Regel, 

R., Rinck-Pfeiffer, S., Salgot, M., Steyn, M., Van Houtte, E., Tredoux, 

G., Wintgens, T., Xuzhou, C., Yu, L. and Zhao X.: Water 

reclamation for aquifer recharge at the eight case study 

sites: a cross case analysis. In Water reclamation technologies 

for safe managed aquifer recharge, C. Kazner, T. Wintgens, 

and P. Dillon (eds) (2012), p. 11-31. 

[17] Eawag : Mix ou no mix ? La séparation des urines sous tous 

les angles. Eawags, 63f, 36 pages (2007). 

[18] Goen, H.: Sustainable water infrastructure of the future – The 

contest of ideas and ideals in sustainability. In Cities of the 

future – Water infrastructure for sustainable communities, X. 

Hao, V. Novotny and V. Nelson (eds), IWA publishing (2010), 

p. 23-34. 

[19] EIN: Le procédé Degrés Bleus® séduit la ville de Paris. In L’Eau, 

l’industrie, les nuisances 341 (2011) No. 10. 

[20] Bundschuh, J. and Hoinkis. J.: Renewable energy applications 

for freshwater production. IWA – CRC press co-publishing 

(2012), 250 pages. 

[21] Malmqvist, P.E. and Heinicke, G.: Strategic planning of the 

sustainable future wastewater and biowaste system in Goteborg, 

Sweden. In Cities of the future - Towards integrated 

sustainable water and landscape management, V. Novotny 

and P. Brown (eds), IWA publishing (2007), p. 284-299. 

[22] OCDE : Les réseaux d’eau alternatifs : nouvelles options et 

implications pour les pouvoirs publics. Direction de 

l’Environnement, OCDE (2009). 

[23] Lorrain, D.: Les institutions de second rang. Introduction à un 

numéro spécial: Gestion de l’eau: conflits ou coopération? 

Entreprises et Histoire, n° 50, avril (2008), p. 6-13. 

[24] Desbordes, M.: Contribution à l’analyse et à la modélisation 

des mécanismes hydrologiques en milieu urbain. Thèse 

d’Etat. Université de Montpellier, France (1987), p. 1-242. 

[25] Nelson, V. and Shephard, F.: Accountability: Issues in Compliance 

with Decentralized Wastewater Management Goals. 

Waquoit, Massachusetts: Waquoit Bay National Estuarine 

Research Reserve (1998). 

[26] Clune, W.H. and Braden, J.B.: Financial, economic, and institutional 

barriers to “green” urban development: the case of 

stormwater. In Cities of the future Towards integrated sustainable 

water and landscape management, V. Novotny and 

P. Brown (eds), IWA publishing (2007), p. 388- 401. 

[27] Hollander, J.B., Pallagst, K., Schwarz, T. and Popper, F.J.: Planning 

Shrinking Cities (2009). Retrieved from: http://policy. 

rutgers.edu/faculty/popper/ShrinkingCities.pdf 

[28] Novotny, V.: Water energy nexus – Towards zero pollution 

and GHG emission effect of future (Eco) cities. In Cities of the 

future – Water infrastructure for sustainable communities, X. 

Hao, V. Novotny and V. Nelson (eds), IWA publishing (2010), 

p. 35-58. 

Authors 

Dr. Michel Lafforgue 

(corresponding author) 

E-Mail: michel.lafforgue@safege.fr | 

SAFEGE | 

Centre d’affaire ABC | 

76 allée Louis Blériot | 

F-30320 Marguerittes (France) 

Vincent Lenouvel 

E-Mail: vincent.lenouvel@safege.fr | 

Catherine Chevauché 

E-Mail : catherine.chevauche@safege.fr | 

SAFEGE | 

Parc de l’Ile, 15-27 rue du Port | 

F-92022 Nanterre cedex (France) 




SCIENCE 

Water Sensitive Urban Design as a 

Role Model for Water Management in 

Germany? 

Lessons learned from Australia 

Water Management, Water Sensitive Urban Design, communication strategies 

Jacqueline Hoyer and Juliane Ziegler 

“Water Sensitive Urban Design” (WSUD), originally developed in Australia, is a planning and design approach 

combining the functionality of water management with principles of urban design. WSUD is mainly used in 

the development of integrated solutions for stormwater management in urban areas. Besides water management, 

WSUD regards urban design and socio-economic aspects, such as usability, functionality, aesthetics and 

public perception (Hoyer et al. 2011). 

This article gives an overview of the (historic) background of WSUD in Australia and describes current developments 

and achievements, while emphasizing the main framework requirements and strategies to establish 

WSUD. Legal and statutory aspects, incentives and further education and communication strategies will be 

highlighted. 

Finally, by comparing the Australian and German situation, the authors draw conclusions on the possibilities 

for applying Water Sensitive Urban Design in Germany. 


The effects of climate change are one of the most challenging 

facts, cities are faced with in the future. Longer 

dry periods in summer and the increase of heavy rain 

events put pressure on existing urban water infrastructure, 

and in consequence can lead to flooding or 

droughts with high damage potential, both on private 

and public property. 

Decentralized stormwater management technologies 

can help to counteract these issues. However, these 

systems are still not seen as daily business. In fact, it 

might be a feature in sustainable housing, but it is not 

mainstreamed yet. 

Having a look at approaches in Australia, the authors’ 

aim was to find out more about how Australia – a country 

where the effects of climate change are already in 

state – deals with droughts and floods. This led to Water 

Sensitive Urban Design (WSUD), a design and planning 

approach which uses decentralized methods for stormwater 

management in order to cope with droughts and 

floods, while enhancing the liveability, and therefore 

competiveness, of a city. 

To gain insight into Australia’s approaches, challenges, 

developments and achievements, the authors 

visited Australia (Melbourne) in 2011 and 2012. Australia 

has a well-established and facilitated network of 

professionals working in the field of WSUD. In 2012, a 

group of young Australian professionals visited Europe 

to learn more about existing ideas and technologies 

back here. 

This article summarizes the results of interviews, literature 

research and personal experiences about Water 

Sensitive Urban Design in Australia and develops first 

ideas on how the approach could be adopted to Germany. 

While having some side views, this article focusses 

on Melbourne as the most active community in Australia 

in terms of WSUD. The final results of the research 

will be shown in the dissertation of Jacqueline Hoyer. 

2. Background 

2.1 WSUD in history 

The term Water Sensitive Urban Design (WSUD) was first 

referred to in the early 1990s (Engineers Australia 2006), 

associated with growing public awareness of environmental 

issues at that time. Defined as a planning and 

design approach which combines the functionality of 

water management with principles of urban design 

(Hoyer et al. 2011), the term “is commonly used to reflect 

a new paradigm in the planning and design of urban 

environments that is ‘sensitive’ to the issues of water 

sustainability and environmental protection” (Engineers 

Australia 2006, 1-2). WSUD is strongly connected to the 




terms Integrated Water Cycle Management and Sustainable 

Urban Development. 

Similarly to Germany, stormwater management in 

Australia has historically been focused on drainage, 

discharging all stormwater runoff from urban areas to 

receiving waters (figure 1). With growing population 

and progressive urban development, urban streams got 

degraded, with bank erosion, increased instances of 

flooding and poor water quality (Engineers Australia 

2006). 

In many Australian cities, stormwater runoff from 

urbanized areas is conveyed to huge bays which are 

located in the immediate vicinity (e.g. Port Phillip Bay in 

Melbourne). These bays are a ground for recreation 

(swimming, diving), fishery and the home of sensitive 

ecosystems. With more and more inflow of polluted 

Figure 1. Urban (stormwater) stream in Melbourne. 

© J. Ziegler 

1,400 

1,200 

1,000 

800 

600 

400 

200 

0 

Water flowing into Melbourne's main water supply reservoirs - annual totals (GL/year) 

Long term 

average inflow 

(1913-1996) 

Pre Millennium drought 

615 GL/year 

Short term 


(2010-2012) 

Post Millennium 

drought 

617 GL/year 

13-year 


(1997-2009) 

Millennium drought 

376 GL/year 

1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 

Figure 2. Water flowing into Melbourne´s main water supply reservoirs 

– annual totals (Melbourne Water 2013). 

water from the urban streams, the water quality in the 

bays became poorer and poorer, setting a serious risk 

for the sensitive ecosystems as well as for the health of 

the population using these waters for swimming or consuming 

fish from the bay. 

While quality problems were the starting point for 

re-thinking urban water management and the birth of 

the term WSUD, the effects of climate change, particularly 

recognizable in Australia, played and still play an 

important role in raising the acceptance as well as promoting 

the application of WSUD around Australia. 

Comparing the approaches of Australian cities, it can 

be recognized that Melbourne is one of the most active 

communities in Australia. Therefore, the next chapters 

focus on the Melbourne metropolitan area. 

2.2 Climate and Climate Change 

Melbourne is the capital of the state of Victoria and the 

second largest city in Australia. The city is situated at the 

south eastern coastline of Australia in a temperate climate. 

The city center is located at the northernmost 

point of Port Phillip Bay within the estuary of the Yarra 

River. 

The average annual precipitation is about 656 mm, 

with a maximum of 67 mm in October and a minimum 

of 48 mm in January. Climate change affects Melbourne 

– as well as other major Australian cities – in several 

ways: sea level rise, decline of precipitation leading to 

reduction of water inflows to water supply catchments, 

increased instances of heavy rain events followed by 

flooding and the increase of high temperature periods 

leading to higher risks for bushfires (www.climatechange.gov.au). 

From 1997–2006, Australia suffered the “Millenium 

Drought” (figure 2). During this period, inflow to water 

supply catchments in Melbourne was 40 % less than 

average, which in consequence led to severe water 

restrictions affecting the whole community. Resulting 

from these experiences, the construction of the first 

desalination plant for Melbourne started in 2011 – 

despite some protests among the population. 

2.3 Population Growth and Urban Development 

Between June 2001 and June 2011, Greater Melbourne 

had the largest population growth of all Australian cities 

with an increase of 18 % over the decade, leading to an 

estimated population of 4.17 million. Two of the three 

main series of projections on population growth in Australia 

assume that population in Melbourne will exceed 

5 million inhabitants before 2030 (ABS 2008). 

From 2001 to 2011, population growth took predominantly 

place in the outer suburbs of Melbourne 

(ABS 2008) and there population growth will go on in 

the future. The Growth Areas Authority set up an overarching 

strategic planning framework to guide future 

development in the four current growth corridors. 




SCIENCE 

Figure 3. Examples for WSUD in Melbourne (raingarden, wetland). 

2.4 Legislation and Policy Framework 

Within the last years, there have been developed several 

policy and legislative requirements for WSUD, both by 

the Federal, State, and by regional and local governments 

in Australia. The policy documents outlining strategic 

policies to foster WSUD in Melbourne are the 

Urban Stormwater: Best Practice Environmental Management 

Guidelines on state level, and the Future Melbourne 

as well as the Total Watermark – City as a Catchment Plan, 

which set the overall aims for WSUD in the city of Melbourne 

and were followed by the WSUD Guidelines for 

the City of Melbourne and additional plans, which ensure 

transfer from the strategic vision towards the ground 

(e.g. Drainage Plan, Parks Plan, Urban Design Strategy). 

Concerning the Federal and Victorian Government level, 

there is the National Water Commission, the body 

responsible for advancing water reform at a national 

level, and the Living Victoria Ministerial Advisory Council 

(MAC), which developed a high-level strategy roadmap 

for managing water in Victoria, the “Living Melbourne, 

Living Victoria Roadmap”. Fundamental legislation 

is set by clauses 54 and 55 (reduce of the impact of 

stormwater runoff by using permeable surfaces), and – 

of capital importance – clause 56, which regulates the 

application of WSUD in all new residential developments 

(De Sousa 2012, City of Melbourne n. d.). 

3. Current Developments and Achievements 

3.1 Paradigm shift towards water sensitive 

developments 

Within the last 20 years, a lot of things have been happening 

with regards to WSUD in Melbourne. Rebekah 

Brown und Jodie Clarke described the process of transitioning 

Melbourne towards a water sensitive city in five 

phases (compare Brown/Clarke 2007). Phase 1, with the 

“Seeds for change” (mid 1960s–1989), where public 

awareness for environmental issues was rising, challenged 

the government to improve the protection and 

rehabilitation of waterways. In phase 2, which can be 

described as the phase of “Building Knowledge & Relationships” 

(1990–1995), the innovation of new strategies 

and technologies began to evolve as well as the development 

of intensive cooperation between research, 

policy and industry. This was followed by the phases 3 

(“Niche Formation”, 1996–1999) and 4 („Niche Stabilisation“, 

2000 – 2006), where research and development 

activities were advanced, best practice guidelines produced, 

pilot projects implemented and funding strategies 

developed. In result, WSUD was recognized and 

taken up by all important stakeholders in Melbourne 

(figure 3). 

Since 2007, Melbourne is in phase 5 „Niche Diffusion“, 

where Melbourne focuses on a capacity building 

program to enable the necessary knowledge and skills, 

resulting in the establishment of Clearwater. 

Figure 4 shows the proposed transitions framework 

by Brown et al. 2009, presenting a typology of six city 

states recognizing the temporal, ideological and technological 

contexts that cities transition through when 

moving towards sustainable urban water conditions. 

By passing through this process, there are four 

important institutions guiding the transitioning of 

Water supply 

access & 

security 

Water 

Supply City 

Supply 

hydraulics 

Public health 

protection 

Sewered 

City 

Separate 

sewage 

system 

Cumulative Socio-Political Drivers 

Flood 

protection 

Drained 

City 

Darinage, 

channelisation 

Social amenity, 

environmental 

protection 

Waterways 

City 

Point & diffuse 

source pollution 

management 

Service Delivery Functions 

Limits on 

natural 

resources 

Water Cycle 

City 

Diverse, fit -forpurpose 

sources 

& conservation, 

promoting 

waterway 

protection 

Intergenerational 

equity, resilience to 

climate change 

Water Sensitive 

City 

Adaptive, multifunctional 

infrastructure & 

urban design 

reinforcing water 

sensitive behaviours 

Figure 4. Historical, current and future states of cities’ development 

towards water sensitive cities (Brown et al. 2009). 




Water 

System 

Melbourne towards a water sensitive city: Monash University 

Melbourne, Melbourne Water with Clearwater 

and the Office for Living Victoria. 

3.2 Melbourne Water, Clearwater and Monash 

University Melbourne 

Melbourne Water is the wholesaler responsible for 

drinking water supply, wastewater treatment and the 

management of drainage systems and water ways in 

Melbourne. Due to the fact, the water ways were seriously 

affected by stormwater inflow and pollution, Melbourne 

Water started to set overall aims and works with 

Water 

Businesses 

Office of 

Living 

Victoria 

Reform Element 2: 

Tranform Water System Performance: 

- clarify roles and responsibilities 

- legislative, policy & regulatory changes 

-… 

Reform Element 1: 

Overhaul Melbourne‘s Water Planning Framework 

-increase understanding of benefits of IWCM 

- develop economic evaluation framework 

-… 

Communities 

Urban Development 

Reform Element 3: Establish the OLV: 

-Fill critical new roles & drive reforms 

-Set up Integrated Water Cycle Management Strategy 

& Integrated Water Cycle Plans for Growths Areas 

- … 

Figure 5. Reform package indentified by MAC (based on MAC 2012). 

Council‘s vision: Smart, secure water for a liveable, 

sustainableand productiveMelbourne 

Decentralised 

and 

distributed 

options 

Overachingcommunityobjectives 

Water Sector 

water utilities & all relevant stakeholders 

Integrated 

Water Cycle 

Management 

Communities 

Link urban 

development 

processes 

with water 

outcomes 

local partners from councils, industry and research to 

test and advance the application of WSUD technologies, 

particularly for cleansing and detention purposes. 

In cooperation with Monash University, technologies 

were invented and advanced (wetlands, biofiltres). Until 

today, Monash University supports and monitors the process 

of transitioning in Melbourne. In 2011, a Cooperate 

Research Centre for Water Sensitive Cities was founded. 

This centre promotes strong cooperation between 

research, practitioners, policymakers and councils. 

Clearwater is the local capacity building program, 

hosted and funded by Melbourne Water, that plays a 

critical role in enabling the transition to a water sensitive 

future by providing technical training, tours, events, 

advice, tools and online information, in order to train 

and inform practitioners who intend to plan and design 

with WSUD or take over its management (www.clearwater.asn.au). 

The outcome of ongoing research, cooperation and 

development in the field of WSUD is the awareness that 

a shared long-term vision is essential to establish Melbourne 

as a Water Sensitive City and that the integration 

of urban and water planning has to be improved (Ferguson 

et al. 2012, MAC 2011). 

3.3 Office of Living Victoria 

In 2011, the Ministerial Advisory Council was appointed 

to provide recommendations on strategic priorities for 

reform in the water sector (compare figure 5), which are 

essential to face the numerous challenges driven by 

population growth, pressure on natural and built environments 

and increased climate risk and variability. 

This resulted in the development of the “Living Melbourne, 

Living Victoria Roadmap” (MAC 2011) and the 

corresponding “Implementation Plan” (MAC 2012). 

As a consequence of these recommendations, the 

Office of Living Victoria (OLV) was established by the 

Victorian government in May 2012, in order to achieve 

the government’s ambitious aims, which are to (MAC 

2011; compare figure 6): 

"" 

establish Victoria as a world leader in liveable cities 

and integrated water cycle management 

"" 

drive generational change in how Melbourne uses 

rainwater, recycled water and stormwater 

"" 

drive integrated projects and developments in Melbourne 

and regional cities to use rainwater, recycled 

water and stormwater (for non-drinking purposes) 

to provide Victoria’s next major water augmentation, 

for which the OLV provides a fund of 50 million $. 

Figure 6. Integrated 

Water 

Cycle Management 

(based on 

MAC 2011). 

Traditional 

centralised 

facilities 

Market based 

solutions 

Demand side 

and efficiency 

solutions 


Is Water Sensitive Urban Design an approach to be 

learned from for German practice in managing urban 

water? Comparing the achievements in Australia with 

that in Germany, it becomes obvious that advanced 

practices in urban water management are dependent 




SCIENCE 

on the provision of political guidance and funding. Even 

if there are well known best practice examples for integrated 

stormwater management in Germany, e.g. Potsdamer 

Platz in Berlin or the RISA project in Hamburg 

(www.risa-hamburg.de), and a well advanced legislation, 

there is still a lot to learn from Down Under, particularly 

with regards to their will to connect science, 

practice and politics, to set a high value on socio-economic 

aspects and develop integrated concepts for 

future development as well as to provide sufficient 

political and financial support. 

While Melbourne is transitioning towards Integrated 

Water Cycle Management, which goes hand in hand 

with a shift from sustainability to liveability and is 

accompanied by strong political and scientific support 

as well as high political and public awareness, we are 

still discussing the positive effects of decentralized 

stormwater methods. Starting to experiment towards 

integrated, locally adapted solutions which incorporate 

a broadening of foci in water management and urban 

planning will help to go a step forward. Moreover, it is 

also necessary to strategically think about how to overcome 

barriers, such as financial and property borders as 

well as responsibility disputes. 

However, a direct comparison of achievements without 

considering basic local conditions, such as climate, 

will only give part of the truth. Due to the climate 

change with limitations in water supply, water quality 

issues and severe floods, Australia is actually in need of 

modifying its water management systems. The goal is to 

set liveability as the core objective for future water 

development, in order to be able to cope with current 

and future changes – a goal which is not just appropriate 

for Australia, but also for Germany. 

References 

ABS: Australian Bureau of Statistics. Report 3222.0 - Population 

Projections, Australia, 2006 to 2101, September 2008. http:// 

www.abs.gov.au/ 

Brown, R.R. and Clarke, J.: Transitioning to Water Sensitive Urban 

Design: The Story of Melbourne, Australia. Monash University, 

Melbourne, 2007. 

Brown R.R., Keath N. and Wong T.H.F.: Urban Water Management in 

Cities: Historical, Current and Future Regimes. Water Science 

and Technology, 59 (2009) No. 5, pp. 847-855. 

City of Melbourne (n.d.): City of Melbourne WSUD Guidelines. An 

Initiative of the Inner Melbourne Action Plan. Melbourne. 

De Sousa, D.: Initiatives to Advance Water Sensitive Urban Design in 

Victoria. In: Maddocks Water Update, December 2012. 

Engineers Australia: Australian Runoff Quality. A guide to Water 

Sensitive Urban Design. Crows Nest (Australia), 2006. 

Ferguson, B.C., Frantzeskaki, N., Skinner, R. and Brown, R.R.: 

Melbourne´s Transition to a Water Sensitive City: Recommendations 

for Strategic Action. Monash Water for Liveability, 

Monash University, Melbourne, Australia, 2012. 

GAA: Growth Corridor Plans: Managing Melbourne’s Growth. 

Growth Areas Authority, 2012. 

Hoyer, J., Dickhaut, W., Kronawitter, L. and Weber, B.: Water Sensitive 

Urban Design. Principles and Inspiration for Sustainable 

Stormwater Management in the City of the Future. Jovis, 

Berlin (Germany), 2011. 

MAC: Living Melbourne, Living Victoria Roadmap. Ministerial Advisory 

Council for the Living Melbourne, Living Victoria Plan 

for Water. Published by the Victorian Government, Department 

of Sustainability and Environment, Melbourne, March 

2011. www.water.vic.gov.au 

MAC: Living Melbourne, Living Victoria Implementation Plan. Ministerial 

Advisory Council for the Living Melbourne, Living 

Victoria Plan for Water. Published by the Victorian Government, 

Department of Sustainability and Environment, Melbourne, 

February 2012. www.water.vic.gov.au 

Melbourne Water: Water Report. http://www.melbournewater. 

com.au/content/water_storages/water_report/water_ 

report.asp?bhcp=1 (28 Feb 2013). 

Authors 

Dipl.-Ing. Jacqueline Hoyer 

E-Mail: jacqueline.hoyer@hcu-hamburg.de | 

Winner of the “William Lindley Award 2012” 

(awarded by HAMBURG WASSER) | 

HafenCity University Hamburg | 

Hebebrandstrasse 1 | 

D-22297 Hamburg 

Dipl.-Ing. Juliane Ziegler 

E-Mail: : juliane.ziegler@hamburgwasser.de | 

HAMBURG WASSER | 

Billhorner Deich 2 | 

D-20539 Hamburg 



SCIENCE Integrated Water Resources Management (IWRM) 

Stormwater Pollution and Management 

Initiatives in Shanghai 

Integrated Water Resources Management (IWRM), low Impact Developments (LID), 

storm water management, combined sewer overflows (CSOs), waterlogging disaster 

K. Yang, Y.P. Lü, Z.Y. Shang and Yue Che 

Stormwater problems have become troubles restricting urban development of Shanghai in recent decades with 

regard to stormwater pollution, urban waterlogging disasters and potable water shortage under increasing 

pressure of rapid urbanization. In rainy season, 33 million cubic meters CSOs flew into the Suzhou Creek in 

the inner city of Shanghai every year. Additionally, an annual average number of 186000 people were affected 

and the average annual direct economic losses caused due to urban waterlogging disasters reached up to US$ 

52.7 million. Integrated Water Resources Management (IWRM), Low Impact Development (LID), rainwater utilization, 

stormwater storage tank for combined sewer overflows (CSOs) and other initiatives have been done for 

stormwater management and produced a marked effect. However, there are still a lot stormwater management 

issues need to be solved including ecological stormwater management approach, increasing design return 

period for sewer systems, drawing up a stormwater master plan, subsidy for rainwater utilization, etc. 


Shanghai, one of the most important economic centers 

of China, possesses abundant water resources. Firstly, 

Shanghai is densely covered with 33 127 rivers and 

26 lakes, and 10 % of the area is covered with water (Che 

et al.‚ 2012a). Secondly, the Yangtze River, the largest in 

China and the third longest in the world, flowing from 

the Tibetan Plateau in the west to the East China Sea is 

flowing through Shanghai (Che et al.‚ 2012b). Thirdly, 

Shanghai receives an average annual rainfall of 1,200 

mm because of a northern subtropical maritime monsoon 

climate (Lü et al.‚ 2012a). 

However, the water quality in most of water function 

areas that still failed to meet the national standard 

brought Shanghai a pollution-induced water shortage. 

It was born of local pollutions and pollutions from 

upstream Taihu Lake which has been heavily polluted 

for many years (Lü‚ 2011). 

In recent decades, industrial and domestic pollutions 

have been effectively controlled and thus stormwater 

pollution has become the main factor affecting the 

quality of water bodies in Shanghai. In recent 10 years, 

Shanghai has started to focus on stormwater pollution 

control and stormwater management (Lü et al.‚ 2012b). 

2. Stormwater pollution and 

management issues 

2.1 Stormwater pollution 

Combined and separate sewer systems are coexisting in 

Shanghai. All of the new towns and new development 

areas are made up of separate sewer systems and the 

combined sewer systems are near Suzhou Creek in the 

inner city of Shanghai. Wastewaters are piped to sewage 

treatment plants in dry weather, while wastewater and 

stormwater are pumped into the nearby rivers in wet 

weather because of low capacity of wastewater treatment 

plants, especially in rainstorm weather (Lü‚ 2011). 

In 2002, there were 366 planned stormwater drainage 

systems with the catchment area of 85 600 ha and 

the pump drainage capacity of 4274 cubic meters per 

second. 237 planned stormwater drainage systems have 

been constructed up to 2008. There were 261 planned 

stormwater drainage systems that have been constructed 

with the pump drainage capacity of 3068 cubic 

meters per second up to 2012. However, 29 % planned 

stormwater drainage systems still have not been constructed 

up to 2012 and the stormwater pollution would 

flow into the nearby rivers in such areas. 

2.1.1 Combined sewer overflows (CSOs) pollution 

Combined sewer systems are near Suzhou Creek in the 

inner city of Shanghai. From the year 2006 to 2010, 

there were 33 million cubic meters CSOs flowing into 

the river in wet weather every year and almost 60 % of 

CSOs occurred in July to September. There were about 

8 billion cubic meters, which was the maximum, flowing 

into the river in August. 

From the year 2006 to 2010, the event mean concentration 

(EMC) of CSOs was a little lower than the Shanghai 

local discharge standard for municipal sewerage 

systems and was 6–15 times of the worst level of 

national standard for water quality of river. When storm 



Integrated Water Resources Management (IWRM) 

SCIENCE 

Table 1. Stormwater pollution in Shanghai (Ballo, 2009; Lü, 2011; Lü, 2012b). 

Pollution 

TSS 

(mg/L) 

COD Cr 

(mg/L) 

BOD 5 

(mg/L) 

TP 

(mg/L) 

NH 4+ -N 

(mg/L) 

EMC of CSOs in inner city 280~ 900 250~410 30~100 2~4 25~35 

EMC of pollution of separate sewer system in inner city 400~1600 160~760 11~ 30 0.4~1.1 0.9~2.6 

EMC of pollution of separate sewer system in new development areas 100~ 300 60~210 10~ 23 0.2~0.4 0.8~1.5 

Shanghai local discharge standard for municipal sewerage system ≤ 400 ≤ 500 ≤ 300 ≤ 8 ≤ 40 

The worst level of national standard for water quality of river / ≤ 40 ≤ 10 ≤ 0.4 ≤ 2 

water occurred, the water where CSOs flowed into the 

river was always dark and thus caused fish dying. The 

COD Cr of the polluted river water was raised from 20 

mg/L to 180 mg/L within 2–5 minutes. The pollution 

phenomenon lasts for 18–36 hours. 

2.1.2 First flush pollution of separate sewer system 

EMC of pollution of the separate sewer system in Shanghai 

was a little lower than the Shanghai local discharge 

standard for municipal sewerage system except TSS, but 

much higher than the worst level of national standard 

for water quality of river except TP and NH4 + -N (table 1). 

Additionally, the degree of pollution of separate sewer 

system in the inner city is much higher than that in the 

new development areas (Lü‚ 2011). 

2.2 Urban waterlogging 

2.2.1 Waterlogging disasters 

There was an average annual number of 186 000 people 

that were affected and the average annual direct economic 

losses caused due to urban waterlogging disasters 

reached up to US$ 52.7 million from the year 1998 

to 2009 (table 2). Stormwater inundated 200 streets and 

flew into 50 000 houses and the waterlogging disaster 

made the direct economic loss of US$ 215.6 million 

during the “Matsa Typhoon” in 2005, while stormwater 

inundated 142 streets during the “Anemones Typhoon” 

in 2012. 

2.2.2 Reasons for waterlogging 

There are at least three reasons for the waterlogging 

disasters in Shanghai in recent decades. 

Firstly, the unique characteristics of rainfall in Shanghai 

lead to the waterlogging disasters. Shanghai records 

an average value of 132 days with precipitation annually, 

which equals to a yearly precipitation of 1200 mm. 

Influenced by typhoons in summer, sixty percent of the 

rainfall pours down in wet weather from May to September. 

Short duration and high intensity are the characteristics 

of rainfall in the wet weather in Shanghai and 

a record was 108.5 mm from 7 : 00 (am) to 8 : 00 (am) on 

August 24, 2008. 

Secondly, urban expansion and its effects play a 

major role in the causes of waterlogging disasters. As 

one of the most urbanized cities in China, urbanization 

Table 2. Urban waterlogging disasters in Shanghai from 1998 to 2009. 

Year 

May-September 

Precipitation 

(mm) 

Number of people 

affected 

(thousand people) 

rate of Shanghai rapidly increased from 75 % in year 

2000 to 89 % in year 2011. On the one hand, rapid 

urbanization alters land cover to impervious surface, 

and produces larger runoff coefficient and runoff. On 

the other hand, rivers that store floodwater, especially 

the small ones, have been filled. From year 1860 to year 

2003, more than 310 rivers in the inner city of Shanghai 

as long as 520 km disappeared. The water area was 

diminished by 10.46 km 2 , with a decrease of 3.61 % in 

the rate of water area. Simultaneously, the total river 

storage capacity was reduced by 2.03 million cubic 

meters, equaling to more than 80 % of the former capacity. 

Thirdly, the design return period for sewer system is 

very low in Shanghai (table 3). At the present time, most 

of the constructed sewer systems in Shanghai just can 

achieve the standard to resist a one-year storm. The 

planning standard for important areas like central business 

areas, the EXPO Area, airports and railway stations 

is to resist a three-to-five-year storm. However, such 

areas only cover 4 % of the planning areas. Compared to 

metropolises abroad and other large cities in China, like 

Beijing and Guangzhou, standard of drainage in Shang 

Direct economic 

losses 

(US$ million) 

1998 654.8 11.6 6.3 

1999 713.6 201.7 152.4 

2000 566.5 107.1 32.9 

2001 1087.7 252.7 51.4 

2002 644.2 108.2 67.5 

2003 430.5 4 2.9 

2004 407 17.9 8.1 

2005 565.8 1036.9 275.7 

2006 442.8 0 0.0 

2007 604 72.3 28.4 

2008 674 50.7 6.3 

2009 698.2 0 0.0 

Data source: Shanghai Water Resources Bulletin (1998–2009) 




Table 3. Design return period for sewer system of cities in the world. 

City Design return period (year) Design rainfall intensity (mm/h) 

1 year 2 years 3 years 5 years 10 years 

Shanghai 1 year, 3–5 years for important area 36 44.3 49.6 56.3 65.8 

Beijing 3-5 years, 10 years for important area 36 44.6 50 56 65 

Guangzhou 1–2 years, 2–20 years for important area 50 58.7 63 69 78 

Hongkong 10 years, 200 years for main pipes and drains / 70.7 / 90.4 103 

Taipei 5 years, 20 years for important area / / / 79 90 

Tokyo 5–10 years / / / 50 60 

Atlanta 2–10 years / 41 / 53 63 

Chicago 5 years / / / 45.7 / 

Paris 5 years / / / 180 / 

hai is relatively low. Under the present standard in 2012, 

there are still 105 sewer systems that have not been 

completely constructed, accounting for 28 % of the 

planned systems. 

2.3 Stormwater management issues 

Storm water management issues in Shanghai include: 

Firstly, the administration has not established a storm 

water management plan or storm water master plan, 

and the storm water management framework of whole 

city has not been built. Secondly, storm water management 

is not attuned to the city development and management. 

The government pays more attention to 

urban construction investment overground than sewer 

systems underground. Thirdly, about 12 % of the storm 

sewers, that is over 1200 km storm sewers, have 

reached or exceeded their serviceable life (30 to 40 

years), which caused the amount of groundwater infiltration 

reached about 30 % to 40 % of the average sewage. 

Maintenance and management of storm sewers is 

difficult and costly. 

3. Initiatives for stormwater management 

3.1 Integrated water resources management 

(IWRM) 

At the national level, river management and drainage 

systems separately belong to the Ministry of Water 

Resources and the Ministry of Housing and Urban-Rural 

Development, which causes a problem of multi-head 

management in stormwater management. But in 

Shanghai, the concept of integrated water resource 

management (IWRM) was firstly accepted, and the 

Shanghai Water Authority is in charge of unified management 

including storm water, sewerage, rivers, water 

supply and other water affairs. 

In 2011, the China government announced a new 

concept of the Strictest Water Resource Management 

System, and Shanghai is chosen as an experimental 

area. Storm water management is one of the most 

important content of the strictest water resource management 

system. Thus, input to the construction of 

storm water infrastructure and storm water management 

will be increased evidently in the next years. 

Additionally, storm water management is a major 

matter in the construction of a water-saving society. Till 

end of the year 2010, there were three districts (Qingpu 

District, Jinshan District and Pudong New District), eight 

eco-industrial parks, one agricultural park, 148 enterprises, 

80 school campuses, and 1341 residential communities 

have been titled “water-saving” by the state 

government. However, the construction of water-saving 

society mainly relies on government leading, and is in 

lack of market regulation and public participation. 

Shanghai’s sewage charges are currently based on 

the consumption of potable water, and there is little correlation 

between the stormwater generated and utilized 

by a development area. Yet as stormwater management 

and regulatory requirements have evolved, 

Shanghai is doing researches to pilot a sewage charge 

for stormwater so as to encourage source controls, to 

awaken public awareness around stormwater issues, 

and provide a dedicated budget for stormwater management. 

3.2 Low impact development (LID) and rainwater 

utilization 

Low Impact Development (LID) is a comprehensive land 

planning and engineering design approach to manage 

stormwater runoff by using engineered, on-site, smallscale 

hydrologic controls (Prince George’s County, 1999). 

Many LID practices and rainwater utilization systems 

have been used in the new development areas in 

Shanghai, including Shanghai Expo Area, Lingang New 

City and Spring Dew Mansion Area, and others. However, 

LID has not been taken as an important approach 

in the master plan and stormwater management plan of 

Shanghai, and the proportion of rainwater utilization is 

less than 10 % of the precipitation every year. 



Integrated Water Resources Management (IWRM) 

SCIENCE 

Table 4. Stormwater storage tanks built in Shanghai. 

Receiving waterway Location of tank Type of 

sewer system 

Storage volume 

(thousand 

cubic meters) 

The year of putting 

into 

operation 

Amount of CSOs 

decrease in 2011 

(%) 

COD Cr of CSOs 

decrease in 2011 

(%) 

Suzhou Creek Chengdu combined 7.4 2006 5.4 8.1 

Xinchangpin combined 15 2009 63.6 78.8 

Mengqing Garden combined 25 2010 78.8 92.3 

Jiangsu combined 10.8 2011 34.3 47.2 

FurongJiang combined 12.5 2012 / / 

Xinshida combined 15 2011 / / 

Yunzhao Creek South Yunzhao Road combined 25 2011 / / 

Huangpu River 

(Shanghai EXPO Area) 

Nanmatou separate 3.5 2010 / / 

Puming separate 8 2010 / / 

Mengzi separate 5.5 2010 / / 

Houtan separate 3.8 2010 / / 

Total / 131.5 / / 

Data source from Shanghai Municipal Sewerage Company Ltd (2006–2012) 

3.2.1 Shanghai Expo Area 

LID practices and the rainwater utilization systems are 

adopted in construction of the EXPO Park and many 

pavilions (Zhang et al., 2010). Some pavilions (like pavilions 

of China, Norway, Singapore, the United State, London), 

the Expo Axis, the Expo Center and other pavilions 

collected and treated roof rainwater for the use of road 

cleaning and plant irrigating. Besides, case pavilions of 

Rhone-Aples, Rotterdam, Prague, London, Chengdu, 

Madrid exhibited the LID practices and rainwater utilization 

technologies in their cities. The plan of the post use 

of EXPO Park also followed LID practices and rainwater 

utilization technologies. 

3.2.2 Lingang New City 

Lingang New City is a planned harbor city approximately 

70 kilometers southeast of downtown Shanghai. 

Upon completion in 2020, it is expected to accommodate 

1.2 million people and supply the deepwater container 

port at Yangshan with multi-modal logistic and 

transportation support (Lü, 2011). The planning area of 

Lingang New City is about 30000 ha, and almost half of 

area is covered by green space. Bio-retention ponds and 

other LID practices are widely used in Lingang New City 

so as to make runoff coefficient below 0.6 and to reduce 

30 % of the stormwater runoff pollutions flowing into 

the water bodies (Lü et al, 2012b). 

3.2.3 Spring Dew Mansion Area 

The Spring Dew Mansion Area (SDMA) is the first socalled 

eco-residential area in Shanghai, which was 

developed in 2006 by China Vanke Co., the largest real 

estate developer in China. SDMA stood out among residential 

areas because of the water-sensitive technologies, 

including the rainwater utilization system and LID 

practices such as green roofs, permeable pavements, 

bio-retention, rain garden and et al. By using such technologies, 

the runoff coefficient has been decreased 

from 0.63 (before development) to 0.42 (after development) 

and US$ 4311 per year was saved by using rainwater 

as an alternative water resource for potable water 

to renew lake, irrigate vegetables, wash roads and wash 

cars (Lü et al.‚ 2012a). 

3.3 Stormwater storage tank for CSOs 

Storm water storage tanks are widely used for mitigating 

impacts of CSOs into receiving waterways in the 

world (Field et al., 1997). There are 11 off-Line storage 

tanks built in Shanghai (table 4). During wet weather, 

the tanks are put into operation for temporary storage 

of the first flush, and the stored wastewater will be 

pumped back to the sewer so as to transport the wastewater 

to the sewage treatment plant during dry 

weather. 

Tank Chengdu, put into operation in 2006, is the first 

storm water storage tank for CSOs in China. It has a service 

area of 3.06 km 2 with a storage volume of 7400 m 3 . 

From 2006 to 2010, it effectively operated 74 times in 

wet weather, and cut down an average of 89 000 m 3 first 

flush overflow annually, equaling to 8.5 % of the first 

flush overflow. Due to experiments, the average consistencies 

of COD Cr , NH 4+ -N and TP of inflow were 420 mg/L, 

30 mg/L and 3 mg/L, while average consistencies of 

those of effluent were 270 mg/L, 20 mg/L and 2.3 mg/L. 

That meant the storm water storage tank would reduce 

COD Cr , NH 4+ -N and TP by 13.35 tons, 0.89 toms, and 0.06 

tons, respectively. Owning to the function of storage 

tank, first flush with high consistency of pollution is 

intercepted, and sewage flowing into the river hardly 

causes fishes in the overflow to die (figure 1). 




for management of urban runoff pollution. Prog. Nat. 

Sci. 19 (2009) p. 873–880. 

Figure 1. Operation efficiency of the first stormwater storage tank for 

CSOs in China. Data source from Shanghai Municipal Sewerage Company 

Ltd (2006 – 2012). 

4. Conclusion and prospect 

Combined and separate sewer systems are coexisting in 

Shanghai. The stormwater pollutions both from combined 

and separate sewer systems were much higher 

than the worst level of national standard for water quality 

of river. There were 33 million cubic meters CSOs flew 

into the Suzhou Creek in the inner city of Shanghai in 

wet weather every year and almost 60 % of CSOs 

occurred in July to September from 2006 to 2010. 

The short duration and high intensity rainfall, rapid 

urbanization and lower design return period for sewer 

system made waterlogging disasters easy to occur in 

the rainstorm weather. An average annual number of 

186000 people were affected and the average annual 

direct economic losses caused due to urban waterlogging 

disasters reached up to US$ 52.7 million from the 

year of 1998 to 2009. 

Integrated Water Resources Management (IWRM), 

Low Impact Development (LID), rainwater utilization, 

stormwater storage tank for CSOs and other useful initiatives 

have been done for stormwater management in 

Shanghai in recent years and sustaining a site’s predevelopment 

hydrologic regime in recent years. 

There are still many stormwater management issues 

that need to be solved in Shanghai, including ecological 

stormwater management approach, increasing design 

return period for sewer systems, piloting a sewage 

charge for stormwater, drawing up a stormwater master 

plan, subsidy for rainwater utilization, stormwater pipeline 

rehabilitation, building tunnels to reduce stormwater 

pollution and waterlogging disasters, etc. 


This research was sponsored by the Natural Science Foundation of China 

(41171017), the Shanghai Rising-Star Program (12QB1404100) and the Key 

Projects of Philosophy and Social Sciences Research of the Ministry of Education 

of China (No. 11JZD024). 

References 

[1] Ballo, S., Liu, M., Hou, L.J. and Chang, J.: Pollutants in 

stormwater runoff in Shanghai (China): Implications 

[2] Shanghai Water Authority. June 2007. Shanghai River 

Report 2006. Shanghai, China. (in Chinese). 

[3] Che‚ Y.‚ Yang‚ K.‚ Wu‚ E.N.‚ Shang‚ Z.Y. and Xiang‚ W.N.: 

Assessing the health of an urban stream: a case study 

of Suzhou Creek in Shanghai‚ China. Environ. Monit. 

Assess.184 (2012b) No. 12, p. 7425–7438. 

[4] Field, R. and O’Connor, T.P.: Control and Treatment of 

Combined Sewer Overflows. In: Control and Treatment 

of Combined Sewer Overflows, P. Moffa (Ed.), 

Van Nostrand Reinhold, New York 1997. 

[5] Lü‚ Y.P.: Process Simulation and Watershed Management 

for Non-point Source (NPS) Pollution in Tidal 

Plain with Dense River Network, China. A Ph.D. Dissertation 

Presented to East China Normal University, 

Shanghai (China). (In Chinese with an English 

abstract) 2011. 

[6] Lü‚ Y.P.‚ Yang‚ K.‚ Che‚ Y.‚ Shang, Z.Y., Zhu, H.F. and Jian, Y.: 

Cost-effectiveness-based multi-criteria optimization 

for sustainable rainwater utilization: A case study in 

Shanghai. Urban Water Journal 10 (2012a) No. 3, 

p. 127–143. 

[7] Lü‚ Y.P.‚ Yang‚ K.‚ Che‚ Y.‚ Xie, S., Liu, C., Ren, X.Y. and 

Shang, Z.Y.: Temporal-spatial characteristic of transport 

flux of non-point source pollution in Lake Dishui 

watershed of Shanghai. Journal of East China Normal 

University (Natural Science), 6 (2012b), p. 1–12. (In 

Chinese with an English abstract) 

[8] Prince George’s County, Maryland. June 1999. Low- 

Impact Development Design Strategies: An Integrated 

Design Approach. Prince George’s County, 

Maryland, Department of Environmental Resources, 

Largo, Maryland. 

[9] Satterthwaite, D.: How urban societies can adapt to 

resource shortage and climate change. Phil. Trans. R. 

Soc. A., 369 (2011), p. 1762–83. 

[10] Zhang, C. , Tan X.J. and Chen, Y.: Interpretations and 

prospects of new water and wastewater wechnologies 

in World Expo Shanghai 2010. China Water & 

Wastewater 26 (2010) No. 20, p. 1–4. (In Chinese with 

an English abstract) 

Authors 

K. Yang (Corresponding author) 

E-Mail: kyang@re.ecnu.edu.cn | 

Z.Y. Shang 

Yue Che 

School of Resources and Environmental Science | 

East China Normal University | 

500 Dongchuan Rd. | Shanghai (China) 

Y.P. Lü 

Research Department | 

Shanghai Municipal Engineering Design Institute (Group) Co. | 

Ltd, 901 North Zhongshan | No. 2 Road – Shanghai (China) 



© Rainer Sturm_pixelio.de

PRACTICE 

SimTejo Implements Real-time Integrated System 

to Accurately Predict Sewer Overflows in Lisbon’s 

Water Network 

Bentley’s WaterObjects.NET Technology Enables AQUASAFE Solution to Automate and Connect 

SewerGEMS to Real-time Data and Weather Forecast 

Frequent Flooding Drives 

Need for Forecasting 

Lisbon Portugal’s sewerage network, 

which is managed by Saneamento 

Integrado dos Municípios do 

Tejo e Trancão (SimTejo), comprises 

separate sanitary sewers and combined 

wastewater systems, as well 

as partially separate systems. As is 

typical in the Mediterranean region, 

Lisbon experiences short, intense 

periods of heavy rainfall that often 

lead to flash floods, which when 

combined with high tides often 

cause the network to fail. Although 

SimTejo had access to large amounts 

of infrastructure and operational 

data from their water network, they 

needed a way to consolidate and 

integrate the huge amount of information 

into useful, actionable data. 

To provide real-time data for modeling 

emergency and planning scenarios, 

and real-time operations, 

SimTejo chose Bentley developer 

partner Hidromod to help create a 

tool that enabled management of 

drainage and wastewater treatment. 

The sewerage systems managed 

by SimTejo were all constructed 

using different materials and components 

such as inverted siphons 

and pumping stations. These components 

were installed at different 

time periods, and consequently 

parts of the system are in better 

condition than others. The network 

flooded regularly at sewers, pumping 

stations, and wastewater treatment 

plants, as uncontrolled stormwater 

and huge quantities of grit 

and coarse solids entered the sewerage 

systems. In addition, Lisbon’s 

topographic and geographic characteristics 

cause the tide to affect 

the downtown river front, where 

permanent tide valves had to be 

installed to prevent flooding when 

heavy concentrated rainfall coincided 

with high tides. 



PRACTICE 

From Reactive to Proactive 

Operational Management 

SimTejo realized it needed to be 

able to consolidate a huge amount 

of information, including SCADA 

data, sampling data, data from quality 

probes, as well as other sources, 

such as hydraulic model results 

from SewerGEMS. SimTejo was 

already using modeling tools such 

as SewerGEMS for planning activities, 

but wanted a way to use these 

tools to enable real-time forecasting 

potential overflows, uncontrolled 

discharges, and flows into the 

wastewater treatment plant. In 

addition, to increase efficiency and 

improve planning, SimTejo needed 

a system that could not only integrate 

all available information, but 

also provide non-specialist staff 

with clear, simple reporting that 

would be customized according to 

the users’ needs and skills. 

SimTejo worked with Hidromod, 

a member of Bentley’s developer 

network, creating AQUASAFE 

according to SimTejo’s needs and 

requirements, to integrate the management 

of drainage, wastewater 

treatment, and disposal information. 

Using AQUASAFE provides 

SimTejo with integrated models and 

real-time data, enabling proactive 

management, including forecasting 

and short-term planning, while simplifying 

the presentation of results 

for non-specialist and operations 

staff. 

AQUASAFE was first applied in 

the pilot system of Beirolas, an area 

in the north of Lisbon with a population 

of about 204,000, which 

includes a wastewater treatment 

plant, eight pumping stations, and 

18 kilometers of sewer mains. 

Real-time Information 

AQUASAFE automated the execution 

of Bentley’s SewerGEMS and 

connected it to real-time data and 

weather forecasts. SewerGEMS – 

used for the analysis of the sewer 

system, including the catchment 

area, and for offline studies to 

improve operations and energy 

efficiency on the pumping system – 

was seamlessly integrated using 

Bentley’s WaterObjects.NET customization 

technology. 

The sewer model automatically 

runs every 15 minutes with updated 

measured rainfall and rainfall forecasts 

from an operational meteorological 

forecast model (MM5 is provided 

by Instituto Superior Técnico). 

This allows SewerGEMS to provide a 

24-hour forecast of flows, velocity, 

water levels and pump behavior in 

the drainage network, land overflows, 

and incoming flows to the 

wastewater treatment plant. Lastly, 

the discharges calculated from SewerGEMS 

are used as boundary conditions 

by MOHID, an estuary currents 

and level model, provided by 

the Instituto Superior Técnico. 

AQUASAFE also connects to 

additional data coming from rain 

gauges, flow meters, pumping stations, 

a water quality probe, and 

radar and satellite images. AQUA 

SAFE automates all of this, providing 

real-time integrated data that 

would have been virtually impossible 

to obtain without the addition 

of numerous engineers and specialists. 

Customized Presentation 

of Results 

To meet the varied needs of SimTejo’s 

users – from management to 

operators – the results AQUASAFE 

generated needed to be simple 

enough for non-specialists, and customizable 

for different users’ skills 

and needs. To achieve this, AQUA 

SAFE was engineered using clientserver 

architecture. A single server 

is responsible for aggregating the 

different data sources and managing 

the sewer model executions. 

Several configurable clients connect 

to the AQUASAFE server and 

display data in the form of maps, 

tables, graphs, charts, and alerts. All 

data sources can be combined in 

Excel reports using templates created 

by users. 

 

Water pipes fire treatment irrigation. 

Project Summary 

Organization: 

SimTejo 

Solution: 

Water and Wastewater 

Location: 

Lisbon, Portugal 

Project Objective: 

Address overflow and flooding issues related 

to the wastewater system and tide 

Integrate the large amount of information generated 

by the sewer, meteorology, and estuary 

models into an integrated system 

Enable proactive operational management 

while simplifying the presentation of results 

enough for non-specialists 

Products used: 

SewerGEMS 

WaterObjects.NET 

Fast Facts 

Regular flooding occurred due to uncontrolled 

stormwater, tide impact, and huge quantities of 

grit and coarse solids entering the sewerage systems 

SimTejo directed Hidromod to develop AQUA- 

SAFE for integrated management of SimTejo’s 

drainage and wastewater treatment 

AQUASAFE integrates data and software, 

including SewerGEMS, to generate accurate 

forecasts for the management and operations 

teams at SimTejo 



PRACTICE 

Making Models Available 

to Operators 

Implementing AQUASAFE enabled 

SimTejo to provide hydraulic and 

AQUASAFE provides results in an easy-to-use layout. 

ROI 

The availability of simplified data and reports 

accounts for € 120,000 savings per year in specialized 

engineers and consulting 

The automated integration of models and data 

saves € 200,000 annually 

The functional failure of pumping stations was 

reduced by 61 percent, saving € 100,000 per 

year in maintenance and € 30,000 in penalties 

annually 

Improved efficiency for 90 pumping stations is 

expected to yield a 2 percent reduction in 

energy consumption, saving approximately 

€ 160,000 

wastewater treatment models typically 

used by engineers to the operators, 

extending the use of these 

models from a planning application 

to a decision-making tool, integrated 

into day-to-day operations. 

Ultimately, AQUASAFE will help Sim 

Tejo personnel prevent, detect, and 

respond to a wide range of situations, 

including normal operation, 

emergencies, and customer complaints. 

Implementing the new system 

reduced pumping station failure 

by 61 percent, saving € 100,000 

in annual maintenance costs and 

€ 30,000 in penalties per year. Additionally, 

improving the efficiency of 

90 pumping stations is expected to 

earn a 2 percent reduction in energy 

consumption. Considering that in 

2011 the cost of energy for pumping 

was close to € 8 million, this 

represents an annual savings of 

approximately € 160,000. SimTejo 

anticipates a further € 180,000 

annual energy savings related to 

the wastewater treatment plant. 

Observed Improvements 

Pedro Povoa, R&D project manager 

at SimTejo, said: “This system has 

been online since February 2011 

providing constant and accurate 

forecasts for the management and 

operations teams at SimTejo. 

“It now takes no more than 

15 minutes to detect and alert 

abnormal behaviors on flow meters 

by comparing measured flow with 

modeled flows, as well as just five 

seconds to produce accurate combined 

sewer overflow (CSO) and 

estuary discharge reports for environmental 

authorities. Preventing 

infrastructure collapse and flooding 

increased public safety and helped 

protect Lisbon’s waterways from 

pollutants.” 

Povoa continued: “Further savings 

were achieved from improved 

operations and maintenance, which 

reduced the number of man-hours 

required for maintenance processes, 

and the need for specialized 

engineers to run models and integrate 

data from different sources. 

This resulted in an annual savings of 

€ 120,000 in specialized engineers 

and consulting, as well as € 200,000 

in integrating models and databases.” 

Contact: 

Contact Bentley, 

1-800-BENTLEY (1-800-236-8539), 

Outside the US +1 610-458-5000, 

www.bentley.com 

Global Office Listings 

www.bentley.com/contact 

© Sigrid Harig_pixelio.de 



PRACTICE 

Distributed Storm Water Treatment Devices: 

Increasing Importance and Efficiency 

On the one hand, the waste water disposal in Germany meets a high standard on an international scale. On the 

other hand, municipal sewer systems currently are heavily loaded as exemplified at the state North 

Rhine-Westphalia. The state North Rhine-Westphalia is characterised by a high density of population and 

infrastructure. 

The following general set-up has 

to be taken into account when 

planning objectives are defined: 

In North Rhine-Westphalia today 

645 municipal waste water plants 

are operated. In addition, approximately 

83,000 small sewage treatment 

plants and 8,500 septic tanks 

are approved by the water authority. 

Further 1,200 industrial enterprises 

discharge the sewage directly 

into the receiving water and approximately 

40,000 plants are registered 

as indirect discharger. In North 

Rhine-Westphalia there exist more 

than 8,000 stormwater tanks and 

combined sewer overflows as well 

as 70,000 km municipal sewers, estimated 

200,000 km private sewers 

and 3 million domestic connections. 

Additionally facts with regard to 

stormwater treatment in North 

Rhine Westphalia: 

"" 

17,9 % of the area are stated as 

urban, industrial and trafficked 

areas 

"" 

approx. 100,000 ha paved and 

runoff effective area (12 %) 

"" 

more than 5,000 combined 

sewage discharges 

"" 

approx. 2,000 discharges from 

seperate sewer systems with 

treatment 

"" 

still approx. 100,000 discharges 

without any treatment 

High volume of reinvestment 

and new investment 

costs 

Considering the average age of 

30 years of the 654 municipal waste 

water treatment plants the measure 

of reinvestment and investment is 

obvious [2]. This is also true for 

sewer systems and other technical 

discharge and treatment facilities, 

which are obviously sometimes 

older. 

Furthermore, it can be assumed 

that the effluent of several distributed 

and central discharge facilities 

does not comply (anymore) with 

the legal requirements, e.g. temporarily 

and permanent ponded 

stormwater sedimentation tanks, 

combined sewer overflows, stormwater 

treatment facilities, and waste 

water treatment plants. 

The situation exemplarily de 

scribed for North-Rhine Westphalia 

is similar in many other states of 

Germany or in neighbouring foreign 

countries, like Austria. Austria 

has concluded that in the fiscal 

period 2013 all public benefits with 

regard to infrastructural measures 

of municipalities are cancelled. The 

cancelled public benefits concern 

installation, maintenance, adaption 

and deconstruction of no longer 

required infrastructure, like over 

dimensioned sewer systems or 

waste water treatment facilities. 

Accordingly, stormwater treatment 

is a great challenge with 

regard to logistical as well as financial 

aspects in the future for municipalities 

and public authorities. A lot 

of receiving water exhibits problems 

attributed to non-treated or 

not sufficiently treated stormwater 

discharges. Every single paving 

results in new aquatic problems of 

the receiving water. 

Because of the sewerage concept 

defined in the federal water 

law, municipalities shall declare 

how to treat stormwater in the 

catchment areas with regard to 

future urban development. The declaration 

has to account for the existing 

drainage situation as well as the 

impact of the measures on groundwater 

and surface water. 

Increasing importance of 

distributed waste water 

treatment 

Generally, a central waste water 

treatment is not realizable because 

of increasing paved areas, urban 

measures, existing infrastructure 

and costs. Therefore, distributed 

waste water treatment becomes 

more important [2]. 

Techniques of waste water treatment 

have to be chosen accordingly 

to the need of treatment. Basic 

requirement for use of distributed 

waste water treatment techniques 

is that the facility meets the standard 

of a conventional central solution 

with regard to treatment efficiency, 

pollutant removal and operating 

life. 

Since some years different na 

tional and international investigations 

are conducted to determine 

the treatment efficiency and operation 

reliability of such facilities even 

under worst conditions, like operation 

in winter at highly frequented 

highways. The investigations in laboratory 

scale are accomplished by 

long time praxis tests [6]. 

The investigations presented in 

this paper illustrate that distributed 

facilities can reach the same proficiency 

level with regard to retention 

and degradation of organic and 

inorganic loads. Otherwise the 

effluent values can be obtained 

only with soil filter and swaletrench-infiltration 

systems, which 

are expensive to build [6]. 

The general approach of distributed 

stormwater treatment is to 

evaluate the runoff effective area 

 



PRACTICE 

with regard to pollutants and discharge 

and to adapt the treatment 

strategy. In urban regions heavily 

trafficked areas need often only 

increased standards with regard to 

the waste water and stormwater 

treatment. Low polluted discharge 

is allowed to be discharged directly 

into the receiving water or to be 

infiltrated top soil. Opposite to low 

polluted discharge, e.g. from private 

real estate, runoff from trafficked 

Table 1. Representative mean concentration of different heavy metals in surface 

runoff (Göbel et al., 2007). 

Heavy metal Parking lot Minor roads 

Lead (Pb) 137 µg/l 137 µg/l 

Copper (Cu) 80 µg/l 86 µg/l 

Nickel (Ni) No information 14 µg/l 

Zinc (Zn) 400 µg/l 400 µg/l 

Tin (Sn) No information No information 

Chromium (CR) No information 10 µg/l 

Cadmium (Cd) 1,2 µg/l 1,6 µg/l 

Table 2. Representative mean concentration of different organic pollutants in 

surface runoff (Göbel et al. 2007). 

Polycyclic aromatic 

hydrocarbons 

Parking lot Minor road Major road 

3,5 f Ê g/l 4,5 f Ê g/l 1,65 f Ê g/l 

0,16 mg/l 0,16 mg/l 4,17 mg/l 

Table 3. Efficience proof of modern substrates with regard to the retention of 

inorganic loads of heavily polluted surface runoff: zinc retention related to 

load doses in long-term simulation. 

ENREGIS/ 

Biocalith MR-F1 

Enregis/ 

Biocalith K 

3 years 4 years 17 years 43 years 85 years 

>99,9 % >99,9 % 99,5 % 96,2 % 90,3 % 

>99, % >99,9 % >99,9 % >99,9 % 97,5 % 

Table 4. Copper retention related to load dosed in long-term simulation. 

ENREGIS/ 


ENREGIS/ 

Biocalith K 

3 years 6 years 22 years 56 years 111 years 

>99,9 % >99,9 % >99,9 % >99,9 % 99,9 % 

>99,9 % >99,9 % >99,9 % >99,9 % 99,2 % 

Table 5. Remaining heavy metal load in the substrate after flushing with NaCl 

solution (tenfold annual load of alpine highway runoff). 

ENREGIS/ 


ENREGIS/ 

Biocalith K 

Zinc 

(ZN) 

Copper 

(Cu) 

Mineral oil hydrocarbons 

Chromium 

(Cr) 

Nickel (Ni) 

Cadmium 

(Cd) 

99,998 % >99,999 % >99,999 % 99,999 % 99,995 % 

>99,999 % 99,997 % 99,997 % >99,999 % >99,999 % 

areas, e.g. streets, parking lots, company 

premises or industrial sites, is 

even more polluted and requires a 

complex treatment [5]. 

In general, the discharge of trafficked 

areas is characterized by its 

high seasonal and local variable 

load of (total) suspended solids 

(TSS) due to dust, abrasion of tires, 

pavement and breaks, vegetable 

components, de-icing salt, crushed 

stones and building activities. Additional 

runoff from trafficked areas is 

loaded with organic pollutants, e.g. 

mineral oil hydrocarbons (MOH) 

and polycyclic aromatic hydrocarbons 

(PAH), which are caused by 

combustion facilities. At least the 

traffic is origin of the PAH in runoff 

from trafficked areas. The concentrations 

of organic compounds are 

below critical values, even often 

below detection limits. Furthermore, 

heavy metals, like copper and 

zinc in temporarily high concentrations 

as well as cadmium, lead, 

nickel and chrome, were detected 

in the surface runoff. Nevertheless, 

even nitrate and phosphorous as 

well as pesticide and phenol got 

into the surface runoff depending 

on the local situation [6]. 

One of the challenging problems 

is to determine the overall load of 

the pollutants included in the surface 

runoff. Pollutant loads differ 

according to project specific, 

regional and seasonal influences on 

the loads. The industry has developed 

various adapted systems 

especially for the complex demands 

with regard to stormwater treatment 

devices installed in public or 

industrial areas. In general, two 

basic processes – so called mechanism 

of action – are differentiated: 

matter separation and matter conversion. 

The processes sedimentation, 

resuspension, filtration 

(mechanical or hydraulic) and 

adsorption can be understood as 

matter separation. Matter conversion 

implies chemical oxidation or 

biological degradation with the use 

of bacteriological processes (compare 

figure 1 and 2). 



PRACTICE 

Figure 1. CRC waste water treatment device. 

Figure 2. CRC double shaft system. 

The majority of producers provide 

stormwater treatment systems 

based on matter separation. Matter 

conversion, especially based on biological 

processes, is rather disregarded. 

Systems with the demand to 

substitute the natural retention of 

pollutants by soil or soil filter break 

new ground. The use of modern 

substrates of 0.2 m filling depth 

assures the same or even higher 

removal efficiency of organic and 

inorganic loads compared to the 

retention of a soil filter buildup 

according to standards. The substrates 

are used in central stormwater 

treatment plants, like soil filters 

downstream of stormwater 

sedimentation tanks, or in semi central 

facilities, like infiltration swale 

trench systems. The producers guarantee 

that their treatment system 

complies with the legal requirements. 

The matter conversion based 

on modern substrates is more and 

more applied in distributed waste 

water treatment plants. Specialised 

producers do not only offer their 

certified substrate for distributed, 

conventional soil filters as a substitution 

for non-classifiable soil materials, 

but they also develop further 

areas and ranges of application as 

well as sites of operation. Infiltration 

swale systems capable of bearing 

are available on the market. 

Additionally shaft systems like 

the ENREGIS/ESAF system are 

offered, e.g. for the directed treatment 

of heavy metal loads. Also line 

shaped drainage systems based on 

substrate technique to converse 

pollutants are placed on the market 

as an adequate alternative for 

swales or subsoil bio filtration 

device. The use of modern substrate 

technique and process engineering 

belongs to the state of the art, 

accounts for saving costs with 

regard to central waste water treatment 

plants and increases the 

treatment quality to a new level 

(figure 3). 

Investigations with 


Opposite to the separation of heavy 

metals, which is subject of numerous 

measurement campaigns 

worldwide since many years, 

organic pollutants so far have been 

only sporadicly investigated. Only 

some investigations exist on polycyclic 

aromatic hydrocarbons (PAH) 

and mineral oil type hydrocarbons 

(MOH). Therefore, these organic pollutants 

were selected to indicate the 

retention capability of persistent 

organic pollutants. 

The storm event based remo 

val efficiency of ENREGIS/Biocalith 

MR-F1 was investigated in pilot plant 

scale tests with regard to the 16 EPA 

polycyclic aromatic hydrocarbons. 

One difficulty was to detect the 

organic bonds in real world surface 

runoff, because the concentrations 

are often below detection limits. 

Polycyclic aromatic hydrocarbons 

could be detected only in three of 

five tests, although the highway runoff 

used was increased. In none of 

 



PRACTICE 

examination and evaluation of the 

effluent to be treated with regard to 

the expected discharge intensity 

and pollutant loads as well as the 

quality requirements of downstream 

processes or technical regulations 

of the discharge is necessary 

and is a precondition for a secure 

distributed waste water treatment. 

The importance of distributed 

waste water treatment plants is 

increasing, especially when considering 

municipal management 

objectives. They also make it possible 

to implement cost optimized 

solutions. Modern distributed waste 

water treatment plants, like the one 

mentioned in this article, and central 

waste water treatment plants 

have to be assessed equally with 

regard to quality aspects like. 

Figure 4a. CRC sink trap according 

to DIN. 

the tests polycyclic hydrocarbons or 

mineral oil type hydrocarbons could 

be detected in the effluent of the 

ENREGIS/Biocalith MR-F1 filter material. 

In all tests conducted, the efficiency 

of the ENREGIS substrate was 

equal or better than that of an infiltration 

swale, or effluent concentrations 

of the PAH and MOH analyzed 

were below detection limits. Thus, 

the removal efficiency obtained with 

the ENREGIS system was equal or 

sometimes even better than that of a 

grassed infiltration swale [6]. 

Conclusion 

The producer ENREGIS showed 

exemplarily that today a directed 

Figure 4b. Installation the Envia sink trap according 

CRC. 

Sink trap with included 

waste water treatment 

The distributed stormwater treatment 

device ENREGIS sink trap CRC 

based on the process of matter separation 

can on the one hand be 

installed subsequently in existing 

sink traps according to DIN 4052 and 

on the other hand be included in 

treatment plants newly constructed. 

Impervious areas of up to 500 m² 

with a discharge of up to 7 l/s corresponding 

to a rain intensity of 150 l/ 

(s ha) can be connected to the CRC 

system. Such distributed stormwater 

treatment systems have to 

meet fundamental requirements. 

One criterion is the retention of suspended 

solids smaller than 300 µm, 

to which usually between 70 % and 

90 % of the entire heavy metal load 

of the surface runoff is bound. Such 

treatment devices can be easily 

placed into even existing shaft systems. 

If the system is accumulated 

completely with sediments, backwater 

will occur at the traffic area. 

Thereby the operator can easily recognize 

the malfunction so as to 

remove it promptly. Units arranged 

downstream to this treatment 

device, like infiltration facilities, are 

not allowed to be stressed by 

hydraulic bypass due to malfunction. 

A significant advantage of such 

systems is the economic operation 

due to absence of costly maintenance 

and change of substrate. 

Distributed stormwater or waste 

water treatment can be combined 

Figure 3. Integrative 

stormwater 

treatment 

process. 



PRACTICE 

with line shaped drainage systems 

or trenches or realized as small 

punctual intakes or by a sequence 

of individual systems. In consequence, 

efficiency with regard to 

hydraulic behaviour and pollutant 

retention capability is increased. 

Additional retention volume for 

sludge as well as supplementary 

matter separation realized by an 

extra treatment increases the treatment 

efficiency and the operational 

reliability of the waste water system. 

The shaft construction is designed 

to connect several single effluents 

or trenches. Additionally, these systems 

are characterized by low maintenance 

effort compared to several 

single treatment systems. 

Depending on the pollutant 

load of the surface runoff, the treatment 

can be adapted by supplementary 

treatment levels based on 

substrate technique. The conversion 

of pollutants takes place in subsoil 

bio infiltration levels. Organic loads 

of the waste water treatment plant’s 

effluent are thereby altered or 

degraded. The following treatment 

process takes place in the substrate 

with the involvement of bacteria, 

constituents of the runoff and dissolved 

oxygen as biotic and abiotic 

sorption, precipitation and complexation. 

Because of the high conductivity 

of the material, an optimum 

hydraulic is provided. The significant 

inner surface of the 

substrate provides on the one hand 

the settlement of microorganisms 

needed for the degradation of 

waste water constituents (like nitrite 

and nitrate) and is on the other 

hand the cause for an optimum 

exchange of chemical substances 

(like bonding of iron to phosphate, 

control of pH-value). The pores of 

the substrate and constant boundary 

conditions contribute to optimum 

environment for the microorganisms 

with regard to treatment 

processes. Reduction processes are 

generally regenerative degradation 

processes. Thereby the substrate is 

long-lasting capable to degrade 

organic pollutants. In most cases, an 

exchange of substrate is not necessary 

under typical conditions (like 

oxygen transfer). The use of such 

substrates is an outstanding and 

secure alternative to organic soil in 

swales or soil filters. 

Companies like ENREGIS GmbH 

have demonstrated by means of different 

praxis tests as well as laboratory 

tests that distributed systems 

are a fascinating alternative to conventional 

central waste water treatment 

plants. Also the possibility of 

subsoil constructions convinces 

planer, private and public clients. 

Costly maintenance and therewith 

incalculable costs are not relevant 

or can be reduced significantly. The 

scope of works of companies selling 

distributed stormwater treatment 

devices is completed by project 

specific adaptability of the process 

engineering used and easy to use 

dimensioning software [7]. 

Literature 

[1] Vgl. Anforderungen an die Niederschlagsentwässerung 

im Trennverfahren 

RdErl. d. Ministeriums für 

Umwelt und Naturschutz, Landwirtschaft 

und Verbraucherschutz 

IV-9 031 001 2104 – vom 26.5.2004. 

[2] Vgl. Vortragsskript Viktor Mertsch, 

Bedeutung zugelassener Niederschlagswasserbehandlungsanlagen 

für die Umsetzung des Trennerlasses 

in NRW, DIBt/FH Frankfurt-Gemeinschaftsveranstaltung, 

25.10.2012. 

[3] Vgl. C. Dirkes, Vortragsskript: Dezentrale 

Anlagen zur Behandlung von 

Niederschlagsabflüssen, DIBt Infoveranstaltung 

25.10.12 Berlin. 

[4] Produktdokumentation ENREGIS/ 

CRC Envia Straßenentwässerungssysteme. 

[5] vgl. DWA Regelwerk, Merkblatt 

DWA-M 153, 08/2007. 

[6] Untersuchungen zur Leistungsfähigkeit 

von ENREGIS/Biocalith MR-F1 

und ENREGIS/Biocalith K, C. 

Engelhard/S. Fach, AB Umwelttechnik, 

Institut für Infrastruktur, Baufakultät 

Universität Innsbruck, 2012. 

[7] Eugen Hillebrand, Fachbeitrag 

Straßen und Tiefbau, Konsequent 

nachhaltig, Ausgabe 12/2010 

Contact: 

ENREGIS GmbH, 

Zu den Ruhrwiesen 3, 

D-59755 Augsburg, 

Phone + 49 (0) 2932 890 16-0, 

Fax + 49 (0) 2932 890 16-16, 

E-Mail: infor@enregis.de, 

www.enregis.de 

Figure 5. Shaft 

as waste water 

treatment system 

combined 

with a 

downstream 

subsoil bio filtration 

unit. 



PRACTICE 

Modern Stormwater Management 

“Am Stadtpark” in Baunatal 

One advantage 

over stonegravel 

infiltration 

ditches is 

the minimum 

amount of excavation 

required 

for D-Raintanks 

® . Shown 

here is the 

installed 52 m³ 

infiltration unit. 

All pictures: © 

Funke Kunststoffe 

GmbH 

After installation, 

the D-Raintanks 

® are covered 

with gravel. 

Visible at the 

front of the 

photo: two HS ® 

cleaning manholes 

DN/OD 

800 in which the 

rainwater drain 

pipes enter. From 

here, the precipitation 

enters the 

infiltration units. 

The authorities in the North Hesse 

city of Baunatal have high expectations 

for the residential district “Am 

Stadtpark.” The building zone was 

called a giant step in urban development 

at a symbolic groundbreaking 

ceremony at the end of April 2012. 

The planning of the 18,000 m² area 

which is directly adjacent to the 

Stadtpark and the city center calls 

for the construction of 120 units 

of high-end, accessible housing. The 

infrastructure development in 

cluded the creation of 400 m of sewage 

network, around 630 m of water 

pipelines, a water meter manhole, as 

well as 385 m corridor of district 

heating pipeline and 200 m of district 

heating house connection lines. 

Since the Water Act does not permit 

an increased flow rate for new 

buildings, the contracting company 

Küllmer Bau GmbH & Co. KG also 

installed two underground rainwater 

retention tanks. The Baunatal 

municipal works department 

decided to use D-Raintanks® from 

Funke Kunststoffe GmbH. The 

D-Raintanks® were put to use in Baunatal, 

albeit in a modified form: Since 

the soil in the development area was 

considered non-seeping, the infiltration 

units were also covered with a 

foil so that the water could be stored 

before gradually being let into the 

Bauna as receiving water. 

Once again, Funke Kunststoffe 

GmbH was able to demonstrate that 

flexibility and personal service are 

important criteria for successful 

teamwork. Namely, the D-Raintanks® 

of the enterprise from Hamm- 

Uentrop were chosen by the Baunatal 

municipal works department 

for their stormwater management 

requirements for the residential district 

“Am Stadtpark.” The plastic elements 

that are joined together in 

the modular system proved in the 

field to be excellent for underground 

water retention and infiltration. This 

time, however, the product was not 

put to its standard use at the construction 

site in Baunatal. After surveys 

of the development area were 

completed, the soil was classified as 

non-seeping. “That’s why we had to 

find a solution where the rainwater 

could be collected and then gradually 

let into the Bauna as receiving 

water,” explains Dipl.-Ing. Klaus 

Döhne, managing director of the 

IWV GmbH and in-charge of the 

development planning project. 

High planning reliability 

With Funke, the planners and the 

municipal works department found 

a partner that could flexibly respond 

to such special conditions. “The particular 

advantage of the D-Raintanks 

® is that with the computerbased 

dimensioning program, a 

high level of planning reliability can 

be offered for the required storage 

volumes. For instance, for the 

urbanization zone, we calculated a 

requirement for two infiltration 

units comprising 96 tanks with 

a storage volume of 26 m³ and 

192 tanks with a storage volume of 

52 m³. As opposed to a seepage version, 

we wrapped the infiltration 

units in PE foil in order to collect the 

accumulated water and let it out 

gradually in the receiving water,” 

says Funke consultant Dipl.-Ing. 

Martin Ritting, describing why Baunatal 

differs from other locations. 



PRACTICE 

Easy installation in just 

two days 

Those on site were amazed at how 

easy it was to install the infiltration 

storage units. It only took two days 

to complete the underground rainwater 

retention system. The foreman 

from Küllmer Bau GmbH & Co. KG, 

Matthias Gier, explains how the civil 

engineers went about it: “First we 

dug a trench. Compared with 

crushed stone-gravel infiltration 

ditches, there wasn’t much to excavate. 

Of course, that helped things to 

move along faster. We then created 

the base grade using 8 to 16 mm 

sized gravel. We covered the doublelayers 

of D-Raintanks ® with fleece 

and then sealed them in PE foil to 

prevent the infiltration of water. 

Finally, we covered it with another 

layer of fleece to protect the PE foil.” 

At the inflow of an infiltration 

unit, the engineers installed the 

required cleaning manhole with filter. 

The rainwater travels from an 

extra flow control chamber in specified 

quantities into the receiving 

water. “What was important here 

was to avoid a so-called increased 

flow rate. That means that only the 

amount of water that would otherwise 

accumulate on unsealed land 

can be introduced,” explains Dipl.- 

Ing. Thorsten Rennebohm, planner 

at IWV GmbH. 

Prepared for any situation 

Also in the event of heavy rain, the 

peaople in Baunatal wanted to be on 

the safe side. Consequently, backflow 

traps were installed in the outlets 

to prevent water from flowing 

back into the storage units from the 

receiving water. “When the backflow 

traps are closed during heavy rainfall, 

an emergency overflow comes 

into play,” says Dipl.-Ing. Gerhard 

Schuchhardt, site manager from 

Küllmer Bau GmbH. “If the infiltration 

ditch is full, then the water can drain 

away here. This way the new residential 

district is prepared for anything 

that might happen.” Other Funke 

products were also made use of in 

Baunatal. The house connections 

were realized with the HS® drainage 

pipe system DN/OD 160, the rainwater 

collectors with HS® drainage 

pipes DN/OD 315, and the waste 

water collector with HS® drainage 

pipes DN/OD 200. The system-based 

nature of the products impressed all 

of the participants. Klaus Wiegand 

from the management at Küllmer 

Bau GmbH: “The parts are well conceived. 

Everything fits together and 

comes from a single source. This is a 

great help in making good progress 

at the construction site.” 

Technically and economically 

the best solution 

In Baunatal, various storm management 

options were debated in 

advance. Dipl.-Ing. Axel Kaiser, technical 

manager of the municipal 

works department, relates why the 

others did not come into consideration. 

“An open stormwater retention 

tank would have taken up too much 

valuable space in the urban development 

area. A sewer with storage 

capacity and overflow channel 

would be inefficient and also more 

expensive than the open version. 

Therefore, we decided on the infiltration 

units from Funke, because 

they are the most sensible solution, 

both economically and technically. 

The costs for the development of 

the area “Am Stadtpark” amounted 

to around 531,000 Euros. The investors 

have started building this year. 

The planning calls for the construction 

of rental units and condominiums 

as well as business establishments 

and offices. A high quality of 

life will be ensured by the preservation 

of the old tree population, the 

barrier-free access to the apartment 

buildings for the most part, as well as 

the solar power systems on the roofs. 

Contact: 

Funke Kunststoffe GmbH, 

Siegenbeckstraße 15, 

Industriegebiet Uentrop Ost, 

D-59071 Hamm-Uentrop, 

Phone +49 (0) 2388-3071-0, 

E-Mail: info@funkegruppe.de, 

www.funkegruppe.de 

The HS ® flow control chamber DN/OD 800 is used 

when specific quantities of rainwater need to be 

diverted. 

In an HS ® cleaning manhole with stainless steel 

filter, the rainwater is cleaned before entering the 

inflitration ditch element. 

Site meeting (l to r): Planners Dipl.-Ing. Thorsten 

Rennebohm and Dipl.-Ing. Klaus Döhne, Dipl.-Ing. 

Gerhard Schuchhardt, Site Manager Küllmer Bau 

GmbH, Foreman Matthias Gier, Klaus Wiegand, Manager 

Küllmer Bau GmbH, Dirk Eskuche, City of Baunatal, 

Funke Consultant Dipl.-Ing. Martin Ritting (in 

the background) and Dipl.-Ing. Axel Kaiser, Technical 

Manager of the Baunatal Municipal works 

department. 



PRACTICE 

Water Treatment Plants Using Large Stainless 

Steel Filters: New Perspectives 

The Norwegian municipality of 

Bamble with headquarters in 

Langesund (Telemark) uses surface 

water from the inland lake “Flåte” to 

supply drinking water to approximately 

12,000 people (water level 

approx. 53 m above sea level) 

(figure 1). The water is drawn by a 

pumping station (figure 2) and a 

supply line erected on the lake itself 

for extraction of subterranean water. 

The water treatment currently in 

use comprises a coarse preliminary 

purification by means of a plane 

sieve with subsequent chlorination 

and water glass dosing to raise the 

pH-value. After the water treatment 

the water is pumped into the elevated 

tank located about 85 m 

higher. 

An entirely new water treatment 

system is currently being set up to 

reduce the colour and the TOC, and 

to increase the hygienic safety. The 

new system with a treatment capacity 

of 680 m³/h includes the processing 

stages 

Ozonation – CO 2 dosing – 

Marble filtration – Bio-filtration – 

UV treatment – Chlorination 

During the preliminary planning 

phase, the consulting office SWECO 

with headquarters in Seljord had 

looked into and compared different 

Figure 2. New water treatment works with existing 

power house. © Source Sweco 

Figure 1. Raw water source inland lake „Flåte“. © Source HydroGroup 

variants. A system entirely made of 

stainless steel components has 

turned out to be the most advantageous 

solution. The system of two 

treatment lines comprises two horizontal 

ozone reaction tanks, two 

upstream filters with filter vessels 

made of stainless steel for hardening, 

two downstream filters with 

filter vessels made of stainless steel 

for bio-filtration and a pure water 

tank also made of stainless steel. 

The primary reasons for deciding in 

favour of stainless steel included 

the distinctly shorter construction 

periods, the easily achievable high 

standards of design and safety at 

the calculated building costs. The 

latter is crucial, because the building 

structure can be completed during 

the summer months and the 

on-site production of the tanks and 

filters can be completed inside the 

building during the severe Norwegian 

winter. 

The companies Hydro-Elektrik 

GmbH and Hydro-Elektrik AS with 

their systems based on HydroSystemTanks 

jointly turned out to be 

the most efficient bidders in the 

competition when tenders were 

invited in the year 2012. 

In addition to the new construction 

(figure 3) the existing power 

house has also been completely 

refurbished and integrated in the 

unit. It is to be noted that this must 

be done while maintaining operations 

so that water supply is 

ensured. The new unit with additional 

rooms for operation and 

monitoring is linked to the existing 

power house by means of a sealed 

pipe canal measuring approx. 3 x 3 m 

in size. An oxygen producing unit 

and an ozone producing unit with 

ozone-mixing system are also 

installed in the existing power 

house. The ozonized water is 

allowed to flow through the pipe 

canal into two parallel low pressure 

contact tanks made of stainless 

steel 1.4571/316 Ti measuring 10 m 

in length and 2800 mm in diameter. 

Distributor plates are welded at the 

inlet as well as the outlet of the contact 

tank to achieve a uniform plug 

flow. Carbonic acid is added to the 

water after it is discharged from the 

contact tank and then using an 



PRACTICE 

Figure 3. New 

water treatment 

works 

refurbished. 

© Source Sweco 

upstream filter it is made to flow 

over a material containing calcium 

carbonate to achieve the desired 

mineralization. The alkaline up 

stream filters having a diameter of 

5.50 m and a height of 7 m work 

with an upstream velocity of about 

15 m/h. The filters are provided with 

compression-resistant nozzle plates 

and complete internal piping of the 

filter for distribution of flushing 

air, discharge of backwash water 

and filter overflow. The filters are 

completely sealed and are operated 

by gravity. They are vented or aerated 

using special filter systems 

(figure 4). 

The ozonized and mineralized 

raw water flows through the filter 

overflow channel into the downstream 

bio-filter. The bio-filters that 

are piled as multi-layer filters have a 

diameter of 6.70 m and a height of 

7 m and work with a maximum filtration 

rate of about 10 m/h. The filters 

are provided with compressionresistant 

nozzle plates and complete 

internal piping of the filter for 

distribution of flushing air, discharge 

of backwash water and regulation 

of filter overflow. The gravity-driven 

filters with a layer of sand 

and with a bio-filter layer made of 

Filtralite are completely sealed and 

are vented or aerated using special 

filtration systems. 

The treated drinking water is 

stored temporarily in the 800 m³ 

pure water storage tank having a 

diameter of 13 m and a height of 

6.3 m. The pure water is supplied by 

the pipe canal to the UV systems in 

the power house, chlorinated and 

then carried by pumps to the distribution 

system. 

All system components necessary 

for the operation can be safely 

accessed from the operator platform. 

The condensation on the 

stainless steel surfaces is avoided, 

because of climate control and the 

fact that the water-conducting systems 

are completely sealed. The 

ambient temperature in the operating 

areas is adjusted to the temperature 

of water, because the large 

stainless steel surfaces serve as radiators 

or heat sinks. 

The project is being implemented 

on time as per the planned 

schedule: Work on the 20 m wide 

and 50 m long building is planned 

for completion in October and production 

of the tank systems shall 

commence immediately thereafter. 

The trial run of the fully operational 

system is planned to commence at 

the end of May 2014, which is 

merely 13 months after commencement 

of construction work. 

4 3 

2 

8 

Figure 4. In-principle arrangement of pure 

water tanks and filters. © Source HydroGroup 

7 

6 6 

Contact: 

Peter Paskert, 

Hydro-Elektrik AS, 

Litleåsveien 49, 

NO-8132 Nyborg / Norway, 

Phone +47 55259300, 

E-Mail: bergen@hydro-elektrik.no, 

www.hydrogroup.no 

Svein Forberg Liane, 

Sweco Norge AS, 

Vekanvegen 10, 

NO-3835 Seljord / Norway, 

Phone +47 3506 4444, 

E-Mail: SveinForberg.Liane@sweco.no, 

www.sweco.no 

10 10 

5 

5 

1 Raw water inlet 

9 2 Marble filter (upstream) 

3 Bio-filter (downstream) 

4 Pure water tank 

5 Backwash water inlet 

6 Backwash water outlet 

7 Pure water outlet 

8 Air filter system 

9 Pipe canal 

10 Nozzle plate 



1

PRACTICE 

Beverage Water Treatment 

Clarification of Surface Water with Microsand 

The treatment of drinking water from surface waters is becoming more important. Clarification tanks are frequently 

used for this purpose. Based on three examples, this article describes how the Actiflo ® technology supplied 

by Berkefeld, a company of the Veolia water technology division, offers this classic system for the beverages 

industry. Small environmental footprint and reduced operating costs are among its main benefits. 

At present, there are above all 

breweries and beverages producers 

in Africa, Central America 

and Asia that use drinking water for 

beverages production from rivers, 

lakes or wells that are near the surface. 

But for reasons of sparing 

resources, lack of availability of 

ground water or uncertain municipal 

supply, this source of raw water 

is becoming more important worldwide 

and also increasingly in focus 

in Europe, including Germany. 

In the treatment of surface 

waters and bank filtrates with high 

contents of undissolved particles 

and organic residues, settling systems 

are widespread. The contaminants 

are coagulated by the addition 

of flocculant and subsequently 

separated from clear water by sedimentation 

and filtration. The Actiflo 

technology is a further development 

of the conventional settling process 

for the beverages industry but also 

in other industries. 

Table 1. Performance parameters of the actiflo process. 

Drinking water/process water. 

Parameter 

Retention rate 

Particles Up to > 99 % 

Turbidity Up to > 99 % 

TOC Up to > 80 % 

Colouration Up to > 95 % 

COD Up to > 90 % 

Particles 2–15 µm 

Up to > 3 log 

Algae Up to > 99 % 

Metals 50–90 % 

Coli bacteria 85–90 % 

BOD (total) 50–80 % 

The microsand accelerates the three-stage coagulation and reduces the 

time spent in the settling tanks. 

Microsand in action 

The process described herein is 

based on the customary system 

steps of coagulation, flocculation 

and sedimentation. What is new is 

the addition of patented microsand, 

which, as a “germ”, promotes the 

formation of especially large flocs. 

In addition, its high bulk weight acts 

as “ballast”, weights down the 

enlarged flocs and favours a very 

fast settling. Thanks to the microsand, 

the flocculation and sedimentation 

times are reduced to about 

13 to 14 minutes. Thus, a significantly 

greater area loading can be 

achieved. Prefabricated plants of 

steel or stainless steel enable 

throughputs up to 520 m 3 /h. As a 

result, depending on the raw water 

quality, Actiflo systems are up to 

20 times smaller than conventional 

plants with comparable capacity. 

The microsand increases the adaptability 

of the system to fluctuating 

raw water qualities and flow rates, 

which makes the process especially 

robust and simplifies the operation. 

The microsand does not react with 

coagulants and can be reused. 

Compared to conventional settling 

tanks, the technology requires up to 

50 per cent less use of chemicals. 

This reduces operating costs and 

spares the environment. 

Coagulation and 

sedimentation 

Image 1 shows the process in detail. 

For the intake of the coagulation 

basin (1) a flocculating agent (such 

as iron or aluminium salt) is given as 

a precipitate. The coagulated water 

is fed into an injection basin (2) 

where microsand is added with 

strong mixing. Depending on the 

raw water quality, the microsand has 

a diameter of 80 to 170 pm. In the 

transition from the injection basin to 

the maturation basin (3) an organic 

flocculating agent is added to the 

water. With a reduced energy input 

compared to the injection basin, 

ideal conditions are created for the 

formation of polymer bridges 

between the microsand and the 

flocs, whereby dense and heavy flocs 

form. Following this three-stage 

coagulation the water reaches the 

settling tank with scraper (4), where 



PRACTICE 

the flocs weighted with the microsand 

settle quickly. The clear water 

flows through the lamellae and 

leaves the installation via the gutters. 

Table 1 shows the typical performance 

parameters of the process. 

The sedimented sludge/microsand 

mixture in the settling tank is 

collected centrally and pumped to a 

hydrocyclone (5). Depending on the 

suspended matter content in the 

raw water, this sludge/microsand 

volume flow is 3 to 6 percent of that 

of the raw water. The pump energy 

is converted in the hydrocyclone to 

centrifugal force, by which the 

heavy microsand is separated from 

the light sludge. The cleaned microsand 

issues from the hydrocyclone 

underflow nozzle and is returned to 

the injection tank. The sludge flows 

out from the hydrocyclone overflow 

immersion tube and is conducted 

to further treatment. 

Drinking water reference 

In municipal drinking water treatment, 

the Actiflo technology is in 

operation in more than 350 plants 

worldwide. In Germany, for example, 

the Iserlohn public utility uses 

the process for treating ground 

waters whose turbidity value averages 

3.5 FNU, but which depending 

on precipitation can for a short 

period increase to up to 130 FNU. 

Despite these high fluctuations the 

turbidity in the outflow of the installation 

(Image 2) is less than 0.5 FNU 

along with a usual flow rate of 

320 m 3 /h. Following the pre-treatment 

with Actiflo the particle-free 

water is cleaned by ozonisation, 

activated carbon filtration and disinfection 

of residual micro-biological 

pollution and trace substances. 

Beverages water reference 

The Mexican bottler Yoli de Acapulco 

since 2009 has used a new 

variant of the system for treating 

well water for the production of soft 

drinks and table water. The previous 

installation consisted of a green 

sand filter and conventional lime 

reactors with the aid of gravity. It 

was replaced by an Actiflo system 

which additionally to clarification 

enables softening of the water in a 

compact installation. For this purpose, 

the classic process is enhanced 

by a softening tank with turbo 

mixer. The mixer is a chemical submerged 

reactor in which the water 

hardness is precipitated as calcium 

carbonate by the addition of lime 

water. Its design enables the mixing 

of the tank content with the smallest 

possible energy consumption. 

Thus, the speed and pressure during 

the mixing is lower than in other 

reactors, and in the precipitation 

larger and faster crystals to be cut 

emerge. The softened water with 

the formation of particles is then 

clarified in the classic Actiflo process 

steps of coagulation, injection, maturation 

and sedimentation. In line 

with the production requirements, 

the plant supplies 100 m 3 an hour in 

constant quality with a total alkalinity 

of 85 mg/1CaCO 3 , 0.1 mg iron/1 

and a turbidity of 0.5 FNU. The system 

management adjusts the process 

automatically to changing raw 

water qualities. The new plant 

reduces the operating costs by the 

optimised need for energy and 

chemicals and is more environmentfriendly. 

Brewing water reference 

An African brewery decided for the 

technology in order to adjust the 

existing river water treatment for 

beer and soft drink production to 

higher throughputs. The classic 

Actiflo process complements or 

replaces the old lamellae clarifier for 

pre-treatment of the raw water. The 

 

Drinking water 

treatment at 

the Iserlohn 

public utility 

in Germany: 

the system is 

designed for 

up to 480 m 3 /h 

with a nominal 

flow rate of 

320 m 3 /h. 

The Actiflo 

system at the 

Mexican bottler 

Yoli de 

Acapulco combines 

the 

highly efficient 

softening step 

in the chemical 

submerged 

reactor with 

the clarification 

performance 

of the 

classical Actiflo 

process. 



PRACTICE 

Company profile: 120 years of Berkefeld 

The Berkefeld water technology company celebrated 

in 2012 its 120th anniversary since its 

founding by Wilhelm Berkefeld in Celle. The company 

trades under the name VWS Deutschland 

GmbH. It is a subsidiary of Veolia Water Solutions 

& Technologies, one of the internationally leading 

suppliers of solutions and plants for treating 

drinking, process and waste water. The product 

offer encompasses solutions for a broad range of 

applications, from building and swimming baths 

technology to power stations and industrial companies, 

such as beverage, food and pharmaceuticals 

producers, and laboratories, municipalities 

and international relief organisations. 

www.berkefeld.de 

Veolia Water Solutions & Technologies is the Veolia 

Water subsidiary specialized in technical solutions 

and design & build projects for water and 

wastewater treatment, for industrial and municipal 

clients. Veolia Water Solutions & Technologies 

recorded revenue of € 2.4 billion in 2012. 

www.veoliawaterst.com 

Veolia Water, the water division of Veolia Environnement, 

is the world leader in water and 

wastewater services. Specialized in outsourcing 

services for municipal authorities, as well as 

industrial and service companies, it is also one of 

the world’s major designers of technological solutions 

and constructor of facilities needed in water 

and wastewater services. With 89,094 employees, 

Veolia Water provides water service to 100 million 

people and wastewater service to 71 million. Its 

2012 revenue amounted to €12.078 billion. 

www.veoliawater.com 

Example of the Actiflo process used to clarify river water for beverages 

production. 

output of the new plant of 150 m 3 /h 

is about twice as high as before. At 

the same time, the system takes up 

with 15 m 2 only 60 percent of the 

area of the old river water treatment. 

Subsequent to the clarification the 

water quality is refined further by 

sand and activated carbon filtration 

(Image 3). 

Summary 

By the use of a special microsand, 

the Actiflo process reduces significantly 

the flocculation and sedimentation 

times of customary settling 

systems, as well as chemicals 

consumption. Thus, the systems 

with comparable clarification output 

are smaller, more economical in 

operation and environment-friendlier. 

The process is very robust and 

insensitive to strongly fluctuating 

raw water qualities. 

The technology, already well 

tried and tested in municipal drinking 

water treatment, is also being 

used increasingly in beverages production. 

Here, the system is especially 

suitable for the treatment of 

drinking or process water from surface 

waters or bank filtrates. If 

required, the process can combine 

the process steps of clarification 

and softening. A further application 

area is the treatment of waste water 

in plants to recover process water. 

Author 

Bernd Hackmann 

Business Unit Manager Beverage Industry 

Berkefeld – VWS Deutschland GmbH 

Veolia Water Solutions & Technologies 

Lueckenweg 5, D-29227 Celle, Germany 

E-Mail: bernd.hackmann@veoliawater.com 


www.berkefeld.com 

© Jörg Klemme, Hamburg_pixelio 



PRACTICE 

PS&S Deploys Bentley Software to Design 

BMW’s U.S. Headquarters Expansion 

Improves Design Time by Replacing Labor-Intensive Hand Calculations with 

Dynamic Modeling 

To win the design contract for 

BMW’s North American Headquarters’ 

South Campus Expansion 

project in Woodcliff Lake, N.J., 

Paulus Sokolowski & Sartor (PS&S) 

needed to address the project’s 

tight schedule. To significantly 

reduce design time, PS&S deployed 

Bentley’s WaterCAD and StormCAD 

software products for water distribution 

and storm sewers modeling 

rather than inefficient and laborintensive 

hand calculations. The 

campus expansion design incorporated 

two existing office buildings, 

an existing maintenance building, 

and an apple orchard. 

PS&S provided comprehensive 

civil and site services for the project, 

including integrated site analysis 

and design, master planning, and 

construction-phase services for the 

entire 80-acre site. It also provided 

surveying services including preparing 

boundary and topographic 

surveys as well as subdivision plans 

and documents. PS&S worked 

together with the borough and its 

professionals to rezone the project 

site prior to initiating the design. 

New construction elements in 

cluded two three-story buildings, 

surface parking, and infrastructure. 

Project Challenges 

The site design incorporated a total 

vertical drop of more than 100 feet, 

creating a challenging site to 

develop within the parameters of 

the new zoning ordinance. Numerous 

retaining walls were required to 

minimize site disturbance and 

address infrastructure requirements. 

Additionally, freshwater wetlands 

and rock outcrops located throughout 

the site impacted the overall 

layout. This required multiple grading 

iterations to meet strict municipal 

zoning and address site constraints. 

Lastly, potable and fire 

water system analyses were required 

by the local water purveyor. 

The project design included a 

very extensive and innovative stormwater 

management plan to meet the 

New Jersey Department of Environmental 

Protection’s (NJDEP) Stormwater 

II regulations. The plan incorporated 

a nearly two-acre wet pond, 

a 1.8 million gallon subsurface detention 

tank, a surface detention basin, 

and groundwater recharge and 

water quality measures. A reduction 

in stormwater runoff at the site positively 

impacted the adjacent properties. 

Moreover, properly sized storm 

sewer systems convey the on-site 

Fast Facts 

 

The project included the design of a very extensive 

and innovative stormwater management 

plan to meet NJDEP Stormwater II regulations. 

The flexibility of StormCAD and WaterCAD 

allowed PS&S engineers to perform multiple 

iterations of the models to determine the most 

efficiently designed system. 

PS&S prepared multiple stormwater studies to 

select the most efficient and cost effective 

stormwater solution for the project. 



PRACTICE 

Retention pond construction complete. 

WaterCAD model of the BMW site expansion. 

Modern looking detention tank vents visible with 

detention tank beneath parking. 

Project Summary 

Project: 

BMW of North America 

Project Location: 

Borough of Woodcliff Lake, N.J., USA 

Organization: 

Paulus Sokolowski & Sartor (PS&S) 

Be Inspired Awards category: 

Innovation in Water, Wastewater, 

and Stormwater Networks 

Project Objectives: 

Site analysis and design master 

planning and construction for the 

expansion of BMW’s North American 

Headquarters South Campus. 

Products used: 

StormCAD ® , WaterCAD ® 

impoundments where the run-off is 

detained prior to release off site. 

PS&S prepared multiple stormwater 

studies to select the most efficient 

and cost-effective stormwater 

solution for the project. Options for 

the southeastern watershed area 

included underground detention 

comprised of a series of large diameter, 

high-density polyethylene 

pipes and manifolds, concrete box 

culverts in series, a large detention 

tank, and an above-ground retention 

pond at the base of the slope. 

While more costly, the project 

team selected a 120-foot diameter, 

22-foot deep Natgun pre-stressed 

wire-wound concrete water tank to 

address peak flow attenuation for 

this area because of site constraints 

and local zoning criteria. 

Design of the subsurface detention 

tank included incorporating 

the outlet control components into 

the tank, HS-20 loading for future 

traffic loads on the tank, and five 

18-inch vertical air transfer vents 

with a modern, stylish appearance. 

WaterCAD and StormCAD 

Model Complex New Infrastructure 

By using Bentley’s WaterCAD and 

StormCAD modeling software products 

, the project team reduced substantially 

the time it took to perform 

storm and water design analysis. 

Indeed, the very flexible and userfriendly 

software eliminated the 

hours of training typically necessary 

to use such tools for project design 

and development. The flexibility of 

the programs allowed for multiple 

iterations of the models to determine 

the most efficient system design. This 

enabled the project team to meet its 

stringent deadlines and successfully 

transform a challenging site into a 

Class A development. 

Implementing an underground 

detention tank beneath a parking 

area preserved the environmentally 

sensitive apple orchard, steep 

slopes, tree buffers, and freshwater 

wetlands. The massive detention 

tank was hidden underground in an 

area already assigned to be disturbed, 

thereby reducing the overall 

site disturbance for the entire project. 

Keeping the apple orchard 

retained the beauty of the complex, 

while tree buffers along the property 

boundaries screened the 

develop ment from the adjacent 

properties and traffic. 

Contact: 

Contact Bentley, 

1-800-BENTLEY (1-800-236-8539), 

Outside the US +1 610-458-5000, 

www.bentley.com 

Global Office Listings 

www.bentley.com/contact 



PRODUCTS + SOLUTIONS 

Major Order from Turkey 

Globally 22.8 Billion Litres of Drinking Water are Filtered Every Day with EVERZIT ® N 

EVERS e.K. is one of the leading 

companies in the field of water 

technology and first-class filtering 

materials from anthracite to zeolite 

for filtration. The German factory 

from Hopsten (near Münster) has 

been demonstrating already for 

more than 40 years the advantages 

of their worldwide proven and selfdeveloped 

EVERZIT® N for singleand 

multi-layer filtration. It is therefore 

no surprise that, in the meantime, 

EVERZIT® N has been 

introduced on all continents. Every 

day around 22.8 billion litres of 

drinking water are filtered with filter 

materials of EVERS. 

Just recently, EVERS e.K. started 

to get involved in a large-scale project 

in Ankara. Therefore, company 

manager Stephan Evers is now frequently 

on site helping with the 

installation. The water supply works 

in Ankara will be extended by about 

50 percent. In addition, the old filtering 

plants are being re-equipped 

from sand-based filtration to Multilayer 

filtration. EVERS is supplying 

4,000 m³ EVERZIT® N to the water 

supply works. „I am supporting the 

operating authorities to complete 

the first filter filling“, says professional 

chemist Stephan Evers. After 

the extension, the water supply 

works will have a total daily capacity 

of 1,500,000 m³. Worldwide more 

than 6,000 installations are 

equipped with EVERZIT® N. 

Freshwater „lens“ supplies 

vacationers on Juist with 

drinking water 

Germany remains a core market for 

EVERS, of course. The water supply 

works on Juist profits from a special 

natural phenomenon, as a freshwater 

„lens“ directly beneath the island 

is sufficiently big to supply more 

than 100,000 vacationers and 1,700 

inhabitants with drinking water. 

Where the rainwater meets the saltwater 

underground, it is deposited 

on top of it on account of its lower 

specific weight and can be accessed 

separately. However, iron and manganese 

must still be filtered from 

the water, and here EVERZIT ® N, produced 

from the purest anthracite 

providing clean and natural drinking 

water, comes into play. Approximately 

150 cubic metres of water 

are processed every hour by three 

closed filters, producing a chemically 

untreated, natural product. 

Reasonable filtration efforts are 

also beneficial for the environment, 

demonstrated for example by the 

German river „Wupper“. Since 1994, 

the quality of the river water has 

clearly improved through the application 

of altogether 28 open multilayer 

filters with more than 2300 

cubic metres of EVERZIT ® N. The 

improvement has become very visible 

as the Wupper has reached 

again its old levels of fish stock. The 

filters are used at the end of a 

7-stage treatment in the wastewater 

treatment plant Buchenhofen. 

Here, up to 370,000 cubic 

metres of wastewater are cleaned 

daily. EVERZIT ® N ensures that phosphate 

and other contaminations are 

filtered out in an efficient and economical 

way. 

„Our company relies on two 

product ranges“, says Stephan Evers. 

Originally, EVERS was founded in 

1971 as an engineering company 

for swimming-pool technology. This 

technology is still a part of EVERS’ 

portfolio, with EVERS supplies 

chemicals and filters to public swimming 

pools in an area of around 150 

km distance from their company 

location. 

Small filter layouts for the 

final consumer 

Strictly speaking, there is even a 

third product range, because for 

some years now EVERS has been 

producing small filter units for the 

end consumer. Under the name 

„EVERS WATER WONDER® mini“, 

small filter systems for high-quality 

drinking water are sold to campers, 

boaters and even households. This 

space-saving processing system 

can, for example, easily be installed 

on boats, ensuring a water supply 

that is germ-free and natural. 

This provides for a considerable 

improvement of taste and is healthier 

than unfiltered water. 

Contact: 

EVERS e.K. 

WATERTECHNOLOGY, 

Stephan Evers, 

Rheiner Straße 14a, 

D-48496 Hopsten, 

Phone +49 (0) 5458-9307-0, 

E-Mail: info@evers.de, 

www.evers.de 

EVERZIT ® N. 




The Perfect Solution to Improve Reliability 

and Greatly Reduce Maintenance Costs 

(Nampa WWTP, Idaho, USA) 

ABEL model EM 100. 

The Task 

The City of Nampa is about 20 minutes 

west of Boise, Idaho, on interstate 

84. With a population of over 

80,000, it is the largest and fastest 

growing city in Canyon County. 

Together with Boise, the area comprises 

the largest metropolitan area 

in Idaho with some 540,000 residents. 

The J.R. Simplot potato processing 

works is located nearby. 

Nampa’s waste water treatment 

plant serves Nampa and surrounding 

areas. 

The plant had been using lobe 

style positive displacement pumps 

to transfer thickened sludge from 

the primary clarifier underflow to 

further waste stream processing. 

These pumps had been a source 

of excessive maintenance. The lobes 

rotate within a close tolerance with 

each other, promoting wear and 

thus requiring maintenance on a 

monthly basis. 

The Primary Clarifier project 

engineered by MWH in Boise 

included a new primary clarifier, retrofit 

of an existing clarifier, and a 

remodel of the primary sludge 

pumping station. 

Along with this upgrade, the 

plant’s lobe pumps were considered 

for replacement. 

Primary clarifier at the Nampa WWTP. 

MWH had previous experience 

with ABEL Pumps in the design and 

utilization of ABEL model EM electromechanical 

pumps at the Weber 

Waste Water Treatment Plant in 

Ogden, Utah, and the Colorado 

Springs Waste Water Treatment 

Plant in Colorado Springs, Colorado. 

Based on this history, MWH 

selected three ABEL EM 100 electromechanical 

diaphragm pumps to 

replace the lobe pumps at Nampa. 

Each ABEL model EM 100 pump is 

capable of pumping some 275 GPM 

(63 m³/h) at pressures up to 90 PSI 

(0.6 MPa). The EM pumps can also 

run dry and have no close-tolerance 

moving metal parts that are expensive 

to replace. Instead, the wear on 

the EM is limited to replacement 

parts, consisting only of balls and 

seats in the suction and discharge 

valve housings, and diaphragms. No 

seals exist on the EM, so process fluids 

cannot escape the confinement 

of the pump and piping system. 

A grinder pump precedes each 

of these EM 100s. As a result, maintenance 

downtime and costs have 

greatly improved with their ABEL 

EM 100s. 

The ABEL EM series of pumps is 

available in 7 sizes with capacities 

ranging form 15 GPM (3 m³/h) to 

275 GPM (63 m³/h). The pump is 

applied for pressures up to 90 PSI. 

Wet end materials include cast iron, 

stainless steel, and plastics. Elastomeric 

materials include Buna N, 

Viton, EPDM, and Teflon. Stroke 

rates vary with each model, but 

range from 70 to 150 maximum 

strokes per minute. 

The pump can be run with a variable 

speed drive to achieve a 10:1 

turndown ratio, making this pump 

an excellent choice for applications 

requiring variable control. 

Benefits of the Electromechanical 

Diaphragm Pump 

"" 

Low energy costs during use as a 

result of high efficiencies 

"" 

Low maintenance and inventory 

costs as a result of the small 

number of wear parts 




"" 

Greater application flexibility: 

The pump can be operated anywhere 

along its performance 

curve without adversely affecting 

efficiency 

"" 

Accommodation of a wide range 

of particle sizes (3-25 mm) 

"" 

Wide range of materials of construction 

"" 

Gentle pumping action ideal for 

shear sensitive media 

"" 

Self-priming, sealless design 

"" 

Operable without the presence 

of media 

"" 

Linear performance curve over 

the entire operating range 

"" 

Designed for high and extended 

use with less part maintenance 

and lower energy consumption 

Contact: 

ABEL GmbH & Co. KG, 

Abel-Twiete 1, 

D-21514 Buechen, 

Phone +49 (0) 4155818-0, 

E-Mail: mail@abel.de, 

www.abel.de 

Overflow of the weir at Nampa’s primary clarifier, 

which is gravity fed to further water purification processes. 

Spectroquant ® Move 100 Mobile Colorimeter for 

Faster, More Reliable Water Analysis 

Enables immediate results on-site or during in-process controls / Portability minimizes 

risk of sample deterioration or contamination that can occur during transport of 

samples back to the lab / Pre-programmed and user-defined methods eliminate 

need for additional instruments 

Merck Millipore, the Life Science 

division of Merck, recently 

announced the launch of the Spectroquant® 

Move 100, a portable colorimeter 

for the analysis of drinking 

and waste water. The instrument 

covers every important parameter 

of drinking and waste water 

analysis. It includes more than 

100 pre-programmed and 35 userdefined 

methods enabling a wide 

selection of measuring ranges without 

the need for additional instruments. 

Traditional systems for water 

analysis are not portable, meaning 

that samples must be collected and 

transported to the lab for testing, 

which increases the risk of sample 

contamination and deterioration. 

The Spectroquant ® Move 100 is 

compact and mobile, which allows 

water to be tested immediately, 

speeding time to result. This enables 

laboratories to avoid sample deterioration 

and identify contamination 

events sooner. 

“Developed for use with our 

high-quality Spectroquant® test 

kits, the Spectroquant® Move 100 

guarantees rapid and reliable 

results,” said Dr. Bärbel Grau, Director 

Water and Food Analytics. “Quality 

Certificate documentation and 

the Spectroquant® Verification 

Standard help achieve Analytical 

Quality Assurance (AQA) and deliver 

complete confidence.” 

The data collected by the Spectroquant 

® Move 100 can be easily 

transferred, printed or saved using 

the Spectroquant ® Data Transfer 

module. Additionally, the instrument 

is dust-tight and water-proof 

according to IP 68 classification, 

which allows use even in difficult 

conditions. 


www.merckmillipore.com 

Spectroquant ® 

Move 100. 

Spectroquant ® 

Data Transfer. 




Top Class Stormwater Treatment 

Highly Efficient two-stage Principle and DIBt Certified: SediSubstrator XL 

No chance for pollutants: SediSubstrator XL separates sediment, dissolved pollutants and light liquids from 

stormwater runoff from trafficked areas in two stages. The combination of adsorption using substrate and 

upstream sedimentation applying the FRÄNKISCHE SediPipe principle effectively treats also heavily polluted 

stormwater runoff – DIBt certified and also for very large connected areas. 

Organic and inorganic particles 

(e.g. fine particles, sand, rocks, 

foliage), PAHs (hydrocarbon compounds), 

but also heavy metals and 

light liquids (petroleum-derived 

hydrocarbons) often severely pollute 

rainwater so that it cannot be 

discharged into the groundwater or 

surface waterbodies. SediSubstrator 

XL is the perfect solution when 

polluted stormwater needs to be 

treated before infiltration: In particular 

highly frequented trafficked 

areas, such as intersections and 

parking lots, but also commercial 

and industrial premises with lorry 

traffic are ideal fields of application 

for FRÄNKISCHE stormwater treatment 

systems. 

SediSubstrator XL 600/12 

and 600/12+12 have been 

DIBt certified 

SediSubstrator XL 600/12 and 

600/12+12 have been developed 

and tested according to the strict 

DIBt test criteria and have been 

awarded the certificate number 

Z-84.2-11. SediSubstrator XL’s DIBt 

certificate guarantees the tested 

treatment performance and facilitates 

official approval procedures 

regarding stormwater infiltration 

systems and, depending on the 

country, also discharge in surface 

waterbodies. 

XL for areas of up to 

3,000 m² 

The XL system now features a substrate 

cartridge with upstream sedimentation: 

The complete system 

consisting of a DN 1000 start shaft, 

DN 600 sedimentation path and 

DN 1000 target shaft with substrate 

cartridge can be installed in an easy 

and space-saving way under trafficked 

areas just like a stormwater 

sewer. Depending on the installation 

size, areas up to 3,000 m² are 

connected and treated by the system. 

SediSubstrator XL can be perfectly 

adapted to match the specific 

project requirements: The installation 

size is only selected according 

to the area to be treated. The system 

is delivered to the construction site 

pre-fabricated and with shafts ready 

to be connected and therefore constitutes 

an extremely cost-saving 

installation. 

Two-stage principle: 

efficiency and high capacity 

SediSubstrator XL efficiently separates 

harmful particles, dissolved 

heavy metals and light liquids in two 

stages. The start shaft retains coarse 

particles like rocks and sand. The 

first treatment stage in the sedimentation 

pipe already accomplishes 98 

percent of the required retention of 

fine and ultra-fine particles. A patented 

flow separator in the lower 

pipe cross-section prevents settled 

particles on the ground from being 

remobilised also during heavy rainfall 

events. This protects the 

upstream substrate cartridge in the 

target shaft – the second treatment 

stage – from mud accumulation. In 

addition, it prevents restricted substrate 

permeability and therefore 

long-term restricted function. This 

secures operating reliability and the 

cartridge remains ready for the reliable 

adsorption of dissolved pollutants. 

At the same time, this minimises 

maintenance. 

Thanks to its high capacity, the 

substrate separates 100 percent of 

the required pollutants and oil. 

Therefore, the system at least 

replaces the treatment performance 

of a root zone upstream of infiltration 

trenches. It convinces with 

proven performance, monitored 

production and controlled operation. 




Access-free maintenance – 

uncomplicated, quick and 

cost-efficient 

SediSubstrator XL can be easily 

maintained without requiring ac 

cess to the shaft. This saves effort, 

time and money. Common and 

comprehensively available sewer 

cleaning technology (cleaning/vacuum 

trucks) initially cleans the sedimentation 

pipes just like usual 

stormwater sewers without requiring 

any heavy lifting tools or special 

technologies. Maintenance of the 

substrate step is even easier. Just 

pull the cartridge out from the shaft 

and replace the substrate on site - 

there is no need to replace the cartridge 

itself. 

SediSubstrator XL’s benefits 

Large connected areas, operating 

reliability in long intervals, easy 

cleaning and inexpensive maintenance 

are among SediSubstrator 

XL’s benefits. By complying with the 

strict requirements of the German 

Institute for Structural Engineering 

(DIBt) regarding stormwater treatment 

systems, SediSubstrator XL 

600/12 and 600/12+12 features 

building authority approval and 

facilitates official approval procedures 

regarding stormwater infiltration 

systems. 

For detailed information and product 

descriptions, please refer to 

www.fraenkische-drain.de or send 

an E-Mail to: 

info.drain@fraenkische.de 

Channel Systems draining London’s Museum Mile 

Exhibition Road is a major tourist attraction. The home to a number of London’s foremost museums underwent 

extensive upgrading in the run-up to the Olympics. The works included the installation of 1600 metres of 

BIRCOsir channels, tailored to the specific needs of the location. CEO of BIRCO Frank Wagner comments: “We 

wanted to underscore the road’s charm. The coverings of our gutters harmonise perfectly with the rest of the 

streetscape. We are delighted to be contributing to this project with our products.” 

As many as 11 million visitors a 

year flock to Exhibition Road, 

located close to Hyde Park and the 

Royal Albert Hall. Until its remodelling, 

the road was very much dominated 

by vehicle traffic. So the city 

planners devised a new concept: 

the creation of a so-called Shared 

Space to provide a more prominent 

setting for the great museums and 

other magnificent buildings, including 

the Natural History Museum 

and Imperial College. The road, 

which is just less than one kilometre 

long, has been turned into a single 

26,000 square metre area shared by 

pedestrians, cyclists and motorists. 

All the kerbs, pavements, road signs 

and lane markings have been 

removed, and replaced by a unified 

space. The elegant black-and-white 

chequerboard pattern of the new 

paving maps out the walking route 

from one museum to the next. The 

planners also specified premium 

quality for the drainage system. And 

Baden-Baden-based guttering specialist 

BIRCO was able to offer a tailored 

solution: The BIRCOsir system, 

in nominal width 150, is particularly 

well suited to the busy museum district, 

as it was developed with load 

class E 600 for busy, high-capacity 

areas. The simple, timeless design of 

the black dip-primed coverings also 

perfectly matches the stylish setting. 

The project was handled by 

the company’s partner Marshalls. 

The remodelled road was officially 

opened in February 2012. A total of 

almost 25 million pounds was 

invested in the project. 

Contact: 

BIRCO GmbH, 

Michael Neukirchen, 

Herrenpfädel 142, 

D-76532 Baden-Baden, 

Phone +49 (0) 7221 500 324, 

E-Mail: info@birco.de, 

www.birco.de 

BIRCO’s pattern-rolled cast coverings are enhancing 

London’s famous Museum Mile on Exhibition Road. 

The BIRCOsir channel system installed in London is 

particularly well suited to high and sustained loads, 

such as delivery truck traffic. 




The Stormwater Solution 

Stormwater is an important subject in public debate. The reasons for this are obvious. Water, as a resource, is 

precious, and using it sparingly is a must. It is necessary to properly discharge stormwater so as to prevent 

flooding and the associated damage to property, and discharging it should cost as little as possible. 

RAUSIKKO Box C subsurface stormwater storage 

system ‒ stacked for efficient transportation. 

Installed 

RAUSIKKO 

Box C elements 

provide 

a storage 

coefficient 

of 

95 %. 

One solution that accommodates 

all three aspects and is 

already possible today is stormwater 

management using central 

and local facilities. This has a positive 

effect on the natural water balance, 

reliably disposes of the water and, 

moreover, is particularly economical 

in terms of charges for the stormwater 

drain. The systems used have 

to be particularly flexible and suited 

to the particular installation situation, 

and they must also provide a 

long-lasting solution. As a specialist 

in sustainable water management, 

REHAU developed the tried and 

tested RAUSIKKO system. With the 

RAUSIKKO Solution REHAU offers a 

full range of systems for the stormwater 

management. From the 

stormwater collection to treatment, 

infiltration and detention REHAU 

provides the optimal solution made 

up of several modules that are used 

according to particular requirements 

and can be adapted to local 

particularities. 

Stormwater pre-treatment – 

RAUSIKKO HydroClean filter 

chamber system 

Stormwater that flows from trafficked 

areas and bare copper or zinc 

roofs is particularly polluted and 

requires treatment before it is 

allowed to seep away or be discharged 

into a body of water. Here 

care has to be taken not to contaminate 

the ground and/or the groundwater. 

The RAUSIKKO HydroClean 

filter chamber system consists of a 

multi-stage purification system 

integrated into DN 1000 polypropylen 

chamber, available with special 

filter media to suit particular circumstances. 

Type HT provides a filter chamber 

system with general German 

building approval (DIBt Z-84.2-6) for 

purifying stormwater drained from 

trafficked areas. Heavy metals as 

well as hydrocarbons are removed 

therein. Type M is available for 

pu rifying stormwater drained from 

metal roofs. Its purification efficiency 

has been confirmed by 

means of long-term tests conducted 

at the University of Munich 

and by certification from the Bavarian 

Environmental Office (LfU BY- 

41f-2011/3.0.0). 

Stormwater storage, detention 

and infiltration 

RAUSIKKO Box C is the new generation 

of tried and tested RAUSIKKO 

Box systems – the next step in ecologically 

sound and economical 

stormwater management. The idea 

is simple: A storage system that 

shows its true worth as soon as it 

arrives on the site. These are specially 

developed storage elements 

that fit one within the other for storage 

and transport purposes and are 

then stacked when installed. Storage 

and transport volume is only 

approx. 30 % of installed volume. 

This compact design and reduced 

volume allows RAUSIKKO Box C to 

make an active contribution to 

improving the CO2 balance and also 

reduces transport costs. On the 

building site itself, storage space is 

often at a premium, but sufficient 

quantities of RAUSIKKO Box C can 

be kept on site at all times due to 

the reduced storage space requirement. 

These ultra-light storage elements 

are very easy to transport, 

handle and install so that big savings 

can be made. Once installed, 

RAUSIKKO Box C elements assume 

their actual size to provide a storage 

coefficient of 95 %. In this way, it is 

possible to store a lot of water in the 




RAUSIKKO Box SC provides an integrated distribution, 

inspection and cleaning channel. 

RAUSIKKO Box C and SC can be easily combined. 

smallest of spaces. Integrated snap 

cams plus possible masonry support 

make for fast, reliable assembly. 

Installed, the storage elements 

achieve the stability that RAUSIKKO 

Box systems are known for and can 

be subjected to SLW60 heavy traffic 

loads without problems. To preserve 

the unique functionality of 

the entire RAUSIKKO system, Box C 

is compatible with popular, tried 

and tested RAUSIKKO Box SC and 

the two are easily combined. To 

make sure the trench / storage system 

functions fully, long-term and 

without problems, RAUSIKKO Box 

SC with integrated distribution, 

inspection and cleaning channel 

with staggered slits for even water 

distribution can be used throughout 

the entire system. These retain 

any pollutants which can then be 

removed from the channel and thus 

from the system by high-pressure 

rinsing at up to 120 bar. Combining 

tried and tested functional 

RAUSIKKO SC boxes and new 

RAUSIKKO C boxes in this way creates 

a system that has no equivalent 

in terms of functionality and 

strength. On top of this, it helps to 

reduce CO 2 emissions. 

Please see the function, performance 

and advantages of RAUSIKKO 

Box SC with the integrated distribution, 

inspection and cleaning channel 

in our newest video: 

http://www.youtube.com/ 

watch?v=mp7d606R5hk 


http://www.rehau.com 

RAUSIKKO 

HydroClean 

stormwater 

treatment consists 

of a multistage 

purification 

system. 

part of it! Be part of it! Be part of it! Be part of 

NETZWERK WISSEN 

The platform for introducing universities and 

colleges to an expert audience: Represent courses of 

studies and places of studies all around water supply 

and wastewater treatment in the leading technical 

and scientific journal gwf-Wasser|Abwasser 

contact the editorial office 


EAZ Netzwerk 1 engl.indd 1 17.10.2013 12:56:21 




Innovation and Efficiency – Connected 

Flexseal Multibush: New Innovation in Pipe Connection Technology 

The Flexseal Multibush is a new innovation in pipe connection technology, providing the contractor with a 

multi-use product to connect pipes of different outside diameters. 

Flexseal Multibush. 

Using a Flexseal Multibush and a 

Standart Coupling avoids the 

need to stock different couplings for 

different connections – no matter 

which pipe materials are being 

repaired, the Flexseal Multibush will 

guarantee a secure connection. The 

PDaS transfer means water companies 

have adopted thousands of kilometres 

of un-mapped sewer network, 

so in most cases there is no 

record of what pipe size or material 

is in the ground. WIS 4-41-01 guidelines 

specify the use of a shearbanded 

coupling, which presents 

difficulties when connecting pipes 

of different ODs. However, use of 

the 100mm Multibush and an SC137 

allows a cost efficient, time efficient 

and stock efficient pipe connection. 

Here are some examples of more 

ways to connect different pipe 

materials using the Flexseal Multibush: 

Product table layout 

"" 

110mm OD PVC 

– 130mm OD Salt glazed clay 

"" 

114mm OD Cast Iron 

– 125mm OD Asbestos Cement 

"" 

118mm OD Ductile Iron 

– 118mm OD Twinwall 

"" 

122mm OD Supersleve 

– 110mm OD PVC 

The new Flexseal Multibush allows 

the contractor the versatility to 

make a cost effective repair in 

accordance with Water Company 

Standards (WIS), with no waste. 

Connect a DN100 Clay to a DN100 

Supersleve and you’re left with a 

reusable 6mm bush. 

Alternatives, such as a coupling 

with an integrated bush, can be 

more expensive and lead to waste 

material, especially if the same size 

pipe and material is being repaired. 

Trimmed sections cannot be reused, 

the job is overspecified and inefficient. 

The Flexseal Multibush. Innovation 

and efficiency - connected. 


www.flexseal.co.uk 

Multibush 100 mm-1. 

Multibush 100 mm-2. 



The leading specialist journal for the water and wastewater profession 

To know what is really important 

gwf Wasser| Abwasser is the leading 

technical and scientific journal for qualitative 

and quantitative water management, 

hydrogeological principles of water 

management, catchment, storage or distribution 

of water as well as wastewater collection or 

drainage. The journal reports on the process 

engineering for water treatment, wastewater 

purification and sludge treatment, on 

developments in analysis, metrology and control 

technology, on hygiene and microbiology and 

operational experiences, common concerns of 

water protection from the perspective of water 

use and wastewater disposal as well as on 

judical subjects and economic concerns. 

The main part, comprising scientific papers 

and contributions, is lectured by experts in an 

anonymous peer-review procedure. Practicians 

find expert informations in industrial news and 

case studies, in groundbreaking statements and 

interviews with leadership personality. 


gwf Wasser|Abwasser erscheint im DIV Deutscher Industrieverlag GmbH, Arnulfstr. 124, 80636 München 

Order now!

INFORMATION Edition Notice 

gwf – Wasser | Abwasser 

The leading German specialist journal for 

the water and wastewater sector 

Official Medium of: 

Journal of DVGW Deutsche Vereinigung des Gas- und 

Wasserfaches e. V., Technisch-wissenschaftlicher Verein, 

of Bundesverband der Energie- und Wasserwirtschaft e. V. (BDEW), 

of Bundesvereinigung der Firmen im Gas- und Wasserfach e. V. 

(figawa), 

of DWA Deutsche Vereinigung für Wasserwirtschaft, Abwasser und 

Abfall e. V. 

of Österreichische Vereinigung für das Gas- und Wasserfach (ÖVGW), 

of Fachverband der Gas- und Wärmeversorgungsunternehmen, 

Österreich, 

of Arbeitsgemeinschaft Wasserwerke Bodensee-Rhein (AWBR), 

of Arbeitsgemeinschaft Rhein-Wasserwerke e. V. (ARW), 

of Arbeitsgemeinschaft der Wasserwerke an der Ruhr (AWWR), 

of Arbeitsgemeinschaft Trinkwassertalsperren e. V. (ATT) 

Publishers: 

Dr.-Ing. Rolf Albus, Gaswärme Institut e.V., Essen 

Prof. Dr.-Ing. Harro Bode, Ruhrverband, Essen 

Dipl.-Ing. Heiko Fastje, EWE Netz GmbH, Oldenburg 

Prof. Dr. Fritz Frimmel, Engler-Bunte-Institut, Universität (TH) Karlsruhe 

Dipl.-Wirtschafts-Ing. Gotthard Graß, figawa, Köln 

Prof. Dr. Ing. Frieder Haakh, Zweckverband Landeswasserversorgung, 

Stuttgart (federführend Wasser|Abwasser) 

Prof. Dr. Dipl.-Ing. Klaus Homann (federführend Gas|Erdgas), 

Thyssengas GmbH, Dortmund 

Prof. Dr. Matthias Krause, Stadtwerke Halle, Halle 

Dipl.-Ing. Klaus Küsel, Heinrich Scheven Anlagen- und Leitungsbau 

GmbH, Erkrath 

Prof. Dr. Joachim Müller-Kirchenbauer, TU Clausthal, 

Clausthal-Zellerfeld 

Prof. Dr.-Ing. Rainer Reimert, EBI, Karlsruhe 

Dr. Karl Roth, Stadtwerke Karlsruhe GmbH, Karlsruhe 

Dipl.-Ing. Otto Schaaf, Stadtentwässerungsbetriebe Köln, AöR 

BauAss. Prof. Dr.-Ing. Lothar Scheuer, Aggerverband, Gummersbach 

Harald Schmid, WÄGA Wärme-Gastechnik GmbH, Kassel 

Dr.-Ing. Walter Thielen, DVGW e. V., Bonn 

Dr. Anke Tuschek, BDEW e. V., Berlin 

Heinz Watka, Open Grid Europa GmbH, Essen 

Martin Weyand, BDEW e. V., Berlin 

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beratungs GmbH, Bergisch Gladbach 

Prof. Dr.-Ing. Mathias Ernst, TU Hamburg-Harburg, Hamburg 

Prof. Dr.-Ing. Frank Wolfgang Günthert, Universität der Bundeswehr 

München, Institut für Siedlungswasserwirtschaft und 

Abfall technik, Neubiberg 

Dr. rer. nat. Klaus Hagen, Krüger WABAG GmbH, Bayreuth 

Prof. Dr.-Ing. Werner Hegemann, Andechs 

Dipl.-Volksw. Andreas Hein, IWW GmbH, Mülheim/Ruhr 

Dr. Bernd Heinzmann, Berliner Wasserbetriebe, Berlin 

Prof. Dr.-Ing. Norbert Jardin, Ruhrverband, Essen 

Prof. Dr.-Ing. Martin Jekel, TU Berlin, Berlin 

Dr. Josef Klinger, DVGW-Technologiezentrum Wasser (TZW), Karlsruhe 

Dipl.-Ing. Reinhold Krumnack, DVGW, Bonn 

Prof. Dr.-Ing. Wolfgang Merkel, Wiesbaden 

Dipl.-Ing. Karl Morschhäuser, figawa, Köln 

Dr. Matthias Schmitt, RheinEnergie AG, Köln 

Dipl.-Geol. Ulrich Peterwitz, AWWR e.V. (Arbeitsgemeinschaft der 

Wasserwerke an der Ruhr), Schwerte 

Prof. Dr.-Ing. Heiko Sieker, Ingenieurgesellschaft Prof. Dr. Sieker mbH, 

Dahlwitz-Hoppegarten 

Prof. Dr.-Ing. Heidrun Steinmetz, Institut für Siedlungswasserbau, 

Wassergüte- und Abfallwirtschaft, Universität Stuttgart, Stuttgart 

Prof. Dr. habil. Christoph Treskatis, Bieske und Partner 

Beratende Ingenieure GmbH, Lohmar 

Prof. Dr.-Ing. Wolfgang Uhl, Techn. Universität Dresden, Dresden 

Prof. Dipl.-Ing. Thomas Wegener, Institut für Rohrleitungsbau an der 

Fachhochschule Oldenburg e.V., Oldenburg 

RA Beate Zimmermann, Kanzlei Büttner Held, Berlin 

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Issue International 2013 


Buyer’s Guide 

www.gwf-wasser.de/einkaufsberater 

Contact person for the 

incorporation of your company 

Inge Spoerel 

Phone +49 89 203 53 66-22 

Fax +49 89 203 53 66-99 

e-mail spoerel@di-verlag.de 

The leading technical and 

scientific journal for the water and 

wastewater profession

2013 

Buyers’s Guide 

Fittings 

Vent- and air flue pipes 

Biogas solution

2013 

Drilling engineering, water procurement, geothermal energy 


Well service 

Information- and communication technology 

Telecontrol

2013 


Roots blower 

Compressors 

Rotary piston compressors 

Rotary screw compressors 

Corrosion protection 

Active corrosion protection 

Passive Corrosion protection 

Rainwater surface treatment, -infiltration, -retention

2013 

Plastic welding technology 

Piping 


Manhole covering 

Smart Metering

2013 


Turbo blower 

Water- and wastewater treatment 

Biological wastewater treatment 

Chemical water- and wastewater treatment plants 

Water treatment

2013 

Pipe penetration 

Water distribution and effluent disposal 

Special structures 


Public tendering 

Federation

Pipeline construction companies 

PIPELINES & PLANTS MECHANICAL ENGINEERING CIVIL & STRUCTURAL ENGINEERING RAW & CONSTRUCTION MATERIAL 

The certifications of the STREICHER Group are: 

ISO 9001 

ISO 14001 

SCC p 

BS OHSAS 18001 

GW 11 

GW 301 

• G1: st, ge, pe 

• W1: st, ge, gfk, pe, az, ku 

GW 302 

• GN2: B 

FW 601 

• FW 1: st, ku 

G 468-1 

G 493-1 

G 493-2 

W 120 

WHG 

AD 2000 HP 0 

ISO 3834-2 

DIN 18800-7 Klasse E 

DIN EN 1090 

DIN EN ISO 17660-1 

Ö Norm M 7812-1 

TRG 765 

MAX STREICHER GmbH & Co. KG aA, Pipeline and Plant Construction · Germany 

Schwaigerbreite 17 · 94469 Deggendorf · T +49 (0) 991 330 - 231 · E rlb@streicher.de · www streicher.de 

Zertifizierungsanzeige_gwf_Wasser-Abwasser_20131014_engl.indd 1 15.10.2013 08:44:59 

Engineering services (for water and wastewater technology) 

engineers for 

water supply 

· wells and water works 

· water supply, reservoir piping 

· hydrogeology, groundwater protection 

· consulting 

· expert’s report 

· planning 

· construction 

management 

consulting engineers for: 

water catchmenz 

treatment 

water distribution 

Phone 05 11/28 46 90 

Fax 05 11/81 37 86 

Darmstadt l Freiburg l Homberg l Mainz 

Offenburg l Waldesch b. Koblenz 

30159 Hannover 

Kurt-Schumacher -Str . 32 

• constulting 

• expert’s report 

• planning 

• construction management 

info@schef fel-planung.de 

www .schef fel-planung.de 

• consulting 

• planning and design 

• construction supervision 

• support 

• project management 

Ing. Büro CJD Ihr Partner für Wasserwirtschaft und 

Denecken Heide 9 Prozesstechnik 

30900 Wedemark Beratung / Planung / Bauüberwachung / 

www.ibcjd.de Projektleitung 

+49 5130 6078 0 Prozessleitsysteme 

water waste energy infrastructure 

UNGER ingenieure • Julius-Reiber-Str. 19 • 64293 Darmstadt 

www.unger-ingenieure.de

INDEX OF ADVERTISERS 

Company 

Page 

Aquadosil Wasseraufbereitung GmbH, Essen, Germany 13 

Blücher GmbH, Erkrath, Germany 11 

Ing. Büro Fischer-Uhrig, Berlin, Germany 13 

Huber SE, Berching, Germany 45 

Infra Tech, Tiefbaumesse, Ahoy Rotterdam, Niederlande 65 

KRYSCHI Wasserhygiene, Kaarst, Germany 38 

Buyers’s Guide 117–124

© Peter Freitag, pixelio.de

gwf international Stormwater Management (Vorschau)

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