ICOLL MANAGEMENT - BMT Group

ICOLL MANAGEMENT 

Strategies for a sustainable future 

Philip Haines 

BE (Hons) MEngSc PhD 

September 2008

ICOLL Management: Strategies for a sustainable future 

Philip Haines 

Published by: 

BMT WBM Pty Limited 

126 Belford Street 

Broadmeadow NSW 2292 

© Philip Haines, 2008 

Written by Philip Haines 

Layout and design by Philip Haines 

Cover photo by Philip Haines 

Diagrams by Philip Haines unless otherwise noted 

Photos courtesy of Department of Environment and Climate Change, unless otherwise 

noted 

Citation: Haines, P. E. (2008) ‘ICOLL Management: Strategies for a sustainable future’ 

BMT WBM Pty Ltd, Broadmeadow NSW 

Haines, P. E. page 2 

ICOLL Management: strategies for a sustainable future

Foreword 

Intermittently Closed and Open Lakes and Lagoons (ICOLLs) are coastal waterbodies that have an 

intermittent connection to the ocean. ICOLLs are prominent feature of the New South Wales 

coast. Although ICOLLs occur elsewhere, their proliferation in NSW creates a range of complex 

planning and management issues that confront scientists, engineers, public servants, developers, 

environmentalists, community groups and of course politicians. 

Even lawyers have had an interest in the distinct character of ICOLLs. Chief Justice Street in 

1921 in a famous case, Attorney-General v Swan, commented on the episodic opening and 

closing of lake entrances. 

Knowledge of the biophysical behaviour of these ICOLLs has developed considerably over the 

past 10 years. So has our understanding of human impacts. This knowledge points to one 

conclusion: that ICOLLs are very sensitive to human disturbances. 

From head of catchment to the sea, there is a connectivity of biophysical processes, which if 

disturbed can transform a healthy ICOLL into a degraded system. Invaluable work by the Healthy 

Rivers Commission demonstrated the range of conditions experienced by ICOLLs and other 

coastal lakes in NSW. 

Some are pristine and require all possible means to protect their natural state. At the other 

extreme are ICOLLs which are the recipients of polluted runoff and need some form of 

remediation. By now we are sufficiently alerted to these different conditions and to system 

dynamics to be able to inform users and managers of what might happen to ICOLLs if not 

managed with care. We also know enough on what should be done to protect their integrity. 

This booklet takes a significant step in providing stakeholders with clear directions for 

maintaining the health of ICOLLs. The author combines his considerable practical experience in 

environmental consulting with his scientific understanding of these systems. He has been able to 

collate and analyse the pressures, conditions and various responses that are affecting ICOLLs 

along the entire NSW coast. His work highlights the need for renewed State and local 

government action in developing both planning protocols and management practices to ensure 

the long-term sustainability of our precious ICOLLs. 

To assist governments, the author has formulated a set of strategies which if adopted and 

implemented will provide the much needed security that ICOLLs demand in order to behave in 

the future as sustainable and healthy systems. We cannot afford to allow the status quo on 

managing ICOLLs to continue. New initiatives are required. This booklet offers clear and 

practical solutions to on-going and future problems. These new strategies should be thoroughly 

considered by all with responsibilities for managing these wonderful natural assets, our ICOLLs. 

Emeritus Prof. Bruce Thom FIAG FTSE 

Member of the Wentworth Group of Concerned Scientists 



Prologue 

This booklet was initiated as an outcome of a PhD by the author undertaken through Griffith 

University and as an associate student of the former CRC for Coastal Zone, Estuary and 

Waterway Management (Coastal CRC), with support from the author’s employer, BMT WBM Pty 

Ltd. The booklet aims to convey the key messages from the PhD thesis to the general 

community. 

The content of this booklet reflects the opinion of the author, and does not represent any 

assumed responsibilities by state or local government. This booklet has been prepared as a 

guide for sustainable management of ICOLLs, and is primarily aimed at natural resource 

managers who have authority over such waterways. Not all strategies discussed in this booklet 

would be applicable to every ICOLL. It is recommended that managers assess the applicability of 

all strategies, and adopt whichever is considered most appropriate, and indeed most feasible 

given particular circumstance for each system. 

Whilst focussing mainly on ICOLLs, a number of the processes and strategies discussed herein are 

also applicable to other types of estuarine environments. 

The NSW State Government is currently embarking on a series of initiatives aimed at reforming 

existing coastal zone management. It is hoped that this booklet can assist in this management 

reform process by providing some solutions to existing (and future) problems associated with 

ICOLLs and other similar environment. 

2008 Update 

Since the initial preparation of this booklet in 2006, there have been a number changes that 

affect the long term management of ICOLLs. For example, the names, roles and guiding 

policies of various statutory authorities have changed. Also, predictions of climate change have 

been refined, and the knowledge of the potential impacts of climate change on ICOLLs has 

advanced. 

As a consequence of these changes, some of the outcomes of the original booklet were 

considered out of date and impractical. This 2008 update of the booklet aims to make the 

outcomes more relevant to the current environmental management and planning landscape. 

The update also addresses some initial feedback on the booklet from readers and aims to make 

the document as practical and implementable as possible. 

Philip Haines BE(Hons) MEngSc PhD 



Executive Summary 

“Intermittently Closed and Open Lakes and 

Lagoons” (ICOLLs) are relatively abundant on 

the south-east coast of Australia and NSW in 

particular. Elsewhere in Australia and across 

the world, ICOLLs are less common. 

Comparable examples can be found in southwest 

Western Australia, South Africa, New 

Zealand, Mexico and the Atlantic coast of 

Brazil and Uruguay. 

ICOLLs have evolved by marine sands 

forming a bar, or barrier, across natural 

coastal inlets and embayments when sea 

level stabilised some 6000 years ago. For 

most of the ICOLLs in NSW, the barrier has 

completely enclosed these embayments 

preventing regular tidal interaction with the 

ocean. ICOLLs are a unique type of estuary 

as they have an intermittent connection to 

the ocean (that is, sometimes open and 

sometimes closed). 

In NSW, most ICOLLs are located on the 

south coast. This section of the coast 

experiences a larger wave environment and 

lower rainfall than other parts of the state’s 

coastline. Also, this area contains smaller 

catchments due to the close proximity of the 

Great Dividing Range to the coast in this 

area. 

ICOLLs are recognised as the most sensitive 

type of estuary to human intervention due to 

their lack of tidal flushing and interaction with 

the ocean. Management of ICOLLs is 

therefore one of the most difficult tasks 

facing coastal managers today. 

There are many issues potentially 

compromising the present and future values 

of ICOLLs. Increasing coastal population is 

no doubt the biggest threat to existing 

coastal resources. More than 430,000 people 

are expected to move to the nonmetropolitan 

NSW coast between 2004 and 

2031. In addition to increasing resident 

population, the coastal zone continues to be 

a major destination for tourists, who impose 

a range of pressures on natural coastal 

resources, including recreational demands 

and increased loads to on-site sewage 

systems. 

Climate change is expected to have a range 

of varying and complex impacts on ICOLL 

processes in the future. In particular, 

increasing sea level rise will result in higher 

typical water levels within the waterways, 

which will exacerbate conflicts with foreshore 

landuse and development, or alternatively 

intensify the demand for artificial entrance 

intervention, which is currently undertaken in 

about half of the ICOLLs in NSW. 

Development around ICOLLs and within their 

catchments increases pollutant loads and 

modifies natural processes, resulting in 

degradation of the waterway. There is only 

one ICOLL in NSW that remains in a pristine 

condition (Nadgee Lake), with the lake and 

its catchment completely enclosed within a 

protected reserve. Existing management of 

ICOLLs is guided by various policies and 

environmental planning instruments. 

However, existing management is considered 

to place insufficient importance on the unique 

and significant differences between ICOLLs 

and other estuary types. Quoting Healthy 

Rivers Commission (2002), “healthier coastal 

lakes [including ICOLLs] will be achievable 

only if there is a fundamental change in the 

way [management] decisions are made”. 

Good science is at the foundation of good 

environmental management. Environmental 

systems need to be well understood before 

they can be managed in a sustainable way. 

Knowledge on ICOLL environments has 

increased rapidly over the past 10 years. We 

now have a good appreciation for the 

physical, chemical and biological processes 

that determine their condition and are the 

basis for their inherent values. 

ICOLL processes are underpinned by 

conditions in the lake’s catchment and the 

condition of its entrance. These attributes 

control the physical passage of water and 



executive summary 

sediment through the system. In simple 

terms, the physical water and sediment 

processes then largely control the chemical 

and geochemical processes, which therefore 

control the biological response of the system. 

When an ICOLL entrance is open, the 

waterway is tidal, and water is exchanged 

with the ocean on a regular basis. When the 

entrance is closed, however, a sand bar 

separates the lake from the ocean. The 

waterway then acts as a reservoir, and 

captures 100% of inputs. The entrance of an 

ICOLL typically opens when the water level in 

the lake exceeds the crest level of the 

entrance sand bar. Overtopping of the 

entrance bar results in massive erosion of the 

bar over a period of a few hours, and 

produces a significant channel for waters to 

flow through. 

About 70% of ICOLLs in NSW are closed for 

the majority of the time, while remaining 

ICOLLs are mostly open. ICOLLs that are 

mostly open typically have large catchments 

(> 100km 2 ) and/or have entrances that are 

well protected from ocean swell waves 

and/or have shallow bedrock under the 

entrance. 

Chemical processes occurring in the 

sediments of ICOLLs can have a significant 

impact on water quality. Organic material 

washing off the catchment during rainfall 

reaches the bed of ICOLLs and is slowly 

recycled. When a lake experiences 

significant catchment loading (through 

extensive catchment development for 

example), the recycling processes are 

modified, resulting in nutrients being released 

directly to the water. Elevated nutrients in 

ICOLLs can result in algal blooms. Without 

regular tidal flushing, these algal blooms can 

be sustained for long periods through internal 

recycling and reuse of nutrients. 

Water quality within ICOLLs can change quite 

significantly following catchment runoff and 

also as a result of an entrance breakout 

event. Given the dynamic nature of the 

entrance, combined with the intermittent 

nature of catchment runoff events, water 

quality within ICOLLs is highly variable. 

The biology of ICOLLs can also be subject to 

significant change. The variability in water 

levels of ICOLLs limits potential for extensive 

estuarine vegetation. Mangroves in ICOLLs 

are rare, except for systems that are mostly 

open to the ocean. Meanwhile, seagrasses 

are virtually absent from most ICOLLs that 

experience relatively rapid changes in water 

level. 

Artificial entrance management of ICOLLs is 

undertaken at about half of the systems 

within NSW for the purposes of flood 

inundation mitigation. Artificial entrance 

management involves opening ICOLL 

entrances at a level lower than the natural 

sand bar breakout level. This process, when 

undertaken consistently over many years, 

can result in a number of environmental 

impacts, including drying out and loss of 

fringing wetlands, reduced fish habitat and 

stock, and increased sand shoaling at the 

entrance. 

Ten strategies have been developed to 

address the sustainable long term 

management of ICOLLs. These strategies, 

presented in Summary Table A, address the 

underlying threats to ICOLL sustainability by 

considering their physical structure and 

behaviour, as well as their prevailing 

chemical and biological processes. 

The ten strategies are not designed to 

provide a complete package for ICOLL 

management. Rather, they should be used in 

conjunction with existing plans (including 

EMPs, CAPs and Regional Strategies), or used 

as a basis for developing specific 

Management Plans for ICOLLs in the future. 

Recommendations have also been provided 

for possible changes to various environmental 

planning instruments, including LEP Zonings, 

LEP Provisions, Plans of Management, 

Estuary Management Plans, Coastal Zone 

Management Manual, Floodplain Risk 

Management Plans, Fisheries Management 

Act 1994, SEPP (Major Projects) 2005, SEPP 



executive summary 

(infrastructure) 2007 and Instruction under 

S117 of the Local Government Act 1993. 

These changes primarily focus on artificial 

entrance management of ICOLLs. 

Summary Table A – Strategies for sustainable future management of ICOLLs 

1 Development planning to protect waterways 

2 Reduce pollutant runoff from existing catchment development 

through landuse diminution 

3 Revegetate critical areas of catchment landscapes, including 

corridors between similar environments, and connections 

between different but complementary habitats 

4 Establish vertical and horizontal buffers around ICOLLs 

5 Opportunistically redress at-risk infrastructure around ICOLL 

foreshores to allow a more natural hydrology regime 

6 Stricter controls on on-site sewage management in low-lying and 

vulnerable areas 

7 Prevent dredging in ICOLL central basins 

8 Aquatic habitat restoration through re-establishing a more natural 

hydrology regime 

9 Formal entrance policies legally connected to relevant Plans of 

Management 

10 Artificially open ICOLL entrances only in accordance with best 

practice procedures 



contents 

Contents 

Foreword .......................................................................................... 3 

Prologue ........................................................................................... 4 

2008 Update ...................................................................................... 4 

Executive Summary.............................................................................. 5 

Contents ........................................................................................... 8 

Purpose of this booklet ....................................................................... 12 

PART A: TECHNICAL REVIEW 

Chapter 1: Introduction....................................................................... 14 

Background .......................................................................................15 

Definitions ........................................................................................16 

Origins .............................................................................................16 

Listing of ICOLLs in South East Australia .....................................................17 

Chapter 2: Existing Planning and Management Regimes................................ 20 

SEPP 71 / SEPP (Major Projects) 2005 ........................................................22 

SEPP (Infrastructure) 2007......................................................................23 

Local Environmental Plans......................................................................23 

Regional Strategies ..............................................................................23 

Estuary Management Program..................................................................23 

Catchment Action Plans.........................................................................25 

National Parks Management ....................................................................25 

Marine Parks Management .....................................................................25 

Independent Inquiry into Coastal Lakes (Healthy Rivers Commission) ...................26 

Coastal Lakes Management Strategies ........................................................27 

How does this booklet fit in? ...................................................................28 

Chapter 3: Coastal Pressures and Management Needs.................................. 29 

Increasing coastal population ..................................................................30 

Tourism............................................................................................30 

Catchment development........................................................................31 

Flood mitigation via entrance manipulation .................................................32 

Climate change...................................................................................33 

Chapter 4: Environmental Processes of ICOLLs .......................................... 34 

Conceptual model of ICOLL processes ........................................................36 

Entrance processes and morphodynamics ....................................................38 

Lake structure and morphometry..............................................................39 

Biogeochemical processes ......................................................................41 

Nutrient and algal dynamics....................................................................42 

Biological processes .............................................................................44 



contents 

Human impacts on ICOLLs ......................................................................45 

Chapter 5: Climate Change................................................................... 46 

Average temperature............................................................................48 

Average rainfall ..................................................................................48 

Extreme rainfall events .........................................................................48 

Drought frequency ...............................................................................48 

Average solar radiation .........................................................................48 

Wind speed and direction.......................................................................48 

Wave height and direction......................................................................49 

Storm surge .......................................................................................49 

Sea level rise .....................................................................................49 

Impacts on ICOLLs ...............................................................................50 

Increase in low tide levels......................................................................50 

Increase in typical waterway depths..........................................................50 

Shoreward translation and increase in berm height at entrance .........................51 

Altered entrance morphodynamics............................................................51 

Climate change conclusions ....................................................................52 

PART B: MANAGEMENT OPTIONS 

Chapter 6: Strategies for Sustainable Management ..................................... 54 

Strategy 1 Development planning to protect waterways...................................57 

Strategy 2 Reduce pollutant runoff from existing catchment development ............60 

Strategy 3 Revegetate critical areas and wildlife corridors ...............................61 

Strategy 4 Establish vertical and horizontal buffers around ICOLLs ......................62 

Strategy 5 Opportunistically redress at-risk infrastructure around ICOLLs..............65 

Strategy 6 Stricter controls for on-site sewage systems in vulnerable areas............68 

Strategy 7 Prohibit dredging in ICOLL central basins .......................................70 

Strategy 8 Aquatic habitat restoration through a more natural hydrological regime..71 

Strategy 9 Establish entrance management provisions within statutory instruments..73 

Strategy 10 Artificially open ICOLL entrance only in accord with best practice........77 

Chapter 7: Recommended Changes to the Existing Planning Framework........... 79 

LEP zonings .......................................................................................80 

LEP provisions ....................................................................................81 

Plans of Management............................................................................81 

Estuary Management Plans .....................................................................82 

Coastal Zone Management Manual ............................................................82 

Floodplain Risk Management Plans ............................................................82 

Fisheries Management Act 1994 ...............................................................83 

SEPP (Major Projects) 2005.....................................................................83 

SEPP (Infrastructure) 2007......................................................................83 

S117 Instruction Local Government Act 1993 ................................................84 

Chapter 8: References ........................................................................ 87 



contents 

Appendix 

Acronyms ........................................................................................ 95 

Glossary of Terms .............................................................................. 96 

List of figures 

Figure 1 Pictorial view of a typical coastal lake (Woodroffe, 2002)...............16 

Figure 2 Relationship between catchment size and waterway size for NSW 

ICOLLs (Haines et al., 2006) ..................................................17 

Figure 3 Stage of Evolution/Maturity of Coastal lakes (Roy, 1984)................17 

Figure 4 NSW Government’s Estuary Management process (adapted from NSW 

Government, 1992) ............................................................24 

Figure 5 Strategic framework for the Coastal Lakes Management Strategy 

(Source: BMT WBM, 2008) .....................................................27 

Figure 6 Kayaking and other passive watersports are popular in most coastal 

lakes (image: BMT WBM) ......................................................31 

Figure 7 Nadgee Lake, near the Victorian Border – the only truly pristine coastal 

lake in NSW......................................................................32 

Figure 8 Order of significance for ICOLL processes ..................................35 

Figure 9 Conceptual Hydrodynamic Model of ICOLLs (source: ozcoast.org.au)..36 

Figure 10 Simple network-based conceptual model of environmental processes in 

ICOLLs (shaded cells represent anthropogenic activities)................37 

Figure 11 Morphodynamic cycle of ICOLL entrance processes .......................38 

Figure 12 Early stage of ICOLL entrance breakout (AWACS, 1994)..................38 

Figure 13 Entrance Closure Indices for most NSW ICOLLs (Haines Et al., 2006) ..39 

Figure 14 Definition of entrance ocean exposure directional window .............39 

Figure 15 Construction of pilot channel at Coila Lake (April 2002) 

(Image: BMT WBM) .............................................................39 

Figure 16 Breakout level vs opening duration for Coila Lake 

(Source: ESC, 2001a)...........................................................40 

Figure 17 Conceptual waterway shapes of ICOLLs.....................................40 

Figure 18 Correlation between typical phosphorus concentrations and ICOLL 

catchment condition (measured by degree of disturbance) .............43 

Figure 19 Correlations between typical Total Nitrogen and ICOLL Catchment 

condition when factoring typical entrance condition.....................43 

Figure 20 Relationship between the Assimilation Factor (AF) and seagrass 

coverage for most NSW ICOLLs (Haines et al., 2006) .....................44 

Figure 21 Australian average temperature variation, 1910 – 2006 compared to 

1961 – 1990 average (Source: BOM, 2007) ..................................47 

Figure 22 Global mean sea level rise, as measured by NASA satellites 

(Source, Uni of Colorado, 2007)..............................................47 

Figure 23 Shoreline response to increasing sea level 

(Source, Hanslow et al., 2000) ...............................................51 

Figure 24 foreshore profile of an ICOLL illustrating the concept of vertical and 

horizontal buffers ..............................................................63 

Figure 25 Scope and context of recommended Entrance Management Provisions 76 



contents 

List of tables 

Summary Table A Strategies for sustainable future management of ICOLLs ........... 7 

Table 1 ICOLLs in South East Australia (from north to south) .....................18 

Table 2 Summary of statutory controls potentially applicable to works within 

ICOLLs (adapted from Haines et al., 2007) .................................21 

Table 3 Population projections for NSW coastal areas (Source: DoP, 2008).....30 

Table 4 Morphometric factors for a number of NSW ICOLLs .......................41 

Table 5 Difference in water quality before and after entrance breakouts ......43 

Table 6 Strategies for sustainable management of ICOLLs.........................56 

Table 7 Ranking of most NSW ICOLLs based on suitability for future 

development intensification..................................................59 

Table 8 Definition of vertical and horizontal buffers around ICOLLs .............64 

Table 9 Prioritised ranking of manipulated ICOLLs for redressing on-going 

entrance management issues.................................................67 

Table 10 Example Table of Contents for an Entrance Management Operations 

Plan...............................................................................78 

Table 11 Standard Instrument LEP landuse zonings (NSW Government, 2006) ...80 

Table 12 Suggested Entrance Management Provisions for the Standard 

Instrument LEP .................................................................85 



purpose of this booklet 

Purpose of this booklet 

This booklet aims to provide guidance to natural coastal resource managers who are responsible 

for ICOLLs and other coastal lakes. The booklet provides a series of strategies that can be 

adopted by government agencies and institutional authorities to achieve more sustainable 

outcomes for these sensitive coastal systems. In addition, this booklet provides recommendations 

on specific changes to the existing planning framework in NSW to ensure greater sustainability of 

ICOLLs in the future. 

This booklet should be used in concert with other relevant coastal management manuals, 

guidelines and planning tools, where available, as well as any location-specific natural resource 

management plans, such as Estuary Management Plans, Coastal Lakes Management Strategies, 

and Catchment Action Plans. This booklet does not aim to duplicate the broader environmental 

management and catchment management objectives of many of these other strategic planning 

documents. Rather, this booklet provides recommendations that are specific to ICOLLs, their 

immediate foreshore areas, and, to a lesser degree, their catchments. This booklet aims to 

complement environmental plans and policies already in place and undergoing implementation. 

It is expected that in the coming years, a increasing number of Coastal Zone Management Plans / 

Estuary Management Plans and / or Coastal Lake Management Strategies will be prepared for 

individual ICOLLs in NSW under various government programs and initiatives. Other states may 

also undertake similar initiatives. It is hoped that this booklet can provide a level of strategic 

direction for these future documents that will ensure potentially consistent and a sustainable 

outcome for ICOLLs across Australia. 



PART A 

TECHNICAL REVIEW 





introduction 

Some coastal lakes and lagoons on the 

east coast of Australia are intermittently 

connected to the ocean. That is, 

sometimes they are open and sometimes 

closed. These particular types of coastal 

lakes are referred to as Intermittently Closed 

and Open Lakes and Lagoons (ICOLLs). 

Background 

ICOLLs are most prominent in NSW, 

however, they can also be found in south 

east Queensland, south-west Western 

Australia, and some parts of Victoria and 

Tasmania. ICOLLs are also found in South 

Africa, New Zealand, Mexico and the Atlantic 

coast of Brazil and Uruguay, but are generally 

considered rare on an international scale. 

When open, ICOLLs are tidal with ocean 

water moving into and out of the estuary on 

a regular basis. When closed, they do not 

interact with the ocean. Instead, water 

levels fluctuate according to rainfall and 

evaporation. Closed ICOLLs are separated 

from the ocean by large sand bars, called 

berms. The berms are built by waves 

pushing beach sand into the entrance. 

For some ICOLLs, ebbing tides can scour 

sand from the entrance channel, which 

results in these entrances remaining mostly 

open. For others, the tides are too weak to 

wash out the sand, and the entrance channel 

chokes up and closes completely. Following 

heavy rainfall, the water level within a closed 

ICOLL may overtop the entrance berm, 

spilling water to the ocean. The overtopping 

of the berm causes an entrance “breakout”, 

wherein sand is eroded from the entrance, 

re-forming a channel through the berm. 

On-going scour caused by the outflowing 

water means that this channel progressively 

enlarges, allowing more and more water to 

discharge from the lagoon, until water levels 

within the lagoon are generally the same as 

the ocean levels. Depending on the final 

depth and dimensions of the entrance 

channel, the lagoon may subsequently be 

subject to tidal variations with tidal flows 

moving in and out of the scoured entrance 

channel. 

There are about 70 ICOLLs in NSW bigger 

than 1 hectare. There are a further 20 coastal 

lakes that are similar in structure to ICOLLs, 

but are permanently open, either by natural 

processes or through artificial entrance 

training works (eg breakwaters) or on-going 

management (eg dredging). 

Most ICOLLs are located south of Sydney due 

to the high wave activity, low rainfall and 

close proximity of the Great Dividing Range to 

the coast. This section of the coast has also 

been less exposed to human development, 

and contains a number of National Parks. The 

NSW south coast contains the greatest density 

of ICOLLs in Australia, and most likely the 

world. 

The conditions of an ICOLL entrance are 

dependent on the relative balance between 

coastal processes (acting to infill the entrance 

with beach sand) and episodic catchment 

runoff processes (acting to scour sand out of 

the entrance). Entrance conditions are also 

influenced by the ability of an ICOLL to sustain 

tidal flows through the entrance channel 

(Elwany et al., 2003; Roy et al., 2001). 

In NSW, about 70% of ICOLLs are closed for 

the majority of the time. Elsewhere, entrance 

conditions tend to be dominated by seasonal 

rainfall, being open during wet seasons and 

closed during dry periods (this is particularly 

true for ICOLLs in South Africa and Mexico, 

where there are strong seasonal rainfall 

patterns). 

Coastal lakes, and ICOLLs in particular, are 

considered to be the most vulnerable type of 

estuary to human intervention (HRC, 2002; 

Boyd et al., 1992). When they are closed to 

the ocean, ICOLLs become ‘terminal lakes’ 

(Haines et al., 2006), capturing and retaining 

100% of catchment runoff and pollutants. 

Even when they are open, tidal flushing within 

the waterways is limited and most catchment 

pollutants are retained. 



introduction 

ICOLLs are recognised as one of the most 

complex and difficult coastal environments to 

manage (Thom, 2004a). ICOLLs are 

ecotones, or transition areas, between 

freshwater and saltwater environments. They 

are also home to many vulnerable species of 

plants and fauna. The variable condition of 

the entrance (ranging from completely open 

to completely closed) also influences a range 

of environmental processes and conditions, 

such as water quality and fish habitat 

(Griffiths, 1999; Pollard, 1994a). 

Historic management of ICOLLs, along with 

most other coastal environments, has not 

always recognised their natural values. For 

more than 50% of ICOLLs in NSW, entrances 

are artificially opened when water levels get 

too high. Artificial opening of ICOLL entrances 

also occurs elsewhere in Australia, as well as 

overseas, and is mainly done to limit the 

impacts of flooding and inundation around the 

foreshore. Premature opening of an ICOLL 

entrance can have a number of environmental 

impacts, including for example drying out of 

fringing wetlands, reduced fish habitat and 

stock, and increased sand shoaling at the 

entrance (Lugg, 1996; Roper, 1998). 

Detailed scientific knowledge ICOLLs has 

advanced significantly over the past 10 years. 

Approaches to coastal zone management have 

also improved over this period. It is now 

considered necessary to transfer our recent 

knowledge of these unique coastal systems to 

a planning and policy level, so that they can 

be managed more effectively in the future, to 

provide ecological, social and economic 

sustainability in the future. 

Definitions 

The term “ICOLL” is a relatively recent 

expression. In the past, these coastal systems 

have been given various titles, including 

‘saline coastal lakes’ (e.g. Roy, 1984), ‘saline 

coastal lagoons’ (e.g. Middleton et al., 1985), 

‘blind estuaries’ (e.g. Fairbridge, 1980 cited in 

Dyer, 1997), ‘seasonally open tidal inlets’ (e.g. 

Ranasinghe & Pattiaratchi, 2003), ‘pocket 

lagoons’ (Phleger, 1981 cited in Pollard 

1994a,b) or simply ‘coastal lagoons’ (e.g. 

Woodroffe, 2002; Kjerfve, 1994; Barnes, 

1980; Bell & Edwards, 1980). Most previous 

descriptions, however, have made little 

distinction between coastal lake systems that 

are permanently open to the ocean, and those 

that are open only intermittently. 

Whilst this booklet focuses on ICOLLs, most 

management recommendations presented 

can indeed be equally applied to those 

coastal lakes that are permanently open 

(either naturally or artificially). 

Origins 

ICOLLs are a form of ‘barrier estuary’, which 

means they are separated from the ocean by 

a sand spit or barrier (Figure 1). 

Ocean waves that strike the coastline on an 

angle create a net transport of sand parallel 

to the shoreline (longshore transport), which 

Figure 1 Pictorial view of a typical coastal lake (Woodroffe, 2002) 



introduction 

forms sand spits across coastal inlets and 

embayments (Bird, 1994; Woodroffe, 2002). 

The sand spits act as natural ‘dams’ and trap 

coastal waters behind to form lakes and 

lagoons. Elsewhere in the world, particularly 

on the east coast USA, coastal lagoons have 

also been formed by the shore-normal 

landward migration of sand bars over the sea 

floor during the most recent sea level rise 

(18,000 to 6,000 years ago) (Bird, 1994; 

Woodroffe, 2002). 

Impoundment by the extensive sand barriers 

means that ICOLLs become effective 

sediment traps, and capture almost 

everything that runs off the catchment. Over 

time, the lakes slowly fill with sediment. The 

rate of shallowing depends on the rate of 

sediment erosion within the catchment and 

the size of the natural basin behind the 

barrier. Big waterways with small 

catchments have infilled by a relatively small 

amount only. These lakes are considered to 

be geologically youthful. In contrast, small 

lakes with large catchments have generally 

infilled considerably, and are regarded as 

more geologically mature (Figure 2). 

When an ICOLL is fully matured, it becomes 

a narrow coastal creek or river, stretching 

from the ocean to the hills, and has extensive 

floodplains that cover the former basin area 

(Figure 3). In this instance, the ocean 

entrance is usually permanently open, or at 

least open for the majority of the time. 

ICOLLs in NSW exhibit a range of 

evolutionary states, including both mature 

and youthful systems. 

Listing of ICOLLs in South East 

Australia 

A listing of the recognised ICOLLs in Southeast 

Australia is provided in Table 1. This 

listing includes a relatively broad selection of 

100 

Geologically youthful 

lagoons, with less 

relative infilling 

10 

Waterway Size (km 2 ) 

1 

0.1 

Two orders of magnitude variance 

Geologically 

mature 

lagoons, with 

more relative 

infilling 

0.01 

0.1 1.0 10.0 100.0 1000.0 10000.0 

Catchment Size (km 2 ) 

Figure 2 Relationship between 

catchment size and waterway size for NSW 

ICOLLs (Haines et al., 2006) 

Figure 3 Stages of Evolution / 

Maturity of Coastal Lakes (Roy, 1984) 



introduction 

ICOLLs and other coastal waterways that are 

similar to ICOLLs in their structure and / or 

function. Included in the listing are some 

coastal lakes and estuaries that may not 

necessarily have closed in recent times, but 

may theoretically close under the right 

conditions (including under future climate 

change conditions). For example, Wonboyn 

Lake closed for the first time in living memory 

during the height of the recent drought. 

Not listed are those estuaries that are 

predominantly riverine in structure (ie they 

represent a fully matured estuarine state), 

and those that are generally small and 

considered to be a minor coastal creek. 

There are literally hundreds of small coastal 

creeks along the east coast of Australia that 

are intermittently connected to the ocean. 

Although at a significantly smaller scale, 

some of the recommendations made in this 

booklet may still be applied to these systems. 

The listing in Table 1 provides an indicative 

classification of ICOLLs and other similar 

waterways into a number of different ‘type’ 

representing different geomorphic structure 

and behaviour. These ICOLL types include: 

Type I: 

Type II: 

Regular intermittently open 

coastal lake 

Smaller intermittently open creeks 

– infilled paleo valley 

Type III: Smaller intermittently open creeks 

– interbarrier swales 

Type IV: Open creeks (riverine system), but 

may close under particular 

conditions (now or in future) 

Type V: Permanently open coastal lake / 

creek due to entrance training 

works 

Type VI: Perched freshwater lagoons – no 

connection to ocean (although 

potential for connection in future 

in response to sea level rise and 

coastal erosion) 

Table 1 ICOLLs in South East Australia (from north to south) 

ICOLL TYPE LGA ICOLL TYPE LGA 

Cudgen Lake V Tweed Oyster Ck III Bellingen 

Cudgera Ck III Tweed Deep Ck IV Nambucca 

Moobal Ck V Tweed Saltwater Lagoon I Kempsey 

Belongil Ck III Byron Korogoro Ck III Kempsey 

Tallow Ck III Byron Killick Ck III Kempsey 

Taylors Lake III Byron Goolawah Lagoon VI Kempsey 

Lake Ainsworth VI Ballina Cathie / Innes I Hastings/Port Macq 

Salty Lagoon III Richmond Valley Khapinghat Ck IV Greater Taree 

Jerusalem Ck III Richmond Valley Wallis Lake V Great Lakes 

Arragan Lake I Clarence Valley Smiths Lake I Great Lakes 

Cakora Lake I Clarence Valley Glenrock Lagoon II Lake Macquarie 

Corindi River IV Coffs Harbour Lake Macquarie V Lake Macquarie 

Pipe Clay Lake III Coffs Harbour Tuggerah Lakes I Wyong 

Arrawarra Ck III Coffs Harbour Wamberal Lagoon I Gosford 

Woolgoolga L I Coffs Harbour Terrigal Lagoon I Gosford 

Hearnes Lake I Coffs Harbour Avoca Lagoon I Gosford 

Moonee Ck IV Coffs Harbour Cockrone Lagoon I Gosford 

Coffs Ck V Coffs Harbour Narrabeen Lagoon I Pittwater / Warringah 

Boambee Ck IV Coffs Harbour Dee Why Lagoon I Warringah 

Bonville Ck IV Coffs Harbour Curl Curl Lagoon II Warringah 

Dalhousie Ck III Bellingen Manly Lagoon II Warringah / Manly 



introduction 

Table 1 cont’d ICOLLs in South East Australia (from north to south) 

ICOLL TYPE LGA ICOLL TYPE LGA 

Fairy Ck II/III Wollongong Nargal Lake VI Eurobodalla 

Lake Illawarra V Wollongong Corunna Lake I Eurobodalla 

Elliot Lake III Shellharbour Tilba Tilba Lake I Eurobodalla 

Bellambi Lagoon II Kiama Little (Wallaga) Lk I Eurobodalla 

Werri Lagoon I Kiama Wallaga Lake I Bega Valley 

Crooked River IV Kiama Baragoot Lake I Bega Valley 

Wollumboola I Shoalhaven Cuttagee Lake I Bega Valley 

St Georges Bas IV Shoalhaven Murrah Lake I Bega Valley 

Swan Lake I Shoalhaven Bunga Lake I Bega Valley 

Conjola Lake I Shoalhaven Wapengo Lake IV Bega Valley 

Narrawallee Inl. IV Shoalhaven Middle (Tanja) Lake I Bega Valley 

Burrill Lake I Shoalhaven Nelson Lake I Bega Valley 

Tabourie Lake I Shoalhaven Bega River I Bega Valley 

Termeil Lake I Shoalhaven Wallagoot Lake I Bega Valley 

Meroo Lake I Shoalhaven Bondi Lagoon VI Bega Valley 

Willinga Lake I Shoalhaven Bournda Lagoon II/III Bega Valley 

Brush Lagoon III Shoalhaven Back Lagoon I Bega Valley 

Kioloa Lake III Shoalhaven Merimbula Lake I Bega Valley 

Durras Lake I Shoalhaven Pambula Lake IV Bega Valley 

Tomaga River IV Eurobodalla Curalo Lake I Bega Valley 

Candlagan Ck I Eurobodalla Towamba River IV Bega Valley 

Congo Ck II/III Eurobodalla Wonboyn Lake I Bega Valley 

Meringo Lake I Eurobodalla Merrica River II Bega Valley 

Bingie (Kellys) L. III Eurobodalla Nadgee River II Bega Valley 

Coila Lake I Eurobodalla Nadgee Lagoon I Bega Valley 

Tuross Lake I Eurobodalla Barracoota Lake VI East Gippsland 

Brunderee Lake I Eurobodalla Mallacoota Lake I East Gippsland 

Tarourga Lake I Eurobodalla Wingan Inlet I East Gippsland 

Brou Lake I Eurobodalla Tamboon Inlet I East Gippsland 

Mummuga Lake I Eurobodalla Mud Lake I East Gippsland 

Kianga Lake I Eurobodalla Lake Corrigle I East Gippsland 

Wagonga Inlet V Eurobodalla Lake Tyers I East Gippsland 

Little (Narooma) II Eurobodalla Lake Bunga II East Gippsland 

Bullengella Lake I Eurobodalla Gippsland Lakes V East Gippsland 

Nangudga Lake I Eurobodalla 

Legend 

Type I: 

Type II: 

Type III: 

Type IV: 

Type V: 

Type VI: 

Regular intermittently open coastal lake or lagoon 

Small intermittently open creek – infilled paleo valley 

Small intermittently open creek – interbarrier swale 

Open creek (riverine system), but may close under particular conditions (now or in 

future) 

Permanently open coastal lake / creek due to entrance training works 

Perched freshwater lagoon – no connection to ocean (possible connection in future in 

response to sea level rise and coastal erosion) 

Note: Victorian ICOLLs are listed for reference only. This booklet primarily focuses on ICOLLs 

(Types I - III) in NSW, particularly in relation to existing and proposed planning frameworks and 

mechanisms. 



existing planning & management regimes 




Historically, ICOLLs have been managed 

in a typical reactionary manner, 

responding primarily to changes in the 

environment after the event (eg catchment 

clearing, foreshore development or 

introduction of jet skis) or changing views or 

opinions held by the general community 

(Smith et al., 2001). 

Until relatively recently, there have been few 

controls on development that have aimed to 

preserve the natural values of ICOLLs. Indeed 

within many rural areas, development has 

been permitted around ICOLLs that focuses on 

minimising risks to private and public amenity, 

and maximising economic opportunity, at the 

expense of natural processes and ecosystems. 

Recent population demands along the coast 

(discussed further in Chapter 3) have 

intensified the conflict between natural and 

developed environments and have been the 

catalyst for numerous (again reactionary) 

controls and strategies that aims to strike a 

better balance. 

There is now potentially a wide range of 

regulatory controls applicable to ICOLLS in 

NSW. This reflects their ecological, aesthetic 

and socio-economic importance, and the 

potential for competing uses. It also reflects 

their location at the interface between land, 

river and sea, where separate legal and 

administrative realms are typically 

demarcated. This menagerie of controls 

means that there is often much confusion over 

what is relevant and what takes precedence. 

As such, ICOLL management can be relegated 

as ‘too hard’ or inevitably driven by political 

motivations. 

Current statutory controls and other 

mechanisms for management and land-use 

planning of ICOLLs and surrounding lands in 

NSW are summarised in Table 2 and described 

further in this Chapter. 

Table 2 

Summary of statutory controls potentially applicable to works within ICOLLS 

(adapted from Haines et al., 2007) 

STATUTORY CONTROL APPROVAL OR LICENCE REGULATORY AGENCY 

(NSW) Environmental 

Planning and Assessment 

Act 1979: 

Approval under Part 3A 

Development consent under 

Part 4 

Environmental assessment 

under Part 5 

NSW Dept of Planning (Minister for Planning) 

Individual Councils are each a ‘consent 

authority’ in relation to their LGAs 

Councils, as proponents, are each a 

‘determining authority’. 

Other (NSW) agencies whose approval is 

required will also be a determining authority in 

their own right. 

(NSW) Threatened Species 

Conservation Act 1995: 

(Cth) Environment 

Protection & Biodiversity 

Conservation Act 1999: 

Licence under Part 6 

(and equivalent provisions in 

Part 7A, Fisheries 

Management Act 1993 

relating to aquatic biota) 

Environmental assessment & 

approval under Chapter 4 

NSW Dept of Environment and Climate Change 

(for Part 6 Licence). 

Individual Councils as consent authority / 

determining authority under EP&A Act 

(Commonwealth) Dept of the Environment and 

Water Resources 

(NSW) Crown Lands Act 

1989: Licence under section 45 NSW Dept Lands 




Table 2 cont’d. Summary of statutory controls potentially applicable to works within ICOLLS 

(adapted from Haines et al., 2007) 

STATUTORY CONTROL APPROVAL OR LICENCE REGULATORY AGENCY 

(NSW) Fisheries 

Management Act 1994: 

(NSW) Protection of the 

Environment Operations 

Act 1997: 

(NSW) Coastal Protection 

Act 1979: 

Permit under sections 200 or 

201 

Permit under section 205 

Permit under section 219 

Environment protection 

licence under section 48 

Environment protection 

licence under section 122 

Concurrence under sections 

38 or 39 

NSW Dept Primary Industries 






(NSW) Coastal Protection 

Regulation 2004: Concurrence under clause 7 NSW Dept of Environment and Climate Change 

(NSW) Rivers and 

Foreshores Improvement 

Act 1948: 

Permit under Part 3A 1 


(NSW) Water Act 1912: 

Licences & permits under 

Part 2 2 

Licence under Part 5 3 

Approval under Part 8 4 

NSW Dept of Water and Energy 

NSW Dept of Water and Energy 


(NSW) National Parks and 

Wildlife Act 1974: Consent under section 90 NSW Dept of Environment and Climate Change 

Notes 

1 To be replaced by controlled activity approvals under the Water Management Act 2000. 

2 To be replaced by access licences under the Water Management Act 2000. 

3 To be replaced by aquifer interference approvals the Water Management Act 2000. 

4 To be replaced by water management work approvals under the Water Management Act 2000. 

SEPP-71 / SEPP (Major Projects) 2005 

State Environmental Planning Policy (SEPP) 

No. 71 – Coastal Protection is a special 

planning policy that has been established 

under provisions of the Environmental 

Planning and Assessment (EP&A) Act 1979. 

The aim of SEPP-71 is to ensure that future 

development within the NSW coastal zone is 

appropriate and suitably located, and 

consistent with the principles of Ecologically 

Sustainable Development (ESD). 

Development proposed within “sensitive 

coastal locations” needs to address specific 

requirements, and needs to be referred to the 

Minister for Planning for comment. SEPP-71 

defines sensitive coastal locations, which 

includes ‘coastal lakes’, along with all lands 

within 100 metres of coastal lake waters. 

Schedule 1 of SEPP-71 provides a list of 

‘coastal lakes’ in NSW (which is essentially 

derived from the 2002 HRC Independent 

Inquiry into Coastal Lakes), and includes most 

type I ICOLLs as listed in Table 1. 




SEPP (Major Projects) 2005 duplicates much 

of the provisions contained within SEPP-71 in 

respect to development within sensitive 

coastal locations and the requirement for 

referral to the Minister. SEPP-71 and SEPP 

(Major Projects) 2005 do not necessarily 

restrict development within and around 

ICOLLs. Rather, they define an additional 

level of assessment for proposed 

developments, with the State government 

taking a more active role in the process. 

SEPP (Infrastructure) 2007 

SEPP (Infrastructure) 2007 has been designed 

to facilitate the development assessment 

process for infrastructure activities undertaken 

by public agencies and utility operators. This 

allows for certain infrastructure works to be 

undertaken without consent, regardless of 

other planning provisions, such as LEPs. 

However, environmental assessments still 

need to be carried under Part 5 of the EP&A 

Act (to the extent that the development is 

carried out by or requires an approval from a 

public authority or minister). 

Part 3 of SEPP (Infrastructure) 2007 contains 

important provisions that would exclude the 

need to obtain development consent for a 

large majority of management activities 

undertaken within ICOLLs, including: 

Flood mitigation work 

Wharf or boating facilities 

 

 

Stormwater management systems 

Waterway or foreshore management 

activities, including in-stream management 

or dredging to rehabilitate aquatic habitat 

or to maintain or restore environmental 

flows or tidal flows for ecological purposes. 

Local Environmental Plans 

Local Environment Plans (LEPs) are prepared 

and administered by local councils and guide 

planning decisions across local government 

areas (LGAs). LEPs typically divide the LGA 

into zones and each zone has a list of 

objective along with a list of development 

types that are permissible with consent, 

permissible without consent and prohibited. 

The LEP essentially provides the community 

with rules on how land can and cannot be 

used. 

As part of state-wide planning reforms, the 

NSW Government has introduced a ‘standard’ 

LEP to which all LEPs across the state need to 

comply. The Standard Instrument LEP uses 

standardised zones, objectives, definitions, 

clauses and formats. It provides for 

mandatory permitted and prohibited uses 

within the zones. 

Neither the Standard Instrument LEP nor its 

associated Planning Circular provide any 

guidance or criteria as to how councils are to 

zone land. As such, the actual zoning of land 

into the prescribed zoning categories is 

therefore at the discretion of individual 

councils. Most Councils in NSW need to revise 

their LEPs to accord to the Standard 

Instrument LEP before 2011. 

Regional Strategies 

Also as part of state-wide planning reform, the 

NSW Government has established a series of 

Regional Strategies. These strategies are 

designed to guide the development of LEPs 

and other instruments in a way that allows for 

the sustainably coordinate the housing, 

employment, and infrastructure requirements 

at a regional scale (and typically over a period 

of about 25 years). 

Regional strategies also provide 

recommendations for specific actions and 

strategic planning mechanisms to protect the 

valuable natural and scenic assets, biodiversity 

and unique characters upon which the 

economic prosperity of individual regions are 

based. The regional strategies also consider 

the management of natural hazards at a 

regional scale. 

Estuary Management Program 

To date, strategic management of ICOLLs is 

mostly guided by individual Management Plans 

prepared for each system under the NSW 

Government’s Estuary Management Program. 

This Program has been developed to meet the 

requirements of the NSW Estuary 




Management Policy 1992 and the NSW 

Coastal Policy 1997. 

The NSW Estuary Management Program is coordinated 

through the NSW Department of 

Environment and Climate Change (DECC) and 

implemented in co-operation with local 

government, the relevant Catchment 

Management Authority and the community in 

accordance with the “Estuary Management 

Manual” (NSW Government, 1992). The 

program incorporates a sequential process 

leading to the preparation and implementation 

of a detailed long-term Management Plan for 

an estuary (Figure 4). The Plan details 

solutions to specific management problems 

through a schedule of activities. These 

activities can include a combination of onground 

works, planning controls, education 

programs and monitoring. 

The NSW Government is undertaking 

initiatives that include modifying the Estuary 

Management Program to include the whole 

Coastal Zone (ie amalgamated with the 

Coastal Management Program). Under the 

amended Part 4A of the Coastal Protection Act 

1979, a ‘Coastal Zone Management Plan’ is to 

be gazetted following approval by the relevant 

Minister. This then provides statutory powers 

to the gazetted Plan, similar to other 

Environmental Planning Instruments held by 

Councils. 

About 1 in 3 ICOLLs in NSW have a formal 

Estuary Management Plan, although to date 

(July 2008) only one such plan has been 

gazetted under the provisions of the amended 

Coastal Protection Act 1979 (that it the 

Tuggerah Lakes Estuary Management Plan). 

A formal Management Plan still does not 

ensure that an ICOLL is managed in an 

efficient and effective manner, nor does it 

ensure that the Plan and its objectives are 

given due considered when proposed 

developments are assessed by authorities. 

Implementation of such Management Plans is 

subject to funding and resources constraints. 

ESTUARY MANAGEMENT COMMITTEE 

 

ASSEMBLY OF EXISTING DATA 

Canvass community input 

Discover and assemble relevant data 

 

ESTUARY PROCESS STUDY 


Hydraulics: tidal, freshwater, flushing, salinity, 

water quality & sediment behaviour, etc 

Biology: habitats, species, populations, 

endangered species, etc 

Impacts: of human activities on hydraulics & boil. 

 

ESTUARY MANAGEMENT STUDY 


Essential Features: physical, chemical, 

ecological, economic, social & aesthetic 

Current Uses: activities, land tenure & control, 

conflicts of use 

Conservation Goals: preservation, key habitats 

Remedial Goals: restoration of environ. quality 

Development: acceptable commercial & public 

works & activities 

Management Objectives: identific. & assessment 

Management Options: implementation of options 

Impacts: of proposed management measures 

 

ESTUARY MANAGEMENT PLAN 


Management objectives 

Description of how the estuary will be managed 

Recommendations 

Schedule of activities to implement 

recommendations 

 

PLAN REVIEW 

Public & Government 

 

IMPLEMENTATION 

Local Government Planning Controls 

State Government Planning Controls 

Remedial Works 

Monitoring Programs 

Education Programs 

Community Services 

Monitoring 

 

MONITORING AND REVIEW OF PREVIOUS 

STEPS, WHERE NECESSARY 

Figure 4 NSW Government’s Estuary 

Management Process (adapted from NSW 

Government, 1992) 




For ICOLLs without a Plan, strategic planning 

decisions are still often made in an ad-hoc 

manner, and with a potentially poor 

appreciation of environmental processes and 

the likely impacts of any actions. 

Catchment Action Plans 

Catchment Action Plans (CAPs) are prepared 

by individual Catchment Management 

Authorities (CMAs). The CAPs outline the 

actions to be taken by the CMA to achieve 

sustainable management of land, water and 

vegetation across the applicable regions. 

CAPs have been prepared for every CMA, 

including the five CMAs along the NSW coast 

(viz: Northern Rivers, Hunter – Central Rivers, 

Hawkesbury-Nepean, Sydney Metro, and 

Southern Rivers). The CAPs cover a wide 

range of natural resources including coast and 

marine waters, rivers and wetlands, soils, 

coastal lakes and estuaries, threatened 

species, and native vegetation. Targets are 

defined along with specific management 

actions that are required in order to meet the 

targets (although these actions are generally 

broad and not specific to particular areas). 

Some CAPs have been based on the NSW 

Natural Resource Commission’s (NRC) Statewide 

Standards and Targets, which are now 

part of the NSW Government’s State Plan. 

The NRC has defined 13 state-wide targets, 

which address quality practice in natural 

resource management and are designed to 

apply to natural resource management at all 

scales including at the state, regional or 

catchment, local and property levels. 

The state-wide target applicable to ICOLLs 

states ‘By 2015 there is an improvement in the 

condition of estuaries and coastal lake 

ecosystems’. A pilot project is currently being 

coordinated by DECC to develop monitoring, 

evaluation and reporting frameworks to assess 

progress against this target. 

The CAPs are considered to play a significant 

role in future catchment management for 

areas around ICOLLs. Not only do the CAPs 

drive physical works such as restoration and 

revegetation, they are pivotal in helping 

councils with strategic landuse planning (eg 

rezoing as part of the LEP review process). 

The CAPs also provide an essential link 

between catchment management initiatives 

and the community groups that are largely 

responsible for undertaking much of the 

environmental rehabilitation espoused by the 

CMAs. 

National Parks Management 

Some ICOLLs and/or catchments of ICOLLs 

(or part thereof) are located within declared 

National Parks. Under the National Parks and 

Wildlife Act 1974, a management plan needs 

to be prepared for each national park. The 

plan needs to address the following issues: 

The conservation of wildlife and its 

habitat; 

The preservation of the national park and 

its special features, including historic 

structures, objects, relics or Aboriginal 

places; 

The encouragement and regulation of the 

appropriated use, understanding and 

enjoyment of the national parks; and 

The preservation of the national park as a 

water catchment area, and protection 

against uncontrolled fires and soil erosion. 

Marine Parks Management 

There are now five (5) Marine Parks along the 

NSW Coast (viz: Cape Byron, Solitary Islands, 

Port Stephens – Great Lakes, Jervis Bay and 

Batemans). These Marine Parks extend into 

inland estuarine waters to the tidal limits. As 

such, a number of ICOLLs, below MHW, are 

located within Marine Parks. 

Provisions of the Marine Parks Act 1997 

require the preparation of a zoning plan and 

an operational plan for each of the marine 

parks. The zoning plan details the location of 

each zone and activities that are permitted in 

that zone, while the operation plan details the 

management intent in providing conservation 

and sustainable use of Marine Park. 

Zonings within the Marine Parks include: 




Sanctuary Zones: This zone has the highest 

level of environmental protection, and typically 

prohibits all fishing; 

Habitat Protection Zone: This zone provides a 

high level of environmental protection, and 

typically prohibits high impact commercial 

activities such as trawling, whilst permitting 

many recreational activities, including 

recreational fishing; 

Special Purpose Zone: This covers all areas 

with special management requirements such 

as oyster leases, scientific study, sites of 

significance to Aboriginal communities; and 

General Zones: For all areas within the 

marine park not subject to other zonings, and 

typically allows for a wide range of activities, 

including recreation and commercial fishing. 

Most ICOLLs are protected within the 

Sanctuary or Habitat Protection zones. 

Independent Inquiry into Coastal 

Lakes (Healthy Rivers Commission) 

In 2000, the NSW Healthy Rivers Commission 

(HRC) initiated an Independent Inquiry into 

the Coastal Lakes of NSW. ICOLLs were 

included in the ‘coastal lakes’ considered by 

the HRC, along with other coastal waterways 

that are permanently connected and 

permanently disconnected from the ocean, as 

well as some occluded lakes that are 

connected to other estuarine systems. 

Following extensive consultation and 

investigations, it was concluded by HRC 

(2002) that current management practices 

did not pay sufficient regard to the unique 

characteristics of coastal lakes. HRC 

considered that a fundamental change in the 

existing management process was required in 

order to achieve ‘healthier’ coastal lakes in 

NSW in the future. 

Community and stakeholder consultation was 

a strong focus of the HRC Inquiry. 

Supported by desktop investigations, the 

consultation confirmed that coastal lakes are 

highly valued for their ecological, social and 

economic benefits to local and wider 

communities. As discussed further in Chapter 

3, the HRC also found that pressures placed 

on the coastal lakes by past and current 

development have caused environmental 

degradation to virtually all NSW coastal lakes 

(HRC, 2002). 

In response to these pressures, the HRC 

formulated a series of management 

frameworks for the coastal lakes. The NSW 

coastal lakes were separated into four (4) 

categories based on their perceived values 

and future management needs: 

Comprehensive Protection: where the 

restoration and preservation of all natural 

ecosystems is considered paramount. These 

lakes generally have pristine or near pristine 

catchments, with little modification to the 

waterway, and a high conservation value. 

Significant Protection: where management 

focus should be placed on restoring and 

preserving critical natural ecosystem 

processes. These lakes generally have largely 

unmodified to somewhat modified catchments 

and slightly affected waterways. The 

recognised conservation value of these lakes 

can be moderate to high. 

Healthy Modified Condition: where key and/or 

highly valued ecosystem processes are to be 

rehabilitated and retained. These lakes 

generally have modified catchment and 

waterway conditions, but can still retain some 

recognised conservation value. 

Targeted Repair: where a preferred lake 

condition is sought through rehabilitation. 

These lakes generally have highly modified 

catchments, with significant impacts on the 

waterways. There is generally little 

recognised conservation value of these lakes. 

For each separate category, the HRC defined: 

management intents and expected 

outcomes; 

scopes for further assessments; 

types of management actions; and 

a selection of management ‘tools’ for 

implementing actions. 




One of the key recommendations made by 

HRC (2002) was for further site-specific 

assessments to be carried out for each 

coastal lake in the form of Sustainability 

Assessment Management Plans (SAMP). 

The NSW Government responded to the HRC 

Independent Inquiry with a series of 

initiatives in 2003, including the preparation 

of SAMPs for eight (8) pilot lakes, as a first 

stage of implementation of the Coastal Lakes 

Strategy. 

Coastal Lake Management Strategies 

Eight coastal lakes, comprising Cudgen Lake, 

Myall Lakes, Lake Wollumboola, Burrill Lake, 

Narrawallee Inlet, Coila Lake, Merimbula Lake 

and Back Lake (ie five Type I ICOLLs) were 

chosen as pilot systems for the preparation of 

individual SAMPs (as per HRC 

recommendations), known as Coastal Lake 

Management Strategies, funded under the 

Comprehensive Coastal Assessment (CCA) 

program. 

The process was enhanced by the 

development of a Coastal Lake Assessment 

and Management (CLAM) tool by ANU 

(iCAM). The tool was designed to model 

potential impacts on coastal lake 

environments under certain management 

scenarios. The CLAM tool utilises Bayesian 

Decision Network techniques to integrate 

social, economic and ecological values for the 

catchment and the waterway. 

Development of the Coastal Lake 

Management Strategies aimed to incorporate 

the strategic planning and management 

actions of a range of existing plans and 

policies relevant to the waterway (refer 

Figure 5). Many of these have been described 

already in this Chapter. 

Figure 5 Strategic Framework for the Coastal Lake Management Strategy (Source: BMT WBM, 2008) 




In addition to providing options for mitigating 

the impacts of past and existing human 

activities, the Coastal Lake Management 

Strategies provide recommendations on 

restrictions and controls on future activities 

and development within the coastal lakes and 

their catchment. For different Management 

Areas (zones within the catchment), potential 

future activities have been categorised as 

‘permitted’, ‘prohibited’, or ‘conditional’. It is 

envisaged that the Management Areas and 

suggested development controls would be 

considered by local authorities when 

preparing LEP amendments and when 

assessing future development applications. 

Broad-brush pilot studies are only just being 

initiated by government authorities that are 

investigating the potential risks on coastal 

assets (including natural assets) due to 

climate change. It is hoped that this booklet 

will facilitate appropriate decision-making in 

the interim period until these investigations, 

and indeed more locally specific 

investigations have been finalised. 

How does this booklet fits in ? 

In addition to providing a concise overview of 

the existing management framework and 

technical appreciation of environmental 

processes within ICOLLs, this booklet 

recommends a series of potential future 

management initiatives that can be 

considered as part of future management 

practices for ICOLLs and their catchments. 

A number of the original initiatives presented 

in this booklet have now been incorporated 

into the more recent Coastal Lakes 

Management Strategies. There is potential 

for these initiatives to be applied more 

holistically across all ICOLLs in NSW, and 

indeed across the whole of the country, to 

gain improved consistency in resources 

management and future development 

control. 

With the need to review LEPs, now is an 

opportune time for local authorities to take 

stock of existing ICOLL values, and to 

implement actions and planning controls that 

will ensure these values are maintained, if 

not enhanced, in the long term. 

Further, this booklet provides significant 

information on the management of ICOLLs 

with respect to future climate change. 





Coastal pressures and management needs 

This chapter provides more detail about 

some of the key pressures facing 

ICOLLs in the future. Management of 

ICOLLs must address these pressures 

if they are to remain environmentally and 

socially sustainable. 

Increasing coastal population 

Like most coastal areas throughout Australia, 

coastal NSW is experiencing unprecedented 

population growth (Thom, 2003, Burnley & 

Murphy, 2004). This growth, particularly in 

non-metropolitan areas, is being driven by socalled 

“downshifters”, who are early-retiring 

baby-boomers leaving the larger cities for a 

“sea change” or a “tree-change” to the coast 

(Lipman & Stokes, 2003). De-regulation of 

the dairy industry in 2000, combined with 

significant improvements to roads and 

highways (such as the Pacific Highway), has 

fuelled the migration to the coast (Lipman & 

Stokes, 2003; Thom, 2004). 

Demographers predict that the population of 

the non-metropolitan coastal zone of NSW will 

increase by some 430,000 between 2004 and 

2031 (DoP, 2008), with regional increases in 

the order of 20 to 30% (Table 3). 

As many existing towns and villages are 

located near, or even on the shores of, 

ICOLLs, it is likely that this population increase 

will affect these estuaries. For example, 

sewage and stormwater disposal will increase, 

while more habitat will be physically disturbed. 

“Suburbanisation” of coastal areas throughout 

Australia has already fragmented bushland, 

introduced exotic plants and fauna, changed 

catchment runoff characteristics and 

microclimates, increased sediment loads to 

estuaries, and introduced urban pollutants 

through stormwater drains (Harvey & Caton, 

2003). 

Without careful planning, the future 

population will paradoxically degrade the very 

environments that attracted people to the 

area initially. 

Tourism 

Despite 75% of the NSW population living 

near the coast and estuaries, the coastal zone 

remains a popular destination for domestic 

and international tourists (Cheng, 1981; 

Harvey & Caton, 2003). Queensland and New 

Region 

Table 3 Population Projections for NSW coastal areas (source: DoP, 2008) 

Richmond-Tweed (incorporating Tweed, Ballina, Byron and 

Richmond Valley LGAs) 

Mid-North Coast (incorporating Bellingen, Coffs Harbour, Clarence 

Valley, Greater Taree, Hastings, Kempsey, and Nambucca LGAs) 

2004 

population 

2031 

population 

Percentage 

population 

increase 

223,900 290,500 29.8% 

291,900 373,700 28.0% 

Hunter Balance (incorporating Great Lakes LGA) 98,900 121,100 22.5% 

Newcastle (incorporating Lake Macquarie, Newcastle and Port 

Stephens LGAs) 

Sydney (incorporating Wyong, Gosford, Pittwater, Warringah, 

Manly, Woollahra, Waverley, Randwick, Botany, and Sutherland 

LGAs) 

Wollongong (incorporating Kiama, Shellharbour and Wollongong 

LGAs) 

505,400 610,200 20.7% 

4,232,100 5,290,000 25.0% 

274,100 323,100 17.9% 

Illawarra Balance (incorporating Shoalhaven LGA) 136,100 184,700 35.7% 

South Eastern (incorporating Eurobodalla and Bega Valley LGAs) 200,500 257,000 28.2% 

(LGA = Local Government Area) 




South Wales account for almost three quarters 

of the non-metropolitan coastal tourism in 

Australia (Harvey & Caton, 2003). Recent 

tourism statistics indicate that the south coast 

is emerging as the most popular holiday 

destination on the NSW coast. 

Tourists are attracted to ICOLLs and other 

coastal waterbodies as they provide a range of 

experiences, and are generally set within 

areas of scenic beauty. The quiet and 

protected nature of ICOLLs is popular for 

passive recreation (such as canoeing and 

fishing – see Figure 6), which contrasts well 

with adjacent coastal beaches that attract 

more active recreational pursuits (eg board 

and kite surfing). Recreational fishing is also 

very popular in most ICOLLs. Indeed many 

ICOLLs were dedicated as Recreational Fishing 

Havens in 2001, when the NSW Government 

initiated broadscale commercial fishing buyouts 

along the coast. These include Conjola, 

Burrill, Tabourie, Meroo, Tuross, Brunderee, 

Nelson and Wonboyn to name a few. 

Populations of popular tourist destinations can 

increase by up to six times during the summer 

school holidays and over Easter. “Summer 

impacts” refers to the detrimental effects that 

this temporary increase in population has on 

the natural coastal environments, and can 

include for example additional usage of septic 

systems and piped sewer networks, additional 

urban pollutants, additional physical 

disturbance of habitats and increased demand 

on recreational facilities. Also, the pressure to 

optimise conditions for tourists can lead to 

artificial management of ICOLL entrances, 

such as at Lake Cathie, near Port Macquarie 

on the NSW mid north coast. 

Catchment development 

There is only one truly pristine ICOLL in NSW, 

Nadgee Lake on the far south coast (HRC, 

2002), refer Figure 7. All remaining ICOLLs 

have been affected by catchment 

development to varying degrees. Two thirds 

of the natural bushland has been cleared from 

the catchments of one in four NSW ICOLLs, 

while over 90% of catchment bushland has 

been lost for about 1 in 10 ICOLLs. 

Impacts of catchment development can be 

observed in virtually all aspects of the coastal 

environment. ICOLLs are particularly sensitive 

Figure 6 

Kayaking and other passive watersports are popular in most ICOLLs 

(Image: BMT WBM) 




to inputs from the catchment. Therefore, 

catchment development can have significant 

effects on these estuaries, including water 

quality. Nutrient runoff loads from even 

partially developed catchments can be 

substantially higher than under natural 

conditions. For example, the Tuross Lakes 

with just 13% of the catchment developed 

receives nitrogen loads that are 5 times higher 

and phosphorus loads that are 25 times higher 

than pre-development conditions (Brown and 

Root, 2001). Within highly urbanised areas, 

nutrient loads from the catchment may be 

more than 100 times higher than under 

natural conditions (see WBM, 2001). 

Some ICOLLs have become shallower as a 

result of increased sediment runoff from the 

catchment, while others have been 

purposefully reclaimed (for landfill and waste 

disposal in the case of Manly, Dee Why and 

Curl Curl Lagoons in Sydney). 

Catchment development threatens most 

ICOLL ecosystems (Webster & Harris, 2004), 

and is likely to have already caused significant 

and largely irreversible changes to some 

(Harris, 2001b). Development of the 

catchment not only increases the nutrient 

(nitrogen and phosphorus) runoff from the 

catchment, but also changes the chemical 

composition of the runoff, making it easier for 

algal blooms to form. 

When an ICOLL becomes overloaded from 

catchment nutrients, it can become eutrophic, 

meaning that the biology of the lake is 

dominated by excessive algae within the 

water. 

Flood mitigation via entrance 

manipulation 

The natural and significant variability in water 

levels of ICOLLs means that large areas of 

foreshore land can be inundated when water 

levels are high. Whilst this situation may 

occur only rarely, it can have social and 

economic repercussions for owners of the 

foreshore land as well as the broader 

community. Subsequently, councils and other 

authorities are often pressured to resolve this 

Figure 7 

Nadgee Lake, hidden within National Park near the Victorian border is the 

only truly pristine ICOLL remaining in NSW 




‘flooding’ dilemma. The simplest means of 

doing this has been to release the build up of 

water within the waterway by creating an 

artificial outlet channel through the entrance 

berm. 

ICOLLs are artificially opened by excavating a 

relatively small ‘pilot channel’. The high flow 

discharge through this channel causes it to 

scour, forming a more substantial outlet within 

a relatively short timeframe (ie hours). 

The demand to artificially open ICOLL 

entrances is usually triggered by the 

inundation of public or private land or assets, 

including roads, grazing lands, septic systems, 

sheds, orchards, backyards and even houses 

in some cases. ICOLLs are typically opened 

when waters are within about 0.5 metres of 

their natural breakout level, although in some 

cases it can be up to 1.5 metres lower (in the 

case of Wallaga Lake). 

The artificial opening of ICOLLs at levels 

continually lower than their natural breakout 

conditions has lead to two significant 

repercussions. 

actions are being undertaken in a number of 

ICOLLs without appropriate legal authority or 

permission. As outlined in Chapter 2, the 

statutory framework surrounding ICOLLs is 

complex. Adding to this complexity is the 

wide variety of land tenure that is applicable 

to ICOLL entrances along the coast. 

Depending on the tenure, difference statutory 

controls are applicable. For example, in areas 

of Crown land with an existing Plan of 

Management, the Plan would need to 

specifically include provisions for artificial 

entrance openings of the ICOLL for the works 

to be lawful. 

Also, for a small number of ICOLLs, entrance 

channels are sometimes illegally dug by the 

community to prevent inundation of private 

foreshores or even just to ‘ride the waves’ in 

the outflowing discharge. 

Climate change 

A detailed assessment of the potential 

impacts of climate change on ICOLLs is 

provided in Chapter 5 of this booklet. 

1) The lowering of the maximum water level 

can modify the ecosystems in fringing 

wetlands, which rely on occasional flooding to 

rejuvenate the plants and prevent pasture 

grasses and weeds from taking over. Further, 

continued artificial opening of an ICOLL 

entrance can lead to greater shoaling within 

the entrance area and changes to the fish 

community structure (Lugg, 1996). 

2) More foreshore development has now 

encroached onto areas that were periodically 

inundated given the artificial control on 

maximum water level. There is now therefore 

an obligation to continue managing these 

entrances in perpetuity to ensure that flood 

risks are not increased. This will become 

increasingly difficult when adapting to future 

climate change (as discussed further in 

Chapter 5). 

Of significant concern regarding entrance 

management of ICOLLs is the fact that these 



ICOLL processes 




“after heavy rains they overflow and break through the beaches, the sea enters, 

and thus between them are made lagoons of salt or brackish water. Those 

lagoons into which there is a constant drain of fresh water, keep their inlets 

always open, but have not force enough at all seasons to clear away from their 

mouths the sand that is constantly accumulating there by the washing up of the 

surf. Others again, being situated in the neighbourhood of small hills, and having 

at dry times, especially, little or no drain of freshes into them, have their outlets, 

made in the wet season, very soon choked up by the surf, and in time banked in 

even with the rest of the beach” 

George Bass, 1798 

The passage above, taken from Coltheart 

(1997), provides the first description of 

the intermittently open and closed 

coastal lakes of NSW by a European. The 

description is remarkably astute for a number 

of reasons: 

i. it distinguishes between lakes that are 

mostly open to the ocean, and lakes 

that are mostly closed; 

ii. it notes the key mechanism for 

entrance breakout, that is, heavy 

rainfall, and 

iii. it notes that entrance sand berm levels 

can build-up to the same height as the 

adjacent beaches. 

A good understanding of the processes 

controlling environmental behaviour is 

considered essential when planning for longterm 

sustainable management of natural 

resources. 

As noted by Dr Daryl Low Choy of Griffith 

University, ‘good science is required to direct 

future management and planning of coastal 

resources to ensure long-term environmental 

sustainability, while pro-active and holistic 

management approaches are required to 

recognise that science is a significant 

constraint to future environmental planning’ 

(pers comm., Sept., 2005). 

Few existing estuary management 

frameworks across Australia are supported 

by, and integrated with, good scientific 

research (Smith et al., 2001). This clearly 

limits the potential for management actions 

to maximise environmental benefits. 

This chapter provides a description of the key 

environmental processes that control the 

behaviour of ICOLLs. Management strategies 

presented in this booklet have been 

underpinned by research and investigations 

into ICOLLs, as detailed below. 

At the most fundamental level, environmental 

processes within ICOLLs are driven by the 

physical transport of water and sediment 

through the system. These physical 

processes tend to control the chemical and 

geochemical properties of the water and 

sediment, which in turn tend to control the 

biological structure of the system (Figure 8). 

Emphasis has therefore been placed on 

describing the physical processes of ICOLLs, 

given their influence on most other 

environmental processes. 

Physical Processes – Primary order 

 

Chemical Processes – Secondary order 

 

Biological Processes – Tertiary Order 

Figure 8 

Order of significance for 





Conceptual model of ICOLL processes 

Golley (1993) states that “Ecosystems are not 

only more complex than we think, 

ecosystems are more complex than we can 

think”. 

Models help us decipher and understand the 

connections and interactions between various 

elements of coastal environments. The most 

basic type of model is called a conceptual 

model. Conceptual models are useful as 

planning and management tools because 

they succinctly communicate the complexity 

of biophysical environments (Ryan et al., 

2003). 

Conceptual models can take the form of a 

pictorial representation of environmental 

processes (Figure 9), or a network-based 

interaction diagram (Figure 10). Pictorial 

models, whilst appearing easy to understand, 

can tend to over-simplify processes and 

interactions. On the other hand, networkbased 

models are often too complex to 

enable easy interpretation. Pictorial models 

are mostly used for consultation purposes, 

while network models provide the best tools 

for management, as they can be used to 

predict likely consequences of actions 

(particularly if assisted by computer 

programs). 

As shown in Figure 10, the physical, chemical 

and biological processes occurring within 

ICOLLs are highly inter-related (Ryan et al., 

2003; Scheltinga et al., 2004). Most 

processes, however, are dependent to some 

degree on the conditions of the entrance and 

the conditions of the catchment, as these 

reside at the top of the ‘processes tree’. 

Coastal processes at the entrance tend to 

apply a relatively constant (press-type) 

pressure to ICOLLs, while the intermittent 

nature of catchment processes apply eventbased 

(pulse-type) pressures. Given that both 

of these elements can be substantially 

modified by anthropogenic activities (eg 

construction of training walls, artificial 

entrance opening, urbanisation, etc.), there is 

potential for virtually all environmental 

processes within ICOLLs to be influenced by 

humans. 

Figure 9 

Conceptual Hydrodynamic Model of ICOLLs (source: Ozcoast.org.au) 




Coastal processes 

Artificial entrance 

management 

Anthropogenic 

development 

ICOLL entrance 

conditions 

Catchment 

condition 

Freshwater 

extractions 

Waterway physical 

structure 

Evaporation 

Oceanic inflows 

and outflows 

Volumetric 

catchment runoff 

Direct rainfall 

Groundwater 

inflows and 

outflows 

Oceanic inputs and 

discharges of 

sediment 

Catchment 

sediment runoff 

Hydrodynamics 

Atmospheric inputs 

and releases of 

chemical 

constituents 


discharges of 

chemical 

constituents 

Catchment runoff 

of chemical 

constituents 

Groundwater 

geochemical inputs 

Sedimentology 

Water Quality 

Catchment runoff 

of organic and 

inorganic 

particulates 

Sediment Quality 


outputs of 

biological species 

Biology 

Benthos and 

marine vegetation 

Microphytobenthos 

(Benthic 

microalgae) 

Mobile oceanic 

species (eg fish 

and invertebrates) 

and marine algae 

Pelagic and 

epiphytic micro and 

macro algae 

Figure 10 

Simple network-based conceptual model of environmental processes in ICOLLs 

(shaded cells represent anthropogenic activities) 




Entrance Processes and 

Morphodynamics 

ICOLLs demonstrate two distinctly different 

hydrodynamic regimes – one when the 

entrance is open, and one when the entrance 

is closed (Ranasinghe & Pattiaratchi, 2003). 

When the entrance is open, an ICOLL will 

exhibit regular tidal behaviour. When the 

entrance is closed, however, an ICOLL will act 

more as a reservoir, with water levels 

responding to catchment runoff, direct rainfall, 

evaporation, and percolation through sand 

dunes. When closed, water levels within 

ICOLLs may vary by up to 3 metres, 

depending on the crest level of the entrance 

sand berm. 

An ICOLL moves from one hydrodynamic 

regime to the other as a result of entrance 

morphodynamics (Figure 11). 

Figure 11 

Morphodynamic cycle of ICOLL 

entrance processes 

The condition of an ICOLL entrance is a 

function of i) the wave climate, ii) incoming 

tidal conditions, iii) ebb tide currents, and iv) 

discharge of floodwaters. The first two tend 

to wash sand into the entrance and close the 

channel, while the latter two tend wash sand 

out of the entrance through scour (Gordon, 

1990; Hanslow et al., 2000, Elwany et al., 

2003). 

ICOLL entrances generally breakout by rising 

water levels within the lagoon overtopping the 

entrance sand berm. Entrance breakouts 

therefore mostly occur in response to heavy 

rainfall, which result in increasing lagoon 

water levels. Breakout involves the initial 

development of a small pilot channel across 

the berm to the ocean (Figure 12). 

Figure 12 Early stage of ICOLL 

entrance breakout (AWACS, 1994) 

Over a period of approximately 2.5 to 3 hours 

(Gordon, 1990), the high currents flowing 

through the pilot channel scour enough sand 

to form a sizable channel. The discharge of 

waters from the ICOLL is then controlled by 

the difference in water level (head difference) 

between the lagoon and the ocean (Gordon, 

1990). Sand scoured from the entrance in 

forming the channel is typically deposited in 

the surf zone to form an offshore sand bar 

(Sheedy, 1996). 

Closure on an ICOLL entrance involves the 

‘recovery’ of the entrance beach berm 

following lagoon entrance breakout. If closure 

occurs relatively rapidly following breakout, it 

is likely that the sediment used to infill the 

entrance was the same material that was 

scoured out during the previous breakout 

(Sheedy, 1996). If closure is delayed, 

however, then the offshore sand bar formed 

by the entrance breakout is likely to be 

reworked onto the adjacent beach, and it 

becomes longshore sand transport that then 

more responsible for infilling the entrance. 

The proportion of time that an ICOLL entrance 

is closed has been given the new term 

Entrance Closure Index (ECI). The ECI is 

calculated over a long term period, and as 

such, represents typical, average entrance 

conditions of an ICOLL. 




Frequency (Number of ICOLLs) 

The majority of NSW ICOLLs are mostly closed 

(i.e., have an ECI > 0.6), while remaining 

ICOLLs tend to be mostly open (i.e., have an 

ECI < 0.2). Few ICOLLs have entrances that 

are open and closed for roughly equal 

proportions of time, thus resulting in a 

distinctive bimodal behaviour of entrance 

condition (Figure 13). ECI values can 

potentially vary on decadal scales due to 

dominant meteorological conditions and shortscale 

climate variability. Further, artificial 

entrance management of ICOLL entrance (see 

discussion below) can modify the ECI. 

25 

20 

15 

10 

5 

0 

1.0 - 

0.9 

0.9 - 

0.8 

0.8 - 

0.7 

0.7 - 

0.6 

0.6 - 

0.5 

0.5 - 

0.4 

0.4 - 

0.3 

0.3 - 

0.2 

Proportion of time lagoon entrance is closed (ECI) 

Figure 13 Entrance Closure Indices for 

most NSW ICOLLs (Haines et al., 2006) 

0.2 - 

0.1 

0.1 - 

0.0 

(iii) 

the entrance channel contains 

geomorphic controls (e.g. shallow 

bedrock outcrops). 

For approximately 50% of ICOLLs in NSW, 

entrances are artificially opened from time to 

time. Artificial ICOLL entrance management 

also occurs elsewhere in Australia, as well as 

overseas (particularly South Africa). 

Entrances are primarily opened artificially to 

limit the extents of foreshore inundation when 

lake levels get too high. 

Artificial opening of an ICOLL entrance 

involves the construction of a pilot channel to 

initiate discharge to the ocean (Figure 15). 

Outflowing waters quickly scour the channel 

and increase its size, as per a natural 

breakout. Because lagoon levels at breakout 

are typically lower during an artificial breakout 

compared to a natural breakout, the energy 

‘head’ of water is less, and the channel 

generally does not scour as large. 

Consequently, the entrance channel does not 

last as long before it is once again becomes 

infilled by marine sand (Figure 16). 

NSW ICOLLs tend to be mostly closed unless 

one or more of the following conditions are 

met: 

(i) the catchment is larger than 100km 2 ; 

(ii) the entrance is exposed to ocean swell 

waves over a directional window of less 

than 60 (Figure 14); 

Figure 15 Construction of pilot channel 

at Coila Lake (April 2002) 

(Image: BMT WBM) 

Lake Structure and Morphometry 

Figure 14 Definition of entrance 

ocean exposure directional window 

Morphometry refers to the physical 

characteristics of ICOLLs. Morphometric 

features of ICOLLs can influence the resilience 

of the waterway to external loadings (Haines 

et al., 2006). 




Opening Duration (weeks) 

Some of the most significant morphometric 

parameters of ICOLLs include the ECI, the 

catchment size, the waterway size, and the 

waterway shape (Figure 17). 

16 

14 

12 

10 

8 

6 

4 

2 

R 2 = 0.5052 

0 

1 1.2 1.4 1.6 1.8 2 2.2 2.4 

Level (m AHD) 

Figure 16 Breakout level vs opening duration 

for Coila Lake (Source: ESC, 2001a) 

Relatively linear ICOLLs have been called 

‘displacement-dominated’ systems, because 

catchment runoff that enters the waterway 

tends to push out, or displace, the resident 

water in the system. Relatively circular 

ICOLLs have been called ‘mixing-dominated’ 

systems. Catchment runoff that enters a 

mixing-dominated ICOLL tends to mix with the 

resident water before discharging to the 

ocean. Mixing in these type of ICOLLs is 

enhanced by wind-generated circulation 

currents. 

Three morphometric factors have been 

developed by Haines et al. (2006) to describe 

the sensitivity of ICOLLs to external inputs: 

The Evacuation Factor (EF) is a 

dimensionless parameter that provides a 

relative measure of the ‘tidal flushing 

efficiency’ of an ICOLL; 

EF = [shape function * Tidal Prism Ratio * 

(1 – ECI)] -1 

The Dilution Factor (DF) describes the 

efficiency of a ICOLL to receive and 

accommodate inputs from the catchment 

without significant impact on waterway 

conditions; 

DF = catchment runoff pollutant load (av. 

annual) * waterway volume -1 * ECI 

The Assimilation Factor (AF) compares the 

catchment runoff volume with the ICOLL 

surface area, and as such, is a de facto 

measure of the average annual water level 

variation for an ICOLL. 

AF = catchment runoff volume (av. annual) 

* Waterway Area -1 * ECI 

Morphometric factors for a select number of 

NSW ICOLLs have been calculated to provide 

an indication of the relative significance of 

these factors in determining individual 

sensitivities of the ICOLLs (refer Table 4). 

Displacement-dominated 

Mixing-dominated 

Figure 17 Conceptual waterway shapes of ICOLLs 




Additional morphometric-based factors could 

also be developed to describe other aspects of 

natural sensitivity to external inputs, including 

for example, susceptibility to stratification 

(Spooner & Spigel, 2005). DLWC (draft, 

2000) also used similar morphometric-based 

parameters to describe relative vulnerability of 

south coast estuaries to existing and future 

development. 

Biogeochemical Processes 

A significant amount of research has been 

carried out on sediment biogeochemistry in 

Australian estuaries, including work by CSIRO, 

Geoscience Australia, NSW State Government 

(DECC), Southern Cross University, and the 

University of Canberra to name a few. A 

summary of the key biogeochemical processes 

likely to occur within ICOLLs is described 

below. 

Dilution Factor 3 Assimilation 

Table 4 Morphometric Factors for a number of NSW ICOLLs 

ICOLL ECI 1 Evacuation 

Factor 2 Factor 4 

Smiths 0.80 32.5 0.10 0.93 

Wamberal 0.96 120.1 1.91 4.41 

Terrigal 0.70 10.0 10.48 8.28 

Avoca 0.90 43.3 3.62 5.06 

Cockrone 0.94 65.7 1.82 5.42 

Narrabeen 0.16 7.3 0.48 1.24 

Dee Why 0.70 4.6 8.78 5.67 

Curl Curl 0.80 19.7 32.30 22.78 

Wollumboola 0.96 63.9 0.30 1.57 

Durras 0.62 30.0 0.14 1.55 

Candlagan 0.05 2.8 0.47 0.63 

Coila 0.95 89.3 0.20 1.39 

Brunderee 0.86 8.0 2.89 4.59 

Tarourga 0.94 24.9 1.04 2.52 

Brou 0.97 144.0 0.52 2.94 

Mummuga 0.64 14.0 0.39 1.72 

Kianga 0.92 22.4 7.24 9.09 

Nangudga 0.73 12.0 1.80 2.30 

Corunna 0.94 113.2 0.72 2.41 

Tilba Tilba 0.97 104.9 2.28 3.56 

Wallaga 0.20 21.5 0.11 1.08 

Baragoot 0.99 170.0 2.22 3.89 

Cuttagee 0.83 35.5 1.11 4.77 

Murrah 0.10 4.0 2.12 3.74 

Bunga 0.84 11.4 18.63 12.92 

Wapengo 0.02 5.5 0.01 0.07 

Middle (Tanja) 0.93 43.4 6.45 9.19 

Nelson 0.02 3.2 0.02 0.07 

Wallagoot 0.96 85.3 0.01 1.02 

Back Lagoon 0.86 38.6 1.90 9.65 

Merimbula 0.01 4.8 0.002 0.01 

Pambula 0.01 7.6 0.02 0.14 

Curalo 0.80 11.7 3.07 4.70 

Wonboyn 0.05 11.5 0.06 0.66 

Nadgee 0.80 6.4 1.70 6.08 

1. Entrance Closure Index (ECI) – proportion of time entrance is closed (long term averaged) 

2. Evacuation Factor, dimensionless unit; higher number = lower tidal flushing potential 

3. Dilution Factor, mg/L; higher number = lower potential to self accommodate inputs 

4. Assimilation Factor, m; higher number = higher potential for variable water level 




Organic material enters an ICOLL from 

catchment runoff or from marine ingress. 

Bacteria then decompose this material, 

remineralising it back into inorganic nutrients 

(nitrogen, phosphorus, carbon) (Heggie et al., 

2003). 

Bacteria within the sediments can convert 

inorganic nitrogen into di-nitrogen gas (N 2 ) 

(called denitrification), which is then released 

to the atmosphere. The efficiency of the 

denitrification process is dependent on the 

amount of organic load in the sediment, the 

availability of oxygen within the sediment pore 

water and the presence of macrophytes 

(seagrass) and benthic algae in the sediment 

(Heggie et al., 2003; Harris, 2001b). Low 

denitrification efficiency will result in most of 

the organic nitrogen being recycled back into 

the water (in the form of ammonia), where it 

can lead to algae blooms. 

Benthic algae (which are micro and 

macroalgae living within the sediment) 

sequester (consume) nutrients released from 

the sediment, thus reducing nutrient levels 

within the water (Eyre & Ferguson, 2000). 

Photosynthesis by benthic algae also helps 

bacterial decay and denitrification processes 

within the sediment. Benthic algae are more 

prevalent in the shallow waters around the 

edges of ICOLLs than the deeper central 

basins (WBM, 2002). 

In oligotrophic ICOLLs, that is, systems that 

have a low level of nutrient input, benthic 

algae tend to dominate the biological 

processes. In eutrophic ICOLLs, however, 

that is, systems that receive high levels of 

nutrient input, phytoplankton (suspended 

mircoalgae) dominate the biology, and can 

‘shade’ benthic algae from the sun, which 

reduces benthic algae productivity, reduces 

denitrification efficiencies, and increases 

nutrient loads to the water (thus perpetuating 

further phytoplankton blooms) (Webster & 

Harris, 2004; Gay 2002). 

An initial phytoplankton bloom may be 

‘seeded’ by a catchment runoff event 

discharging inorganic nutrients to the 

waterway. Internal recycling of nutrients may 

then sustain the algae bloom for weeks to 

months after the catchment runoff event. The 

original external nutrient inputs may be 

recycled many times over before being 

removed from the system (Ryan, 2002; 

Heggie et al., 2003). 

‘Steady state’ water chemistry conditions in an 

ICOLL are established when nutrients recycled 

within the sediment are approximately 

balanced by uptake from benthic algae. In 

oligotrophic systems, the time to reach ‘steady 

state’ conditions would be relatively short, 

whereas in eutrophic systems, significant 

nutrient removal would first be required (via 

relatively inefficient processes). It is therefore 

considered that ‘steady state’ conditions may 

not be reached in many eutrophic systems 

before the next nutrient ‘seeding’ event (e.g. 

catchment runoff) (Harris, 1999b). 

Nutrient and Algae Dynamics 

The biophysical condition of an ICOLL is often 

in a state of transition, responding to 

antecedent catchment runoff events and 

continual coastal processes at the entrance. 

‘Typical’ water quality conditions in ICOLLs are 

difficult to define without extensive amounts 

of data. 

A number of data sources have been compiled 

by the author to provide an indication of 

“typical” water quality conditions within 

ICOLLs, including monitoring programs 

undertaken by state government as well as 

local authorities and university researchers. 

Whilst is it recognised that the resulting 

database is not extensive, it is considered 

reasonable for first-pass, or indicative, 

assessments. 

Analysis of the data shows that water quality 

conditions within ICOLLs can be correlated to 

the degree of development within the 

catchment. For example, ‘typical’ phosphorus 

concentrations show a distinct increase as the 

proportion of forested land within the 

catchment reduces (Figure 18). A similar 

correlation exists for chlorophyll-a (a de facto 

measure of the amount of phytoplankton 

within the water). 




Total Nitrogen (ug/L) 

Total Phosphorus (ug/L) 

120 

100 

80 

60 

40 

20 

0 

y = -112.22x + 117.02 

R 2 = 0.5089 

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 

Proportion of Catchment Forested 

Figure 18 Correlation between typical 

phosphorus concentrations and ICOLL 

catchment condition (measured by degree of 

disturbance) 

2000 

1800 

1600 

1400 

1200 

1000 

Prima facie, typical nitrogen concentrations for 

NSW ICOLLs show no correlation with the 

amount of development within the catchment. 

When the data is separated into ICOLLs that 

are mostly open and ICOLLs that are mostly 

closed, however, a distinct correlation 

emerged for mostly open ICOLLs (Figure 19). 

For ICOLLs that are mostly closed, it appears 

that the proportion of development within the 

catchment does not significantly affect the 

resulting nitrogen concentrations in the water 

(Figure 19). Further, the nitrogen 

concentrations in mostly closed ICOLLs are 

relatively high, even for near ‘pristine’ 

systems, exceeding the ANZECC (2000) 

guidelines for NSW estuaries. 

800 

600 

400 

Mostly Open ICOLLs 

200 

Mostly Closed ICOLLs 

y = -970.28x + 1062.2 

Linear (Mostly Open 

R 2 = 0.8447 

0 

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 

Percentage of Catchment in Forested Condition 

Figure 19 Correlations between typical Total 

Nitrogen and ICOLL catchment condition when 

factoring typical entrance condition 

It is therefore concluded that the 

predominant, or typical, condition of the 

entrance can influence the ‘typical’ water 

quality of an ICOLL (and nitrogen in 

particular). 

Water quality within an ICOLL can also change 

significantly as a result of an entrance 

breakout event. Pre and post-breakout data 

from a number of water quality investigations 

in NSW ICOLLs have been assessed, including 

the extensive Warringah lagoons database 

and university research undertaken by Daniel 

Wiecek, University of Wollongong. For most 

systems, significant reductions in several 

water quality parameters were recorded 

following entrance breakout, including total 

nitrogen, total phosphorus and chlorophyll-a 

(Table 5). 

Table 5 Difference in water quality 

before and after entrance breakouts 

Parameter 

Total Nitrogen (g/L) 

Oxidised nitrogen (g/L) 

Total Phosphorus (g/L) 

Chlorophyll-a (g/L) 

Median difference 

61% reduction 

86% reduction 

68% reduction 

52% reduction 

The dynamic nature of the entrance, 

combined with the intermittent nature of 

catchment runoff events and the variable 

interactions with the sediments, means that 

water quality within ICOLLs is naturally highly 

variable. Further, water quality monitoring 

typically records only the ‘bits left over’ after 

all internal biological and biogeochemical 

processes have taken place (Scanes et al., 

2002). Water quality data for ICOLLs should 

therefore be used with caution, particularly 

when used to justify particular management 

regimes (artificially opening an entrance for 

example). 




Biological Processes 

ICOLLs are ecotone environments (Vadineanu, 

2005) that provide habitat for both saltwater 

and freshwater species. Biological 

communities within ICOLLs are subject to 

change, depending on other environmental 

conditions. Estuarine vegetation in ICOLLs, 

given the diversity of water levels, is more 

variable than any other estuary type. 

Biological data presented by West et al. 

(1985) shows that saltmarsh is generally 

absent from ICOLLs that have substantially 

disturbed catchments. It is assumed that 

such development has extended to foreshore 

areas previously containing saltmarsh 

communities. 

West et al. (1985) also show that mangroves 

in ICOLLs are rare. Most mangrove 

communities in ICOLLs are found in small 

numbers, and in systems that are mostly 

open. There are some exceptions to this, 

however, with a number of mostly closed 

ICOLLs on the north coast of NSW also 

containing mangroves, including Pipe Clay 

Lake, Woolgoolga Lake, Deep Creek, 

Dalhousie Lake and Hearnes Lake. For some 

of these systems, mangrove pneumatophores 

(or peg roots / breathing tubes) have grown 

to be more an a metre in length (pers. 

comms., R. Glover, NRCMA, June 2004; L. 

Whetham, Coastcare, July 2005). This is 

assumed to be a natural adaptation to the 

highly variable water level regime experienced 

by these systems. 

Seagrass cover within ICOLLs is also highly 

dynamic. The significant variability in water 

levels would change light penetration to 

waterway beds, meaning that seagrass 

extents would be ever-changing, in response 

to changes in light availability. For ICOLLs 

that experience quite rapid water level 

variations (as identified by systems with a 

high morphometric-based Assimilation Factor 

– see previous discussion), seagrass tends to 

be absent (Figure 20). It is hypothesised that 

the water level variations are too rapid for 

seagrasses to continually adjust to. 

ICOLLs also tend to exhibit lower fish and 

macrofauna species diversity when compared 

to permanently open estuaries (Pollard, 

1994a; Roy et al., 2001; Williams et al., 2004; 

Dye and Barros, 2005), presumably due to the 

limited opportunity for migration between the 

90.0% 

80.0% 

Seagrass coverage of ICOLL bed 

70.0% 

60.0% 

50.0% 

40.0% 

30.0% 

20.0% 

10.0% 

Essentially zero seagrass cover for 

ICOLLs with AF > 10 

0.0% 

0 10 20 30 40 50 60 

Assimilation Factor 

Figure 20 

Relationship between the Assimilation Factor (AF) and seagrass coverage 

for most NSW ICOLLs (Haines et al., 2006) 




lake and the ocean when the entrance is 

closed. 

The state of the entrance (i.e. closed, shoaled 

or open) is therefore viewed as the single 

most important factor governing the biology of 

intermittently open and closed estuaries 

(Smakhtin, 2004). 

Artificial management of ICOLL entrances can 

result in a reduction of estuarine vegetation 

and wetland communities from foreshore 

areas. Truncation of the natural water level 

range (meaning that water levels no longer 

reach as high as under natural conditions) 

prevents the occasional saline inundation that 

is required by some estuarine wetland species. 

Without this periodic inundation, the wetland 

species no longer retain a competitive 

advantage over other terrestrial species, and 

the foreshore becomes ‘terrestrialised’. 

Artificial management of ICOLL entrances can 

also impact on fish recruitment patterns. 

Some attempts have been made in the past to 

artificially open ICOLL entrances to maximise 

juvenile prawn recruitment into the 

waterways. This practice is not supported by 

the NSW Department of Primary Industries 

(Fisheries). 

Human impacts on ICOLLs 

waterway health of ICOLLs, as discussed 

below: 

Catchment runoff has been altered for some 

ICOLLs by the construction of dams, river 

regulation and water extraction (Harris & 

Webster, 2004). These can significantly 

reduce freshwater inputs and can modify the 

natural entrance breakout frequency. 

Point source pollution from on-site sewage 

(septic) systems can increase nutrient loads 

to the waterway. As most ICOLLs within 

NSW are located in rural areas, on-site 

sewage systems surround most waterways. 

For ICOLLs with variable water levels, some 

on-site systems may even become 

inundated when ICOLLs levels are high 

(generally prompting artificial opening of the 

entrance as a mitigation measure). The 

impacts of many on-site sewage systems 

may increase during summer periods when 

there is a higher demand due to larger 

populations. 

Commercial and recreational use of ICOLLs 

is likely to result in waterway pollution due 

to littering (intentional or accidental) and 

direct pollutant discharges to the water (e.g. 

petro-chemical spills and leaks, 2-stroke 

motor use, sullage and holding tank 

disposal). 

Human impacts on the environmental 

processes of ICOLLs manifest principally from: 

 

 

Catchment development, and 

Entrance modifications 

Catchment development increases nutrient 

loads to downstream waterways, and modifies 

the form of the nutrients to be more readily 

available for algal uptake. 

Entrance modifications change the chemical 

and biogeochemical processes occurring 

within ICOLLs. 

In addition to these two principal drivers of 

human impact on ICOLLs, there are a number 

of other avenues whereby human activities 

can influence environmental processes and 





climate change 

Climate change, as a response to 

increased greenhouse gases in the 

Earth’s atmosphere, is now a widely 

accepted phenomenon. Impacts of a 

changing climate are already beginning to 

emerge (Steffen, 2006). For example, WMO 

(2005) state that, with the exception of 1996, 

the 10 years between 1996 & 2005 were the 

hottest years on record (globally averaged). 

In Australia, 2005 was the hottest year on 

record, at a temperature of 1.09C higher 

than the 1961-1990 average (BoM, 2007). 

The past five years in Australia have been 

consistently significantly hotter than the 

1961-1990 average (Figure 21). 

Figure 21 Australian average 

temperature variation, 1910 – 2006 

compared to 1961-1990 average, black line 

shows running 11 year average (Source: 

BoM, 2007) 

Mean sea level, on a global scale, has been 

increasing over the past century, due 

primarily to the thermal expansion of the 

oceans as ocean temperature has increased 

(Cabanes et al., 2001), as well as glacial 

melting (Walsh et al., 2002). Over the past 

50 years or so, the widely adopted average 

sea level rise has been approximately 

1.8mm/yr (Walsh, 2004; Church et al., 2005). 

Sea level rise has not occurred consistently, 

however, with the most recent trend (since 

the early 1990s) having an accelerated rise or 

around 3.4 mm/yr, as measured by satellite 

data (Figure 22). 

Figure 22 Global Mean Sea Level Rise, 

as measured by NASA satellites (Source: 

University of Colorado, 2007) 

The Australian CSIRO and NSW DECC have 

been undertaking investigations into the likely 

response of the Australian coastal 

environment to future climate change. Two 

pilot study areas have been targeted in NSW, 

the Wooli Wooli estuary on the North Coast, 

and Batemans Bay on the South Coast. These 

investigations (Macadam et al., 2007; McInnes 

et al, 2007) build on a raft of previous 

investigations and studies carried out by 

scientists across the globe (including IPCC), 

giving specific attention to the NSW coastline. 

The CSIRO investigations have given 

particular attention to the uncertainty of 

climate response models. In providing 

predicted outcomes, CSIRO adopted the result 

of two different regional climate models 

(CCM2 and CCM3) that were found to have 

distinctly different responses with regard to 

wind (considered to be once of the principal 

climate variables, as it drives a number of 

processes that influence coastal response). 

Both regional climate models adopted by 

CSIRO adopted a future CO 2 emissions rise 

that is considered sufficiently conservative for 

a risk averse approach to future decision 

making (McInnes et al, 2007). 

The outcomes of the CSIRO pilot 

investigations are summarised below. 




Average Temperature 

Macadam et al (2007) report changes to 

average temperature based on previous work 

by Holper et al (2006), scaled by global 

warming values to produce projections of 

change for 2030 and 2070. Using the two 

climate models and a range of global warming 

values, the daily maximum air temperature is 

likely to increase by between 0.5 and 1.5C by 

2030, and by between 1.1 and 4.6C by 2070 

(annually averaged). The annually averaged 

daily minimum air temperature is also likely to 

increase, by between 0.5 and 1.4C by 2030, 

and by between 1.1 and 4.3C by 2070. 

Average Rainfall 

As for average temperature, average rainfall 

estimates were determined based on work by 

Holper et al (2006). The changes in rainfall 

are given as the change in total quantity of 

rain falling on a unit area over a year. 

Macadam et al (2007) reports that at Wooli 

average annual rainfall will decrease by 

between 0 and 6% by 2030, while by 2070, 

annual average rainfall will decrease by 

between 0 and 19%. At Batemans Bay, 

however, average annual rainfall is likely to 

change by -8 to +10% by 2030, and by -23 to 

+30% by 2070, depending on the climate 

model adopted. The scenarios considered by 

Macadam et al (2007) showed considerable 

variation, highlighting the lower degree of 

certainty associated with future rainfall 

projections. 

Extreme Rainfall Events 

Extreme rainfall events have been considered 

previously by CSIRO (Hennessy et al., 2004). 

Extreme daily rainfall is predicted to be 

modified by future climate change (Walsh 

2004a,b; Hennessy et al., 2004) with 

potentially greater storm intensity even if 

overall precipitation decreases (Walsh, 

2004a). 

Consideration was given to 1 in 40yr, 1 in 

20yr, 1 in 10yr and 1 in 5yr rainfall events. 

Changes predicted by Hennessy et al. (2004) 

were averaged across return periods to give a 

single change for each simulation considered 

(Macadam et al., 2007). The intensity of 

extreme rainfall events is likely to change by 

between -10 and +10% (averaged annually). 

Typically the intensity of storms is more likely 

to increase during spring and summer, and 

decrease during autumn and winter. 

Drought Frequency 

Macadam et al (2007) refer to investigations 

carried out by Mpelasoka et al (2007), using 

CSIRO and Canadian Climate Centre 

modelling. The results of Mpelasoka et al 

(2007) suggest that the Southeast Coast 

Drainage Division, containing the NSW 

coastline, is likely to have an increase in the 

frequency of drought of up to 20% by 2030, 

and up to 40% by 2070. Drought is therefore 

projected to occur for up to 24% of months 

per decade by 2030, and up to 28% of 

months per decade by 2070. 

Average Solar Radiation 

Average solar radiation was assessed by 

Macadam et al (2007) based on previous work 

by Holper et al (2006). The solar radiation 

was defined as the energy transferred to a 

unit area by incoming shortwave 

electromagnetic radiation from the sun. It 

was assessed that the average solar radiation 

is likely to increase by between 0.1 and 0.6% 

by 2030, and by between 0.2 and 1.8% by 

2070 (annually averaged). Considerable 

variability in the average solar radiation was 

recorded between the different models and 

global warming scenarios, with some seasons 

reporting significantly greater increases (and 

even decreases) compared to the annual 

averaged values. 

Wind Speed and Direction 

McInnes et al (2007) used the CSIRO climate 

models to determine winds over 40 year 

periods centred on 1980, 2030 and 2070. A 

frequency analysis on daily average winds was 

carried out based on binned wind directions 

and wind speed classes. On an annual 

averaged basis, the models showed no 

difference in wind direction, indicating that 




any change in wind direction was less than 

45 (the resolution of the model). For wind 

speed, however, the percentages of time that 

winds from the dominant wind direction 1 were 

within the different wind classes were 

determined (McInnes et al 2007). The model 

results indicate only small differences (both 

positive and negative) in the percentage of 

time within each wind class for both 2030 and 

2070, when considered on an annual and a 

seasonal basis. 

Wave Height and Direction 

The wind speed changes calculated by 

McInnes et al (2007) were used to estimate 

changes to the ocean wave climate. Winds 

close to the coast were used to generate a 

time series of storm waves, while winds 

offshore were used to generate swell waves – 

the two time series were then combined. 

Storm waves originate most frequently from 

the southeasterly and southerly directions. 

Considerable variability in the models was 

found, with increases and decreases occurring 

in both climate models for different directions 

and time periods. However, the CCM3 model 

predicted an increase in the maximum storm 

wave height and period from the southerly, 

easterly and southeasterly directions in 2070. 

The frequency of occurrence of swell waves 

was found to increase, with a clockwise shift 

in swell waves by 2070. The average wave 

height and period of the swell waves are 

typically shown to increase. 

Storm Surge 

A 50 year return period storm surge level of 

0.61m +/- 0.12m was determined for Wooli 

and 0.66m +/- 0.13m for Batemans Bay, from 

extreme sea level residual data using a 

Generalised Pareto Distribution (GPD) 

(McInnes et al., 2007). The predicted change 

in frequency of storm waves was used to 

modify the GPD parameters. For 2070, the 50 

yr return period storm surge increased to 

0.64m +/- 0.14m using the CCM3 model, but 

1 Dominant wind direction is SE (annually), SE (summer), 

SE (autumn), S (winter) and N (spring) 

decreased to 0.59m +/- 0.11m using the 

CCM2 climate model. 

Sea Level Rise 

While there is a high degree of uncertainty 

with respect to projections for future change 

to rainfall and wave climate, future sea level 

rise is more certain. 

IPCC (2007) project an increase in mean sea 

level of between 0.18 and 0.59m by the end 

of the 21 st century, with the possibility of an 

additional 0.1 to 0.2m due to ice sheet flow. 

Further, CSIRO has predicted additional 

localised sea level rise of up to 0.12m on the 

east coast of Australia due to thermal effects 

of the East Australian Current (McInnes et 

al., 2007). 

Based on the trend measured by most recent 

satellite observations, it is likely that future 

sea level rise will track close to the upper 

limit of these projections, while a level of up 

to 1.4m above 1990 sea levels may be 

possible (Rahmstorf, 2007). 

Importantly, we must recognise that sea level 

rise will not stop at the end of this century 

(the limit of most reasonable projections). 

Indeed it is reported that the inertia of 

thermal expansion held within the oceans 

now will result in continued sea level rise for 

many centuries or even millennia, regardless 

of any future controls on CO 2 emissions or 

global air temperature changes. Thus, sea 

levels may be several metres higher than 

present before they once again stabilise, 

particularly if large land ice masses, such as 

Greenland, melt (IPCC, 2007). Such 

circumstances would essentially re-start 

geomorphic evolutionary processes on the 

coast, including the landward transgression 

of coastal barriers and the associated 

impoundments behind them. 

Sea level rise in Australia is also likely to be 

affected by the El Nino Southern Oscillation 

(ENSO), a decadal cycle characterised by 

periods of drought and dryer weather during 

the El Nino phase of the cycle, and relatively 

high rainfall and wetter weather during the 




La Nina phase. The likely effects of a warmer 

climate on the ENSO are not currently well 

understood. 

Impacts on ICOLLs 

As outlined before, the environmental 

processes of ICOLLs are largely driven by the 

condition of its entrance. Meanwhile, 

entrance behaviour is driven by the dynamic 

balance between catchment runoff (rain 

events) and ocean wave / beach processes. 

Future climate change is expected to change 

both rainfall and coastal processes. Climate 

change therefore will lead to potentially wide 

ranging changes to ICOLL environments 

(including physical, chemical and ecological 

processes that underpin local ecosystems). 

Given the uncertain context of climate 

change on rainfall and wave climate, the 

remainder of this chapter is primarily 

focussed on the potential impacts on ICOLLs 

of projected sea level rise. These impacts 

include: 

Increase in low tide (and high tide) levels, 

Increase in typical waterway depth, 

Shoreward translation and increase in 

entrance berm height, and 

Changes to entrance morphodynamics. 

Increase in Low Tide Level 

A major change to ICOLLs as a result of sea 

level rise will be an increase in low tide level. 

That is, ICOLL water level won’t get as low as 

under existing conditions, following breakout 

or when subject to normal tidal behaviour. 

For ICOLLs that are opened artificially (and 

assuming no change to the definition of the 

existing breakout trigger level), there will be 

less potential storage of water within the 

lagoon before the trigger level is reached. 

This will result in a more frequent need to 

artificially open the entrance (ie the trigger 

level will be reached more quickly following 

rainfall events). 

Maintaining a consistent entrance trigger while 

sea levels increase will be difficult, and can be 

regarded the equivalent as slowly reducing the 

trigger level if the sea was to remain static in 

time. Rising sea levels will therefore most 

likely necessitate more frequent artificial 

entrance management intervention. 

Further, due to the reduced hydraulic head 

across the entrance (ie difference in water 

levels between the lagoon and the ocean), 

the scouring processes associated with 

entrance breakout will be less effective. Less 

sand will be scoured from the entrance, 

leading to more rapid re-shoaling (and reclosure) 

of the entrance channel after the 

breakout event. 

Upward translation of low tide levels would 

potentially ‘drown’ existing fringing 

vegetation (eg mangroves in mostly open 

ICOLLs). Also, the increase in low tide levels 

would potentially elevate local groundwater 

tables around the lagoon foreshores. 

Increase in Typical Waterway Depth 

The typical water depth within the ICOLL will 

increase due to the increase in low tide (and 

high tide) levels. This may have impacts on 

benthic ecology, which has already adapted 

to existing light conditions, and geochemical 

processes within the sediments. 

Greater typical water depth over marine and 

fluvial deltas will likely result in vertical 

accretion of these primary deposition areas. 

Such accretion is expected to occur 

contemporaneously with the rate of sea level 

rise (ie, up to ~10mm/yr). 

Increased ICOLL depths will theoretically 

reduce the potential for mixing by wind 

driven circulation and stirring of fine bed 

sediments. This may lead to a greater 

potential for stratification, particularly within 

existing deeper areas of the ICOLL. 

Increased water depths, particularly within 

entrance channels, may also diminish the 

impact of specific flow controls, such as 

shallow rock shelfs and bars. If these 

controls currently help maintain a mostly 

open entrance condition, then the ICOLL may 




adopt a greater tendency for natural closure. 

Any changes to the connectivity between the 

ocean and the lagoon (because of reduced 

breakout frequency) may affect the tidal 

flushing capacity of the ICOLL and the 

oceanic recruitment and dispersal behaviour 

for fish, prawns etc. 

Shoreward translation and increase in 

berm height at entrance 

It is well understood that an increase in 

mean sea level would result in an upward 

and landward translation of ocean beach 

profiles (Bruun 1962, Dean and Maurmeyer 

1983, Hanslow et al. 2000). With respect to 

ICOLLs, a sea level rise will cause the 

entrance sand berm to move inland and to 

build up to a higher level relative to local 

topography. The increase in berm height is 

expected to match the increase in sea level 

rise, given that the berm is built primarily by 

wave run-up processes (Figure 23). 

The increase in entrance berm heights would 

be most apparent for mostly closed ICOLLs. 

For such systems, water levels would 

therefore need to reach a higher level before 

inducing a natural breakout to the ocean (in 

the absence of artificial intervention) (Haines 

and Thom, 2007). This may prompt an 

increased demand for artificial entrance 

manipulation in order to limit foreshore 

inundation, even for ICOLLs that currently 

are not subject to artificial entrance 

management. 

As the foreshores around ICOLLs are 

generally flat, the lagoon would actually store 

more water before a breakout occurs (as 

there is a non-linear relationship between 

ICOLL volume and water level). Therefore, 

ceteris paribus, the frequency of breakouts 

would reduce. Potentially exacerbating this 

outcome would be an increased evaporation 

from an ICOLL given its larger water surface 

area, and the higher air temperatures 

resulting from future climate change. 

Elevated water levels within ICOLLs, as a 

consequence of higher entrance berm levels, 

or higher tide levels, will potentially result in 

a landward migration of fringing lagoon 

vegetation. If vegetation communities cannot 

migrate upslope, however, due to 

obstructions or topography, then the 

vegetation communities may be lost 

altogether. 

Altered Entrance Morphodynamics 

An increased mean sea level will alter the 

existing dynamic balance of ICOLL entrances, 

which may change the proportion of time 

that the ICOLL is open or closed. Depending 

on the position of the entrance within the 

coastal compartment (ie at northern end, 

middle, or southern end), broadscale 

responses of adjacent ocean beaches to sea 

level rise may result in more, or less, sand 

availability within the entrance channel. An 

overall increase in water level is also likely to 

induce accretion, and possible landward 

progradation, of the marine flood tide delta. 

The tidal range within an ICOLL, when the 

entrance is open, is dependent on the flow 

constrictions imposed by the entrance. 

Under a higher sea level, and hence a higher 

lagoon level, the same tidal prism (ie the 

total volume of water held between low tide 

and high tide, which moves into and out of 

the lagoon) can be met by a smaller lagoon 

tidal range (given the larger lagoon surface 

area under higher water level conditions). 

Therefore, an increase in mean sea level will 

Figure 23 Shoreline response to increasing sea level (Source: Hanslow et al., 2000) 




not automatically translate to an equivalent 

increase in ICOLL water level. 

Entrance morphodynamic processes involve a 

complex interplay between beach processes 

(in particular, longshore sediment transport 

processes), tidal flows, and episodic rainfallinduced 

breakout or entrance scouring 

events. Consequences of sea level rise and 

indeed the broader climate change variables, 

on all these processes is difficult to predict 

and will most likely involve site-specific 

responses. 

Climate change conclusion 

Climate change is expected to have a wide 

range of impacts on ICOLLs. Sea level rise is 

arguably one of the most predictable climate 

change variables. Future sea level rise of up 

to 0.91m (McInnes et al., 2007), or even up 

to 1.4m (Rahmstorf, 2007) could be expected 

by the end of this century. Climate change, 

and sea level in particular, will have notable 

impacts on the behaviour of ICOLL entrances, 

which will potentially affect the fundamental 

structure of the lagoon ecosystem. 

Whilst it is relatively straightforward to assess 

the ‘theoretical’ impact of sea level rise on 

ICOLLs, it is more difficult to quantify the 

potential magnitudes of change. When 

considering all climate change variable, it 

may be possible that the impact of one 

climate variable could offset the impact of 

another, resulting in a net no change; or 

indeed that the impact of one variable may 

exaggerate the impact of another, making 

the result much worse than initially projected. 

As such, it is difficult, if not impossible, to 

predict the likely result on ICOLL processes 

once all factors are taken into consideration. 

Overall, it can be concluded that climate 

change is likely to have a significant and 

fundamental impact on ICOLLs in a range of 

different ways. Quantifying such impacts, 

however, would require site specific analysis, 

and a better appreciation of the likely change 

to some climate parameters as such changes 

start to manifest in the future. 



PART B 

MANAGEMENT OPTIONS 





strategies for sustainable management 

Aseries of management strategies have 

been developed to address the key 

management issues facing ICOLLs 

today (Table 6). 

The strategies target the four key areas of 

Catchment Management, Foreshore 

Management, Waterway Management, and 

Entrance Management. Strategies have been 

arranged to either involve works (eg, onground 

activities), or strategic planning (aimed 

at controlling future landuse). The different 

approaches to management primarily reflect 

the different organisations and institutions 

that have a role in ICOLL management. For 

example, Catchment Management Authorities 

and Natural Resources Departments within 

Councils would be responsible for works 

strategies, while Department of Planning, 

DECC and Strategic Planning Departments of 

Councils would be responsible for the Planning 

Strategies. 

in the following chapter, as a supplement to 

these management strategies. This includes 

changes to LEPs in light of the Standard 

Instrument LEP and intended reviews over the 

next couple of years. 

A total of ten (10) strategies have been 

developed, and are presented in detail in this 

chapter. These strategies target the physical, 

chemical and biological processes that 

dominate the structure and function of ICOLLs 

and their wider landscapes. 

There are many other strategies that can also 

be applied to ICOLLs and their catchments, 

including a wide range of conservation, 

natural resource management, indigenous 

management and education strategies. Many 

of these strategies are documented within a 

range of existing Plans, such as Catchment 

Action Plans or Plans of Management for 

National Parks. This booklet does not attempt 

to replicate these more general environmental 

strategies, but rather, provides largely unique 

strategies that specifically target the unique 

environments presented by ICOLLs. 

As well as addressing long-term sustainability 

of ICOLLs, the ten strategies attempt to 

redress some of the constraints and limitation 

that have hampered effective management of 

ICOLLs in the past. 

Recommendations regarding possible changes 

to specific planning instruments are provided 




Table 6 

Strategies for sustainable management of ICOLLs 

Catchment 

Management 

Planning 

1. Development planning to protect 

waterways 

Works 

2. Reduce pollutant runoff from 

existing catchment development 

through landuse diminution 

3. Revegetate critical areas of 

catchment landscapes, including 

corridors between similar 

environments, and connections 

between different but 

complementary habitats 

Foreshore 

Management 

4. Establish vertical and horizontal 

buffers around ICOLLs 

5. Opportunistically redress at-risk 

infrastructure around ICOLL 

foreshores to allow a more natural 


6. Stricter controls on on-site 

sewage management in low-lying 

and vulnerable areas 

Waterway 

Management 

7. Prevent dredging in ICOLL 

central basins 

8. Aquatic habitat restoration 

through re-establishing a more 

natural hydrology regime 

Entrance 

Management 

9. Formal entrance policies legally 

connected to relevant Plans of 

Management 

10. Artificially open ICOLL 

entrances only in accordance with 

best practice procedures 




Strategy 1. Development planning to protect waterways 

As for most situations, prevention is a more 

economic solution than treatment. Therefore, 

one of the most important duties of current 

ICOLL managers is to ensure that currently 

good to reasonable ICOLLs do not degrade 

any further. In order to conserve ICOLL 

environments that are currently in good 

condition, future development that potentially 

would increase pollutant loads and 

anthropogenic pressures should be limited 

within catchments of these more natural 

and/or highly valued ICOLLs. 

Some ICOLLs are in good condition and retain 

significant natural ecological value, while 

many other ICOLLs have experienced some 

catchment development, but as yet have not 

suffered significant environmental 

degradation. These ICOLLs may be ‘on the 

brink’ of degradation, and should be protected 

to avoid the systems falling into a downward 

spiral. Water quality data for NSW ICOLLs 

show that environmental conditions within an 

ICOLL notably deteriorate once natural 

vegetation is lost from more than half of the 

catchment. 

HRC (2002) provided a ranking of coastal 

lakes in NSW (including most ICOLLs) based 

on management needs. Lakes identified for 

‘Comprehensive Protection’ were 

recommended for the highest level of 

protection, while lakes identified as ‘Significant 

Protection’ were also regarded as requiring 

substantial conservation and management. 

For this strategy, the management ranking of 

HRC has been combined with the 

morphometric weighting for ICOLLs, as 

discussed previously (in particular the 

entrance closure index, as a surrogate for 

sensitivity to catchment inputs), to give a 

refined ranking of NSW ICOLLs for 

conservation purposes (Table 7). 

specifying where future development is 

considered most appropriate, and where 

future development should be limited. The 

Strategies aim to protect the valuable natural 

and scenic assets, biodiversity and unique 

character upon which the economic prosperity 

of the separate regions of NSW are based. In 

general, the Strategies recommend urban 

consolidation and continued development of 

land around existing urban centres, while 

minimising urban development around 

environmentally sensitive locations and 

productive agricultural land. 

The South Coast Regional Strategy is most 

relevant to the conservation of ICOLLs, as this 

area of the NSW coast contains the greatest 

number of ICOLLs, particularly those ICOLLs 

that have significant conservation potential. 

The South Coast Regional Strategy identifies a 

series of coastal lakes and estuaries (shown 

on Map 2 of the Strategy, but not listed) for 

which future urban or rural-residential 

development is not permitted (unless suitable 

water quality runoff from the development can 

be assured). The South Coast Regional 

Strategy also advises local councils to review 

the planning controls on both urban and 

undeveloped lands across the catchments of 

nominated coastal lakes (provided as 

Appendix 4 of the Strategy). On balance, the 

list of coastal lakes in Appendix 4 of the 

Strategy largely corresponds with the top two 

classifications of Table 7, with only a few 

exceptions, namely Kiah, Coila and Pambula 

Lakes. 

It is expected that the restrictions imposed on 

development within ICOLL catchments, as 

detailed below, can be incorporated into LEPs 

and DCPs as appropriate. Further 

recommendations for zonings around ICOLLs 

in accordance with the Standard Instrument 

LEP are provided in Chapter 7. 

Future development, at a regional scale, is 

guided by a series of Regional Strategies, 

which have been prepared by the Department 

of Planning over the past two years. These 

strategies are to inform future LEPs by 




This strategy recommends the following: 

For ICOLLs identified as Category A in Table 7, no further intensification of development be 

permitted anywhere within the ICOLL catchments. This would include for example, converting rural 

land to rural-residential land; small holdings to urban lots; forested land to cleared agricultural land; 

and general agriculture to improved or intensive agriculture. 

For ICOLLs identified as Category B in Table 7, any future intensification of development must 

demonstrate a neutral or beneficial impact on pollutant runoff to the ICOLL. This may be potentially 

achieved through pollutant offsets within the catchment. Development within the catchments of 

these ICOLLs would preferentially occur in areas that are already degraded, as this would represent 

the easiest opportunities for achieving a neutral or beneficial impact. Alternatively, any offsets 

offered against future intensification of development would likely address some of the impacts of 

existing degraded sections of the catchment. The offsets would operate similar to the recently 

introduced bio-diversity-based Biobanking scheme, except that the offsets would target catchment 

pollutant runoff specifically in order to maintain or improve the health of the ICOLL receiving water. 

For ICOLLs identified as Category C in Table 7, any future development must accord with best 

practice for pollutant runoff treatment and reduction. Best practice should incorporate stormwater 

management and total water cycle management. Water Sensitive Urban Design (WSUD) and 

Integrated Water Cycle Management (IWCM), which include practices such as water harvesting from 

rainwater tanks, dual reticulation systems, stormwater infiltration and greywater effluent reuse 

(WSUD, 2006; Engineers Australia, 2005), are regarded as current best practice for stormwater and 

urban water management. Pollutant runoff from developments that incorporate these water 

management principles can be reduced by up to 70% compared to standard urban development 

(Engineers Australia, 2005). 




Table 7 

Ranking of most NSW ICOLLs based on suitability for future development 

intensification 

Category A: 

(No further catchment 

development 

intensification) 

Arragan a 

Bondi a 

Baragoot b 

Bournda a 

Brou a 

Brunderee a 

Bunga b 

Durras a 

Kiah a 

Meroo a 

Nadgee a 

Nelson a 

Tarourga a 

Termeil a 

Wollumboola a 

Category B: 

(No increase in pollutants 

from the catchment) 

Back Lagoon b 

Bingie (Kellys) b 

Cakora b 

Candlagan b 

Cockrone c 

Coila c 

Congo c 

Conjola b 

Corunna b 

Curl Curl d 

Cuttagee b 

Dalhousie b 

Deep b 

Meringo b 

Middle (Tanja) b 

Mummuga b 

Oyster b 

Nargal b 

Pambula b 

Pipe Clay Lake d 

Smiths b 

Swan b 

Tabourie b 

Wallagoot b 

Wamberal c 

Wapengo b 

Willinga b 

Wonboyn b 

Category C: 

(Catchment development 

to best practice) 

Ainsworth d 

Avoca c 

Bellambi d 

Brush (Swan) c 

Bullengella c 

Burrill c 

Cudgen c 

Curalo c 

Dee Why d 

Hearnes c 

Illawarra d 

Kianga c 

Kioloa c 

Little (Narooma) d 

Little (Wallaga) c 

Macquarie d 

Manly d 

Merimbula c 

Murrah c 

Nangudga c 

Narrabeen c 

Narrawallee c 

Saltwater Lagoon c 

St Georges Basin c 

Terrigal d 

Tilba Tilba c 

Tuggerah d 

Tuross c 

Wagonga c 

Wallaga c 

Wallis c 

Werri c 

Woolgoolga c 

a: Classified as Comprehensive Protection in HRC (2002) 

b: Classified as Significant Protection in HRC (2002) 

c: Classified as Healthy Modified Conditions in HRC (2002) 

d: Classified as Targeted Repair in HRC (2002) 

Note, refer to Table 1 for full listing of ICOLLs and ICOLL definition / types. 




Strategy 2. Reduce pollutant runoff from existing catchment development through 

landuse diminution 

For an ICOLL that has unfortunately already 

become degraded, it is likely that significant 

efforts at catchment pollutant reduction will be 

required in order to have notable effects on 

the waterway environment (as a consequence 

of a ‘hysteresis’ effect; see Webster & Harris, 

2004). 

Usual options for reducing catchment 

pollutants typically include stormwater 

management (eg artificial wetlands), sediment 

ponds, improved farm management practices, 

vegetated buffer strips etc. However, most of 

these treatments generally target smaller 

catchment runoff events. Given their large 

storage volume, water quality within ICOLLs 

tends to be dominated by large rainfall and 

runoff events. It is these events that provide 

the nutrient ‘seed’ for algal growth and more 

general environmental degradation. Reducing 

catchment pollutant runoff during the big 

events is much more challenging, as 

traditional pollutant reduction methods rely on 

detention, infiltration and biological uptake 

(which all have a relatively slow response 

time). 

It is considered that the only effective means 

of addressing existing pollutant runoff to 

ICOLLs is to address existing landuse within 

the catchments of the ICOLLs. There is a 

weight of evidence demonstrating that 

intensification of landuse results in increasing 

pollutant loads (ie: forested < rural < ruralresidential 

< residential < industrial / 

commercial). It is posited therefore that to 

reduce catchment pollutants to ICOLLs a 

general diminution of landuse intensity will be 

required. 

In reality, the only diminution of landuse that 

is potentially feasible is to revert general 

farming / cleared land back to forested land. 

Once land has been developed with significant 

infrastructure (eg dwellings), any 

opportunities for landuse reversion are 

extremely limited. 

Revegetation of existing rural lands should be 

undertaken in accordance with individual 

Property Vegetation Plans (PVPs). Catchment 

Management Authorities are responsible for 

administering PVPs. It is considered that one 

of the key mechanisms for instigating 

revegetation of existing rural lands is the 

recently enacted Biobanking scheme. This 

scheme is based on establishing biodiversity 

offsets for proposed development that has a 

heavy environmental footprint. Another 

mechanism that may drive revegetation and 

reforestation of critical areas is carbon 

offsetting. Planting of native trees is currently 

one of the primary methods for offsetting 

carbon emissions (eg Greenfleet). 


 

 

 

Governments and government authorities actively pursue opportunities for native revegetation 

as formal offsets for carbon emissions as part of any future statutory or non-statutory 

requirements, 

Revegetation schemes associated with biodiversity and carbon offsetting target catchments of 

ICOLLs that have become degraded due to past landuse intensification. A key advantage of 

the revegetation within these areas would be a reduction in pollutant runoff to naturally highly 

vulnerable waterways, as well as increasing local (and regional) biodiversity, 

CMAs work with private landholders within ICOLL catchments to establish PVPs that include 

significant revegetation / reforestation. All possible opportunities for balancing the loss of 

economic productivity of the land associated with revegetation should be explored (including 

financing from carbon offsetting, Biobanking, trading of development rights etc). 




Strategy 3. Revegetate critical areas of catchment landscapes, including wildlife 

corridors between similar environments, and connections between different but 

complementary habitats 

This strategy involves the re-establishment of 

i) foreshore vegetation around individual 

ICOLLs, and ii) vegetated wildlife corridors 

across catchment landscapes to reconnect the 

lake environment with other habitat types, 

including other nearby estuarine environments 

as well as upslope habitats. 

Riparian vegetation plays a significant role in 

the ecosystem of an ICOLL, providing food 

and shelter for aquatic fauna when inundated, 

as well as a source of nutrients for ecological 

productivity. Riparian vegetation also provides 

habitat and refugia for wading birds (some of 

which may be threatened, eg Black Bittern) 

and other fauna, as it acts as a corridor for 

wildlife movement around the waterway 

fringe. Regeneration of ICOLL foreshores 

should consider any potential future change in 

typical lake water level, particularly if there is 

to be a change in standard entrance breakout 

level (refer Strategy 9). 

Vegetated wildlife corridors enable movement 

of species between primary habitats. This has 

potential advantages for food, shelter, genetic 

diversity, and providing access to alternative 

habitat during times of drought and bushfire. 

Wildlife corridors will also enable migration of 

species as they adapt to future changes in 

climate. 

Corridors should be at least 100 metres wide 

to maximise their use by wildlife, and to 

overcome ‘edge effects’. Even larger corridors 

would allow for greater utilisation by a wider 

range of species, especially macrofauna. 

Regional Strategies have identified some 

potential wildlife corridors as part of Regional 

Conservation Plans. A number of these 

corridors link ICOLL foreshores with nearby 

National Parks. 

Revegetation of ICOLL foreshores and 

potential wildlife corridors across catchments 

is most likely to be best facilitated through 

Private Vegetation Plan (PVP) agreements 

between individual property owners and the 

CMAs. 


 

 

 

Opportunities for creation of wildlife corridors that specifically link ICOLLs to other habitats 

(similar and complementary) are explored in detail. This should build on works already 

conducted as part of Regional Conservation Plans to ensure that ICOLLs specifically are 

connected to other highly valued habitats wherever possible. These corridors need to be 

‘earmarked’ (as per the corridors in the Regional Strategy) for consideration by future planning 

mechanisms and development opportunities, 

Priority is given to revegetation of ICOLL foreshores and other areas of critical importance that 

would enable wildlife passage between ICOLL foreshore and other habitats and environments, 

As for Strategy 2, CMAs work with private landholders within ICOLL catchments to establish 

PVPs that include significant revegetation / reforestation, with an emphasis on foreshore areas 

and areas that would create wildlife corridors. All possible opportunities for balancing the loss 

of economic productivity of the land associated with revegetation should be explored (including 

financing from carbon offsetting, biobanking, trading of development rights etc), 




Strategy 4. Establish vertical and horizontal buffers around ICOLLs 

Development around the foreshores of ICOLLs 

should be kept a sufficient distance away from 

the waterway to allow it to maintain natural 

functionality. ICOLLs have a significantly 

different water regime compared to other 

estuary types. Specific development buffers 

around ICOLLs are recommended, which cater 

for the natural processes causing foreshore 

inundation, and accommodate expected 

responses by the waterways to future climate 

change. 

Increasing coastal populations in the future 

will result in pressure to develop lands close to 

ICOLLs. When this pressure is combined with 

the potential physical response of coastal 

lakes to future climate change, the natural 

foreshores of ICOLLs will be ‘squeezed out’, 

significantly limiting their habitat and 

environmental values. 

Foreshore areas of ICOLLs are also likely to be 

relatively rich in Aboriginal cultural values and 

sites of significance. Establishing generous 

buffers around ICOLL foreshores is expected 

to provide an increased level of conservation 

for Aboriginal sites and associated relics. 

Similarly, the establishment of buffers for 

development around ICOLL foreshores is likely 

to reduce the potential for issues arising from 

exposure and disturbance of Acid Sulfate Soils 

(ASS). 

Future development buffers around ICOLL 

foreshores should based on a number of 

fundamental management principles: 

The ICOLL should be permitted to 

experience a full natural range of water 

level conditions; 

Water levels in the ICOLL will increase in 

the future as a natural response to 

increasing sea levels, and associated 

increases in entrance berm conditions; 

Groundwater levels will increase in 

response to sea level rise (Bird, 2002), 

which may compromise the existing 

functionality of foreshore landuses; 

 

 

 

Buffers should be provided around the 

ICOLL foreshores, beyond the natural 

range of water level conditions, to allow 

for natural ecosystem functioning, 

including an environmental corridor and 

adequate interaction between estuarine 

and terrestrial environments; 

Buffers around ICOLLs should be 

vegetated to maximize opportunities for 

ecological processes and for dissipating / 

assimilating the impacts of adjacent 

development; and 

Some ICOLLs are more sensitive than 

others, and thus may require additional 

buffering between the development and 

the waterway. 

When defining appropriate development 

setbacks, consideration should be given to two 

separate buffers (Figure 24). First, a vertical 

buffer should be established to allow for the 

natural expansion and contraction of the 

waterway, and for allowance of future sealevel 

rise. Second, a horizontal buffer should 

be established, landward from the lateral 

extents of the vertical buffer, to maintain 

riparian ecosystems, and to protect the 

waterway environment from the potential 

impacts of development. Instructions for 

establishing vertical and horizontal buffers are 

presented in Table 8. 

The concept of vertical and horizontal buffers 

around ICOLLs has been successfully applied 

by Coffs Harbour City Council at Hearnes 

Lake. Development buffers based on setbacks 

from the RL 3.5m AHD contour were 

prescribed within a site-specific DCP and LEP 

amendment. 





 

 

Local Environment Plans should be adjusted to prohibit future development within an 

appropriate buffer zone from ICOLLs. The buffer zone is to be determined giving consideration 

to firstly the vertical limit of water levels within the ICOLL within a reasonable planning horizon 

(say 100 years) and secondly to the minimum lateral requirement for an environmental buffer 

at the maximum water level. 

Appropriate buffer zones give consideration to the sensitivity and natural value of the ICOLL. 

In this regard: 

For ICOLLs identified as Category A in Table 7, no development should be permitted within 200 

metres of the ICOLL’s expected maximum water level in 100 years, 

For ICOLLs identified as Category B in Table 7, no development should be permitted within 100 

metres of the ICOLL’s expected maximum water level in 100 years, 

For ICOLLs identified as Category C in Table 7, no development should be permitted within 50 

metres of the ICOLL’s expected maximum water level in 100 years 

 

 

Buffer zones should be revegetated, as recommended by Strategy 3, using a range of 

opportunities and underpinned by PVPs, 

Buffer zones around ICOLLs should be returned to public ownership. 

Total buffer between water and 

development 

Horizontal buffer 

Vertical buffer 

Max. ICOLL WL 

Buffer to provide for 

ecological function 

around waterway 

foreshores 

Buffer to allow for 

the natural 

expansion of the 

ICOLL with time 

Figure 24 

Foreshore profile of an ICOLL illustrating the concept of vertical and 

horizontal buffers 




Table 8 

Definition of vertical and horizontal buffers around ICOLLs 

Defining a vertical buffer 

The vertical buffer should be defined as a specific 

level above a standard datum such as Australian 

Height Datum (AHD). The vertical buffer is to 

represent the approximate maximum water level of 

the ICOLL at the end of an appropriate planning 

horizon (ie 100 years). In this regard, the buffer 

incorporates two components, (i) a maximum water 

level, assuming no artificial entrance manipulation, 

which is determined by the maximum berm height at 

the entrance, and (ii) a factor for future sea-level rise. 

Maximum berm heights for ICOLL entrances in NSW 

are typically between RL 2m and 3m AHD (Gordon, 

1990; Hanslow et al., 2000), while current projections 

for future sea level rise suggest an increase in mean 

sea level of up to 0.91m (refer Chapter 5). 

As a default value, a vertical buffer of RL 3.5m AHD 

should be applied to all NSW ICOLLs, subject to more 

detailed site-specific assessments. 

Defining a horizontal buffer 

A horizontal buffer, beyond the lateral limit of the 

vertical buffer, is provided to maintain ecological 

functioning of the ICOLL and foreshore environments. 

Clearly, the larger the horizontal buffer the greater the 

protection of the ICOLL from catchment development. 

As a minimum, the horizontal buffer should be 50 

metres, consistent with an environmental corridor 

within the NSW Government’s methodology for 

“Strategic Assessments of Riparian Corridors”. 

For ICOLLs that are considered more sensitive or 

require more protection, the horizontal buffer should 

be increased. Table 7 should be used as a guide for 

different horizontal buffer widths. That is, Category C 

ICOLLs in Table 7 should have a 50m horizontal 

buffer, Category B ICOLLs in Table 7 should have a 

100m horizontal buffer, and Category A ICOLLs in 

Table 7 should have a 200m horizontal buffer. 

The horizontal buffer is to be measured landward from 

the lateral extents of the vertical buffer (eg typically 

the 3.5m AHD contour based on the default value). 

For periods when ICOLL water levels are not at their 

maximum, the buffer width would be larger than the 

minimum defined here. 




Strategy 5. Opportunistically redress at-risk infrastructure around ICOLL foreshores 

to allow a more natural hydrology regime 

This strategy is only applicable to ICOLLs that 

are currently subject to artificial entrance 

manipulation. For most ICOLLs that are 

artificially manipulated, assets, infrastructure 

and private lands have been established 

within the extents of natural inundation. 

Trigger levels for artificially opening entrances 

have subsequently been determined based on 

the level of potential risk or damage to these 

assets and infrastructure. 

Inevitably, future sea level rise will result in 

impacts on most low-lying infrastructure 

around ICOLLs and other coastal waterways. 

Appropriate forward planning for foreshore 

and fringing infrastructure and its on-going 

maintenance will be a fundamental 

component of future climate change 

mitigation and adaptation plans for local 

authorities and other land management 

authorities. 

This strategy recommends the opportunistic 

removal, relocation or flood-proofing of public 

and private assets and infrastructure so that 

trigger levels for entrance manipulation can be 

progressively increased in the future. 

Changes to assets and infrastructure should 

be carried out as the structures progressively 

require maintenance and/or redesign and/or 

replacement. In some instance, however, it 

may be appropriate to pro-actively modify 

assets and infrastructure to precipitate the 

opportunities for modifying entrance 

management regimes. 

Minimising the impacts of existing entrance 

management practices should initially target 

ICOLLs that are in a mostly good condition 

and/or contain significant habitat value. An 

indicative priority ranking of NSW ICOLLs that 

should reduce their reliance on artificial 

entrance management has been developed 

(Table 9). This priority ranking is based on 

the rankings provided in Table 7, but contains 

just those ICOLLs that are artificially 

manipulated. 

It is recognised that significant existing 

development (eg residential housing) may 

prohibit the complete return to natural water 

level regimes in some ICOLLs. In these 

circumstances, it may be acceptable that a full 

return to natural opening regime is 

unachievable. Nonetheless, there are 

substantial advantages to raising the opening 

trigger level as much as possible, including 

gaining some capacity to accommodate a 

degree of future sea level rise. 




This strategy recommends that the following steps be taken to restore a more natural entrance 

opening regime: 

1. Using land survey information, determine the ICOLL inundation extents based on i) the current 

entrance trigger level, and ii) the natural entrance breakout level (assuming no artificial 

intervention). If the natural entrance breakout level is not known, adopt as an interim default a 

level of RL 2m AHD for ICOLLs where entrances are located immediately adjacent to rocky 

headland, and RL 3m AHD for ICOLLs where entrances are located midway along a beach 

compartment. 

2. Itemise all public and private infrastructure located within ICOLL inundation extents determined 

at Step 1. Where available, ground levels associated with the infrastructure should be 

documented, along with the condition of the infrastructure and expected remaining lifespan. 

3. Prioritise public and private infrastructure identified at Step 2. Infrastructure that is lower, is in 

poorer condition, and has a shorter remaining lifespan should be given a higher priority for 

removal and/or re-location to higher ground. 

4. Progressively remove and/or re-locate prioritised infrastructure on an opportunity basis as the 

infrastructure becomes due for maintenance and/or replacement. 

For public infrastructure, the public authority should be required to relocate assets considered atrisk, 

particularly if a viable alternative location is available. These requirements could be 

incorporated into a Plan of Management, or similar, for the ICOLL, such as an Estuary 

Management Plan, Coastal Lake Management Strategy, or Floodplain Risk Management Plan. 

For private infrastructure, the requirement for re-location or modification to an asset would need 

to be tied to a special development control. As such, the ICOLL inundation extents determined 

at Step 1 would need to be incorporated into local planning instruments to map the area affected 

by the proposed restrictions on future development. Councils could define the inundation 

extents within a ‘planning overlay’ as part of their new LEPs to define them as areas having 

particular environmental qualities requiring special consideration, 

5. When the lowest lying infrastructure around an ICOLL becomes redressed, or is considered 

tolerable to periodic inundation, increase accordingly the artificial entrance trigger value 

(avoiding impacts on the next lowest critical infrastructure). 

6. If low-lying existing infrastructure is in good condition (and unlikely to require replacement within 

the next 10 years or so), investigate opportunities for modifying the infrastructure to make it 

tolerable to periodic inundation (eg raising road levels, flood-proofing pump stations etc). 




Table 9 

Prioritised ranking of manipulated ICOLLs in NSW for redressing ongoing 

entrance management issues 

Category A: 

Bournda a 

Brou a 

Durras a 

Termeil a 

Wollumboola a 

Category B: 

Back Lagoon b 

Cakora b 

Cockrone c 

Coila c 

Congo c 

Conjola b 

Corunna b 

Curl Curl d 

Middle (Tanja) b 

Mummuga b 

Smiths b 

Swan b 

Tabourie b 

Wallagoot b 

Wamberal c 

Category C: 

Avoca c 

Burrill c 

Curalo c 

Dee Why d 

Kianga c 

Manly d 

Narrabeen c 

Saltwater Lagoon c 

Terrigal d 

Tuggerah d 

Wallaga c 

Werri c 

Woolgoolga c 

a: Classified as Comprehensive Protection in HRC (2002) 

b: Classified as Significant Protection in HRC (2002) 

c: Classified as Healthy Modified Conditions in HRC (2002) 

d: Classified as Targeted Repair in HRC (2002) 

Note: Other ICOLLs not listed above may also be artificially managed from time to time. 




Strategy 6. Stricter controls for on-site sewage systems in low-lying and vulnerable 

areas 

In an assessment on conditions of septic 

systems in coastal NSW, Codd (1997, cited in 

Geary, 2003) reports failure of some 50-90% 

of systems investigated. The mostly rural 

landscape surrounding most ICOLLs in NSW 

means that there are many potentially failing 

on-site sewage systems that could be 

affecting and contaminating ICOLL waters. 

When the entrance of an ICOLL is closed, all 

inputs, including leachate from on-site 

systems, are retained within the waterway. 

Elevated concentrations of bacteria, other 

pathogens and algae can represent a 

significant public health risk. Paradoxically, 

the greatest risks of on-site sewage 

contamination are likely to occur during peak 

holiday seasons (with maximum load on onsite 

systems), when demands on recreational 

amenity of the ICOLL are also a maximum. 

of the maximum inundation extents of the 

ICOLL, or have a ground elevation within 2 

vertical metres of the maximum inundation 

level. For circumstances whereby the 

inundation extents are progressively expanded 

due to an increase in breakout level (as 

recommended by Strategy 9), the area of 

stricter compliance should also be expanded 

with time. 

Where repairs to existing on-site systems 

cannot meet the stricter compliance 

requirements, property owners should replace 

existing systems with more eco-friendly 

alternatives, such as Aerated Wastewater 

Treatment Systems (AWTS), sand filters, 

biological filters, reverse osmosis or microfiltration 

filters, waterless composting toilets 

and greywater reuse systems. 

It is considered that the low-lying lands 

immediately surrounding ICOLLs are largely 

unsuitable for on-site sewage systems that 

rely on infiltration and absorption, given the 

variable water levels, and hence variable 

groundwater levels. Further, for some 

ICOLLs, artificial entrance breakouts are 

initiated inter alia because of flooding on-site 

sewage systems. 

Local Councils are generally responsible for 

the periodic inspection of on-site systems, 

with compliance requirements prescribed in 

various Council policies and other planning 

instruments. This strategy aims to reduce the 

potential for leachate and contamination from 

on-site systems to affect ICOLL waters by 

ensuring that on-site systems in low-lying and 

vulnerable areas meet the highest standard 

for effectiveness and minimal environmental 

impact. 

As an initial guide, and in the absence of a 

more detailed hydrogeological vulnerability 

assessment, it is suggested that critical areas 

that should meet an enhance level of 

compliance would be those areas within 500m 





 

 

 

 

A minimum standard compliance criteria be developed by individual councils in consultation 

with DECC. In the absence of site-specific soil details, this should be based on “typical” alluvial 

soil conditions around ICOLLs, and assuming shallow groundwater tables. 

The revised compliance criteria should be applied to all on-site systems within 500 metres, or 

within 2 vertical metres, of the maximum inundation extents of an ICOLL. All non-compliant 

systems should be repaired, or replaced as necessary, in order to meet the new criteria. 

For new developments, no on-site systems that rely on infiltration or absorption should be 

permitted within the critical areas surrounding an ICOLL. 

The critical area surrounding an ICOLL should be increased appropriately if the maximum 

water level of the ICOLL is permitted to increase in the future. 




Strategy 7. Prevent dredging in ICOLL central basins 

ICOLLs are natural depositionary 

environments (Roy et al., 2001). Their 

physical structure has generally been 

established over the past 6000 years, in 

response to catchment and coastal sediment 

processes. Most larger ICOLLs contain three 

distinct zone: the fluvial delta, the central mud 

basin, and the flood tide delta (Roy et al., 

2001). The fluvial delta is where coarse 

sediments from the catchment are deposited. 

The central mud basin is where fine sediments 

from the catchment are deposited, and the 

flood tide delta contains marine sands washed 

in by flood tide processes. 

The flood tide delta is highly dynamic, and can 

be washed out and then rebuilt following 

every entrance breakout event. The fluvial 

delta also is quite dynamic due to the higher 

velocities associated with catchment inflows. 

The central mud basins, however, are 

essentially large silt traps, with generally slow 

accumulation of fine sediment. Wind driven 

circulation within these basins can result in an 

even settlement pattern, thus giving a flat 

bottom profile to ICOLLs (especially ICOLLs 

that are more circular in shape - ie are ‘mixing 

dominated’ systems – see Figure 17). 

It is considered that modifying the bathymetry 

of an ICOLL through dredging can influence a 

number of knock-on processes, including 

sedimentation, water quality and benthic 

ecology. For example, dredging within the 

central mud basin will lead to preferential 

sedimentation with the dredged area due to 

the reduced water circulation. Further, given 

the fine grained bed material within the basin, 

existing sediment would be readily mobilised 

and transported into the dredge hole resulting 

in accelerated rates of infill. Depending on the 

depth of the works, dredging may also lead to 

stratification, which in turn may influence 

localised biogeochemical processes (which 

may be exacerbated further if the dredge hole 

preferentially accumulates organic matter and 

other detritus). 

Dredging within the flood tide delta is 

considered less of a concern given its natural 

dynamic state, while dredging within the 

fluvial delta may have some environmental 

impacts, but is generally considered not as 

significant as dredging within the central mud 

basin. 


 

 

 

Provisions be included within local planning instruments that prohibit dredging (of any sort) 

from within the central mud basins of ICOLLs. This would most conveniently be included as a 

provision within new LEPs based on the specific waterway zoning given to the ICOLL 

waterbody. 

Amendments be made to SEPP (Infrastructure) 2007 that currently allow ‘environmental’ 

dredging without the need for consent under standard LEP provisions within the central mud 

basins of ICOLLs. 

All new Coastal Zone Management Plans (CZMPs) for ICOLLs specifically recommend against 

dredging within the central mud basins. To facilitate this, it is recommended that the draft 

Coastal Zone Management Manual be amended to standardise future CZMPs for ICOLLs to 

include this particular provision. 




Strategy 8. Aquatic habitat restoration through re-establishing a more natural 


The bathymetry of ICOLLs is generally quite 

simple. With a large flat bottom and relatively 

small fluvial and marine deltas, the aquatic 

habitat complexity of ICOLLs is driven 

primarily by variability in water levels. 

As outlined in Strategy 7, physical changes to 

the bathymetry of an ICOLL would be counterproductive. 

Improvements to the complexity 

and diversity of aquatic habitats should 

therefore be derived by re-establishing a more 

natural and variable water level regime. 

For ICOLLs that are artificially managed, the 

range of water levels is restricted. This means 

that there is a commensurate restriction in the 

extents of inundation around the ICOLL 

foreshores, and thus a restriction in the 

shallow, ephemeral and ecologically diverse 

habitats that exist around the foreshores. 

In an assessment of macrofauna within 

ICOLLs, Dye and Barros (2005) demonstrate 

that the central mud basins contain lower 

fauna diversity and abundance than the 

waterway fringes. Although mostly open 

ICOLLs contain greater diversity of aquatic 

species than mostly closed ICOLLs (Pollard, 

1994a; Roy et al., 2001; Williams et al., 2004, 

Dye and Barros, 2005), water level variability 

is generally more restricted in mostly open 

ICOLLs, resulting in relatively confined 

ephemeral (intertidal) zones around the 

foreshores. 

period between breakouts therefore allows 

these processes to become more mature and 

thus more complex in their interactions and 

knock-on influences. 

It is recommended that improved potential for 

aquatic habitat within ICOLLs be achieved by: 

i. Reducing the frequency of artificially 

opening an ICOLL; and 

ii. 

Increasing the artificial breakout trigger 

and thus increasing the potential for 

periodic foreshore inundation. 

These steps are preferred when compared to 

the introduction of artificial structural works 

within an ICOLL waterway, such as ‘reef balls’, 

or ‘environmental dredging’. Consideration 

should also be given to removing existing 

structures that currently degrade aquatic 

habitats, such as jetties that shade seagrass 

beds, or swing moorings that completely 

scarify bed surfaces through dragging of slack 

mooring chains. 

As outlined previously, ICOLLs that have a 

highly dynamic water level (and thus a large 

Assimilation Factor) tend to be absent of 

seagrasses. It is hypothesised that the 

changes in water level within these ICOLLs 

occur too rapidly for the seagrasses to 

continually adapt to the varying light 

conditions (given the varying depths of water) 

and the potential frequency of desiccation. 

Also, it is considered that some ecological 

processes essentially ‘reset’ each time an 

ICOLL breaks out, which causes draining and 

exposure of bed sediments. Extending the 




For ICOLLs that are artificially opened from time to time, this strategy recommends the following: 

 

 

 

 

 

Increase the permissible range of water levels within the ICOLL by increasing the trigger level 

for artificial breakouts. The additional storage within the ICOLL that would be achieved by this 

change would reduce the need to undertake artificial breakout activities, and thus would 

reduce the frequency of breakouts for the ICOLL. 

Change to the artificial entrance breakout procedures would need to be incorporated into a 

formal entrance management plan (refer Strategy 9). 

Infrastructure inhibiting the ability to increase the artificial breakout trigger should be removed, 

relocated or flood-proofed (refer Strategy 5). 

Physical works within an ICOLL waterbody to improve aquatic habitat should be considered 

only when changes to the hydrology regime cannot be practically achieved. 

A desire to improve aquatic habitats within ICOLLs that already experience a natural hydrology 

regime should be scientifically justified, recognising that ICOLLs (and in particular mostly 

closed ICOLLs) contain a naturally lower diversity of aquatic species than other estuary types. 




Strategy 9. Establish entrance management provisions within statutory planning 

instruments 

The entrances of more than half of the ICOLLs 

in NSW are artificially opened from time to 

time. Artificial entrance manipulation has 

been adopted as a ‘quick fix’ to manage the 

issue of inappropriate landuse planning 

around waterway foreshores in the past. 

Interestingly, few of these ICOLLs have 

specified plans or policies that aim to control 

such activities, and fewer still actually hold 

legal status. For example, even if a council 

has an entrance management policy, if the 

entrance is located on Crown land with a Plan 

of Management, unless artificial entrance 

management is included within the Plan of 

Management, it is deemed an illegal activity. 

To the author’s knowledge, entrance 

management provisions are not included in 

any Plan of Management for a Crown reserve. 

Clearly it is not feasible to simply prohibit 

entrance management activities in those 

systems that are reliant upon it for flood 

mitigation and asset protection. Rather, 

formal entrance management provisions 

should be incorporated into statutory 

instruments, such as Plans of Management for 

Crown reserves as well as Local Environment 

Plans (LEPs). To stream-line future entrance 

management activities it is recommended that 

special local provisions are included within 

LEPs. Given that all LEPs across NSW are 

currently undergoing review to accord to a 

Standard Instrument LEP, an opportunity 

exists to standardise entrance management 

provisions as part of the LEP template (see 

Figure 25). Example LEP provisions regarding 

entrance management are provided and 

discussed further in Chapter 7. 

Since entrance management activities are 

usually required to be carried out at short 

notice, in response to rapidly changing 

environmental conditions, the development 

consent process under Part 4 of the EP&A Act 

is not an ideal mechanism for environmental 

assessment and authorisation. For this 

reason, it is recommended that any special 

entrance management provisions exclude the 

need to obtain development consent, thereby 

bringing the activities under Part 5 of the 

EP&A Act. This concession should only apply 

where the activities are specifically authorised 

by provisions (termed ‘entrance management 

provisions’) contained within an applicable 

Plan of Management that is adopted under 

relevant legislation relating to various 

categories of public land (Crown Lands Act, 

Local Government Act, etc). 

The effect of the entrance management 

provisions is that prior consideration will need 

to be given to entrance management when 

developing (or updating / modifying) the 

applicable Plan of Management. Any prior 

consideration would need to include address 

issues such as environmental impacts, 

consistency with sustainability and risk 

management principles, statutory approvals, 

climate change impacts, public consultation, 

notification procedures and periodic 

evaluation and review. 

Entrance management provisions should 

therefore include (for example, as an 

appendix or a supporting volume) a formal 

Review of Environmental Factors (REF), 

covering all works authorised by the 

provisions. The REF should be suitable for 

assessment under Part 5 of the EP&A Act, 

and applied whenever entrance management 

works are required. However, it is important 

that the REF be applied having regard to any 

change in conditions that has or is likely to 

have occurred during the intervening period. 

The entrance management provisions should 

provide detailed instructions on when and 

how to manage the ICOLL entrance, in 

response to a range of potential public health 

risks, property damage risks, and 

environmental risks (Figure 25). In addition 

to the management of maximum water levels 

(as per the historical approach), ICOLL 

entrances may also be managed for water 

quality improvement, with specific water 

quality triggers defined to initiate opening 

protocols. Water quality triggers should 

relate to demonstrable public health and 




safety risks, and may vary during the year 

depending on the risks to the public (eg 

higher risks during summer when utilised 

more). 

provide consistency with the state-based 

approach as directed by the SEPP. 

Given the broad application of artificial 

entrance management of ICOLLs across the 

NSW coast, special entrance management 

provisions (as presented in Chapter 7) should 

ideally be considered for inclusion as optional 

provisions within the Standard Instrument 

LEP. This would promote a consistent Statewide 

approach to entrance management. The 

provisions could also be broadened to 

encompass a wider range of management 

activities undertaken by public authorities on 

public land within the coastal zone. 

On 1 st January 2008, SEPP (Infrastructure) 

2007 came into effect. As outlined in 

Chapter 2, SEPP (Infrastructure) 2007 

provides for exception of development 

consent for a range of activities applicable to 

ICOLLs, including flood mitigation works. 

This SEPP can therefore be used as a 

statutory basis for artificially opening an 

ICOLL entrance, providing those works are 

for flood mitigation. In applying the 

provisions of SEPP (Infrastructure) 2007, a 

council would still be required to fulfil 

obligations under Pt 5 of the EP&A Act 1979, 

including preparation of an REF. 

It is considered that the recommendations 

made above in respect to the Standard 

Instrument LEP should be equally applied to 

SEPP (Infrastructure) 2007 (Figure 25). That 

is, the instrument should be amended to 

require entrance management works in 

ICOLLs to be exempt from development 

consent only if the works comply with special 

entrance management provisions included 

within an approved Plan of Management. 

As the existing provisions of SEPP 

(infrastructure) 2007 only relate to flood 

mitigation works, it is considered that 

proposed provisions still be incorporated into 

future LEPs to allow for future entrance 

works under a wider range of environmental 

objectives. Changes to the LEP would also 





 

Standard provisions be included within LEPs and SEPP (Infrastructure) 2007 that allow specific 

ICOLL entrance management activities to be exempt from development consent. These 

activities must be included within special ‘entrance management provisions’ documented as 

part of statutory Plans of Management of the lands covering ICOLL entrances. 

For lands covered by an existing Plan of Management, these provisions need to be inserted as 

an amendment to the Plan, 

For lands not covered by an existing Plan of Management, an entirely new Plan will need to be 

prepared incorporating the special entrance management provisions. 

 

 

 

 

 

The Plans of Management will need to identify all the potential statutory approvals required to 

undertake the entrance management activities. A range of approvals may be required given 

potentially different land tenures, zonings etc, including a Crown lands licence (refer Part 4, 

Division 4 of the NSW Crown Lands Act 1989), a fisheries dredging permit (refer Division 3, 

Part 7 of the NSW Fisheries Management Act 1994), or other approvals / licences under the 

National Parks and Wildlife Act 1974 or the Marine Parks Act 1997. 

An REF be prepared to accompany the Plan of Management that identifies and addresses any 

potential environmental impact of the entrance management activities. 

Appropriate agency and public consultation be undertaken in developing (or amending) the 

Plan of Management. 

Entrance management provisions should contain specific requirements for periodic review (say 

every 5 years), including a re-evaluation of environmental impacts, and updating of the 

accompanying REF 

A notice under Section 117 of the EP&A Act be issued requiring councils to include entrance 

management provisions for ICOLLs within their LEPs and to amend or create as appropriate 

Plans of Management for the lands at ICOLL entrance that incorporate these entrance 

management provisions within the appropriate statutory framework. 




CZMM – instructions 

S733 Notification 

Standardized LEP / 

SEPP (Infrastructure) 

2007 

Entrance 

Management 

Provisions 

Management 

Plan 

Review of 

Environmental 

Factors 

Entrance 

Mgt Activities: 

How, when, who etc 

Stat. authorisations, 

Consultation, review 

Climate change, especially 

sea level rise 

Figure 25 

Scope and Context of Recommended Entrance Management Provisions 




Strategy 10. Artificially open ICOLL entrances only in accordance with best practice 

procedures 

In addition to the Entrance Management 

Provisions discussed in Strategy 9, it is 

recommended that any entrance management 

activities are conducted in strict compliance 

with a pre-defined set of procedures. These 

procedures should be established as bestpractice 

for each individual ICOLL, and should 

be derived from i) a detailed understanding of 

the environmental processes within the 

ICOLLs, and ii) experience in undertaking 

artificial entrance openings at the ICOLL in the 

past (ie what works, what doesn’t). 

Entrance opening procedures should be 

outlined in an Entrance Management 

Operational Plan (EMOP). The EMOP should 

stipulate when and how to open the ICOLL 

entrance, giving specific trigger values for 

water levels etc, and concurrent desirable 

environmental conditions, such as tides, wave 

conditions, anticipated rainfall etc. It should 

also provide for a check on local shorebird 

activity (roosting / breeding). 

The EMOP would be comparable to existing 

Entrance Management Plans / Policies, and 

would specify who is responsible and who has 

delegated authority for undertaking the works. 

It should detail monitoring requirements, 

trigger levels for action, and detailed steps of 

how to open the ICOLL entrance (including 

specifications for pilot channel width depth, 

location and how to construct, eg from the 

ends inwards leaving a narrow plug to be 

removed quickly at the end). Depending on 

the environmental conditions at the time of 

opening, follow-up excavation works within 

the entrance channel may be required to 

ensure that it achieves the desired objectives. 

The EMOP should also outline measures to 

preserve the safety of workers and the public 

during and following the entrance opening 

works, as well as a monitoring program to 

obtain information and gain a better 

appreciation of the entrance behaviour 

following entrance breakout. 

Triggers defined within the EMOP should be 

given as a range of water levels (or range of 

water quality parameters if this is desired), 

rather than an absolute value. This would 

give the opportunity to be more flexible in 

delaying excavation works until more desirable 

environmental conditions are available (eg 

tides, waves etc). A range of breakout levels 

would also enable the ICOLL to reach different 

maximum water levels each time. This would 

prompt greater diversity in habitat around the 

foreshore compared to having a single 

maximum water level. 


 

 

 

 

Councils and other authorities responsible for ICOLL entrance management should prepare 

EMOPs for each ICOLL that requires artificial entrance manipulation. An example table of 

contents for an EMOP is provided in Table 10. 

Councils and other relevant authorities undertake entrance management of ICOLLs in strict 

compliance to the EMOPs only. 

EMOPs should undergo periodic review, taking into account outcomes from additional research, 

monitoring and experience in undertaking the entrance management works. 

A notice under Section 117 of the EP&A Act be issued requiring councils to prepare EMOPs and 

undertake entrance management of ICOLLs only in strict compliance with the EMOPs. This 

notice would be tied to the S117 notice requiring councils to include entrance management 

provisions within appropriate planning instruments, as recommended in Strategy 9. 




Table 10 Example Table of Contents for an Entrance Management Operations Plan (EMOP) 

1. Preliminaries 

- Purpose of document 

- Objectives / justification for works 

- Responsibilities 

- Contacts 

- Approvals / licences 

- Plans of Management / Entrance Management Provisions 

- Document review 

- Definitions 

2. Triggers 

- Monitoring requirements (water levels, water quality variables, other environmental triggers) 

- Specification of trigger ‘range’ for different variables (eg water levels, water quality, etc). Triggers may be 

different depending on season. 

- Measurables against objectives (to determine if works are successful or not) 

3. Responses 

- Actions when lower bound of ‘range’ is reached (eg prepare for opening, but delay until most desirable 

concurrent environmental conditions are available). Actions may be different depending on season. 

- Actions when upper bound of ‘range’ is reached (eg open entrance immediately regardless of concurrent 

environmental conditions). Actions may be different depending on season. 

- Actions / contingencies if objectives of opening are still not met (determined through measurables) 

4. Desirable Concurrent Environmental Conditions 

- stage of diurnal tide (ie high / low) 

- stage within fortnightly tidal cycle (ie spring / neap) 

- ocean conditions (waves, storm surge) 

- seasonality (eg breeding / roosting of shorebirds) 

- rainfall (including predicted) 

5. Opening Procedures 

- channel location 

- channel dimensions 

- order of excavation works 

- Access 

- Spoil disposal 

- OH&S / safety measures 

6. Closing Procedures (as relevant) 

- source of material 

- order of infill works 

7. Other Considerations (as relevant) 

- seaweed ingress into channel 

- odour and organic decay following breakout 

- mosquitoes and biting midge 

- Caleurpa taxifolia 

8. Record of Entrance Openings 

- dates, times, environmental conditions, triggers, channel dimensions, staff involved, photos 

- post-opening recovery / entrance re-closure 

9. Document Amendments Record 





ecommended changes to the planning framework 

Presented below are a series of 

recommended changes to a number of 

NSW environmental planning 

instruments that would potentially improve the 

long term sustainability of ICOLLs. 

LEP Zonings 

Presented below are recommendations for 

landuse zonings within and around ICOLLs in 

accordance with the Standard Instrument LEP 

(refer Table 11). These zonings 

recommendations should be considered by 

councils as part of proposed LEP reviews. 

Waterways 

Many studies have been carried out on the 

ecological values of ICOLLs in NSW, which 

conclude that they play a significant role in the 

total fisheries value of the state and adjacent 

coastal waters (eg Pollard, 1994a; Pease, 

1999). With respect to conservation, Jones 

and West (2005) suggest that measures to 

protect fish diversity within ICOLLs should be 

carried out at a ‘whole-of-lake’ scale, rather 

than selective ‘sanctuary’ areas within the 

waterway. In recognition of this, ICOLL 

waterways should be zoned W1 – natural 

waterways. The landward limit of this zoning 

should be the maximum landward extent of 

inundation when the ICOLL is at maximum 

water level. For artificially opened ICOLLs, 

this would correspond to the maximum level 

that the ICOLL is permitted to reach before 

intervention. For natural systems, the 

landward limit would correspond to maximum 

inundation behind a natural berm height 

(typically between RL 2 and 3m AHD). The 

opportunity exists for the definition of the 

waterway zoning to incorporate provisions for 

future sea level rise (ie increase the lateral 

extents beyond existing inundation areas to 

cater for a future increase in maximum water 

levels). 

The entrance area of ICOLLs subject to 

artificial opening should be included within the 

W1 – natural waterways zoning. 

Foreshores 

Surrounding the ICOLL should be a riparian 

conservation area, zoned E2 – environmental 

conservation. The width of this conservation 

zone should correspond to the recommended 

buffer, as outlined in Strategy 4. That is, 

Category C ICOLLs in Table 7 should have a 

50m conservation zone, Category B ICOLLs in 

Table 7 should have a 100m conservation 

zone, and Category A ICOLLs in Table 7 

should have a 200m conservation zone. 

Table 11 Standard Instrument LEP landuse zonings (NSW Government, 2006) 

Rural Zones Residential Zones Business Zones Industrial Zones 

RU1 – primary production R1 – general residential B1 – neighbourhood centre IN1 – general industrial 

RU2 – rural landscape R2 – low density 

B2 – local centre IN2 – light industrial 

RU3 – forestry 

residential 

B3 – commercial core 

IN3 – heavy industrial 

RU4 – rural small holdings R3 – medium density B4 – mixed use IN4 – working waterfront 

RU5 – village 

residential 

B5 – business development 

RU6 - transition 

R4 – high density 

residential 

R5 – large lot residential 

B6 – enterprise corridor 

B7 – business park 

Special Purposes Recreation Environmental Protection Waterways 

SP1 – special activities RE1 – public recreation E1 – National Parks and Nature W1 – natural waterways 

SP2 – infrastructure RE2 – private recreation 

Reserves 

W2 – recreational 

SP3 - tourist 

E2 – environmental conservation 

waterways 

E3 – environmental management 

E4 – environmental living 

W3 – working waterways 




Catchment 

Within the catchments of ICOLLs areas of 

substantial vegetation on public or private 

land should be zoned for environmental 

protection. Of particular importance are 

existing wildlife corridors, which should be 

zoned E2 – environmental conservation, while 

potential corridors subject to revegetation 

(refer Strategy 3) should be zoned E3 – 

environmental management. 

Other areas within the catchment should be 

zoned according to existing landuses, with due 

consideration to recommendations for future 

intensification of catchment development as 

outlined in Strategy 1. This includes no 

further allowance for future intensification of 

development within the catchments of 

Category A ICOLLs in Table 7. 

LEP Provisions 

Strategy 9 recommends the inclusion of 

specific provisions within individual LEPs that 

address entrance management of ICOLLs, and 

streamline the process for undertaking 

entrance management works. Suggested 

entrance management provisions have been 

drafted and are presented in Table 12. It is 

recommended that these provisions be 

included within the Standard Instrument LEP 

or within individual LEPs for LGAs that 

contain ICOLLs. 

The provisions exclude to need to obtain 

development consent for entrance 

management works, providing that the works 

are specifically authorised by provisions 

(termed ‘entrance management provisions’) 

contained within an applicable plan of 

management that is adopted under relevant 

legislation relating to various categories of 

public land (Crown Lands Act, Local 

Government Act, etc). 

It should be noted that the entrance 

management provisions do not prevail over 

any requirement for approval under Part 3A 

of the EP&A Act (for example, where the 

works constitute an ‘extractive industry’), 

nor any requirement for development 

consent under various State Environmental 

Planning Policies. Approval requirements 

under other legislation are also unaffected by 

the provisions. 

Plans of Management 

As outlined above, the recommended LEP 

provisions allow entrance management 

activities that are explicitly authorised by 

‘entrance management provisions’ 

contained within an adopted plan of 

management for an ICOLL. This may include 

any plan of management prepared for the 

ICOLL and surrounding land made under the 

provisions of: 

• Division 2 of Part 2 of Chapter 6 of the 

Local Government Act 1993 (relating to 

community land), or 

• Division 6 of Part 5 of the Crown Lands 

Act 1989 (relating to a Crown reserve), 

or 

• Section 197A of the Fisheries 

Management Act 1994 (relating to an 

aquatic reserve), or 

• Part 5 of the National Parks and 

Wildlife Act 1974 (relating to certain 

lands that are dedicated or reserved 

under that Act) 

• Part 4A of the Coastal Protection Act 

1979 (relating to land or waters within 

the coastal zone), or 

Consequently, it is recommended that 

entrance management provisions be inserted 

in existing plans of management. Where 

there are no current plans of management 

covering specific ICOLLs, preparation of an 

entirely new plan of management is 

recommended that includes the entrance 

management provisions. 

Sub-section (5) of the suggested new LEP 

provision (as presented in Table 12) outlines 

the requirements for the entrance 

management provisions to be included as 

part of Plans of Management. This generally 

includes an environmental impact 

assessment, an outline of how the works 

would be undertaken, all statutory 

requirements, consultation, provisions for 

climate change, and if appropriate, a longterm 

strategy for reducing the need for 

artificial entrance management of the ICOLL 




(ie redressing at-risk property and 

infrastructure through alternative means) 

(see also Figure 25). Details on how the 

works are to be carried out would best be 

described as part of a formal Entrance 

Management Operational Plan, as 

recommended by Strategy 10. 

Estuary Management Plans 

In 2002, amendments were made to the 

Coastal Protection Act 1979 that requires 

Coastal Zone Management Plans to be 

prepared for parts of the NSW coastal zone. 

ICOLLs, and indeed all estuaries, are included 

within the definition of the coastal zone, and 

thus, Estuary Management Plans can be 

regarded as Coastal Zone Management Plans 

for the purposes of this Act. Under provisions 

of the Act, Coastal Zone Management Plans 

are required to be approved by the Minister 

prior to being gazetted by Councils. Thus, all 

new Estuary Management Plans are 

essentially required to be gazetted. New 

Estuary Management Plans for ICOLLs, once 

gazetted, will therefore have a statutory role 

in the management of an ICOLL. 

Importantly, regulations provided within the 

Plan need to be complied with by future 

development and activities within the lands 

covered by the Plan (for Estuary Management 

Plans, this typically covers the waterway and 

all areas of the catchment that have a 

potential impact on estuary condition). In 

the absence of a Plan of Management for the 

Crown land reserve, it would be appropriate 

for a gazetted Estuary Management Plan to 

specify entrance management provisions, as 

outlined above. 

To date (2008) only one Estuary Management 

Plan for an ICOLL has been gazetted – 

Tuggerah Lakes. It is recommended that all 

existing Estuary Management Plans for ICOLLs 

across NSW be reviewed and amended as 

necessary (to include appropriate entrance 

management provisions for example along 

with other changes in line with concurrent 

regional and local initiatives such as CMA 

CAPS and Regional Strategies), and then 

submitted to the Minister for approval prior 

to gazettal by the relevant councils. 

Coastal Zone Management Manual 

Preparation of new Coastal Zone Management 

Plans (CZMPs) is to be guided by the Coastal 

Zone Management Manual. This document is 

yet to be released by DECC, however, it is 

essentially an amalgamation of the existing 

Estuary Management and Coastline 

Management Manuals. 

It is recommended that the Coastal Zone 

Management Manual incorporates all of the 

strategies and recommendations made within 

this booklet in respect to CZMPs made for 

ICOLLs. In particular, the Manual should 

outline the requirements for inclusion of 

entrance management provisions for ICOLLs 

as discussed above. The Manual should also 

provide strategic direction regarding the 

long-term management of ICOLL entrances in 

accordance with current best practice and 

scientific knowledge. 

It is also recommended that the Coastal Zone 

Management Manual be notified by the 

Minister for Planning under Section 733 of the 

Local Government Act 1993. This would 

mean that all works carried out by 

authorities that are consistent with the 

notified Manual carry a statutory exemption 

from civil liability. 

Floodplain Risk Management Plans 

It is noted that the NSW Government’s 

Floodplain Development Manual is already 

notified under Section 733 of the LG Act 

1993, giving exemption of civil liability to 

works undertaken in accordance with the 

Manual. Most entrance management works 

are undertaken for flood mitigation purposes, 

however, the Manual does not specifically 

advocate entrance management of ICOLLs for 

flood risk mitigation. Therefore, unless a 

Floodplain Risk Management Plan has been 

prepared for the ICOLL and specifically 

details entrance management as a flood risk 

strategy, exemption from civil liability may 

not be valid under S733. 

It is recommended that all existing Floodplain 

Risk Management Plans for ICOLLs across NSW 

be reviewed and amended as necessary to 

include appropriate entrance management 




provisions, as appropriate. For ICOLLs (and 

specifically ICOLLs that are subject to 

periodic entrance management) that do not 

have a Floodplain Risk Management Plan, it is 

recommended that such a Plan be developed 

as a matter of priority. 

Fisheries Management Act 1994 

Key Threatening Process 

It is recommended that a new Key 

Threatening Process (KTP) be added to the 

Act. This KTP should be known as “temporary 

or permanent artificial opening of ICOLL 

entrances at levels consistently lower than 

natural breakout levels”. 

Artificial manipulation of ICOLL entrances is 

considered justified as a KTP because it meets 

the necessary requirements as specified in 

Section 220F (6) of the Fisheries Management 

Act 1994. That is, it adversely affects two or 

more threatened species, populations or 

ecological communities, or could cause 

species, populations or ecological communities 

that are not threatened to become 

threatened. 

The listing of artificial entrance works as a KTP 

would not legally prohibit entrance 

manipulation works. However, it would add 

weight to the requirement for a detailed 

management plan covering entrance 

management provisions. 

Habitat Protection Plan 

It is recommended that a new Habitat 

Protection Plan (HPP) be added to the Act. 

This new HPP, prepared under the provisions 

of Part 7, Division 1 of the Act, would 

specifically relate to ICOLLs. Three HPPs have 

been prepared to date; the first is a general 

Plan, the second addresses conservation of 

seagrass beds, and the third relates 

specifically to the Hawkesbury-Nepean River 

system. Under Clause 192 (2) of the Act, a 

Habitat Protection Plan: 

(a) may relate to habitat that is essential for 

spawning, shelter or other reason, and 

(b) may apply generally or to particular areas 

or fish, and 

(c) is to describe the importance of particular 

habitat features to which it applies, and 

(d) may set out practical methods for the 

protection of any such habitat features, 

and 

(e) may contain any other matter concerning 

the protection of the habitat of fish that 

the Minister considers appropriate. 

Given the outcomes of recent and more 

historic studies (e.g., Pollard, 1994a; Griffiths, 

1999; Williams et al., 2004; Jones and West, 

2005; Dye, 2005; Dye and Barros, 2005), it is 

considered that a HPP specifically covering 

ICOLLs is justified given their significance to 

regional and state-wide fisheries and their 

relatively unique habitat structure. 

SEPP (Major Projects) 2005 

State Environmental Planning Policy (SEPP) 

(Major Projects) 2005 contains provisions that 

were previously held in the now repealed 

SEPP 35 - Dredging of Tidal Waterways. A 

survey of ICOLL entrance managers 

undertaken by the author revealed that a 

number of artificial opening works have been 

carried out in the past, inappropriately, using 

SEPP 35 provisions. 

It is recommended that an amendment be 

made to the definition of tidal waterways in 

the SEPP to specifically exclude waterways 

that are intermittently non-tidal. This way, it 

will be absolutely clear that the maintenance 

dredging provisions of this SEPP are not 

applicable to ICOLLs, and ICOLL entrance 

management in particular. 

SEPP (Infrastructure) 2007 

SEPP (Infrastructure) 2007 allows flood 

mitigation works to be carried out without the 

need for development consent under Pt 4 of 

the EP&A Act 1979. Theoretically, this would 

include artificially opening ICOLL entrances 

providing it is done for flood mitigation 

purposes (which is the case for the vast 

majority of openings to date). 




It is recommended that SEPP (Infrastructure) 

2007 quality the exemption of development 

consent by stating clearly that ICOLL entrance 

management works are included in the SEPP 

provisions only if the works are undertaken in 

strict compliance with “entrance management 

provisions” included within an approved plan 

of management. Reference should be made 

to Table 12 for example provisions that could 

be included within SEPP (Infrastructure) in 

respect to ICOLL entrance management. 

Inclusions of entrance management works 

within SEPP (Infrastructure) 2007 would 

achieve a state-wide consistent approach to 

ICOLL entrance management, which may not 

necessarily be achieved through the LEP 

process alone, given that individual councils 

are responsible for creating their own LEPs. 

S117 Instruction, Local Government 

Act 1993 

As outlined in Strategy 10, it is recommended 

that an instruction be issued to all coastal 

councils in NSW, under the provision of 

Section 117 of the EP&A Act, requiring 

councils to prepare Entrance Management 

Operation Plans (EMOPs) for ICOLLs that are 

artificially managed. The instruction should 

continue to state that entrance management 

of ICOLLs can only occur in strict compliance 

with these EMOPs and associated provisions 

within an approved Plan of Management. 




Table 12 

Suggested Entrance Management Provisions for the Standard Instrument LEP 

39 Entrance management of ICOLLs 

(1) Land to which clause applies 

This clause applies to: 

(a) 

(b) 

(c) 

a selection of Intermittently Closed and Open Lakes and Lagoons (ICOLLs) in NSW 

that require artificial entrance management to reduce risks and damage to existing 

infrastructure when water levels are high, as listed in Annexure X (2) , and 

adjacent coastal foreshores, and 

adjacent coastal waters of the State, to the extent that such waters are taken to be within 

the Council’s area under section 205 of the Local Government Act 1993. 

(2) Objectives 

The objective of this clause is to enable entrances of select ICOLLs to be managed in a 

timely, cost effective and environmentally responsible manner in response to changing 

environmental conditions, and in particular: 

(a) 

(b) 

(c) 

(d) 

(e) 

(3) Definitions 

In this clause: 

to provide a uniform assessment regime for entrance management activities, and 

to simplify and rationalise planning controls applicable to entrance management 

activities, by providing that such activities may be undertaken without development 

consent where they are authorised by an adopted plan of management, and 

to ensure that all environmental impacts of entrance management activities are 

adequately considered in advance at the plan of management stage, and 

to set minimum requirements for entrance management provisions contained within an 

adopted plan of management, including matters relating to the assessment of proposed 

activities, consistency with sustainability and risk management principles, consultation 

with interested bodies, statutory approvals, notification procedures and periodic review, 

and 

to ensure that the circumstances, extent and manner of entrance management activities 

follow best practice and are documented within an entrance management operational 

plan. 

adopted plan of management means a document having the status of: 

(a) 

a plan of management adopted under Division 2 of Part 2 of Chapter 6 of the Local 

Government Act 1993 (relating to community land), or 

(b) a plan of management adopted under Division 6 of Part 5 of the Crown Lands Act 1989 

(relating to a Crown reserve), or 

(c) 

a management plan that is in force under section 197A of the Fisheries Management Act 

1994 (relating to an aquatic reserve), or 

(d) a plan of management adopted under Part 5 of the National Parks and Wildlife Act 1974 

(relating to certain lands that are dedicated or reserved under that Act) 

(e) 

(f) 

a coastal zone management plan adopted under Part 4A of the Coastal Protection Act 

1979 (relating to land or waters within the coastal zone), or 

any combination of the matters referred to in paragraphs (a) - (e). 

entrance management activities means works or land management activities undertaken to 

artificially manipulate the connection between an ICOLL and the sea, whether for any of the 

following purposes: 

2 specific ICOLLs within each applicable LGA can be listed here. 




Table 12 cont’d. 

LEP Entrance Management Provisions 

(a) 

(b) 

(c) 

(d) 

(e) 

(f) 

managing flood risk, or 

managing coastal risk, or 

managing hydrology or water quality, or 

managing terrestrial, riparian, aquatic, estuarine or marine ecosystems, or 

managing public health, safety or amenity, or 

undertaking scientific research or land management evaluation, 

and includes the erection of warning and information signs, temporary fencing and any other 

minor ancillary structures that are necessary for or incidental to undertaking the works or land 

management activities. 

entrance management operational plan means a document that describes when, how, by 

whom, and by what authority entrance management activities would be carried out. 

entrance management provisions means provisions contained within an adopted plan of 

management that incorporate the matters specified in subclause (5). 

(4) Consent not required for authorised entrance management activities 

A public authority may, without consent, undertake entrance management activities that are 

authorised by applicable entrance management provisions. 

(5) Requirements for entrance management provisions 

Entrance management provisions must incorporate each of the following matters with 

specific reference to the coastal lake to which it applies: 

(a) 

(b) 

(c) 

(d) 

(e) 

(f) 

(g) 

(h) 

(i) 

a statement of objectives for entrance management activities, and 

a review and assessment of proposed alternatives, and 

a description and review of environmental factors of entrance management activities 

proposed to be undertaken during the management period, and 

an assessment of the consistency of proposed entrance management activities with: 

(i) 

(ii) 

the principles of ecologically sustainable development, and 

the NSW Coastal Policy, and 

(iii) principles contained in manuals notified under section 733 of the Local 

Government Act 1993 relating to the management of flood liable land and 

coastlines, and 

(iv) any relevant catchment action plan, floodplain risk management plan, coastline 

management plan, estuary management plan, habitat protection plan, recovery 

plan, threat abatement plan or similar natural resource management plan, and 

details of consultation held with public authorities, public utility operators, indigenous 

groups, community bodies and individuals likely to be affected by or have an interest in 

the proposed entrance management activities, and the outcomes of that consultation, and 

details of the circumstances, extent and manner in which entrance management 

activities are authorised to be carried out during the management period, and 

details of all statutory approvals that are required to be obtained for the proposed 

entrance management activities, and 

details of procedures relating to the notification of public authorities or other bodies 

prior to the initiation of entrance management activities, and 

a program of periodic review to evaluate the implementation, effectiveness and impacts 

of entrance management activities during the management period. 



eferences 



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acronyms 

Acronyms 

AHD 

ASS 

AWTS 

CAP 

CMA 

CRC 

CSIRO 

CZMM 

CZMP 

DCP 

DECC 

DPI 

DoP 

ECI 

EIS 

EMC 

EMOP 

EPBC 

ESD 

GIS 

HPP 

HRC 

ICOLL 

ICZM 

IPCC 

IWCM 

KTP 

LEP 

LES 

LGA 

NPWS 

NRM 

NSW 

PVP 

REF 

RL 

SAMP 

SEPP 

TN 

TP 

WSUD 

Australian Height Datum 

Acid Sulfate Soils 

Aerated Wastewater Treatment System 

Catchment Action Plan 

Catchment Management Authority 

Co-operative Research Centre 

Commonwealth Science and Investigation Research Organisation 

Coastal Zone Management Manual 

Coastal Zone Management Plan 

Development Control Plan 

NSW Department of Environment and Climate Change 

NSW Department of Primary Industries 

NSW Department of Planning 

Entrance Closure Index 

Environmental Impact Statement 

Estuary Management Committee 

Entrance Management Operational Plan 

Environmental Protection and Biodiversity Conservation 

Ecologically Sustainable Development 

Geographical Information System 

Habitat Protection Plan 

Healthy Rivers Commission of NSW (now disbanded) 

Intermittently Closed and Open Lake or Lagoon 

Integrated Coastal Zone Management 

Inter-governmental Panel on Climate Change 

Integrated Water Cycle Management 

Key Threatening Process 

Local Environmental Plan 

Local Environmental Study 

Local Government Area 

National Parks and Wildlife Service (part of DECC) 

Natural Resources Management 

New South Wales 

Property Vegetation Plan 

Review of Environmental Factors 

Reduced Level 

Sustainability Assessment and Management Plan 

NSW State Environmental Planning Policy 

Total Nitrogen 

Total Phosphorus 

Water Sensitive Urban Design 



Glossary of terms 


Anthropogenic Relating to humans 

ANZECC guidelines Guidelines for water and sediment quality, prepared by the 

Australian and New Zealand Environmental Conservation Council 

Benthic metabolism Where organic material is broken down within the sediments 

Benthic algae Micro and macro algae that reside within bed sediments 

Berm Sand bar at the entrance of an ICOLL. Can completely close the 

entrance. 

Biobanking A system of compensatory habitat and biodiversity provisions 

established by the NSW Government that is to be considered when 

developing land (particularly if habitat is to be lost as a result of the 

development) 

Biogeochemistry Relating to the interaction of biological and chemical processes 

within a soil matrix 

Catchment The land surface area (watershed) where runoff drains to a common 

point (eg river, lake) 

Catchment runoff The flow of water across the ground surface within a catchment 

following rainfall 

Chlorophyll-a A measure of green plant material abundance and biomass in the 

water and is considered to be a good surrogate measure for 

phytoplankton productivity within the water. 

Denitrification Process of converting dissolved oxidised nitrogen to di-nitrogen gas 

Ebb tide Outflowing tide (flowing seaward) 

Ecotone Transition area between two adjacent ecological communities 

(ecosystems) 

Eutrophic Water that is characterized by large nutrient concentrations and 

high productivity (ie algae). (see also oligotrophic) 

Flood tide Incoming tide (flowing landward) 

Flood tide delta A shoal located immediately inside the mouth of an estuary, which 

has developed from landward sediment transport during flood tide 

conditions. 

Fluvial shoal Sediment shoal that has formed by deposition of sediment washed 

off the catchment 

Geochemical Relating to the chemistry of soils 

Geomorphology Study of landforms, including their origin and evolution, and the 

processes that shape them 

Hydrodynamics The movement of water 

Integrated Water Cycle Integration between water supply, wastewater and stormwater to 

Management minimise water demands and optimise system efficiencies 

Longshore transport The movement of sand parallel to the coast within the active wave 

zone. Also called alongshore transport as it is move along the 

shoreline. 

Macroalgae Marine algae visible to the naked eye 

Macrophytes Aquatic plants, growing in or near water that are emergent, 

submergent, or floating. Examples include seagrass. 

Marine ingress Progressive movement of oceanic water into an estuary or ICOLL 

Marine sand Sands derived from the ocean (typical of beach sand) 




Marine shoal Sand shoal that has formed by the deposition of marine sands as they 

enter an estuary or ICOLL. 

Microalgae Marine algae that is not visible to the naked eye (requires 

microscopic identification) 

Microclimate Area where climate differs from surrounding areas due to local 

geographical features, such as hills, lakes, escarpments 

Morphological Relating to the form or surface features of the earth (more correctly 

known as ‘geomorphological’) 

Morphodynamics The process in which geomorphological changes take place in 

response to changing water flows, wave forces etc. 

Morphometry The key physical characteristics of ICOLLs 

Nutrients An element or simple compound necessary for the health and 

survival of an organism. Mostly refers to Carbon, Phosphorus, and 

Nitrogen. 

Oligotrophic Water characterized by extremely low nutrient concentrations, 

resulting in limited productivity within the water column. 

On-site sewage system Individual sewage management system designed to treat a single 

dwelling (eg septic tank, envirocycle unit) without connection to a 

reticulated sewerage system. 

Photosynthesis The conversion of sunlight to energy by plants (including algae) 

producing oxygen as a byproduct 

Phytoplankton Tiny, free-floating, photosynthetic organisms in water (usually unicellular 

algae) 

Pneumatophores Peg roots of some mangrove species through which the tree 

breathes. Pneumatophores are usually submerged for some of the 

time in tidal areas. 

Remineralise Conversion of organic nutrients back into inorganic nutrients 

Riparian vegetation Vegetation that grows in close proximity to a waterway. 

Salinity Measure of the amount of dissolved salts within water 

Saltmarsh An area that is colonised by salt-adapted (‘halophytic’) plants 

Sediment nutrient flux The transfer of dissolved nutrients between the sediment and the 

water column 

Tidal prism The volume of water that is conveyed during a tide. Can be 

measured at any point within the estuary as the total volume passing 

between low water slack and high water slack 

Tidal prism ratio The ratio of tidal prism volume to resident low tide volume within an 

estuary or ICOLL 

Water Sensitive Urban 

Design 

Integration of water cycle management into urban planning and 

urban landscape design 



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