evaluation of the ADDAMS computer program modules relevant

EVALUATION OF THE ADDAMS COMPUTER
PROGRAM MODULES RELEVANT TO THE
DISPOSAL OF MAINTENANCE DREDGING SPOIL
FROM MARINAS AND SMALL BOAT HARBOURS
By Peter H. Morris
RESEARCH REPORT

RESEARCH REPORT SERIES
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EDITORS
Prof Chris Cooper University of Queensland Editor-in-Chief
Prof Terry De Lacy CRC for Sustainable Tourism Chief Executive
Prof Leo Jago CRC for Sustainable Tourism Director of Research
National Library of Australia Cataloguing in Publication Data
Morris, P.H. (Peter H.).
An evaluation of the ADDAMS computer program modules relevant to the disposal
of maintenance dredging spoil from marinas and small boat harbours.
Bibliography.
ISBN 1 876685 16 6.
1. Dredging spoil – Queensland. 2. Sediment transport – Queensland. 3. Waste
disposal in the ocean – Queensland. 4. Dredging spoil – Computer programs. 5.
Sediment transport – Computer programs. 6. Waste disposal in the ocean –
Computer programs. I. Cooperative Research Centre for Sustainable Tourism. II. Title.
627.730285
© 2002 Copyright CRC for Sustainable Tourism Pty Ltd
All rights reserved. No parts of this report may be reproduced, stored in a retrieval
system or transmitted in any form or by means of electronic, mechanical,
photocopying, recording or otherwise without the prior permission of the publisher.
Any enquiries should be directed to Brad Cox, Director of Communications or Trish
O’Connor, Publications Manager to info@crctourism.com.au

ACKNOWLEDGEMENTS
The author wishes to thank and acknowledge the following
contributors whose combined efforts and willing cooperation made
this research possible:
• WBM Oceanics Pty Ltd – Mr Craig Witt and Mr Chris Nielsen
• Environmental Protection Agency (Queensland) – Mr Chris
Pattearson and Ms Katrina Wilkes
• Lawson and Treloar Pty Ltd – Mr Ray Rice
• Mackay Port Authority – Mr Ian Meech
• Port of Brisbane Corporation
• Ports Corporation of Queensland – Mr Steve Hillman
• Queensland Government Hydraulics Laboratory – Mr David
Robinson and Mr Jim Waldron
• Queensland Transport, Hydrographic Services – Mr Rod Ridley and
Mr Bill Page
• Queensland Transport, Maritime Division – Captain J Watkinson
and Mr John Broadbent
• The University of Queensland – Prof Colin Apelt and Mr Peter
McMillan’
• Townsville Port Authority – Ms Caryn Anderson, Mr John Neal,
and Mr Mick Fitzpatrick
• US Army Engineer Waterways Experiment Station, Vicksburg – Dr
Paul Schroeder
• WestHam Dredging Pty Limited – Mr Kevin Green

EXECUTIVE SUMMARY
This report summarises research conducted at The University of
Queensland into the suitability of the ADDAMS suite of computer
program modules for application to the preliminary assessment of the
ocean disposal of sediments from marinas and small boat harbours
under Australian conditions. The ADDAMS suite is under continuing
development by the US Army Engineer Waterways Experiment
Station, Vicksburg. The research comprised evaluations of the ability
of relevant ADDAMS modules to model the short and long term fate
of dredged sediments dumped at ocean disposal sites at the Ports of
Weipa, Townsville, Hay Point, and Mackay in far north, north, and
central Queensland.
The ADDAMS modules of primary interest are STFATE, LTFATE,
MDFATE. The module STFATE models the short-term fate of a single
dump of contaminated dredged sediments from a hopper dredge or
barge. LTFATE models the long-term fate of sediments on the seabed,
but is limited to relatively simple bathymetry. MDFATE incorporates
the capabilities of both STFATE, except that contaminants are not
considered, and LTFATE, except for some graphical output options,
and can also model multiple dumps and complicated bathymetry. All
of the outputs of MDFATE and LTFATE are in US units, but the outputs
of STFATE are a mixture of metric and US units.
The ADDAMS module PSDDF is also of interest. It models the
consolidation over time of dredge spoil freshly deposited on the
seabed and of the underlying sediments. Any consistent set of
engineering units can be used.
For Weipa, the 1998 dredging campaign and the inter-campaign
periods from 1994 to 1996 and from 1996 to 1998 were modelled.
During these periods, two overlapping 4 km diameter offshore
disposal sites, denoted the 1994 and 1998 sites, in Albatross Bay were
used. Their average depths were about 9.7 m and 12.3 m MSL,
respectively. Areas about 2.8 km 2 and about 4.0 km 2 respectively
centred on the 1994 and 1998 sites were modelled.
i

For Townsville, the period from June 1991 to January 1998 was
modelled. This included dredging campaigns of varying magnitude in
all years except 1998. During this period, two overlapping offshore
disposal sites in Cleveland Bay with a total area of about 22 km 2 were
used. Only the area common to both disposal sites, with an area of
about 3.6 km 2 and an average depth of about 14.0 m MSL, was
modelled.
For Hay Point, the period from February 1981 to April 2000 was
modelled. This included major capital and minor maintenance
dredging campaigns that were undertaken in 1993 and 1995,
respectively. Only the 1993 campaign was modelled in detail. All spoil
from these campaigns was dumped at an offshore disposal site in
Dalrymple Bay. The entire site, which had an area of about 1.3 km 2
and an average depth of about 15.3 m MSL, was modelled.
For Mackay, the period from April 1998 to April 2000 was modelled.
During this time continuous maintenance dredging by a small grab
dredge, but no capital dredging, was undertaken. All spoil was
dumped at the Mackay ocean disposal site, which has an area of
about 1.3 km 2 and an average depth of about 14.9 m MSL. Unlike the
other disposal sites modelled, this disposal site is very dispersive. The
entire site was modelled.
All four of the disposal sites modelled are located in low energy wave
environments. In contrast, many US disposal sites, for which STFATE,
LTFATE, and MDFATE were developed, are located in high energy
wave environments. Thus the analyses summarised in this report
evaluated STFATE, LTFATE, and MDFATE for relatively distinctive
Australian conditions.
The data available for the four disposal sites were unsuitable to
evaluate STFATE and LTFATE independently of MDFATE. In the present
analyses, LTFATE was used only to provide graphical output of tidal
current and elevation input data, and STFATE was not used at all.
However, MDFATE was used to model both the short and long term
fate of sediments, and such evaluations of MDFATE’s capabilities also
constitute partial evaluations of STFATE and LTFATE. PSDDF was used
only in the Townsville analyses to investigate whether the effect on
ii

the bathymetry of the consolidation of freshly deposited spoil was
significant.
Extensive bathymetry data were available for all of the disposal sites
modelled. However, the vertical control was greater than most of the
(averaged) changes in bathymetry that were modelled. In addition,
the Townsville and Hay Point data contained significant systematic
errors. Consequently, most of the analyses summarised in this report
constituted relatively weak tests of the ability of MDFATE, STFATE, and
LTFATE to model the short and long term fate of dredged sediments.
However, the analyses of the 1998 Weipa dredging campaign, during
which comparatively large changes in the bathymetry occurred,
constituted a relatively strong test of the ability of MDFATE and hence
STFATE to model their short term fate.
Extensive wave height and period data for the four disposal sites were
provided by the Environmental Protection Agency (Queensland). No
wave direction data were available, but the sediment behaviour at all
four sites was shown to be insensitive to the wave direction. The
spectrally significant wave height and the wave period at the peak
spectral energy were used in the analyses. The wave recorder sites
were located considerable distances from the disposal sites, but
existing and new analyses showed that the recorder data could be
applied to the disposal sites without change. Because the Waterways
Experiment Station wave data pre-processing program HDPRE, which
generates wave cross-correlation matrix input files for LTFATE and
MDFATE, is not available to the public, average wave parameters were
used in the analyses.
Tidal harmonic constituent input files for MDFATE and LTFATE were
compiled by combining tidal elevation constituent data sets with tidal
current time series data or constituents from a number of sources. The
tidal current time series data were processed into constituent sets
comprising between 19 and 38 constituents using a program supplied
by WBM Oceanics Pty Ltd. The largest elevation constituent set used
comprised 36 constituents. Each of the input files was reduced to 20
constituents, the maximum that can be used in MDFATE, by culling
either the smallest elevation constituents or the smallest current
constituents. (More than 40 constituents may be used in LTFATE.) The
resulting input files for each of the four sites differed considerably.
iii

This had little effect on the results of the analyses for Weipa,
Townsville, and Hay Point, but a significant effect on those for Mackay.
The dredge dimensions and operating parameters that were required
for MDFATE were supplied by the dredging contractors and the
various Port Authorities. Data on the quantities of spoil dumped
during the dredging campaigns were supplied by consultants with the
consent of the Port Authorities, or by the Port Authorities themselves.
In the absence of detailed data, simplified dumping sequences were
adopted in all of the analyses.
The dredged sediment geotechnical parameter values and the
seawater density data required for MDFATE were estimated using data
taken from consultants’ reports, representative data incorporated in
MDFATE, and existing geotechnical correlations. Analyses showed
that the Townsville, Hay Point, and Mackay disposal site sediment
behaviour was relatively insensitive to most of these parameters.
Representative geotechnical data incorporated in PSDDF were used in
the analysis of the consolidation of the Townsville spoil.
The dredged sediments dumped at the four disposal sites modelled
contained a high proportion of silts and clays, but the cohesive
sediment option in MDFATE is currently unavailable and the noncohesive
sediment option was perforce used in all cases. While it was
possible to input realistic sand and silt content and in-hopper solids
fraction values for the Hay Point sediments, it was necessary to use
unrealistically high values for both the Weipa and the Townsville
sediments. Sensitivity analyses indicated that this had relatively little
effect on the overall results obtained. It was also necessary to use an
unrealistically high value for the median particle size of the Mackay
dredge spoil. This led to the significant underestimation of the losses
from that disposal site. The performance of MDFATE in analyses
involving fine-grained, cohesive sediments may be expected to
improve significantly when the cohesive sediment option becomes
available.
No attempt was made to optimize the results of the analyses by
varying individual inputs arbitrarily. However, a range of input data
was used in each case with little effect on the overall outcomes.
iv

MDFATE matched poorly the changes in the detailed bathymetry of all
four disposal sites modelled. This was at least partly attributable to the
simplified dumping sequences used in the analyses.
MDFATE matched well the overall short-term changes in the Weipa
disposal site that occurred during the 1998 dredging campaign.
However, the sediment losses that occurred during the descent from
the dredge to the seabed were overestimated significantly. This may
have been attributable to the unavailability of the cohesive sediment
option. MDFATE matched poorly the volume of sediments retained on
the Hay Point disposal site at the end of the 1995 dredging campaign.
This was probably largely attributable to errors in the bathymetric data,
but the results of the analyses suggested that MDFATE might have
significantly overestimated the short-term losses from the Hay Point
site. No data suitable for the investigation of the short-term fate of
sediments were available for the Townsville or Mackay disposal sites.
The discrepancies between the measured and calculated long term
overall changes in the bathymetry at all four disposal sites modelled
were relatively large, but readily accounted for by the uncertainties
and errors in the input data and the poor vertical control. Analyses of
the consolidation of freshly deposited Townsville spoil conducted
using PSDDF showed that it could not account for the systematic error
in the Townsville bathymetry data. Thus MDFATE matched the long
term changes at the four sites reasonably well, in that the measured
and calculated sediment movements were of comparable magnitude,
but too small to measure accurately.
Overall, within the limitations of the available data, MDFATE modelled
the long-term behaviour of the dredged sediments at the essentially
non-dispersive Weipa, Townsville, and Hay Point disposal sites and the
very dispersive Mackay disposal site reasonably robustly and well. The
MDFATE estimates matched the measured changes in the bathymetry
at all four sites to a first approximation satisfactory for the preliminary
assessment of ocean disposal sites. No conclusions could be drawn
regarding the ability of MDFATE to model the short-term behaviour of
the Townsville and Mackay sediments. However, the analyses of the
short-term behaviour of the Weipa and Hay Point sediments
suggested that MDFATE might overestimate significantly the losses
from disposal sites that occur during spoil disposal.
v

CONTENTS
ABSTRACT ....................................................................................1
1. INTRODUCTION...................................................................2
2. THE ADDAMS SUITE ...........................................................4
2.1 ADDAMS program modules .......................................4
2.2 Scope of research........................................................5
2.3 ADDAMS modules relevant to ocean disposal of
sediments from marinas and small boat harbours........6
3. OCEAN DISPOSAL SITES MODELLED ................................9
3.1 Weipa ocean disposal site ...........................................9
3.2 Townsville ocean disposal site....................................10
3.3 Hay Point ocean disposal site ....................................12
3.4 Mackay ocean disposal site .......................................13
3.5 Disposal site environments ........................................15
4. INPUT DATA USED IN ANALYSES.....................................16
4.1 Compatibility with ADDAMS modules .......................16
4.2 Bathymetric data .......................................................16
4.3 Wave data.................................................................19
4.4 Tide data...................................................................20
4.5 Dredged sediment and seawater data .......................27
4.6 Dredge dimensions and operating constraints ...........30
5. RESULTS OF ANALYSES ....................................................32
5.1 Weipa ocean disposal site .........................................32
5.2 Townsville ocean disposal site....................................34
5.3 Hay Point ocean disposal site ....................................36
5.4 Mackay ocean disposal site .......................................38
6. CONCLUSIONS...................................................................41
REFERENCES...............................................................................44
APPENDICES
1: Input data requirements for STFATE v. 5.01 .........................48
vi

2: Input data requirements for LTFATE v. 1.0............................51
3: Input data requirements for MDFATE v. 1.1 .........................55
4: Bathymetry input file for Cleveland Bay ocean disposal site .59
5: Tidal harmonic constituent input file for Mackay ocean
disposal site.........................................................................60
6: Input data requirements for PSDDF v. 2.1 ............................62
AUTHOR .....................................................................................64
LIST OF TABLES
1. The ADDAMS suite................................................................5
LIST OF FIGURES
1.1 Locations of disposal sites modelled ......................................2
3.1 Location of Albatross Bay ocean disposal sites.....................10
3.2 Location of Cleveland Bay ocean disposal sites ....................11
3.3 Location of Dalrymple Bay ocean disposal site .....................13
3.4 Location of Mackay ocean disposal site ...............................14
4.1 Albatross Bay 1994 ocean disposal site bathymetry at
September 1996 ................................................................17
4.2 Cleveland Bay ocean disposal site bathymetry at June 1991 18
4.3 Dalrymple Bay ocean disposal site bathymetry at July 1993 .18
4.4 Mackay ocean disposal site bathymetry at April 2000 .........19
4.5 Cleveland Bay tidal elevations based on Australian National
Tide Tables elevation and WBM Oceanics current data
emphasising currents...........................................................23
4.6 Cleveland Bay north-south tidal velocity magnitudes
corresponding to Figure 4.5 ................................................24
4.7 Cleveland Bay east-west tidal velocity magnitudes
corresponding to Figure 4.5 ................................................24
4.8 Cleveland Bay tidal velocity directions corresponding to
Figure 4.5............................................................................25
4.9 Cleveland Bay tidal elevations based on Townsville Fairway
Beacon (Queensland Transport) elevation and WBM Oceanics
current data emphasising currents.......................................25
4.10 Cleveland Bay north-south tidal velocity magnitudes
corresponding to Figure 4.9 ................................................26
4.11 Cleveland Bay east-west tidal velocity magnitudes
corresponding to Figure 4.9 ................................................26
vii

4.12 Cleveland Bay tidal velocity directions corresponding to
Figure 4.9............................................................................27
5.1 Measured change in Albatross Bay ocean disposal site
bathymetry between May and July 1998.............................33
5.2 Estimated change in Albatross Bay ocean disposal site
bathymetry between May and July 1998 based on Australian
National Tide Tables elevation and WBM Oceanics current
data emphasising elevations ................................................34
5.3 Measured change in Cleveland Bay ocean disposal site
bathymetry between June 1991 and June 1993 ..................35
5.4 Estimated change in Cleveland Bay ocean disposal site
bathymetry between June 1991 and June 1993 based on
Australian National Tide Tables elevation and WBM Oceanics
current data emphasising elevations....................................36
5.5 Measured change in Dalrymple Bay ocean disposal site
bathymetry between July and November 1993....................37
5.6 Estimated change in Dalrymple Bay ocean disposal site
bathymetry between July and November 1993 based on
Australian National Tide Tables elevation and WBM Oceanics
current data emphasising currents.......................................38
5.7 Measured change in Mackay ocean disposal site bathymetry
between September 1998 and April 2000...........................39
5.8 Estimated change in Mackay ocean disposal site bathymetry
between September 1998 and April 2000 based on
Australian National Tide Tables elevation and Lawson and
Treloar current data emphasising currents............................40
viii

ABSTRACT
The potential for the application the ADDAMS suite of computer
program modules to the preliminary assessment of the ocean disposal
of sediments from marinas and small boat harbours under Australian
conditions has been investigated at The University of Queensland. The
ADDAMS suite is under continuing development by the US Army
Engineer Waterways Experiment Station, Vicksburg. Data from
offshore disposal sites at Weipa, Townsville, Hay Point, and Mackay
have been used to assess the three ADDAMS modules that model the
short and long term fate of dredged sediments. A fourth ADDAMS
module that models the consolidation of sediments was used in a
minor way in the analyses of the Townsville disposal site. The
performance of the first three ADDAMS modules was reasonably
robust and generally satisfactory for the preliminary assessment of
disposal sites. However, because of limitations of the data for all four
of the sites modelled, all but one of the analyses were relatively weak
tests of their capabilities.
1

1. INTRODUCTION
Research is being undertaken at The University of Queensland for the
CRC for Sustainable Tourism Pty Ltd on the land and ocean disposal
of sediments dredged from marinas and small boat harbours. This
report summarises the work on the application of the ADDAMS
(Automated Dredging and Disposal Alternatives Management
System) suite of computer program modules to the preliminary
assessment of the ocean disposal of such sediments under Australian
conditions. The ADDAMS suite, which is under development by the
US Army Engineer Waterways Experiment Station, Vicksburg, the
relevant modules, and their applications are described in Chapter 2 of
the report.
The remainder of the report summarises analyses of the short and
long term behaviour of dredged sediments dumped at the offshore
ocean disposal sites at the Ports of Weipa, Townsville, Hay Point, and
Mackay in far north, north, and central Queensland (Fig. 1.1). More
detailed descriptions of the analyses for the individual disposal sites
are presented in Morris (2001a-d).
2
Figure 1.1 Locations of ocean disposal sites modelled

The ocean disposal sites and the periods modelled are described in
Chapter 3 of the report. The input data required for the ADDAMS
modules are described in Chapter 4 and the Appendices, and the
results of the analyses are described in Chapter 5. The conclusions
reached regarding the ability of the ADDAMS modules to model the
short and long term behaviour of dredged sediments are presented in
Chapter 6.
The references cited throughout the report and the Appendices follow
Chapter 6.
3

2. THE ADDAMS SUITE
2.1 ADDAMS Program Modules
The US Army Engineer Waterways Experiment Station, Vicksburg, has
developed the ADDAMS suite of computer modules as a continually
evolving personal computer based system that provides a comprehensive
set of tools for modelling the land and ocean disposal of dredged
sediments. Each module comprises computer programs designed to
assist in the evaluation of a single aspect of a dredging project.
The ADDAMS modules are relatively simple and lend themselves to
relatively inexpensive, preliminary investigations of the viability of the
ocean and land disposal of dredged sediments. They thus have the
potential to provide valuable guidance for the more detailed and
hence more expensive investigations required for final approval for
dredged sediment disposal.
The ADDAMS dredged material management modules currently
available are listed in Table 1. (Water quality modules are not listed).
Most are DOS based, but some are now available in Windows versions
(Table 1). Both the ADDAMS modules and the associated user’s
manuals may be down-loaded, free of charge, from the US Army
Engineer Waterways Experimental Station Internet site at
www.wes.army.mil/el/elmodels/index.html#addams. However, source coding
is available only for the HELP3 module.
4

Table 1: The ADDAMS suite
MODULE APPLICATIONS CURRENT VERSION
SETTLE Combined disposal facilities (CDFs) design 3.0
DYECON Hydraulic retention and efficiency of CDFs 3.0
EFFLUENT Combined effluent pathway evaluation (EFQUAL + LAT-E) 1.0 (Windows)
EFQUAL Modified elutriate test analysis (effluent quality) 3.0
LAT-E Laboratory analysis of toxicity – CDF effluent 1.0
RUNQUAL Runoff water quality and dilution needs analysis 1.0
LAT-R Laboratory analysis of toxicity – CDF runoff 1.0
RUNOFF Combined runoff pathway evaluation (RUNQUAL + LAT-R) 1.0 (Windows)
HELPQ Leachate quality and production prediction 2.1
PUP Freshwater plant uptake prediction 1.0
PSDDF Consolidation and desiccation of dredged fill 2.1
D2M2 Dredged material disposal management SPN
CDFATE Fate of continuous discharge – mixing zone 1.0
STFATE Short term fate of disposal in open water 5.01
LTFATE Long term fate of disposal in open water 1.0
MDFATE Fate of multiple discharges in open water 1.1
RECOVERY Contaminant release from bottom sediments 3.0
DREDGE Resuspension and contaminant release by dredge 1.1
DEMO Demonstration of ADDAMS modules 2.0
HELP3 Hydrologic evaluation of landfill performance 3.07
2.2 Scope Of Research
The algorithms incorporated in all ADDAMS modules have been
extensively researched and verified experimentally and analytically by
US Army Engineer Waterways Experiment Station personnel for North
American conditions. The research summarised in this report did not
seek to duplicate this work, but was restricted to verifying the
suitability of the relevant ADDAMS modules (Section 2.3) for the
preliminary assessment of the disposal of sediments from marinas and
small boat harbours under Australian conditions.
5

The ADDAMS modules of primary interest (Section 2.3) are intended
to be used with tide, wave, and storm data files prepared by the
Waterways Experiment Station Wave Information Study for sites
within the United States. No comparable pre-packaged data files are
available for Australian sites, but the ADDAMS modules permit
alternative methods of inputting equivalent data (Section 2.3). The
consequences of this for the application of ADDAMS modules in
Australia were explored in the research summarised here.
2.3 ADDAMS Modules Relevant To Ocean Disposal Of
Sediments From Marinas And Small Boat Harbours
The ADDAMS modules relevant to the ocean disposal of relatively
small quantities of dredged sediments are STFATE, LTFATE, MDFATE,
and, to a lesser extent, PSDDF (Table 1). The corresponding user’s
manuals are E. P. A. Office of Water and Office of Science and
Technology and US Army Corps of Engineers (1995), Scheffner et al.
(1995), Moritz (1994), and Stark (1996).
A mixture of metric and US units are used for the input data for
STFATE, LTFATE, and MDFATE, and for the output data from STFATE,
but the outputs of LTFATE and MDFATE are in US units only. Any
consistent system of units can be used with PSDDF. For compatibility
with the outputs of the other modules, US units were used in the
PSDDF analyses summarised here. However, preference is given to
metric units in this report. Input and output data for the ADDAMS
modules are accordingly expressed in metric units followed, where
appropriate, by equivalent data in US units in brackets. Nevertheless,
US units are retained in the figures incorporated in this report that
were generated using LTFATE and MDFATE.
STFATE models the Short Term FATE of sediments containing
contaminants disposed of in a single dump from a dredge or barge.
LTFATE models the Long Term FATE of sediments on the seabed.
MDFATE (Multiple Dump FATE) models the long-term fate of
sediments disposed of by multiple (or single) dumps.
In STFATE, disposal is assumed to occur from a split-hull barge or a
hopper dredge. The behaviour of the dredged material is separated
into three phases: convective descent, dynamic collapse, and passive
6

transport-dispersion. In convective descent, the disposal cloud falls
under the influence of gravity. Dynamic collapse occurs when the
descending cloud either impacts the seabed or arrives at a level of
neutral buoyancy, where descent is retarded and horizontal spreading
dominates. Passive transport-dispersion commences when material
transport is determined more by ambient currents and turbulence
than by the dynamics of the disposal operation.
LTFATE uses coupled hydrodynamic, sediment transport, and
bathymetry change models to compute the stability over time of
dredged sediments placed in a mound on the seabed as a function of
local waves, tides, currents, bathymetry, and sediment size. Mound
avalanching is modelled and the effects of storms may be simulated.
The seabed sediments may be fixed or moveable. Thus, LTFATE will
provide an estimate of the temporal and spatial fate of the dredged
sediments and, if applicable, the seabed sediments. However, only
relatively simple mound and seabed geometry can be modelled.
MDFATE models the same phenomena as both STFATE and LTFATE,
except that contaminants are not considered. Almost identical
programming is used in both cases. The short-term phenomena
modelled by STFATE and wave, tidal, and residual current effects can
be neglected if desired. (If tidal effects are neglected, non-zero default
inputs are used.) Sediments can be placed in any number of dumps
over any length of time and any pattern of dumping can be specified.
Complicated mound or seabed geometry can be modelled.
The input data requirements for STFATE, LTFATE, and MDFATE and the
associated pre and post processing programs are described in
Appendices 1 to 3, respectively. Notably, the wave data pre-processing
program HDPRE (Appendices 2 and 3), which is used by the US Army
Engineer Waterways Experiment Station to produce wave crosscorrelation
matrix input files for United States sites for LTFATE and
MDFATE, is currently unavailable to the public. The cross-correlation
matrix input files are used to generate time series data files within
LTFATE or MDFATE. Consequently, it is not possible to generate such
data files for Australian sites. Thus, the alternatives of user-supplied
time series (available for LTFATE only) or average wave parameters
(available for both LTFATE and MDFATE) must be used, or the effects
of waves neglected (available for MTFATE only).
7

There are numerous minor discrepancies between the STFATE, LTFATE,
and MDFATE modules and the corresponding user’s manuals, but the
modules generally perform in accordance with the documentation.
However, some options are inoperative, some outputs are unavailable,
and there are some minor programming errors. The user’s manuals
also contain minor errors. These shortcomings are discussed in detail
in Morris (2002). The consequences for the analyses of the ocean
disposal sites modelled of these and other limitations of the ADDAMS
programs are discussed in Chapters 4 and 5.
PSDDF models the primary consolidation, secondary consolidation,
and desiccation processes (if any) in fine-grained soils such as dredge
spoil using the one-dimensional finite strain theory of Gibson et al.
(1967), the secondary compression theory of Mesri and Godlewski
(1977), and the empirical desiccation model of Cargill (1985). It can
be applied to both land and sea disposal. PSDDF calculates the total
settlement of multi-layered fills based on the consolidation
characteristics of each layer and the foundation material, the surface
water management techniques used, and local climatological data.
Additional layers of fill can be added at any time. The input data
required by PSDDF are described in Appendix 6.
No inoperative options, unavailable outputs, or significant
programming errors were found in PSDDF, and there are only a small
number of minor errors in the PSDDF user’s manual.
8

3. OCEAN DISPOSAL SITES MODELLED
3.1 Weipa Ocean Disposal Site
The Port of Weipa is located on Albatross Bay on the western side of
Cape York Peninsular (Figs 1.1 and 3.1). Maintenance dredging at
Weipa is normally undertaken at intervals of approximately two years
(Morris 2001a), and most of the dredge spoil is dumped at the
Albatross Bay ocean disposal site (Fig. 3.1). From 1961 onwards, this
site has been moved gradually seaward into progressively deeper
water.
The analyses of the Albatross Bay ocean disposal site summarised in
this report covered the period from May 1994 to July 1998 (Morris
2001a). This was determined by the availability of suitable
bathymetric data (Section 4.2). During that time, all dredge spoil was
dumped at disposal site locations that were first used in 1994 and
1998. The 1994 and 1998 disposal sites are both 4 km (13,100 ft) in
diameter and are respectively centred about 20 km and 23 km east of
Weipa (Fig. 3.1). Their average depths are about 7.9 m (25.9 ft) and
10.5 m (34.4 ft) LAT, equivalent to 9.7 m (31.8 ft) and 12.3 m (40.4
ft) MSL, respectively. The tidal range is about 3.1 m (10.1 ft).
During the period modelled, there were dredging campaigns only in
1996 and 1998. Insufficient dredge spoil data were available to
enable the 1996 dredging campaign to be modelled, but both the
two inter-dredge periods, 1994-1996 and 1996-1998, and the 1998
dredging campaign were modelled. The two inter-dredge periods
were respectively 750 days and 630 days in duration. Due to
limitations in the bathymetric data, it was possible to model only a
2750 m (9000ft) square area centred on the 1994 disposal site in the
analyses of these periods. The 1998 dredging campaign was 56 days
in duration. During that time, approximately 1,260,000 m 3 (1,650,000
cu.yd) of spoil were dumped on the 1998 disposal site. An area 3960
m (13,000 ft) square centred on that site was modelled in the analysis
of this period.
9

Figure 3.1 Location of Albatross Bay ocean disposal sites
3.2 Townsville Ocean Disposal Site
The Port of Townsville is located on Cleveland Bay (Figs 1.1 and 3.2).
Maintenance dredging of the Port is normally carried out every year,
and major capital dredging was last undertaken in 1993 (Morris
2001b). Since 1990, all dredge spoil has been deposited at two
offshore disposal sites in Cleveland Bay (Fig. 3.2).
The analyses of the Cleveland Bay disposal sites summarised in this
report covered the period from June 1991 to January 1998, a total of
about 2395 days, encompassing ten dredging campaigns with a total
duration of 252 days (Morris 2001b). This period was subdivided in
the analyses into periods of 724 days, 1257 days, and 414 days,
which encompassed three, five, and two dredging campaigns,
respectively. All of these periods were determined by the availability of
suitable bathymetric data (Section 4.2).
10

Because only limited dredge spoil placement data were available, it
was possible to model only the area common to the two offshore
disposal sites (Fig. 3.2). This is approximately 2 km by 1.8 km (6600 ft
by 5900 ft) in extent, equivalent to about one-third of the each of the
two sites. The area modelled has an average depth of about 12.1m
(39.7 ft) LAT, equivalent to about 14.0 m (46.0 ft) MSL, and a tidal
range of about 4.0 m (13.1 ft). It was estimated that about 303,000
m 3 (397,000 cu.yd) of spoil were dumped on this area over the period
modelled.
Figure 3.2 Location of Cleveland Bay ocean disposal sites
11

3.3 Hay Point Ocean Disposal Site
The Port of Hay Point is situated approximately 18 km south-east of
the City of Mackay (Figs 1.1 and 3.3). Capital dredging of about
225,000 m 3 (in situ volume prior to dredging) was undertaken at the
Port in 1993, but maintenance dredging has always been minimal.
None was carried between 1981 and 2000, except for a small
campaign in 1995 that removed about 14,400 m 3 (in situ volume) of
spoil (Morris 2001c). Both the capital and the maintenance dredging
spoil were dumped at a single disposal site located in Dalrymple Bay,
about 3 km north-north-west of the northern most berth at Hay Point
(Fig. 3.3). The average depth of the natural seabed at the disposal site
is about 12.0 m (39.4 ft) LAT, equivalent to about 15.3 m (50.2 ft)
MSL, and the tidal range is about 7.1 m (23.4 ft).
The analyses of the Dalrymple Bay disposal site summarised in this
report covered the period from February 1981 to April 2000 (Morris
2001c), a total of about 8080 days. This was subdivided into periods
of 4522 days, 120 days, and 2358 days, which were determined by
the availability of suitable bathymetric data (Section 4.2).
The 1993 capital dredging campaign was modelled explicitly, but the
1995 maintenance dredging was accounted for only indirectly in the
analyses of the changes in the volume of spoil on the seabed. The
entire disposal site, which is 1.5 km by 0.85 km (4900 ft by 2800 ft)
in extent, was modelled in the analyses.
12

Figure 3.3 Location of Dalrymple Bay ocean disposal site
3.4 Mackay Ocean Disposal Site
Mackay Outer Harbour is an artificial harbour situated about 7 km
north-east of the City of Mackay (Figs 1.1 and 3.4). Almost
continuous maintenance dredging and occasional capital dredging is
undertaken within the Harbour (Morris 2001d). All dredge spoil is
dumped at a single disposal site located about 4 km east-north-east
of the Harbour (Fig. 3.4). The average depth of the seabed at the
disposal site is about 12.0 m (39.4 ft) LAT, equivalent to about 14.9 m
(49.0 ft) MSL, and the tidal range is about 6.4 m (21.0 ft). In contrast
to the Weipa, Townsville, and Hay Point disposal sites (Sections 3.1 to
3.3), the Mackay disposal site is very dispersive.
13

The analyses of the Mackay ocean disposal site summarised in this
report covered the period from September 1998 to April 2000 (Morris
2001d), a total of about 581 days. This period was determined by the
availability of suitable bathymetric data (Section 4.2). Approximately
66,500 m 3 (87,000 cu.yd) of maintenance dredging spoil (in-hopper
volume) from Mackay Outer Harbour was deposited at the disposal
site during that time, but there was no capital dredging. The entire
disposal site, which is 1.3 km by 1.0 km (4300 ft by 3300 ft) in extent,
was modelled in the analyses.
14
Figure 3.4 Location of Mackay ocean disposal site

3.5 Disposal Site Environments
The average depths of the Albatross Bay, Cleveland Bay, Dalrymple Bay,
and Mackay disposal sites modelled (Sections 3.1 to 3.4) are
comparable to those of many Australian and United States (Hands and
DeLoach, 1984; Hands and Allison, 1991; Scheffner, 1991) ocean
disposal sites, although some United States sites are considerably
deeper (Demars et al., 1984). However, the disposal sites modelled are
all located in low wave energy environments, whereas many United
Sates sites are located in comparatively high wave energy environments.
Thus the analyses summarised in this report evaluated STFATE, LTFATE,
and MDFATE for relatively distinctive Australian conditions.
15

4. INPUT DATA USED IN ANALYSES
4.1 Compatibility With ADDAMS Modules
Few data related to the short term phenomena associated with the
dumping of sediments from dredges were available for any of the
ocean disposal sites modelled. Consequently, STFATE could not be
evaluated independently for these sites. Since none of the disposal
sites modelled had simple topography, they were unsuited to
modelling using LTFATE, and all were modelled using MDFATE. LTFATE
was used only to provide graphical output of tidal elevation and
current data that is not available from MDFATE (Section 4.4).
However, MDFATE incorporates most of STFATE and LTFATE (Section
2.3). Hence evaluations of MDFATE in which short term processes are
considered are also partial evaluations of STFATE, and evaluations of
MDFATE for long term processes are also evaluations of LTFATE.
4.2 Bathymetric Data
Extensive bathymetric data were available for the four disposal sites
modelled. However, the vertical control was estimated to be about
plus or minus 0.3 m (1ft) for the Weipa disposal site, and about plus
or minus 0.1m (0.3 ft) to 0.2 m (0.7 ft) for the Townsville, Hay Point,
and Mackay sites. Since the magnitudes of these errors were greater
than many of the long term changes in bathymetry (averaged over the
disposal site) that were modelled (Chapter 5), they constituted major
constraints on the interpretation of the results of the analyses. There
were also significant systematic errors in the Townsville and Hay Point
bathymetric data.
All bathymetric data were converted into ASCII files (Appendix 4) in
US units for input into MDFATE. The eastings and northings were
truncated to six significant figures to suit the limitations of the
MDFATE graphical output program. (The MDFATE grid creation
program cannot accept more than seven digits.)
Contour plots of the Weipa (Albatross Bay), Townsville (Cleveland
Bay), Hay Point (Dalrymple Bay), and Mackay ocean disposal sites
16

generated using MDFATE are shown in Figures 4.1 to 4.4. These
figures were colour-coded prior to reproduction in this report. All
dimensions in them are expressed in ft.
Figure 4.1 Albatross Bay 1994 ocean disposal site bathymetry
at September 1996
17

Figure 4.2 Cleveland Bay ocean disposal site bathymetry at
June 1991
Figure 4.3 Dalrymple Bay ocean disposal site bathymetry at
July 1993
18

Figure 4.4 Mackay ocean disposal site bathymetry at April
2000
4.3 Wave Data
The wave heights and periods used in LTFATE and MDFATE are not
defined in the user’s manuals (Scheffner et al., 1995; Moritz, 1994).
However, data are available from the US Army Engineer Waterways
Experiment Station Wave Information Study Internet site that are
intended for use with these programs. These indicate that Hm0, the
spectrally significant wave height, and either Tsig, the average period
of the highest one-third of zero up-crossing wave heights, or Tp, the
period at the peak spectral energy, should be used.
Digital data comprising time series of Hm0, Tsig, and Tp for the four
disposal sites modelled were supplied for the analyses summarised in
this report by the Environmental Protection Agency (Queensland). The
period Tp was used in all of the analyses in preference to Tsig. No
wave direction data were available for any of the sites modelled, and
there were numerous large and small gaps in all of the data sets.
19

Because the Waterways Experiment Station wave data pre-processing
program HDPRE is unavailable (Section 2.3, Appendices 2 and 3), it is
possible in MDFATE only either to neglect the effect of waves, or to
specify average wave parameters. When wave effects are neglected,
MDFATE uses default values that represent a low energy wave
environment comparable to that of the Townsville, Hay Point, and
Mackay disposal sites, but a significantly higher energy environment
than that of the Weipa disposal site. Nevertheless, the option to
neglect wave effects was not used in for any of these sites. The
average Hm0 and Tp for the Weipa, Townsville, and Hay Point
disposal sites ranged from 0.30 m (1.0 ft) to 0.37 m (1.2 ft) and from
3.3 s to 3.9 s, from 0.55 m (1.8 ft) to 0.85 m (2.8 ft) and from 4.6 s
to 5.3 s, and from 0.60 m (2.0 ft) to 0.69 m (2.3 ft) and from 4.4 s to
5.1 s, respectively. Those at the Mackay disposal site were 0.72 m (2.4
ft) and 5.3 s, respectively.
The Environmental Protection Agency wave recorders were located
between about 1 km and about 20 km from the four disposal sites,
and the depths of water at the wave recorders differed somewhat
from those at the disposal sites. However, an existing consultant’s
report indicated that the data from the Weipa recorder site could be
adopted unchanged for the Weipa disposal site. Analyses showed
that the behaviour of the sediments at the Townsville, Hay Point, and
Mackay disposal sites was insensitive to variations in both the wave
height and wave period, and the data from the associated recorder
sites were also adopted unchanged for these disposal sites.
Wave direction data are not used in LTFATE (Scheffner et al., 1995),
but are used in MDFATE. In the absence of wave direction data,
sensitivity analyses were conducted that showed that the effect of
wave direction on sediment behaviour at all of the disposal sites
modelled was small, and arbitrary wave directions were adopted in
the analyses.
4.4 Tide Data
In MDFATE, tidal effects may either be ignored or accounted for by
means of the input file TIDAL.DAT (Appendices 2, 3, and 5). The latter
option was adopted in all of the analyses summarised in this report.
TIDAL.DAT files comprise tidal amplitude and Greenwich epoch
20

harmonic constituents for both the elevations and the currents at the
location to be studied. Identical files are used in LTFATE.
Both MDFATE and LTATE are intended to be used with the TIDAL.DAT
files that are available from the US Army Engineer Waterways
Experiment Station Wave Information Study Internet site. These files
represent sites located at intervals of about 32 km (20 miles) around
the US coast (Scheffner, 1994). They are derived from deep-water
hindcasting studies and hence typically comprise only the eight
primary harmonic constituents, K1, O1, P1, Q1, M2, S2, N2, and K2,
for both elevation and currents (US Army Engineer Waterways
Experiment Station, 1994). However, MDFATE allows up to 20
constituents in TIDAL.DAT files, and LTFATE allows more than 40.
The tidal elevation harmonic constituents published in the Australian
National Tide Tables (Department of Defence, Navy Office, 1999,
2000) are suitable for use in both LTFATE and MDFATE, and were used
for all four disposal sites modelled. Tidal elevation constituents
supplied by Queensland Transport were also used for the Weipa and
Townsville sites. The various constituent sets used comprised between
18 and 36 constituents. The recording periods for all sites were
comparatively long, and all of the elevation constituents used are
consequently of good accuracy. The recorder sites were located within
about 4.5 km or less of the associated disposal sites, and all of the
elevation constituents were used unchanged in the MDFATE analyses.
The tidal ranges at Weipa, Townsville, Hay Point, and Mackay were
about 3.1 m (10.1 ft), 4.0 m (13.1 ft), 7.1 m (23.4 ft), and 6.4 m (21.0
ft), respectively.
Current meter time series data were supplied by WBM Oceanics Pty
Ltd and the Environmental Protection Agency (Queensland) for sites
located within about 4 km or less of the four disposal sites modelled.
Sets of 22 and 37 current constituents were also supplied by
Queensland Transport and Lawson and Treloar Pty Ltd for sites within
1 km of the Hay Point and Mackay disposal sites, respectively. The
data supplied by the two consulting firms were the property of the
various Port Authorities and were supplied with their consent. The
peak currents at Weipa, Townsville, Hay Point, and Mackay were
about 60 cm/s, 60 cm/s, 45 cm/s, and 87 cm/s, respectively. The
recording periods for the Weipa, Townsville, and Hay Point time series
21

data were all less than a month, and the constituents based on them
are consequently of relatively poor accuracy. The recording periods for
the Mackay time series data and constituents were comparatively
long, and the Mackay constituents are consequently of good
accuracy. All of the recording sites were located in depths of water
reasonably comparable to those at the corresponding disposal sites
and all of the current constituents supplied or derived from time series
data were used unchanged in the MDFATE analyses.
The tidal current time series data were analysed using an executable
file supplied by WBM Oceanics Pty Ltd that was based on programs
from the Institute of Ocean Sciences, Patricia Bay, British Columbia
(Foreman, 1978). These data were converted to the current velocity
component amplitudes and epochs required by MDFATE and LTFATE
(Appendix 5) using an Excel spreadsheet based on Foreman (1978)
and Godin (1972). The final constituent sets each comprised from 19
to 38 constituents.
TIDAL.DAT files for each disposal site were compiled by combining the
associated elevation and current constituent sets. The combined sets
were reduced to the MDFATE limit of 20 constituents by deleting
either the elevation constituents or the current constituents with the
smallest amplitudes. Extensive culling was necessary in most cases
since the elevation and current constituent sets had relatively few
constituents in common.
The tidal elevation and velocity plots for the Townsville (Cleveland Bay)
disposal site shown in Figures 4.5 to 4.12 were derived from the
Townsville TIDAL.DAT files using LTFATE. Similar plots were obtained
for the other disposal sites modelled. All data in Figures 4.5 to 4.12
are expressed in US units. The elevation and velocity magnitude plots,
which represent a period of one year, show clear seasonal variation.
The velocity direction plots are restricted to periods of 312 days, the
maximum period permitted by LTFATE.
There are considerable differences between the various TIDAL.DAT
files for each of the disposal sites modelled. Nevertheless, the results
of the analyses (Chapter 5) for the Weipa, Townsville, and Hay Point
sites suggest that there was relatively little to choose between the
TIDAL.DAT files for those sites (Morris 2001a,b,c). However, the
22

esults obtained for the Mackay disposal site differed significantly. This
was attributed to local effects at the two recorder sites used, and to
the large numbers of constituents that were eliminated to reduce the
sets to the MDFATE limit of 20 (Morris 2001d). The results of the
analyses for Townsville and Mackay were sensitive to changes in the
velocity of the tidal currents, but those for Hay Point were not.
As well as the tidal current harmonic data in TIDAL.DAT files, both
MDFATE and LTFATE require residual current input data. Since the
TIDAL.DAT files used for all four disposal sites modelled incorporated
the residual currents, residual current values of zero were used
throughout the analyses.
Fig. 4.5 Cleveland Bay tidal elevations based on Australian
National Tide Tables elevation and WBM Oceanics current
data emphasising currents
23

Fig. 4.6 Cleveland Bay north-south tidal velocity magnitudes
corresponding to Figure 4.5
Fig. 4.7 Cleveland Bay east-west tidal velocity magnitudes
corresponding to Figure 4.5
24

Fig. 4.8 Cleveland Bay tidal velocity directions corresponding
to Figure 4.5
Fig. 4.9 Cleveland Bay tidal elevations based on Townsville
Fairway Beacon (Queensland Transport) elevation and WBM
Oceanics current data emphasising currents
25

Fig. 4.10 Cleveland Bay north-south tidal velocity magnitudes
corresponding to Figure 4.9
Fig. 4.11 Cleveland Bay east-west tidal velocity magnitudes
corresponding to Figure 4.9
26

Fig. 4.12 Cleveland Bay tidal velocity directions corresponding
to Figure 4.9
4.5 Dredged Sediment And Seawater Data
The dredged sediment data that are required by MDFATE if only long
term processes are modelled are the bulk void ratio of the sediments
on the seabed; the respective percentages of sand, silt, and clay in the
sediments; and the median particle size. If both short and long term
or only short term processes are modelled, it is necessary to specify
the total volume and the number (to a maximum of 4) of sediment
types to be dumped. The specific gravity, the volume fraction of solids
in the dredge hopper, the sediment particle size, the bulk void ratio of
the sediments on the seabed, and the critical shear stress for
avalanching are required for each sediment type. It is also necessary
to specify whether each sediment type is cohesive or non-cohesive,
whether it is stripped during descent, and whether the seabed
sediments are fixed or moveable.
The volumes of spoil dumped at Weipa and Hay Point during the
periods modelled were taken from consultants’ reports, while those
27

dumped at Townsville and Mackay were supplied, in a variety of
forms, by the respective Port Authorities.
For all four of the disposal sites modelled, representative median
particle sizes and percentages of sand, silt, and clay for the capital and
maintenance dredge spoil and the seabed sediments were taken from
or estimated using data from consultants’ reports and other published
data (Morris, 2001a-d). The median particle sizes of the Weipa,
Townsville, Hay Point, and Mackay maintenance dredging spoils were
about 0.05 mm, 0.05 mm, 0.1 mm, and 0.0024 mm, respectively.
Those of the Townsville, Hay Point, and Mackay capital dredging
spoils were about 0.1 mm, 0.6 mm, and 0.14 mm, respectively.
Because the cohesive sediment option is currently unavailable in
MDFATE, the minimum median particle size permitted is 0.006 mm.
This is smaller than the representative median particle sizes used for
the Weipa, Townsville, and Hay Point analyses, but significantly larger
than that of the Mackay maintenance dredging sediments. The results
of the Mackay analyses suggested that the losses of spoil from that
disposal site were consequently underestimated significantly.
It was also necessary, because of the unavailability of the cohesive
sediment option, to use higher than appropriate sand and silt
fractions for the Weipa, Townsville, and Hay Point sediments. The
effect of this on the results of the analyses is uncertain. However,
increasing the sand fraction had little effect on the results of the Hay
Point analyses.
The specific gravity of the Hay Point and Mackay dredged sediments
were obtained from consultants’ reports. In the absence of relevant
data, the specific gravity of both the Weipa and Townsville dredged
sediments was assumed to be 2.65.
It was assumed that the Weipa, Townsville, and Hay Point seabed
sediments were moveable in all cases. The relatively coarse Mackay
seabed sediments were assumed to be fixed in most analyses, but the
assumption that they were moveable gave similar overall results.
The volume fraction of solids in the dredge hopper for the sediments
for all four disposal sites modelled were estimated from data taken
28

from consultants’ reports or supplied by the respective Port
Authorities, or estimated from correlations of void ratio with particle
size (Morris and Williams, 2000).
MDFATE tended to terminate prematurely in the Weipa and Townsville
analyses when the volume fraction of solids in the dredge hopper was
about 0.5 or less. This instability appeared to be linked to the
unavailability of the cohesive soil option. It was circumvented by
inputting a higher volume fraction of solids in the hopper, and
reducing the in-hopper volume of spoil to compensate. This was
considered to have had little effect on overall results of the analyses,
but may have had a significant but unquantifiable effect on the
(calculated) detailed topography of the disposal sites (Morris,
2001a,b).
The bulk void ratios and in-hopper densities of the dredge spoils for
the four sites modelled were estimated using data from consultants’
reports or supplied by the various Port Authorities. Varying the seabed
void ratio of the spoil had comparatively large effects on the estimated
changes in the bathymetry, but little effect on the estimated losses
from the Townsville, Hay Point, and Mackay disposal sites
In the absence of data for any of the sediments modelled, the critical
shear stresses for avalanching were taken from a table of representative
geotechnical sediment parameters incorporated in MDFATE. The overall
results of the Townsville, Hay Point, and Mackay analyses were
insensitive to moderate changes in the critical shear stress.
It was assumed that the Weipa, Townsville, and Hay Point dredged
sediments were stripped during descent, but that the Mackay
sediments were not. Sensitivity analyses showed that the overall
effects of these assumptions on the results of the Townsville, Hay
Point, and Mackay analyses were small.
Because the cohesive sediment option was unavailable, it was
assumed that the sediments at all of the disposal sites modelled were
non-cohesive. It was difficult to gauge the effect of this assumption
on the analyses, but the results obtained suggest that overall, it was
small. However, it may have had a significant effect on the detailed
topography of the Weipa, Townsville, and Mackay disposal sites.
29

To model the avalanching of spoil on a disposal site, it is necessary to
specify whether the dredge spoil has been dredged mechanically or
hydraulically. Capital dredging material may have a steeper angle of
repose than maintenance dredging material, depending on the
dredging and disposal equipment used and the sediment type
(Moritz, 1994). For the four disposal sites modelled, it was assumed
that the capital dredging was mechanical and the maintenance
dredging was hydraulic. Sensitivity analyses for the Townsville and
Mackay disposal sites indicated that the overall effect of these
assumptions was small.
The seawater data that are required by MDFATE are the water column
density at the disposal site and at the site of the dredging. In the
absence of data for the sites modelled, representative seawater
densities incorporated in MDFATE were used in all of the analyses.
4.6 Dredge Dimensions And Operating Constraints
Split hull or hopper dredges or barges were used in all of the dredging
campaigns modelled (Morris 2001a-d). The dimensions of and
operating parameters for such vessels that are required by MDFATE
are the capacity, length, and beam of the hopper; the loaded and
empty drafts; the time to empty the hopper; and the speed during
dumping. For the four disposal sites modelled, these data were
supplied by or estimated from data supplied by the dredging
contractors and the various Port Authorities.
The dumping sequences used for all of the dredging campaigns
modelled were very complicated, and in the absence of detailed data,
were not replicated in the analyses (Morris, 2001a-d). Instead,
dumping was assumed to occur at random positions within fixed radii
of specified points within the disposal sites, with the dredge or barge
moving in an arbitrary direction. In MDFATE, only one direction may
be specified for random dumping, and it is reflected strongly in the
estimated detailed final topography of the disposal site. However,
sensitivity analyses showed that this had little effect on the overall
results obtained. Alternative dumping patterns may be specified
(Appendix 3).
30

Dumping is normally prohibited within specified distances of disposal
site boundaries to minimise losses from the site (Morris, 2001a-d).
This practice was modelled in the analyses for all of the disposal sites.
Critical navigable depths, above which dredge spoil cannot be placed,
were also specified in all cases.
31

5. RESULTS OF ANALYSES
The analyses summarised in this report were aimed at evaluating the
suitability of the ADDAMS programs, STFATE, LTFATE, and MDFATE,
for application to the preliminary assessment of the ocean disposal of
dredged sediments. Since the results of such assessments cannot be
refined by varying individual inputs (Chapter 4) to optimise matches
to known outcomes, no attempt was made to do this in these
analyses. However, all of the tidal harmonic constituent data sets
derived for each site (Section 4.4) were used in the analyses.
All of the figures presented in this Chapter were generated using
MDFATE and were colour-coded prior to reproduction in this report.
All of the dimensions shown on the figures are expressed in ft.
5.1 Weipa Ocean Disposal Site
For the Weipa (Albatross Bay) ocean disposal site, the two intercampaign
periods from 1994 to 1996 and from 1996 to 1998 and the
1998 dredging campaign were modelled (Section 3.1; Morris, 2001a).
The analyses of the 1998 dumping campaign data were primarily an
evaluation of STFATE independently of LTFATE, while the intercampaign
periods were sufficiently long for the corresponding
analyses to constitute evaluations of LTFATE completely independently
of STFATE.
The measured and calculated (averaged) changes in the Albatross Bay
disposal site bathymetry that occurred during the two inter-campaign
periods differed by up to 500%. Nevertheless, because they were of
comparable magnitude and, given the poor vertical control (Section
4.2), too small to measure accurately, it was concluded that they were
mutually consistent. It was thus concluded that MDFATE had
modelled the changes in the bathymetry reasonably well, but also that
these analyses were relatively weak tests of the abilities of MDFATE
and hence LTFATE.
MDFATE matched the measured volume of sediments retained on the
Albatross Bay disposal site at the end of the 1998 dredging campaign
within about 18% (Figs 5.1 and 5.2). However, within MDFATE,
32

STFATE may have overestimated the short term losses from the site by
up to about 49%, or about 13% of the total volume of sediments
dumped (Morris, 2001a). The unavailability in the current version of
MDFATE of the cohesive sediment option (Section 4.5) may have
contributed significantly to this comparatively poor performance.
Because the changes in bathymetry averaged over the disposal site
were large compared to the vertical control (Section 4.2), it was
concluded that these analyses were relatively strong tests of the
abilities of MDFATE and hence STFATE.
Fig. 5.1 Measured change in Albatross Bay ocean disposal site
bathymetry between May and July 1998
33

Fig. 5.2 Estimated change in Albatross Bay ocean disposal site
bathymetry between May and July 1998 based on Australian
National Tide Tables elevation and WBM Oceanics current
data emphasising elevations
5.2 Townsville Ocean Disposal Site
For the Townsville (Cleveland Bay) ocean disposal site, the periods
modelled were from June 1991 to June 1993, from June 1993 to
December 1996, and from December 1996 to January 1998 (Section
3.2; Morris, 2001b). These periods respectively encompassed three,
five, and two dredging campaigns of varying duration. The duration
of each period was ample for the corresponding analyses to constitute
an evaluation of LTFATE, but no pre and post dredging bathymetric
data suitable to enable STFATE to be evaluated independently of
LTFATE were available.
PSDDF was used to investigate whether the consolidation of freshly
deposited spoil could account for the systematic error in the
34

Townsville bathymetric data (Section 4.2). The analyses, which, in the
absence of consolidation data for the Townsville sediments, were
based on data for a range of sediments from the tables incorporated
in PSDDF, showed clearly that it could not.
MDFATE matched poorly the measured volume of sediments retained
on the Cleveland Bay disposal site at the end of each of the three
periods modelled, with errors of up to 160% for the first period (Figs
5.3 and 5.4) and even larger errors for the second and third periods
(Morris, 2001b). However, these errors were easily accounted for by
the uncertainties in the input data, and the measured and estimated
changes in the bathymetry were of comparable magnitude but too
small to measure accurately (Section 4.2). Thus it was concluded that
the overall changes in the Cleveland Bay disposal site bathymetry
were modelled reasonably well for all three periods, but that the
analyses were relatively weak tests of the abilities of MDFATE and
hence LTFATE.
Fig. 5.3 Measured change in Cleveland Bay ocean disposal site
bathymetry between June 1991 and June 1993
35

Fig. 5.4 Estimated change in Cleveland Bay ocean disposal site
bathymetry between June 1991 and June 1993 based on
Australian National Tide Tables elevation and WBM Oceanics
current data emphasising elevations
5.3 Hay Point Ocean Disposal Site
For the Hay Point (Dalrymple Bay) disposal site, the three periods
modelled were from February 1981 to July 1993, from July to
November 1993, and from November 1993 to April 2000 (Section
3.3; Morris 2001c). There was no dredging during the first period
modelled, and only minor maintenance dredging was undertaken
during the third. Both of these periods were long enough for the
corresponding analyses to constitute evaluations of LTFATE. The
second, much shorter period modelled encompassed a major capital
dredging program, and the corresponding analyses constituted an
analysis of STFATE that was essentially independent of LTFATE.
The measured changes in the bathymetry at the Dalrymple Bay ocean
disposal site during the first and third periods modelled were, at most,
only slightly greater than the vertical control (Section 4.2), and the
corresponding estimated changes (averaged over the disposal site)
36

were negligibly small. Thus, the estimated and measured long term
changes in the disposal site bathymetry were mutually consistent to the
extent that both were too small to measure accurately (Morris 2001c).
The estimated and measured volumes of sediments retained on the Hay
Point disposal site at the end of the second period modelled (Figs 5.5
and 5.6) matched poorly, with a discrepancy approaching 300% of the
calculated volume (Morris 2001c). This could not be accounted for by
the poor vertical control or errors in the estimated void ratio of the
dredged sediments (Chapter 4), but was attributed to errors in the
bathymetric data. It was thus difficult to draw firm conclusions
regarding the ability of MDFATE to model the short term changes in the
disposal site bathymetry. However, the results obtained suggested that
the short term losses from the site were overestimated significantly.
Both the long and short term analyses for the Hay Point disposal site
were thus also relatively weak tests of the abilities of MDFATE.
Fig. 5.5 Measured change in Dalrymple Bay ocean disposal site
bathymetry between July and November 1993
37

Fig. 5.6 Estimated change in Dalrymple Bay ocean disposal site
bathymetry between July and November 1993 based on
Australian National Tide Tables elevation and WBM Oceanics
current data emphasising currents
5.4 Mackay ocean disposal site
For the Mackay ocean disposal site, the period from September 1998
to April 2000 was modelled (Section 3.4; Morris 2001d). During the
period modelled, there was almost continuous maintenance dredging
but no capital dredging. The duration of this period was ample for the
Mackay analyses to constitute an evaluation of LTFATE, but no data
suitable to enable STFATE to be evaluated independently of LTFATE
were available.
The estimated and measured gains over the Mackay disposal site
differed markedly (Figs 5.7 and 5.8), with discrepancies up to about
230% of the volume of sediment dumped. However, the vertical
control of the bathymetric data was poor (Section 4.2), and the data
were inconsistent with the known dispersive nature of the site
38

(Morris, 2001d). This readily accounted for the discrepancies between
the estimated and measured gains over the disposal site, which were
mutually consistent to the extent that both were too small to measure
accurately. Hence the Mackay analyses were also a relatively weak test
of the abilities of MDFATE.
The estimated gains over the disposal site were equivalent to the
retention on the site of about 14% to 27% of all the sediments
dumped. They were thus broadly consistent with the dispersive nature
of the site, but, because an unrealistically large representative
sediment particle size for the dredge spoil was perforce used in the
analyses (Section 4.5), were probably significant overestimates. The
lower estimates of the percentages retained were considered the
more reliable (Morris, 2001d).
Fig. 5.7 Measured change in Mackay ocean disposal site
bathymetry between September 1998 and April 2000
39

Fig. 5.8 Estimated change in Mackay ocean disposal site
bathymetry between September 1998 and April 2000 based
on Australian National Tide Tables elevation and Lawson and
Treloar current data emphasising currents
40

6. CONCLUSIONS
The analyses of the Weipa (Albatross Bay), Townsville (Cleveland Bay),
Hay Point (Dalrymple Bay), and Mackay ocean disposal sites
summarised in this report were aimed at evaluating the suitability of
the ADDAMS programs STFATE, LTFATE, and MDFATE for application
to the preliminary assessment of the ocean disposal of sediments from
marinas and small boat harbours under Australian conditions. The
available data were incompatible with the requirements of STFATE
and LTFATE, and the analyses were conducted primarily using
MDFATE. LTFATE was used only to generate graphical output not
available from MDFATE, and STFATE was not used at all. However,
since MDFATE incorporates programming that is almost identical to
that of both STFATE, except that contaminants are not considered,
and LTFATE, the evaluations of MDFATE summarised here also
constitute partial evaluations of both STFATE and LTFATE.
The four disposal sites modelled (Chapter 3) are all located in low
wave energy environments, whereas many United Sates sites are
located in comparatively high wave energy environments. The
analyses summarised in this report thus evaluated STFATE, LTFATE, and
MDFATE for relatively distinctive Australian conditions. In addition, the
tidal conditions and the properties of the dredge spoils and seabed
sediments at four sites modelled differ significantly from one another
(Chapter 4). Most notably, the Weipa, Townsville, and Hay Point sites
are essentially non-dispersive, while the Mackay site is very dispersive
(Chapter 5).
All of the periods modelled at the four disposal sites were defined by
the availability of suitable bathymetric data. While extensive data
were available for all sites, the vertical control was relatively poor in all
cases (Section 4.2), and in most cases, greater than the changes in
bathymetry (averaged over the disposal site) that were modelled. In
addition, there were significant systematic errors in the data for the
Townsville and Hay Point disposal sites. (The ADDAMS program
PSDDF was used only to investigate whether the consolidation of
freshly deposited spoil could account for the error in the Townsville
bathymetric data, but it was found that it could not (Section 5.2).)
41

Consequently, all but one of the analyses summarised in this report
were relatively weak tests of the ability of MDFATE, STFATE, and
LTFATE to model the short and long term fate of dredged sediments.
The sole exception was the analysis of the 1998 Weipa dredging
campaign, during which the changes in bathymetry were
comparatively large (Section 5.1). The analysis of this campaign was
consequently a relatively strong test of the ability of MDFATE and thus
STFATE to model the short term fate of dredged sediments.
The changes in the detailed topography were not modelled well at any
of the disposal sites, at least partly because the complicated dumping
patterns used were not replicated in the analyses (Section 4.6).
In the absence of the cohesive sediment option in MDFATE, it was
necessary use the non-cohesive option, and hence to input
unrealistically large particle sizes for the Weipa, Townsville, and
Mackay dredged sediments and unrealistically high sand and silt
fractions for all of the sediments modelled (Section 4.5). This probably
caused the losses of the fine-grained, cohesive Mackay sediments
from that disposal site to be underestimated, but the effects on the
analyses of the other three sites were probably small. The
performance of MDFATE in the modelling of fine-grained cohesive
sediments thus may improve significantly when the cohesive sediment
option becomes available.
The measured and calculated long term net sediment movements
were all of comparable magnitude but too small to measure
accurately (Chapter 5). Hence, notwithstanding the shortcomings of
the analyses summarised in this report, it was concluded that MDFATE
modelled the overall long term changes in the bathymetry of the four
disposal sites reasonably well.
The data available for the Townsville and Mackay sediments were
unsuitable to enable conclusions to be drawn regarding the ability of
MDFATE and hence STFATE to model their short term behaviour. The
analyses of the short term behaviour of Hay Point sediments were
somewhat inconclusive, but both they and the corresponding
analyses for Weipa and suggested that MDFATE and hence STFATE
might overestimate significantly the losses from disposal sites that
occur during spoil disposal. However, the estimated losses at Weipa
42

were a relatively small fraction of the total quantity of spoil dumped
(Section 5.1).
Thus, within the constraints imposed by the available data, MDFATE
and hence both STFATE and LTFATE modelled reasonably robustly and
well the long term behaviour of the sediments at both the essentially
non-dispersive Weipa, Townsville, and Hay Point disposal sites, and
the very dispersive Mackay disposal site. The ability of MDFATE and
hence STFATE to model the short term losses from the Weipa and Hay
Point disposal sites well is less certain. However, in all cases, the
MDFATE estimates matched the overall measured changes in the
bathymetry to a first approximation satisfactory for preliminary
assessments of ocean disposal sites.
43

APPENDIX 1: INPUT DATA REQUIREMENTS FOR STFATE V.
5.01
STFATE models a single dump of contaminated sediments from a splithull
barge or hopper dredge. If more than one contaminant is present
in the sediments, the most significant, which is denoted the
“contaminant of concern”, can be determined using STFATE before
the disposal operation is modelled. Alternatively, each contaminant
may be considered in turn. The input data required to perform these
calculations are described below.
(A) Determination of contaminant of concern
The data required for each contaminant considered are the
contaminant water quality criterion (µg/l), the background
concentration (µg/l), and the solids concentration of the dredged
material (g/l) and the contaminant concentration in the bulk sediment
(µg/kg), or the contaminant concentration in the elutriate (µg/l).
(B) Modelling disposal from a split-hull barge or hopper
dredge
To model disposal, it is necessary to specify the disposal site
topography and seawater parameters; controls for the input,
execution, and output; descriptions of the dredged sediments and the
disposal operation; and a number of model coefficients.
44
1. Disposal site topography:
• The data required to define the disposal site topography are
the topographic grid (ft), the water depth (ft), and the
bottom roughness (ft). Guidance for the latter is provided
within STFATE. The elevation of the seabed may be constant
or vary irregularly. Alternatively, the seabed may be planar
and slope in two directions (degrees).
• The water density profile (g/cc) or the salinity (ppt) and
temperature (Celsius) profiles must also be specified.

2. Seawater velocities:
• The seawater velocity may be input as an average velocity or
a two-point velocity profile, or velocities for the entire grid
(ft/sec, in two directions) may be specified.
3. Controls for input, execution, and output:
• The input, execution, and output controls to be specified are
the location of the mixing zone, the water quality standard
(mg/l) at the border of the zone or the dilution required to
meet the toxicity standard (% of initial concentration), the
initial concentration of the contaminant in the sediment
(mg/kg) or in its fluid fraction (mg/l), and the contaminant
background concentration at the disposal site (mg/l).
• Alternatively, the location of a zone of initial dilution (ft) and
the water quality standard at its border (mg/l) or the dilution
required to meet the toxicity standard at the border (% of
initial concentration) may be specified.
4. Description of dredged sediments:
• The description of the dredged sediments comprises the
number of layers of dredge spoil in the disposal vessel, to a
maximum of six; the volume of each layer (cu.yd); the velocity
of the vessel during the dumping of each layer (ft/sec, in two
directions); and the number, to a maximum of four, of distinct
solid fractions (clumps, gravel, sand, silt, and/or clay) and
their volumetric concentration in each layer. The specific
gravity, fall velocity (ft/sec), void ratio after deposition, and
critical shear stress (lb/sq.ft) of each solid fraction, and
whether it is cohesive or non-cohesive and stripped or not
stripped during descent must also be specified.
• If desired, the entrainment and drag coefficients for the
dredged sediments may be adjusted in accordance with their
moisture contents. The moisture content/liquid limit ratio for
each layer of dredged sediments, and the water density
45

46
(g/cc) or the water salinity (ppt) and temperature (Celsius) at
the dredging site are then required.
5. Description of disposal operation:
• The data required to describe the disposal operation are the
position of the vessel on the topographic grid (ft); the number,
size, and position of bins (ft); the number of bins opened
simultaneously; the velocity of the vessel while each bin is
opened (ft/s in 2 directions); its draft before and after dumping
(ft); and the total time required to empty all bins (sec).
• An option that allows dumping in a seabed depression is also
available. The disposal vessel must be stationary and the
depression dimensions (ft) must be specified.
6. Model coefficients:
• Values of fourteen coefficients are required for the model to
accurately specify entrainment, settling, drag, dissipation,
apparent mass, and density gradient differences.
• The default values should be used unless site-specific
information is available.
• Alternatively, the diffusion coefficient may be calculated
within STFATE. The Pritchard expression is used and no input
data are required.

APPENDIX 2: INPUT DATA REQUIREMENTS FOR LTFATE V. 1.0
The module LTFATE consists of three main programs: PC_WAVEFIELD,
PC_TIDAL, and PC_LTFATE. The programs PC_WAVEFIELD and
PC_TIDAL are primarily used to generate input files required by
PC_LTFATE, but may also be used independently.
Data are entered interactively in PC_WAVEFIELD, PC_TIDAL, and
PC_LTFATE. In addition, LTFATE may require the external, user-supplied
input files, HPPRE.OUT, HPDSIM.OUT, TIDAL.DAT, and STORM.DAT.
(A) External user-supplied files required by LTFATE
1. Wave data files HPDSIM.OUT and HDPRE.OUT:
• HPDSIM.OUT comprises a 3-hr-increment time series of wave
height, period, and direction at the location of the mound to
be studied.
• The data stored in HPDSIM.OUT are analyzed statistically by
PC_WAVEFIELD to generate a simulated wave field database
for input into PC_LTFATE.
• HPDSIM.OUT may be generated internally in PC_WAVEFIELD
or supplied in appropriate format by the user.
• Internal generation has the advantage that an arbitrarily long
sequence of simulated wave data may be created that
preserves the primary statistical properties of a full Wave
Information Study (WIS) 20-year hindcast, including wave
sequencing and seasonality (Borgman and Scheffner, 1991;
Scheffner and Borgman, 1992). At present, HPDSIM.OUT can
be generated internally for some US sites only.
• To generate HPDSIM.OUT internally in PC_WAVEFIELD, the
input file HPDPRE.OUT is required.
47

48
• HDPRE.OUT comprises the pre-computed cross-correlation
matrix corresponding to the WIS station nearest the mound
to be studied. HDPRE.OUT files are available for some US sites
only.
• If no HPDPRE.OUT file is available for the location of interest,
one can be computed using a WIS 20-year hindcast input file,
which available for US sites only, or user-supplied time series
of wave height, period, and direction, and the program
HPDPRE, as described in Borgman and Scheffner (1991).
However, HPDPRE is not normally available to the public.
• WIS 20-year hindcast data files comprise inferred data
derived from historic barometric pressure maps and ship
observations of air-sea temperatures and winds (Hands and
Allison, 1991).
2. Tidal data file TIDAL.DAT:
• TIDAL.DAT comprises TIDAL amplitude and epoch harmonic
constituents for both elevations and currents at the location
of the mound to be studied.
• TIDAL.DAT is used by PC_TIDAL to generate elevation and
current constituents in the appropriate format as the file
TIDE.DAT for input into PC_LTFATE.
• TIDAL.DAT files are available for some US sites only.
• For other sites, the user must generate TIDAL.DAT files by
harmonic analyses of tidal elevation and current time series
data.
• An example of the use of external data is given in Scheffner
and Talent (1994).
3. Storm data file STORM.DAT:
• STORM.DAT is required only if the user desires to simulate the
passage of a storm event over the disposal site.

• STORM.DAT comprises a 3-hr-increment STORM surge
elevation and current time series hydrograph and a storm
wave height and period corresponding to the selected event.
• STORM.DAT must be assembled from existing databases or
assembled by the user.
• STORM.DAT should describe a particular storm event or a
storm event of assumed shape and duration.
• A database of 134 tropical storm hydrographs from locations
on the US Gulf and East coasts and Puerto Rico is available
(Scheffner et al., 1994).
(B) Data requested interactively by LTFATE programs
1. Data requested by PC_WAVEFIELD:
• If HDPRE.OUT is to be used to generate HPDSIM.OUT: the
month and year of the beginning and end of the simulation,
and a random number seed.
• If HPDSIM.OUT is available or has been generated: the
duration of the simulation (days)
2. Data requested by PC_TIDAL:
• The duration of the simulation (days)
3. Data requested by PC_LTFATE:
• To create a topography file for a mound with complicated
geometry: the drive, path, and name of the file; the file
description; the (averaged) ambient depth (ft); the grid
spacing (ft); the mound boundaries (ft); and the elevations of
the mound within the boundaries (ft). (Existing files may be
revised, but only the elevations can be changed.)
49

50
• To create a topography file for a mound with simple
geometry: the grid spacing (ft), the average depth (ft), the
maximum mound elevation above the seabed (ft), and the
average mound diameter (ft)
• To plot mound contours for verification of data entry: the
number of contours, and the minimum and maximum
contours (ft)
• To simulate long term mound movement: output files from
PC_WAVEFIELD and PC_TIDAL (No interactive data inputs are
required.)
• To simulate storm induced mound movement: the file
STORM.DAT (No interactive data inputs are required.)
• To describe the residual current: the current velocity (ft/sec)
and direction (deg).
• To define the period and output time intervals of the
simulation: the duration of the simulation (days), and the
output interval (hrs) (A multiple of 3 hrs is required to match
the input data.)
• To describe the dredged material: the sediment D50 (median)
grain size (mm); the material type (sand, clay/sand mixture,
inorganic clays, or organic clays); the angle of initial yield for
avalanching (deg); and the residual angle after shearing (deg)
• To plot the mound contours and cross-sections at the
preselected output time intervals: the number of contours,
and the distance of the cross-section from the mound centreline
(ft)

APPENDIX 3: INPUT DATA REQUIREMENTS FOR
MDFATE V. 1.1
To model the disposal of sediments using MDFATE, it is necessary to
define the disposal site topographic grid, select the processes of
interest, and specify the wave and tidal environments. The input data
required for this and for the pre and post processing utility programs
included in MDFATE is listed below.
(A) Definition of disposal site grid
• The bathymetry of the disposal site can be defined using an
ASCII data file based on survey information. The required
data comprise eastings, northings, and elevations compiled in
any order in three columns separated by spaces.
• Alternatively, disposal site co-ordinates and depths can be
entered interactively. Constant depth and constant slope site
geometry options are also available, and simple mound
geometry can be input using UTILITIES (Section F).
(B) Long term processes
• If only the long term processes affecting material already on
the disposal site seabed are of interest, it is necessary to
consider only sediment transport, consolidation, and
avalanching.
• The duration of the simulation, the residual (non-tidal) water
speed and direction, and the sediment material type must be
specified. Up to three material types may be considered.
(C) Short term and short and long term processes
• If only short term processes are of interest, it is necessary to
model the descent of the dredge spoil from the disposal
vessel to the seabed. If both short and long term processes
are of interest, sediment transport, consolidation, and
avalanching must also be modelled.
51

52
• In both cases, the data required are the type of disposal vessel
(barge, scow, or hopper dredge) used; its operating capacity,
length, beam, and loaded and unloaded drafts; the time
required to empty it of a single load; and its speed and
heading during dumping.
• If the disposal vessel is a multiple hopper dredge, the total
number of bins, the number of bins to be emptied
simultaneously, the dimensions of individual bin door
openings, and the distance between the bins are also
required.
• In all cases, it is necessary to specify the navigable depth, that
is, the depth above which dredge spoil cannot be placed; the
minimum distance from the disposal site boundaries that
spoil may be placed; the duration of the simulation; the
densities of the water at the dredging and disposal sites; the
geotechnical properties of the dredge spoil; and the total
volume of spoil to be placed.
• During dumping, the disposal vessel may be located at
random positions within a specified radius of a
predetermined point, or along a transect with specified
beginning and ending co-ordinates. Alternatively, individual
disposal points may be specified by the user on a load-byload
basis, or disposal may be controlled by co-ordinate
locations listed in an ASCII file supplied by the user. The file
must comprise eastings and northings in any order, in two
columns separated by spaces.
(D) Wave environment
• The wave data file HDPRE.OUT required by MDFATE
comprises the pre-computed cross-correlation matrix
corresponding to the Wave Information Study (WIS) station
location nearest the mound to be studied. This is available for
some US sites only. The combined capabilities of LTFATE and
HDPRE.OUT are described in Borgman and Scheffner (1991)
and Scheffner and Borgman (1992).

• If no HPDPRE.OUT file is available for the location of interest,
one can be computed using a WIS 32- or 20-year hindcast
input file, available for US sites only, and the program
HPDPRE. (HPDPRE is not included in MDFATE and is not
normally available to the public.) WIS hindcast data files
comprise inferred data derived from historic barometric
pressure maps and ship observations of air-sea temperatures
and winds (Hands and Allison, 1991).
• If a WIS input file is not available, the user may supply time
series of wave height, period, and direction. The
HDPPRE.OUT matrix may then be computed using HDPRE, as
described in Borgman and Scheffner (1991).
• Alternatively, if HPDRE.OUT is unavailable or cannot be
assembled by the user, mean wave parameters can be
specified, or wave effects can be ignored completely.
(E) Tidal environment
• The tide data file TIDAL.DAT required by MDFATE comprises
tidal amplitude and epoch harmonic constituents for both
elevation and currents at the location of the mound to be
studied. User-ready TIDAL.DAT files are available for some US
sites only. For other sites, the user may generate TIDAL.DAT
files by harmonic analyses of tidal elevation and current time
series data. An example of the use of external data is given in
Scheffner and Talent (1994).
• Alternatively, if no suitable data are available, the effects of
tides may be ignored. Non-zero default input data are then
used automatically in MDFATE.
(F) Utility programs
(1) Pre processing:
• A simple circular mound or an elongated berm may be
generated on a disposal site topographic grid. The inputs
required for the mound are the location of its centre, its
53

54
diameter, its maximum elevation above the seabed, and the
side slope. The inputs required for the berm are the locations
of the ends, the elevation and width of the crest, and the side
slope.
• Potential sediment transport rates may be calculated for a
range of depth-averaged water column currents. The wave
height and period, the water depth, and the sediment grain
size are required inputs. A cohesive or a non-cohesive
transport relationship is used, depending on the grain size.
(2) Post processing:
• MDFATE can calculate the volume above a specified elevation
in a disposal site topographic grid or that between two grids,
or generate a grid representing the difference between two
grids. The input data required are the disposal site
topographic grids generated by MDFATE.

APPENDIX 4: BATHYMETRY INPUT FILE FOR CLEVELAND
BAY OCEAN DISPOSAL SITE
The truncated ASCII bathymetry input file for MDFATE for the
Cleveland Bay ocean disposal site shown below originally consisted of
more than 6000 lines of data. (The files used for the Albatross Bay,
Dalrymple Bay, and Mackay disposal sites consisted of less than 600
to more than 9000 lines.) File names must consist of [any six character
root name].[any three character extension] (Moritz, 1994). No
headings may be used. Here, the columns represent eastings,
northings, and depths, respectively, but the data may be entered in
any order. The units are ft in all cases. The eastings and northings
shown were reduced to six digits to comply with the programming
limits of MDFATE (Section 4.2).
619208 862127 44.6
619260 862193 44.7
619383 862395 44.7
619416 862477 45.0
619476 862572 45.2
618852 860623 42.9
619552 862676 45.4
619609 862757 45.6
619679 862850 45.5
619725 862925 45.5
619778 863026 45.8
619840 863119 45.7
619924 863282 45.9
618914 860738 43.0
619974 863390 46.2
620020 863469 46.2
620076 863555 46.1
620174 863690 46.4
620278 863881 46.5
620320 863956 46.8
620396 864082 46.9
620449 864155 47.1
etc
55

APPENDIX 5: TIDAL HARMONIC CONSTITUENT INPUT FILE
FOR MACKAY OCEAN DISPOSAL SITE
The tidal harmonic constituent data file shown below conforms to the
format required for TIDAL.DAT files to be used with both LTFATE and
MDFATE (Scheffner et al., 1995; Moritz, 1994). It is based on the
Mackay Outer Harbour tidal elevation constituents published in the
Australian National Tide Tables 2000 (Department of Defence, Navy
Office, 2000) and tidal current data supplied by Lawson and Treloar
Pty Ltd. The data were culled to conform to the limit of 20
constituents permitted in MDFATE.
The file consists of two lines of informational data followed by the
variables NHARM, H0, U0, and V0. These represent the number of
harmonic constituents in the file, the average elevation (m), and the
velocity components (cm/s) directed towards the north and east,
respectively. Two additional lines of informational data are then
followed by the data for each constituent. These comprise the
constituent name and speed (deg/hr), and the amplitudes (m or cm/s)
and epochs (deg) of the tidal elevation and currents. They are read
using a Fortran FORMAT(10x,F10.6,6F10.2) statement (Scheffner et
al., 1995).
56

MACKAY, QUEENSLAND
TIDAL HARMONIC CONSTITUENTS
20 0.0 -2.1 9.2
CONST SPEED-D/H AMP-M EPOCH-D AMP-C/S EPOCH-D AMP-C/S EPOCH-D
HEIGHT VEL-U VEL-V
M2 28.984104 1.67 322.00 53.3 22. 2.9 113.
S2 30.000000 .61 320.80 23.4 29. 0.3 132.
K1 15.041070 .39 186.80 3.0 186. 1.5 302.
O1 13.943034 .20 147.40 1.4 93. 0.7 268.
Sa 0.041067 .10 350.10 0.0 0. 0.0 0.
Msf 1.015895 .01 282.70 2.9 157. 2.2 355.
Q1 13.398661 .04 123.80 0.6 128. 0.1 359.
P1 14.958932 .12 183.50 0.8 183. 0.4 298.
2N2 27.895355 .06 296.80 0.0 0. 0.0 0.
MU2 27.968208 .05 64.80 0.2 233. 0.9 299.
N2 28.439730 .41 304.00 14.7 6. 0.4 2.
NU2 28.512583 .10 301.40 0.0 0. 0.0 0.
L2 29.528479 .09 308.90 6.0 19. 0.2 282.
T2 29.958933 .03 303.90 0.0 0. 0.0 0.
K2 30.082136 .18 318.50 7.0 19. 0.1 123.
MN4 57.423834 .00 0.00 1.5 166. 1.0 71.
M4 57.968208 .02 188.90 2.9 176. 1.0 68.
MS4 58.984103 .02 182.30 2.4 170. 1.2 75.
2MN6 86.407938 .00 0.00 2.3 296. 0.3 3.
2MS6 87.968208 .04 252.20 3.1 311. 0.4 5.
*******************************************************************************
57

APPENDIX 6: INPUT DATA REQUIREMENTS FOR
PSDDF V. 2.1
PSDDF requires a description of the geometry of and a placement
sequence for the fill for the consolidation problem that is to be
analysed. The following geotechnical material properties, disposal site
management data, and local climatological data are also required.
58
• Specific gravity of solids
• Initial void ratio
• Void ratio – effective stress relationship: Smoothed data are
required to avoid numerical instability.
• Void ratio – permeability relationship: Smoothed data are required
to avoid numerical instability.
• Ratio of secondary and primary compression indices
• Ratio of recompression and primary compression indices
• Void ratio at saturation limit
• Void ratio at desiccation limit*
• Degree of saturation at desiccation limit*
• Depth to second-stage drying*
• Evaporation efficiency*
• Surface drainage efficiency
• Monthly Class A pan evaporation potential*
• Average monthly rainfall*

PSDDF incorporates a database of these data for dredged material
disposal sites throughout the United States. New data can be added
as required. The database can be used for planning-level analyses
prior to laboratory testing, small projects where laboratory testing is
impractical, and parametric studies of consolidation. The unified soil
classification and Atterberg limits of materials for which no other data
are available may be used to select comparable materials from the
PSDDF database to represent them (Stark, 1996).
Data for compressible foundation materials, which may have
properties significantly different from those of the normally
consolidated fill materials incorporated in the PSDDF database, should
be determined by direct testing (Stark, 1996). Climate-dependent
data, which are marked with an asterisk* in the foregoing list, must
also be used with caution. Dummy values of the latter are used in
analyses of the consolidation of submerged materials.
59

REFERENCES
Borgman, L. E. and Scheffner, N. W. (1991). The simulation of time
sequences of wave height, period, and direction, Technical Report
DRP-91-2, US Army Engineer Waterways Experiment Station,
Vicksburg, MS.
60
Cargill, K. W. (1985). Mathematical model of the
consolidation/desiccation processes in dredged material, Technical
Report D-85-4, US Army Engineer Waterways Experiment Station,
Vicksburg, MS.
Demars, K. R., Long, R. P., Stanton, S., and Charleton, W. (1984).
Settlement and stability of ocean disposal mounds, in
Montgomery, R. L. and Leach, J. W. (Eds), Dredging and Dredged
Material Disposal, Proceedings of the Conference Dredging ’84,
Clearwater Beach, Florida, November 14-16, 1984, 2 1040-1049.
Department of Defence, Navy Office (1999). Australian National Tide
Tables 1999. Australian Hydrographic Publication 11. Department
of Defence, Canberra. 412 pp.
Department of Defence, Navy Office (2000). Australian National Tide
Tables 2000. Australian Hydrographic Publication 11. Department
of Defence, Canberra. 386 pp.
E. P. A. Office of Water and Office of Science and Technology and US
Army Corps of Engineers (1995). Evaluation of dredged material
proposed for discharge in waters of the US – Testing Manual:
Appendix C – Evaluation of initial mixing. 80 pp.
Foreman, M. G. G. (1978). Manual for tidal currents analysis and
prediction, Institute of Ocean Sciences, Patricia Bay, Sidney, British
Columbia.
Gibson, R. E., England, G. L., and Hussey, M. J. L. (1967). The theory
of one-dimensional consolidation of saturated clays,
Geotechnique 17(3) 261-273.

Godin, G. (1972). The analysis of tides. University of Toronto Press,
Toronto. 264 pp.
Hands, E. B. and Allison, M. C. (1991). Mound migration in deeper
water and methods of categorising active and stable depths, in
Krause, N. C., Gingerich, K. J., and Kriebel, D. L. (Eds), Coastal
Sediments ’91, Proceedings of the A.S.C.E. Specialty Conference
on Quantitative Approaches to Coastal Sediment Processes,
Seattle, Washington, 25-27 June 1991, 2 1985-1999.
Hands, E. B. and DeLoach, S. R. (1984). An offshore mound
constructed of dredged material, in Montgomery, R. L. and Leach,
J. W. (Eds), Dredging and Dredged Material Disposal, Proceedings
of the Conference Dredging ’84, Clearwater Beach, Florida,
November 14-16, 1984, 2 1030-1039.
Mesri, G. and Godlewski, P. M. (1977). Time- and stresscompressibility
interrelationship, Journal of Geotechnical
Engineering 103(5) 417-430.
Moritz, H. R. (1994). Users Guide for the Multiple Dump Fate Model
– Final Report for US Army Waterways Experiment Station. 43 pp.
Morris, P. H. (2001a). Land & ocean disposal of sediments dredged
from marinas and small boat harbours: modelling of ocean
disposal at the Port of Weipa. Cooperative Research Centre for
Sustainable Tourism, Griffith University, Gold Coast.
Morris, P. H. (2001b). Land & ocean disposal of sediments dredged
from marinas and small boat harbours: modelling of ocean
disposal at the Port of Townsville. Cooperative Research Centre
for Sustainable Tourism, Griffith University, Gold Coast.
Morris, P. H. (2001c). Land & ocean disposal of sediments dredged
from marinas and small boat harbours: modelling of ocean
disposal at the Port of Hay Point. Cooperative Research Centre for
Sustainable Tourism, Griffith University, Gold Coast.
61

Morris, P. H. (2001d). Land & ocean disposal of sediments dredged
from marinas and small boat harbours: modelling of ocean
disposal at the Port of Mackay. Cooperative Research Centre for
Sustainable Tourism, Griffith University, Gold Coast.
62
Morris, P.H. (2002). User's Guide for the MS DOS-based ADDAMS
Program Modules: STFATE v. 5.01, LTFATE v. 1.0, and MDFATE v.
1.1 in the MS Windows Environment. Cooperative Research
Centre for Sustainable Tourism, Griffith University, Gold Coast.
Morris, P. H. and Williams, D. J. (2000). The porosity of co-disposed
coalmine wastes, International Journal of Surface Mining,
Reclamation, and Environment 14 63-73.
Scheffner, N. W. (1991). A systematic analysis of disposal site stability,
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Sediments ’91, Proceedings of the A.S.C.E. Specialty Conference
on Quantitative Approaches to Coastal Sediment Processes,
Seattle, Washington, June 25-27, 1991, 2 2012-2026.
Scheffner, N. W. and Borgman, L. E. (1992). A stochastic time series
representing wave data, Journal of Waterways, Ports, Coastal,
and Ocean Engineering 118(4) 337-351.
Scheffner, N. W. and Talent, J. R. (1994). Dispersion analysis of the
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Miscellaneous Paper DRP-94-1, US Army Engineer Waterways
Experimental Station, Vicksburg, MS.
Scheffner, N. W., Mark, D. J., Blain, C. A., Westerink, J. J., and
Luettich, R. A. (1994). ADCIRC: An advanced three-dimensional
circulation model for shelves, coasts, and estuaries; Report 5,
Tropical storm database for the East and Gulf of Mexico Coasts of
the United States, Technical Report DRP-92-6, US Army Engineer
Waterways Experimental Station, Vicksburg, MS.

Scheffner, N. W., Thevenot, M. M., Talent, J. R., and Mason, J. M.
(1995). LTFATE: A model to investigate the long term stability of
dredged material sites, Technical Report DRP-95-1, US Army
Engineer Waterways Experimental Station, Vicksburg, MS.
Stark, T. D. (1996). Program documentation and user’s guide: PSDDF
Primary consolidation, Secondary compression, and Desiccation of
dredged Fill, US Army Corps of Engineers Instructional Report EL-
96-XX. 132 pp.
US Army Engineer Waterways Experiment Station. (1994). Tidal
constituent database – east coast, Gulf of Mexico, and Caribbean
Sea, Technical Note DRP-1-13, Vicksburg, MS.
63

AUTHOR
Dr Peter H. Morris
Peter H. Morris, who holds B.E. (Hons 1) and Ph.D. degrees in civil
engineering worked in the heavy construction industry in Australia
and New Guinea, with emphasis on marine and riverine structures,
prior to joining The University of Queensland in 1986. From 1986 to
1999, he was engaged in investigating the engineering behaviour and
the disposal of coarse and fine mine wastes. Since February 1999, he
has been engaged in the investigation of the ocean and land disposal
of dredged sediments from marinas and small boat harbours.
E-mail: p.morris@mailbox.uq.edu.au
64

The Cooperative Research Centre for Sustainable Tourism was established under the Australian
Government’s Cooperative Research Centres Program to underpin the development of a
dynamic, internationally competitive, and sustainable tourism industry.
Our mission: Developing and managing intellectual property (IP) to deliver innovation to
business, community and government to enhance the environmental, economic and social
sustainability of tourism.
DEVELOPING OUR IP
Director of Research – Prof Leo Jago
1. Tourism, conservation and
environmental management
research
Co-ordinator – Prof Ralf Buckley
(r.buckley@mailbox.gu.edu.au )
• Wildlife Tourism
• Mountain Tourism
• Nature Tourism
• Adventure Tourism
2. Tourism engineering design and
eco-technology research
Coordinator – Dr David Lockington
(d.lockington@uq.edu.au)
• Coastal and marine infrastructure and
systems
• Coastal tourism ecology
• Waste management
• Physical infrastructure, design and
construction
3. Tourism policy, events and
business management research
Coordinator – Prof Leo Jago
(Leo.jago@vu.edu.au)
• Consumers and marketing
• Events and sports tourism
• Tourism economics and policy
• Strategic management
• Regional tourism
• Indigenous tourism
4. Tourism IT and Informatics research
Coordinator – Dr Pramod Sharma
(p.sharma @uq.edu.au )
• Electronic product & destination
marketing and selling
• IT for travel and tourism online
development
• Rural and regional tourism online
development
• E-business innovation in sustainable
travel and tourism
5. Post graduate education
Coordinator – Dr John Fien
(j.fien@mailbox.gu.edu.au)
6. Centre for Tourism and Risk
Management
Director – Prof Jeffrey Wilks
(j.wilks@uq.edu.au )
7. Centre for Regional Tourism
Research
Director – Prof Peter Baverstock
(pbaverst@scu.edu.au)
MANAGING OUR IP
General Manager – Ian Pritchard
(ian@crctourism.com.au)
1. IP register
2. Technology transfer
3. Commercialisation
4. Destination management products
5. Executive training
6. Delivering international services
7. Spin-off companies
• Sustainable Tourism Holdings
CEO – Peter O’Clery
(poclery@iprimus.com.au)
• Sustainable Tourism Services
Managing Director – Stewart Moore
(sts@crctourism.com.au)
• Green Globe Asia Pacific
CEO – Graeme Worboys
(graeme.worboys@ggasiapacific.com.au )
For more information contact:
Communications Manager – Brad Cox
CRC for Sustainable Tourism Pty Ltd
Griffith University, PMB 50
GOLD COAST MC, Qld 9726
Ph: +61 7 5552 8116, Fax: +61 7 5552 8171
Visit: www.crctourism.com.au or email:
Brad@crctourism.com.au
65

PERTH
Western Australia
Node Coordinator
Prof Jack Carlsen
Ph: 08 9266 1132
CarlsenJ@cbs.curtin.edu.au
DARWIN
Northern Territory Node
Coordinator
Ms Alicia Boyle
Ph: 08 8946 6084
alicia.boyle@ntu.edu.au
CANBERRA
Industry Extension Coordinator
Mr Peter O’Clery
Ph: 02 6230 2931
poclery@iprimus.com.au
Australian Capital Territory
Node Coordinator
Prof Trevor Mules
Ph: 02 6201 5016
tjm@comedu.canberra.edu.au
ADELAIDE
South Australia Node
Coordinator
Prof Graham Brown
Ph: 08 8302 0313
graham.brown@unisa.edu.au
CAIRNS
Cairns Node
Coordinator
Prof Philip Pearce
Ph: 07 4781 4762
philip.pearce@jcu.edu.au
MELBOURNE
Director of Research
Prof Leo Jago
Ph: 03 9688 5055
Leo.jago@vu.edu.au
LAUNCESTON
Tasmania Node Coordinator
Prof Trevor Sofield
Ph: 03 6324 3578
trevor.sofield@utas.edu.au
BRISBANE
Tourism Engineering,
Design and Technology Research
Dr David Lockington
Ph: 07 3365 4054
d.lockington@uq.edu.au
IT & Informatics Research
Dr Pramod Sharma
Ph: 07 3365 6513
p.sharma@uq.edu.au
Sustainable Tourism Services
Mr Stewart Moore
Managing Director
Ph: 07 3211 4726
sts@crctourism.com.au
Education Program Coordinator
Dr John Fien
Ph: 07 3875 7105
j.fien@mailbox.gu.edu.au
GOLD COAST
Chief Executive
Prof Terry De Lacy
Ph: 07 5552 8172
t.delacy@mailbox.gu.edu.au
Conservation and Environmental
Management Research
Prof Ralf Buckley
Ph: 07 5552 8675
r.buckley@mailbox.gu.edu.au
LISMORE
Centre for Regional
Tourism Research
Prof Peter Baverstock
Ph: 02 6620 3809
pbaverst@scu.edu.au
SYDNEY
New South Wales
Node Coordinator
Mr Tony Griffin
Ph: 02 9514 5103
tony.griffin@uts.edu.au
International Program
Co-ordinator
Dr Johannes Bauer
Ph: 02 6338 4284
jbauer@csu.edu.au