IMPLEMENTATION OF STORMWATER MANAGEMENT PLANS –
“IT COSTS A LOT TO BUILD BAD PRODUCTS”1
Peter J. Morison2; peter.morison@blacktown.nsw.gov.au
Geoffrey J. Hunter3; watershed@bigpond.com
2
3
Stormwater Management Engineer, Blacktown City Council, NSW, Australia.
Engineering Coordinator: Stormwater, Penrith City Council, Penrith, NSW, Australia.
Abstract
Since 1997, the preparation of catchment based Stormwater Management Plans has become a
mandatory requirement for local councils that administer urban areas of population 1500 or greater
in NSW. These Plans, prepared in association with relevant State Government agencies and
other significant stormwater managers, address ‘environmental protection’ as the minimum
requirement of the EPA. This paper focuses on stormwater management planning in the South
Creek Catchment in western Sydney, including a review of implementation restraints and a
summary of value selection methodologies to assist Local Government Engineers and Stormwater
Managers with the implementation of structural and non-structural strategies. A precis of case
studies is provided outlining the effective implementation of various Stormwater Management
Plans in the Greater Metropolitan Region of Sydney.
Key Words: stormwater management plans, local councils, EPA, implementation
Introduction
Context
‘Stormwater is pure rainwater plus anything
the rain carries along with it. In urban areas,
rain that falls on the roof of your house, or
collects on paved areas like driveways, roads
and footpaths is carried away through a
system of pipes that is separate from the
sewerage system’ (NSW EPA, 2000).
‘Stormwater Management is the planning,
design and operation of the natural and
constructed
conveyance
systems
for
stormwater, which are subject to varying flow
rates and pollutant loads, so as to achieve
the multiple objectives of flood regulation,
water quality and environmental and
1
Norman Augustine (1935 - )
ecological protection
(SCSMP, 1999).
and
management’
Since 1997, the preparation of catchment
based Stormwater Management Plans has
become a mandatory requirement for local
councils. These Plans must be prepared in
association with relevant State Government
agencies and other significant stormwater
managers within the catchment.
This
requirement was placed on local councils by
the State Government through the NSW
Environment Protection Authority (EPA),
which issued legal directions under Section
12 of the Protection of the Environment
Administration Act, 1991.
The ‘primary goal of urban stormwater
management plans is to facilitate the
coordinated management of stormwater
within a catchment to maximise ecological
sustainability and the social and economic
benefits of sound stormwater management
practices’ (NSW EPA, 1997a). A stormwater
management plan prepared to comply with
the Section 12 direction of the EPA is to
address ‘environmental protection’ as the
minimum requirement.
Flood protection,
stormwater management of rural lands and
the management of existing stormwater
assets were considered ancillary to the
Stormwater Management Plan by the EPA
and were not required under the Section 12
direction.
Whilst many pollutants in stormwater can be
attributed to urban development, Chang et al
(1990) found that the amount of impervious
surface within a catchment increased
stormwater runoff volume and velocities,
which resulted in greater energy to mobilise
pollutants
within
the
catchment.
Consequently there is a direct correlation
between the quality of the stormwater runoff
and the quantity of stormwater that runs off a
site. The more impervious a catchment the
greater the energy in the runoff and the
greater is its potential to mobilise pollutant.
Quantity and quality are interrelated and
should be addressed within a Total
Catchment Management framework. The
relationship between impervious surface and
runoff is shown in Figure 1.
Figure 1: Changes in Runoff Flows
Resulting from Paved Surfaces (Source:
Livingston and McCarron, 1992)
This
paper
focuses
on
stormwater
management planning in the South Creek
Catchment and also includes a precis of case
studies
pertaining
to
the
effective
implementation of various Stormwater
Management
Plans
in
the
Greater
Metropolitan Region of Sydney.
South Creek Catchment
The South Creek Catchment is located in the
west of Sydney, comprises an area of 620
square kilometres and represents 30% of the
Sydney Region (SCCMC, 1998). Figure 2
shows the South Creek Catchment in the
context of the river systems and their
tributaries and local government area. South
Creek forms part of the Hawkesbury-Nepean
catchment and confluences the Hawkesbury
River 1.6 km north-east of Windsor. The
South Creek catchment suffers severe
environmental pressures mainly from urban
development.
The waterways within the
catchment contain excessive nutrients and
other pollutants and are often choked with
dense weed growth (SCCMC, 1998).
Overbank areas, away from the immediate
proximity of the creeks, are relatively
unobstructed and during high flows the
majority of the flows, in South Creek, is within
these areas (DWR, 1991).
The majority of the population of the South
Creek Catchment falls within the City of
Blacktown (approx. 225,000 people). The
rest of the catchment falls within the Local
Government Areas (LGAs) of Penrith,
Hawkesbury, Liverpool and Camden as well
as discrete portions of Fairfield and
Campbelltown. Land use in the catchment is
generally represented by agriculture in the
southern and northern areas with urban
development in the east and west, including
a mixture of residential, industrial and
commercial uses. The South Creek
Catchment includes areas earmarked to
contain a significant proportion of Sydney’s
future urban development (Fisher et al,
1993). It is expected to contain the fastest
population growth in Sydney up to the year
2021 (SCCMC, 1998) and includes the
release areas of Erskine Park, St. Clair,
Huntingwood, Arndell Park, Glendenning and
Bligh Park as well as the Eastern Creek
Grand Prix Circuit and Wonderland Theme
Park.
Other major development considerations
include the Badgery’s Creek airport option
and an 8000 residential unit release on the
1500 ha Australian Defence Industry site at
St. Marys. Four Sewerage Treatment Plants
discharge their wastewater into South Creek
and account for the majority of its base flow.
The South Creek Stormwater Management
Plan included the following sections:









Catchment description
Existing catchment conditions
Catchment values, identified from
community consultation
Management Objectives, designed to
protect the catchment values
Management Issues that may impede the
achievement of the management
objectives
Potential Management Options, divided
into structural and operational
components
Implementation Strategies for each local
council and relevant State Government
departments and stormwater managers
based on the management options
Monitoring program to determine the
performance of the Plan
Reporting mechanisms for the
implementation of the Plan.
The Plan did not include options for flood
protection, the management of stormwater
from rural lands or the management of
sewage overflows.
Figure 2: South Creek Catchment (Source:
DLWC)
South Creek Stormwater Management
Plan
The Councils of Penrith City, Blacktown City,
Camden, Liverpool City, and Hawkesbury
City participated in the preparation of the
South Creek Stormwater Management Plan
over 1998 and 1999. Fairfield City Council
applied for and was granted an exemption
from jointly preparing the Plan by the EPA.
The
Hawkesbury-Nepean
Catchment
Management Trust, the Roads and Traffic
Authority and the South Creek Catchment
Management Committee were also involved
in preparing the Plan.
The impact of the Stormwater Management
Plans has been in the authors’ opinion
generally very positive.
This has been
confirmed
by
an
EPA-coordinated
‘Stormwater Futures Workshop’ (NSW EPA
2001) with key stakeholders from Local and
State Governments who identified the
following benefits of the Urban Stormwater
Programme:





Increased council capacity in managing
urban stormwater quality
Increased recognition of stormwater as
an issue with officers and Councils
Increased focus on source control and
preventative action solutions
Development of catchment-based
relationships between officers in different
Councils
Ownership of the process by officers and
commitment to see that it proceeds
effectively (Close to 100% of surveys
returned).
Implementation of the plan
Urban
SMP
Integration with Local Council
Management Structures
In order for stormwater management
planning and implementation to occur, the
actions within each Stormwater Management
Plan must be represented in the Council
Management Plan. Consequently, all actions
from each Stormwater Management Plan
must be ranked and prioritised across the
Local Government Area before they can be
listed in the Management Plan and included
within the council’s annual capital works
programme for funding.
This creates a
conundrum for councils to fast track actions
into the Council Management Plan, as each
action should be workshopped through a
committee to maintain transparency and
objectivity. Figure 3 outlines the role of the
Stormwater Management Plan (Urban SMP)
within the existing management planning
functions of a typical local council in Western
Sydney.
A Stormwater Management System (SMS),
based on ISO 14000, is a useful tool for
incorporating the Stormwater Management
Plan
into
the Council’s Operational
Management Plan (Prior, 2001). The key to
the SMS is a Taskforce made up of senior
Council officers responsible for stormwater
management.
The Taskforce must be
represented by senior managers within the
council to ensure consensus between
Directors and the General Manager with
regard to the implementation of each action.
This is most important where Stormwater
Management Plan actions involve more than
one authority, particularly where it is
necessary to maintain consistency with the
timing and funding of such actions.
Councils in the South Creek Catchment have
yet to embrace this approach, and the
officers involved with the day-to-day
operational
issues
associated
with
stormwater, rather than senior management,
typically represent their Council on the
implementation Taskforce.
Parks
Management
Plans
Bushland
Management
Plan
Waste Collection
Street Sweeping
D’ment Guidelines
Hazard Plans
s.94 Contributions Plan
Environmental Ed. Pgm
Operational Training
etc.
Policies
DCPs &
LEPs
Local SMP
Catchment
Management
Plan
Rural
SMP
Floodplain
Management
Plan
Water
Quality
Control Plan
Environmental
Management
Plan
Council
Management
Plan
State
of the
Environment
Report
MAINTENANCE
Capital
Works
Program
Figure 3: Integration of the Stormwater
Management Plan into Local Government
Management Structures
To achieve an integrated and comprehensive
Council Management Plan and to meet
legislative requirements, it is necessary for
each council to develop a multiplicity of
management plans and policies.
Capital Works
The councils within the South Creek
Catchment manage a range of capital works
programs from the very simple to the very
complex. In general terms, each council
must justify its capital expenditure to its
constituents
by
using
an
objective
methodology to prioritise all its projects within
the financial year. Refer to Appendix A for a
copy of the ranking methodology used by
Blacktown City Council to justify the ranking
of Stormwater Management actions within
the Works Improvement Program. Note this
only allows the Stormwater Management
strategy to be ranked against all the other
core actions identified with Council’s
Management Plan and does not evaluate one
treatment technology against another.
The task of assigning and ranking individual
stormwater quality technologies is complex,
and requires a detailed knowledge of each of
the technologies as well as the particular site
constraints, and Council’s capacity to
maintain them.
New technologies are
entering the marketplace at a rapid rate, and
each one has strengths and weaknesses in
comparison with the others. Comparing each
stormwater treatment measure against
another is not only difficult but requires
objectivity
and
consistency
in
the
assessment.
The South Creek Stormwater Management
Plan incorporated a Benefit First ranking
methodology to prioritise actions within the
catchment. Councillors make the decision as
to how much of the budget will be allocated
to core business activities each year.
Consequently the only relevance that the
cost of a particular action has is in comparing
the various treatment technologies against
one another to achieve the desired result
from implementing the action. The Benefit to
the environment by implementing the action
then becomes paramount and the costbenefit of the action is left to the decisionmakers in Council. Eliminating the cost of
the action from the ranking procedure
simplifies the whole process and reduces
much of the subjectivity that is involved in a
conventional cost-benefit analysis.
Engineers and Environmental Scientists
administering
stormwater
management
programs need to keep up to date with the
latest technologies and understand the target
pollutants, pollutant retention efficiencies,
hydraulic
losses
and
maintenance
requirements of each treatment measure.
They also need to have intimate knowledge
of the catchments and drainage systems
within their jurisdiction and Council’s financial
commitment to the implementation of the
whole Stormwater Management Plan. Until
an Environmental Technologies Verification
(ETV) program (US EPA, 2000) is prepared
that allows an independent assessment of
the efficiency of each treatment technique,
word-of-mouth, results from Stormwater
Trust grant projects and independent
technology assessments by academics, will
remain the most reliable sources of
information available. Although a cursory
assessment of technologies is made as part
of the selection process for Period Contract
019 administered by the NSW Department of
Public Works and Services, there is no
comprehensive
determination
of
the
efficiency
and
the
advantages
and
disadvantages
of
each
technology.
Moreover, there is no objective way to factor
into such a Period Contract the constraints
peculiar to each site.
To assist Stormwater Managers with the
determination of technologies for specific
municipal applications, a consortium of
stormwater practitioners representing the
stormwater industry, Local and State
Government has produced a draft value
selection methodology. A simplistic selection
methodology is reproduced in Figure 4. A
methodology developed by the authors has
been used in the Phase 2 Drainage
Programme of the Blue Mountains Urban
Runoff Control Programme (BMURCP),
which could be used for the ranking of
options in Stormwater Management Plans.
Appendix B provides examples of the data
input sheet with embedded formulae and the
results table of ranked options used in the
BMURCP. The examples in Appendix B
have been modified to represent a generic
catchment as described in the NSW EPA’s
Example Stormwater Management Plan
(NSW EPA, 1999).
Furthermore, the
Stormwater
Industry
Association
has
established a sub-committee to prepare
appropriate value selection criteria in the
near future.
Structural stormwater treatment measures
need to be monitored with consideration to
the values and objectives identified in the
catchment Stormwater Management Plan
and by the local community. Parameters for
monitoring structural treatment measures
include:




The efficiency of the device to retain or
remove the target pollutants to a suitable
predetermined treatable flow rate or to
the manufacturer’s claims
The frequency, time and cost of required
maintenance
Ease of access for cleaning and
maintenance
The effectiveness of the measure as a
community education method, ie. is it
highly visible?
In general all the structural actions that were
identified in the South Creek Catchment
Stormwater Management Plan have been
implemented. This is mainly because funds
were secured as grants from the Stormwater
Trust and funds were made available in the
Capital Works Programs for the first year of
the Implementation Strategy.
implementing and maintaining stormwater
controls becomes more apparent, stormwater
authorities, in particular Councils, are looking
more closely at appropriate source control
strategies.
For example, Blacktown City
Council has run effective ‘micro-catchment’
education programs at Woodcroft and the
Metella Creek catchment at Prospect.
Thanks to programs facilitated by the NSW
EPA and other agencies, officers within Local
and State Governments and consultants are
becoming more better educated in the
techniques required to raise the public
awareness of stormwater management
issues. Penrith and Blacktown Councils alike
possess officers that dedicate a large
proportion of their working time to stormwater
education and this is increasing across the
catchment and indeed across the State.
It is not easy to increase the efficiency of
operations or change practices in longstanding
departments
of
government
departments and businesses. However, with
the assistance of the Stormwater Trust
sponsored programs, the ‘old dog’ is learning
new tricks. The results of these sponsored
pilot programs have been integrated into
information modules that are available on the
EPA web site:
Figure 4: Simple Value Selection
Methodology for the Selection of Some
Stormwater Quality Improvement Devices
Education Programs and Efficiency of
Operations
According to Aponte-Clarke et al (1999), the
most successful stormwater management
programs in the USA accomplished three
goals:
1. They educated the public about the
nature of the problem
2. They informed the people about what
they can do to solve the problem
3. They involved citizens in hands-on
activities to achieve pollutant reduction or
restoration targets.
The concept of ‘Source Control’ embraces
these elements and more. As the cost of
http://www.epa.nsw.gov.au/stormwater/localc
ouncils.htm
Ecologically Sustainable Development or
bust?
The control of development within Western
Sydney is difficult given the complexities of
population increase and the subsequent
urban expansion of Sydney, the diversity of
political objectives, the slowing economy and
the obvious indicators of environmental
decline.
The NSW EPA through the Stormwater
Management Planning process has required
that water quality objectives for new
developments be addressed in the SMPs.
The steering committee for the South Creek
SMP adopted interim Stormwater Objectives
for New Developments that were created in
consultation with the stormwater industry.
These objectives were adopted by a number
of councils in the State and were used with
some
amendment
in
the
‘Example
Stormwater Management Plan’ produced by
Sinclair Knight Merz for the NSW EPA.
The Stormwater Objectives for New
Developments have been complimented by a
Stormwater Quality Control Policy developed
by G. Hunter and P. Morison with associated
pollutant loading rates for Penrith and
Blacktown to assist with modelling and device
selection. The policy aims to encourage and
require in some cases the implementation of
structural stormwater treatment measures on
new development sites. This policy has been
developed with consideration to existing
policies of a similar nature, particularly those
of Bankstown City Council (2000), Brisbane
City Council (1999, 2000) and Hornsby Shire
Council (1998), as well as technical
publications of the NSW EPA (1997b),
Terrene Institute (1996), the Victorian
Stormwater Committee (1999) and others.
Blacktown City Council adopted the policy on
31 May 2001 and will soon be incorporated
into Council’s Engineering Guide for New
Development. The policy affects the large
majority of new commercial, industrial and
multi-unit residential developments occurring
in Blacktown City. Penrith City Council has
integrated the policy provisions into the
Development Control Plan for the new
release area at Erskine Park. Councils within
the Upper Parramatta River Catchment and
the Upper Parramatta River Catchment Trust
are now considering implementing this policy
wholly or with minor variations to achieve a
consistent approach to managing new
developments across western Sydney.
Funding
Fortunately, the Stormwater Trust has
provided the impetus through the $60M
program to commence implementation of
many of the Stormwater Management Plans.
This has certainly been the case with the
South Creek Catchment SMP. However,
funding is not certain into the future beyond
2001, and Councils need to take stock of
their existing funds and determine their
financial needs into the future. In general
terms, it costs about $5,000-10,000 per
hectare of catchment to control pollution from
urbanised catchments (capital cost only) and
approximately $8,000 per annum per large
device (GPT) for maintenance. A review of
recently constructed treatment devices in
Western Sydney established that this level of
funding would still not achieve Primary
Contact Recreation water quality conditions
in recreational waters based on NHMRC
(1990). Costs are dependent upon the level
of treatment (determined by the value placed
on the environment), land use, geology, soils
and demographic and social considerations.
In the South Creek Catchment, this equates
to about $150 M for capital works and an
annual maintenance budget of about $6 M.
There is considerable subjectivity in these
figures and no account has been taken of
increases in the cost of disposal of waste
material collected from Gross Pollutant
Traps.
At present the only cost effective structural
options suitable for nutrient control are
constructed wetlands, reed bed and root
zone systems and some of the filter media
technologies (Bosworth, 1999).
Wetland
treatment systems cost approximately
$500,000 per hectare of surface area to
construct, including gross pollutant control,
major
engineering
structures
and
landscaping. They require a surface area in
the order of 3% of their catchment area and
the cost of this land acquisition is additional
to the costs associated with their
construction.
Furthermore, they require
approximately $3,000 per hectare of surface
area per annum to maintain.
These costs are approximate only but give
some guidance towards the real cost of water
quality control and allow broad scale costs to
be allocated when contemplating Capital
Works
Programs
and
Section
94
Contributions for New Release Areas.
Council budgets for stormwater management
presently do not reflect this level of
expenditure, and it is the search for
innovative funding mechanisms that will
ultimately effect and maintain healthy aquatic
ecosystems.
Irvine (2000) in his report to the State
Stormwater Advisory Committee provides an
overview of funding mechanisms available to
local councils that are separate to Grant
programmes:


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





Ordinary rates – used to fund general
works (s. 494 LG Act).
Special rates – used to raise additional
revenue for particular works or services
(s. 495 LG Act).
Joint special rates – levied by 2 or more
councils through a committee established
under s.355 of the Local Government Act
(LG Act).
Capital special rate – levied on a time
basis to raise revenue for a special
purpose.
Annual charges – levied for the provision
of services to a particular parcel of land
eg drainage services (s. 501; ss. 551-553
LG Act).
Approved fees – charged for a service
provided by council (s. 608 LG Act).
Loans – may be raised from approved
lenders (ss. 621-624 LG Act).
Developer contributions – works required
as a condition of consent or contributions
for stormwater required under s.64 (LG
Act 1993) or s.94 (Environmental
Planning and Assessment Act 1979).
Rate pegging – general income from
rates and charges is subject to rate
pegging.
The Department of Local Government, as
reported by Irvine (2000), has found the
following
characteristics
common
to
unsuccessful applications by Councils when
applying for a Special Variation to their
General Income:





Specification of objectives, strategies,
works and targets is inadequate
There is little evidence of strategic review,
proper consultation or planning
The council has adequate financial
resources to fund the project
The service delivery strategy is not well
integrated into other Council functions
Project proposals are short term and can
be accommodated within existing
financial resources
Implementation challenges
Fragmentation Within and Without
Organisations
As previously discussed, all actions from
each Stormwater Management Plan must be
ranked across each Local Government Area
before they can be listed in the Management
Plan and included within the council’s annual
budget for funding. This process is similar
for the Roads and Traffic Authority, Sydney
Water Corporation and other authorities that
are preparing Stormwater Environment
Improvement Programs (SEIPs), where all
management actions allocated to the
authority must be considered across the
region of the authority’s responsibility.
The implementation of the actions is
contingent upon the financial and human
resources of each stormwater management
authority. Without senior management and
political commitment to the implementation of
the Stormwater Management Plan, the Plan
will stagnate.
It is imperative that a
committee involving senior management of
each authority is set up to effect the
implementation of the Plan. Only then can
the actions be considered for funding and put
to Council or the relevant Cabinet Minister for
consideration. Where senior management
commitment is not available, officers charged
with the responsibility of implementing the
SMP can lobby for funding using the Council
Management Plan and Capital Works
Program and engendering community
support.
Gaining community support is
probably the most important consideration in
the process.
Robert Irvine of the NSW Department of
Local Government (pers. comm.) noted that
the Department is not aware of any
catchment-based Section 355 committees
that facilitate the implementation of the
Stormwater Management Plan.
Such a
committee requires the impetus and
involvement of the Council Mayors.
However,
in
the
Hawkesbury-Nepean
Catchment, the now defunct Hawkesbury
Nepean Catchment Management Trust
provided a similar function to engender
political and community support for
environmental management programs.
Departmental fragmentation within councils
and other authorities can be a major
constraint to the implementation of the
Stormwater Management Plan. An internal
implementation Taskforce representing all
council
directorates
should
reduce
duplication of responsibilities and facilitate
the integration of actions. Blacktown City
Council’s Internal Environment Committee
acts in this capacity.
Rural precincts
The EPA did not require Councils to consider
runoff from rural precincts including rural
residential areas in the Stormwater
Management Plans under the Section 12
direction. This was an option at the disposal
of all councils, and in the large majority of
cases, the option was not taken up as a
result of time constraints and political
pressures. Polluted runoff from rural areas
can be significant, and this is the case in the
South Creek Catchment, where agricultural
land use is prevalent.
In contrast, the
Maryland’s Tributary Strategies for restoring
Chesapeake Bay (USA) gained an estimated
23% reduction in nitrogen and a 38%
reduction in phosphorus in 8 years. These
gains were made through a ban on the use of
phosphorus based detergents in the
catchment,
upgrades
to
wastewater
treatment plants and improved nutrient
management practices on agricultural land
(Glendenning, 1996).
These management options do not appear in
the SMPs of the Greater Metropolitan Region
of Sydney, yet such low cost source control
strategies can yield significant reductions in
nutrient loadings in estuaries. Councils will
need to address the impacts of rural
precincts in the short term, coordinate STP
discharges
with
the
Sydney
Water
Corporation and create partnerships with
industry to reduce the stress placed on the
waterways
by
urban
development.
Monitoring of pollutant loads is necessary to
determine the efficacy of
individual
management strategies.
New Release Areas
The ADI site at St Marys is earmarked for
8000 residential units that may comprise
more than 25,000 people over the next five
years. This site with other major subdivisions
and major infrastructure projects such as the
Western Sydney Orbital provides significant
challenges for Stormwater Managers in the
South Creek Catchment.
Typically the
council does not control the release of these
areas for urban development and other
authorities make the decision as to the
appropriate nature of the release area.
Having detailed Objectives for New
Developments documented in the SMP
provides the council with significant leverage
in accomplishing catchment-wide stormwater
management objectives at the local level.
It is the responsibility of both State and Local
Governments to work in partnership to
formulate and achieve consistent objectives
for developments of this nature especially
where a coordinated approach to stormwater
management is required if impacts on water
quality and stream health are to be
minimised.
Urban Salinity
The presence of soil salinity in Western
Sydney was initially recognised by Old
(1942), who attributed the extent of salinity in
the Cumberland Plain to the underlying
Wianamatta Shales created from ancient
marine sediments. The majority of soils
within the South Creek Catchment have been
derived from Wianamatta Shales.
In simple terms, soil salinity occurs where
land management practices allow saline
watertables to rise up to or close to, the soil
surface. A salinity hazard map has been
produced by the Department of Land and
Water Conservation (DLWC) for western
Sydney. It indicates that almost all of the
South Creek Catchment is affected by
salinity.
According to Dias and Thomas (1997), the
primary cause of salinity within the South
Creek Catchment is seepage lines created by
saline groundwater in lower lying topographic
areas. The number of seepage lines is
increasing, and possible causes include the
alteration of natural drainage patterns
through the construction of stormwater
systems and other infrastructure, and the
reduction in evapotranspiration caused by
land clearing activities.
The Rivers and Foreshores Improvement
Act, 1948 provides opportunities for the
maintenance of natural drainage lines.
However, the altered hydrology within the
catchment
(as
a
consequence
of
urbanisation, increased imperviousness, loss
of vegetative cover and irrigation) can cause
an increase in infiltration of the now more
regular freshets experienced within the
watercourses. The highly saline groundwater
is recharged; the watertable rises and
evaporates on reaching the soil surface
leaving behind a white crust of crystalline
salt.
Hence, pre-development infiltration
rates need to be determined in order that
water sensitive urban design can occur
without the problems associated with dry land
salinity.
Sewerage
The only Council within the South Creek
Catchment that has some control over
reticulated sewerage systems within its Local
Government Area is Hawkesbury City
Council.
Sydney Water Corporation is
responsible for the treatment of sewerage in
all other areas within the catchment.
On-site sewerage systems are typically
associated with rural areas. These systems
are not considered under the Stormwater
Management Plan as recommended by the
EPA.
However, in the Scope Creek
Catchment (Middle Hawkesbury Nepean
SMP) discharges from the on-site sewerage
systems have been identified as contributing
to elevated nutrient, dissolved solids and
Faecal coliform levels in the Sydney
International Regatta Centre.
Unless these point sources of pollution are
controlled, the overall water quality of the
catchment can not be managed by the
Stormwater Management Plan. This holds
true for those areas where the management
of the sewerage system is outside the
council’s control and it is unable to ameliorate
pollution events caused by sewerage
exfiltration, overflow or treatment plant
failure.
The Rebuff of 40 m Riparian Buffer Zones
Under
the
Rivers
and
Foreshores
Improvement Act 1948, the Department of
Land and Water Conservation (DLWC)
regulates the maintenance of riparian buffer
zones known as ‘protected land’, and other
management practices to protect ‘rivers’ as
defined by the Act. Developments adjoining
or including rivers generally need to avoid or
maintain protected land, which can be the
area in, and within 40 m of the top of the
bank or shore of ‘protected waters’, as cited
in the Act. “The term ‘protected waters’
includes Rivers, lakes connected to rivers,
estuaries, small streams, and even streams
that have been artificially improved or
diverted whether flowing or not” (Bourne,
2001). The Act contains provisions under
Part 3A for the issue of permits for certain
activities on ‘protected land’ and these
permits usually contain conditions that relate
to maintaining the geomorphic stability of the
waterways and the protection of the
environment (ibid).
The recent judgement of Talbot J in
Silverwater Estate Pty Ltd v Auburn Council
& Anor (2001) (NSWLEC 60) established a
precedent that a nexus needs to established
between the impact of the proposed
development and the provision of a
vegetated setback or riparian zone. Based
on the balance of numerous testimonies of
expert witnesses, the development adjacent
to Duck River and a saltmarsh wetland was
deemed to proceed with reduced riparian
buffer zones. The implication of this case is
that councils and catchment management
authorities can not rely on a 40 m riparian
zone for rivers and may need to conduct
specific research to determine the nexus.
Activities proposed under Stormwater
Management Plans for river rehabilitation
may be seriously compromised by this
precedent.
Drawing the line in the wetland?
Constructed
wetlands
are
principally
designed to retain and treat key pollutants
such as nutrients.
However, many
beneficiaries such as the local community
misconstrue
their
primary
objective,
considering the wetland as a recreational
asset and wildlife refuge. Recreational and
habitat
characteristics
of
constructed
wetlands are indeed attributes that embellish
the value of these systems although
sometimes at the expense of improved water
quality (Winning and Beharrell, 1998). It is
important that the objectives of constructed
wetlands are defined, preserved and
communicated carefully to the users of the
facility and the community. If the objectives
are not communicated proficiently, the
community may not accept the maintenance
of constructed wetlands such as the removal
of nuisance plants as a means of water
quality improvement, but rather as a means
of habitat destruction.
products will arise from the Stormwater
Management Plans.
References
Aponte-Clarke, G.P., Lehner, P.H., Cameron,
D.M. and Frank, A.G. (1999). Community
responses to runoff pollution: finding from
case studies on stormwater pollution control.
In: Proceedings of the Sixth Biennial
Stormwater Research and Watershed
Management Conference, Sept 14-17, 1999,
USA.
Conclusion
In many cases, the concept of water quality
control has only addressed anthropogenic
pollution and the physical and chemical
constituents of the waterbodies. Control of
only these parameters does not necessarily
equate with healthy aquatic ecosystems.
Consequently if a Stormwater Management
Plan is to provide acceptable results in the
field, it must incorporate:










Surface drainage and flood protection;
The preservation or rehabilitation of
natural systems;
Protection of aquatic habitat and biota;
Reduction of stormwater pollutants;
Erosion and sediment controls;
Enhanced aesthetics and recreational
opportunities;
Reuse of stormwater as a valuable
resource;
A comprehensive community education
(awareness raising and action) program;
Adequate funding; and
Commitment from the Stormwater
Manager.
The urban SMPs prepared in response to the
Section 12 direction go a long way to
addressing the above considerations, but
only in the urban areas. These Plans now
need to be expanded to encompass the rural
areas, sewerage treatment and discharge,
and flooding issues as an integrated Total
Catchment Management Plan.
It costs a lot to build bad products, but with
good planning, financial management and a
multi-disciplinary approach, only good
Bankstown City Council (2000). Engineering
Requirements
for
Development,
Development
Control
Plan
No.
30,
Bankstown City Council, Bankstown.
Bosworth, N. (1999). Tertiary Treatment of
Urban
Stormwater,
Civl455
Project,
University of Newcastle. Available at
http://www.stormwaterresources.com/library.htm.
Bourne, P. (2001). How Natural Resource
Management Issues are Affecting Riparian
Design Forms. Proceedings of Stormwater
Industry
Association
2001
Regional
Conference, Port Stephens, NSW,
Brisbane City Council (1999).
Design
Guidelines
for
Stormwater
Quality
Improvement Devices, final draft, 4
November 1999.
Prepared by Geo-Eng
Australia Pty Ltd and City Design – Water &
Environment Brisbane City Council.
Brisbane City Council (2000). Brisbane City
Council’s
Water
Quality Management
Guidelines, Version 1 – 2000. Waterways
Program, Urban Management Division,
Brisbane City Council.
Chang G., Parrish J. and Souer C. (1990)
The First Flush of Runoff and its Effects on
Control Structure Design.
Environmental
Resource Management Division, Department
of Environmental and Conservation Services,
City of Austin Texas USA.
Dias A. and Thomas D. (1997). Salinity in
the South Creek Catchment. SSC 02/97,
Department
of
Land
Conservation, Goulburn.
and
Water
Government Area.
Prepared by Sinclair
Knight Merz, NSW EPA, Sydney.
DWR (1991).
South Creek Floodplain
Management Study.
February 1991.
Prepared by the Department of Water
Resources, Sydney.
NSW EPA (2000). Environmental Protection
Authority
Stormwater
Web
Site
–
http://www.epa.nsw.gov.au/stormwater/
Fisher I.H., Mokhlesur R., Jivajirajah J.T. and
Salbe I. (1993).
HSPF water quality
modelling on the South Creek. Hydrology
and
Water
Resources
Symposium,
Newcastle, 30 June – 2 July 1993.
Glendenning P.N. Gov. (1996) Overview –
Maryland’s Tributary Strategies: Restoring
the Chesapeake. Maryland Department of
Natural Resources.
Tawes State Office
Building, E-2, Annapolis MD 21401 USA.
(April 1996)
Hornsby Shire Council (1998). Sustainable
Water Development Control Plan, Prepared
by the Planning Branch, Hornsby Shire
Council.
Irvine R. (2000) Management Planning and
Funding Issues for Better Stormwater
Management. Report prepared for the NSW
State Stormwater Advisory Committee. (15
November, 2000)
Livingston E.H. and McCarron M.E. (1992)
Stormwater Management: A Guide for
Floridians.
Florida
Department
of
Environmental
Regulation,
Tallahassee,
Florida.
NHMRC (1990). Australian Guidelines for
the Recreational Use of Water. Cat. No.
9000018, National Health and Medical
Research Council, Canberra.
NSW EPA (1997a).
Managing Urban
Stormwater: Council Handbook.
Draft.
Environment Protection Authority, Sydney.
NSW EPA (1997b).
Managing Urban
Stormwater:
Treatment
Techniques.
Publication EPA 97/97, November 1997,
Environment Protection Authority, Sydney.
NSW EPA (1999).
Management Plan
Example Stormwater
for Waters Local
NSW EPA (2001). Evaluation of Urban
Stormwater Program Stakeholder Workshop,
Friday, October 13th 2000. Prepared by
Brian Elton and Associates for the
Stormwater Trust.
Old, A.N. (1942). The Wianamatta Shale
Waters of the Sydney District: their salinity
and a suggested geological explanation. The
Agricultural Gazette of New South Wales,
53(5): 215-221.
Prior, N. (2001). Stormwater Management
Systems approach using QA. HawkesburyNepean Stormwater Management Workshop,
Windsor,
Sydney, 6th March 2001.
Stormwater Industry Association, Sydney.
SCCMC (1998). South Creek Environmental
Opportunities Study. Prepared by Webb
McKeown and Associates for the South
Creek Catchment Management Committee.
SCSMP (1999). South Creek Stormwater
Management Plan. Prepared by Penrith City
and Blacktown City Councils.
Terrene Institute (1996).
A Watershed
Approach to Urban Runoff: Handbook for
Decision Makers.
Terrene Institute,
Washington DC.
USEPA (2000). Environmental Technologies
Verification scheme.
United States
Environmental Protection Authority web site http://www.epa.gov/etv/
Victorian Stormwater Committee (1999).
Best Practice Environmental Management
Guidelines for Urban Stormwater. CSIRO
Publishing, Melbourne.
Winning, G. and Beharrel, M. (1998). Design
of Habitat Wetlands, Wetland Rehabilitation.
In: Department of Land and Water
Conservation (DLWC), The Constructed
Wetlands Manual, Vol. 2, DLWC, Sydney.
Appendix A
Appendix B: Example Value Selection Methodology for Stormwater Management Plans
Data Entry
Option
Project
Ref.
Option Description
Rec. Funding
Authority
Capital
Cost
Cap An. Maint. An. Compliance/A Land
Cost
Cost
Maint. cceptance/TC Use &
Score
Score
M Rank
Area
(CA)
Rel.
Rel. Effective Effective Waterc Water
Toxicity Harm
ness
ness
ourse cours
Score Protect
e
ed (%) Score
CI
BI
BI-CI
LV1
Sediment Cres - Reseal road
LCC
$50,000
0.35
$3,000
2.5
2
0.1
L-M
0.2
M
5
70%
7
1.62
4.07
2.45
LV2
Bountiful Lane - stabilisation works
LCC
$10,000
0.06
$5,000
4.5
2
10
L-M
20
M
5
20%
2
2.19
9.00
6.81
LV3
LV Park - pilot Adopt-a-SQID program
LCC
$10,000
0.06
$10,000
8.5
2
0.1
L-M
0.2
M
5
70%
7
3.52
4.07
0.55
LV4
LV Park - GPT retrofit
LCC
$5,000
0.06
$60
0.5
1
0.1
L
0.1
H
10
80%
8
0.52
6.03
5.51
LV5
LV CBD - at-source treatment
LCC
$7,500
0.06
$1,980
1.75
3.5
2.5
M
7.5
70
7
100%
10
1.77
8.17
6.40
LV6
LV7
LV Shops Car Park - Sand Filter
Mesic Street - pit modification
LCC
$80,000
$5,000
0.75
0.06
$2,000
$60
1.75
0.5
1
1
3
0.1
M-H
L
12
0.1
70
H
7
10
100%
80%
10
8
1.17
0.52
9.67
6.03
8.50
5.51
LV8
Verdant Road - seal road shoulders
LCC
$50,000
0.35
$5,000
4.5
1
0.2
L-M
0.4
H
10
70%
7
1.95
5.80
3.85
LV9
LV Industrial Area - council depot
LCC
$250,000
1.75
$8,000
8.5
4
2
H
10
M-H
8
50%
5
4.75
7.67
2.92
LV10
LV Industrial Area - private industrial
Bus. Prop.
$3,000
0.06
$5,000
4.5
2
3
H
15
M-H
8
50%
5
2.19
9.33
7.15
LV11
LV High School - litter control
School
$2,000
0.06
$500
0.5
1
1
L
1
H
10
80%
8
0.52
6.33
5.81
LV12
$10,000
0.06
$3,000
2.5
1
1
L-M
2
M-H
8
40%
4
1.19
4.67
3.48
LV13
Lush National Park - Trash Rack offline NPWS
Lush
Creek
Phillips
Oval - GPT
LCC
$50,000
0.35
$20,000
10
3
15
M
45
M
5
50%
5
4.45 18.33 13.88
LV14
N. Freeway - Middle Ck. rehab works
RTA
$70,000
0.75
$500
0.5
1
3
L
3
H
10
40%
4
0.75
5.67
4.92
LV15
Succulent Avenue - Baffle Box
LCC
$50,000
0.35
$10,000
8.5
2
3
L-M
6
M-H
8
60%
6
3.62
6.67
3.05
WT1
WT CBD - litter control
WSC
$20,150
0.35
$4,772
4.5
3.5
3
M-H
12
M-H
8
100%
10
2.78 10.00
7.22
WT2
Bountiful Avenue - GPT retrofit
WSC
$70,000
0.75
$5,000
4.5
3
0.1
M
0.3
H
10
90%
9
2.75
6.43
3.68
WT3
WT Industrial Estate - TCM
WSC
$5,440
0.06
$1,056
1.25
2
4
M-H
16
M
5
70%
7
1.10
9.33
8.23
WT4
N. Freeway drain #33 - baffle box
RTA
$10,750
0.15
$5,000
4.5
2
2
M
6
M
5
80%
8
2.22
6.33
4.12
WT5
WT Station Carpark - GPT/Sand Filter
WSC
$75,000
0.75
$5,000
4.5
2.5
1
M-H
4
H
10
100%
10
2.58
8.00
5.42
WT6
$35,000
0.35
$1,500
1.25
1
1
M
3
H
10
100%
10
0.87
7.67
6.80
WT7
Green Park - Car Park Stabilisation
WSC
Works St - Sed. Traps & Revegetation WSC
Flowing
$30,000
0.35
$10,000
8.5
3
0.1
L-M
0.2
H
10
50%
5
3.95
5.07
1.12
WT8
Mannings Place - GPT
WSC
$60,000
0.75
$4,000
3.5
1
0.1
L-M
0.2
M
5
80%
8
1.75
4.40
2.65
WT9
Rehab of Little Creek - Stage 1
DLWC
$100,000
0.75
$5,000
4.5
3
0.5
M
1.5
H
10
90%
9
2.75
6.83
4.08
Legend
WT
LV
LCC
WSC
RTA
DLWC
NPWS
Data Input Required
Waters Town
Lushville
Lushville City Council
Waters Shire Council
Roads & Traffic Authority
Department of Land and Water
National Parks and Wildlife Service
LCC
The data entry table has been formulated to meet the following criteria:
1. Simple data entry.
2. Transparency of calculations and ranking formulae.
3. A nexus between the options and the health of the receiving waters.
4. Cost efficiencies.
5. Does the option fit in with existing maintenance programs?
6. Benefits to the community, such as Total Catchment Management.
7. Applicability to Council operations.
Simplicity and transparency of data entry was given the highest priority in the development of the
spreadsheet. The final product therefore includes:





Drop-down lists for selection of the recommended funding authority.
Look-up tables in the ‘Criteria’ sheet that can be simply modified and subsequently alter the
ranking of the options.
Comments associated with specific cells that provide detail and justification for the data input.
‘Pivot Tables’ that summarise the data and rank options based on benefit, cost and
cost/benefit. The tables automatically update the ranking of options upon opening the
spreadsheet.
Colour coding of cells that require data input.
The spreadsheet consists of the following conditions for prioritising each stormwater treatment
measure:






Capital Cost: The estimated initial cost involved to implement the option. It includes the cost
associated with design and construction costs. This cost is indicative only. The capital cost
score is based on the capital cost data and assigns on a linear basis scores from 1 (lowest) to
10 (highest), the highest being in excess of $1M.
Annual Maintenance Cost: The estimated annual cost to review, update or maintain the
option. This cost is averaged over a 3-year period and is indicative only. The maintenance
cost score is based on the maintenance cost data and assigns on a linear basis scores from 1
(lowest) to 10 (highest), the highest being n excess of $10,000.
Compliance/Acceptance/TCM Rank: (1) The option accords with the principles of Total
Catchment Management, i.e. that the proposed option is complementary to existing options in
the catchment. (2) The option can be implemented by the responsible organization with
existing resources such as staff, plant and equipment.
Land Use & Area: A simplified equation based on the rational method in which the fraction of
imperviousness (%) is multiplied by the catchment area draining to the structural measure or
the catchment area targeted by the non-structural measure.
Relative Toxicity: Based on existing literature. The use of the table in the EPA’s Managing
Urban Stormwater: Council Handbook is recommended for determining the relative toxicity of
the pollutants prevailing in the target catchment.
Relative Harm: The product of the land use and area and relative toxicity values. This
assumes that area of imperviousness combined with the level of toxicity will reflect on
ecosystem impact.


Relative Effectiveness of Option: The effectiveness of the option in addressing the target
issue in that particular location or area. Where an option is a non-structural solution, the
effectiveness has been given as a qualitative value (ie High to Low). Where the option is a
structural solution and its efficiency able to capture/remove the target pollutant(s) is
documented, the effectiveness of the option can be inputted as a percentage. The
Effectiveness Score from 1-10 inclusive (low-high effectiveness respectively) is determined
from the data.
Watercourse Protected: The length of watercourse, as a proportion (%) of the entire
watercourse length in the catchment, likely to be protected as a result of implementation of the
option. The Watercourse Score reflects the data as an integer from 1-10 inclusive.
A linear scoring system was adopted to ensure that the ranking was not weighted against high
cost options. This was particularly important as many source control options, such as education
programs, and studies to determine baseline conditions in the catchment, such as water quality
monitoring, have high on-going costs associated with them but provide a large benefit to the
catchment.
Ranking of Options
The stormwater management options were ranked using a simplified benefit-first analysis adapted
from the South Creek and Cattai Creek Stormwater Management Plans. It was recognised that
there were significant advantages to this methodology.
Calculation of Cost Index (CI)
The average of the capital cost, maintenance cost and Compliance-Acceptance-TCM scores gives
the CI value. The higher the CI, the greater the cost, with a CI of 10 being the highest cost option.
Calculation of Benefit Index (BI)
The average of the relative harm, effectiveness and watercourse scores gives the BI value. The
higher the BI, the greater the benefit, with a BI of 10 being the option with the greatest benefit.
The CI and BI values were then used in three separate ways to rank the options.
1. Cost Index Analysis
This method involved sorting options on cost index alone, from lowest CI to highest CI.
The results of this ranking showed that more source control options were ranked higher than
using the BC value as they have a greater ability to address the issues within the catchment.
However, it was still obvious that options were being weighted heavily based on cost.
2. Benefit Index Analysis
This method involved ranking the options based on the Benefit Index (BI) first, with Cost Index
(CI) secondary. This was done for two reasons:


To compare options based on their benefits. This is the method used by some of the
councils to rank works for inclusion in capital works programs. It has the effect of ensuring
that options having the greatest benefit are implemented first.
A plot of CI vs BI showed that for the majority of options there was a large variation in BI
over a small range of CI. Therefore the options could be better ranked using BI only.
The option with the highest BI is assigned first priority. Ranking 2nd, 3rd, etc. follows for all
subsequent options. Where two options have the same BI value, they are secondarily ranked
using the CI value from lowest CI to highest CI.
Results in Pivot Table Format
The table below is an automatically updated Pivot Table in Microsoft Excel that provides a simple
overview of the ranked options according to Benefit Index. Separate Pivot Tables have been
created to show the options ranked according to Cost Index and Cost – Benefit Index respectively
for comparison. Benefit index in this example has been found to provide the most accurate
portrayal of priority works.
Options Sorted by Benefit Index
BI
Option Description
18.33 Phillips Oval - GPT
10 WT CBD - litter control
9.667 LV Shops Car Park - Sand Filter
9.333 LV Industrial Area - private industrial
WT Industrial Estate - TCM
9 Bountiful Lane - stabilisation works
8.167 LV CBD - at-source treatment
8 WT Station Carpark - GPT/Sand Filter
7.667 Green Park - Car Park Stabilisation Works
LV Industrial Area - council depot
6.833 Rehab of Little Creek - Stage 1
6.667 Succulent Avenue - Baffle Box
6.433 Bountiful Avenue - GPT retrofit
6.333 LV High School - litter control
N. Freeway drain #33 - baffle box
6.033 Mesic Street - pit modification
LV Park - GPT retrofit
5.8 Verdant Road - seal road shoulders
5.667 N. Freeway - Middle Ck. rehab works
5.067 Flowing St - Sed. Traps & Revegetation
4.667 Lush National Park - Trash Rack offline Lush Creek
4.4 Mannings Place - GPT
4.067 Sediment Cres - Reseal road
LV Park - pilot Adopt-a-SQID program
CI
4.45
2.7833
1.1667
2.1867
1.1033
2.1867
1.77
2.5833
0.8667
4.75
2.75
3.6167
2.75
0.52
2.2167
0.52
0.52
1.95
0.75
3.95
1.1867
1.75
1.6167
3.52
Author Biography
Peter Morison has worked in local government specialising in
environmental management since 1993. His specialties include
catchment management planning, State of the Environment reporting,
management of water quality assessment programs and
environmental education programs. In 1998-9, Peter researched and
compiled the Stormwater Management Plan for the Upper Parramatta
River Catchment.
Peter is currently the Stormwater Management Engineer at Blacktown
City Council, NSW managing the implementation of the Stormwater
Management Plans and providing expert advice on water quality
programs.
Peter holds a Bachelor of Applied Science degree from the University
of Western Sydney.
Postal Address: PO Box 63, Blacktown NSW 2148
E-mail: Peter.Morison@blacktown.nsw.gov.au
Geoff Hunter is the Engineering Coordinator: Stormwater at Penrith
City Council and has 30 years experience in Stormwater
Management, 17 years in Local Government and 13 years with
private Consultants and Contractors. Penrith is located 60 kms west
of Sydney on the Hawkesbury-Nepean River, at the foot of the Blue
Mountains
Geoff holds qualifications in Surveying, Soil and Water Management,
Stormwater Wetland Management and Environmental Management.
He was awarded a Churchill Fellowship to investigate “The Use of
Wetlands for Soil and Water Management” in the USA (1996) and a
Bursary from the IMEA to research “Comprehensive Stormwater
Management” in NZ and the USA (1998). His areas of interest
include Constructed Wetlands, Bio-filtration, sand filters, stormwater
pollution control, natural resource management and stream
rehabilitation. In the last 5 years, Geoff has presented numerous
papers on Environmentally Sensitive Stormwater Management,
structural stormwater controls and the impacts of urbanisation on
aquatic ecosystems.
He is the Local Government representative to the Stormwater
Industry Association (NSW), provides technical assistance to the
State Stormwater Advisory Committee and is a member of the
Environment Panel of the Institute of Public Works Engineering
Australia (NSW)
Postal Address: Geoffrey Hunter,
Australia 2751
E-mail: watershed@bigpond.com
PO Box 63, Penrith NSW