HCCREMS Hunter and Central Coast Regional Environmental Management Strategy

1.1 Urban Water Cycle and Source Control
This research program will identify optimal means to improve the way the urban water cycle is managed. The cycle starts with water extracted from streams and aquifers, stored in reservoirs and then processed to potable quality before delivery through an extensive pipe system to consumers. Some of this water is then used to transport wastes through a network of sewers to treatment plants which discharge effluent into receiving waters such as rivers, lakes and oceans. Rainfall falling on the consumer's allotment contributes to the urban catchment's stormwater that is collected by an extensive drainage system for disposal into receiving waters.

At the allotment all three components of the urban p?water cycle meet with water consumed and storm and wastewater discharged. Source control through management of the cycle at this level offers the opportunity to provide benefits for the consumer and the environment.

The philosophy of source control is to minimize cost-effectively the consumption of mains water and the production of storm and wastewater. Source control can be implemented through retention of roof rainwater (rainwater tanks), stormwater detention, on-site treatment of greywater (laundry, bathroom and kitchen) and blackwater (toilet), use of water efficient appliances and practices, and on-site infiltration.

1.2. Economic and Environmental Benefits of Source Control
In Australia the management of water supply, wastewater and stormwater systems is often compartmentalised. This institutional constraint has resulted in sub-optimal outcomes for both the community and the environment. Here we document evidence of how to improve upon some of these sub-optimal outcomes, first by describing our recent research findings and then by considering national and international perspectives on source control.

1.2.1 Figtree Place research project
In the last three years we have worked on a research project called the Figtree Place Project. The objectives of this project were to monitor and evaluate the efficacy of a water-sensitive cluster housing redevelopment located at Figtree Place, Newcastle and explore possible system-wide implications. To date this work has been reported in Coombes et al. (1998; 1999; 2000a,b,c,d; 2001) and can be accessed from http://rambler.newcastle.edu.au/~cegak/Coombes/.

It suffices here to summarize the key findings:

Finding 1: Rainwater tanks and water supply
Use of rainwater tanks in domestic allotments to provide water for toilet, hot water and irrigation uses can result in major infrastructure savings to the community. A detailep?d case study of the Lower Hunter water supply system considered options for water supply and stormwater infrastructure to cater for 0.9% p.a. population growth.

It was found that if each allotment in new subdivisions used a 10 kL rainwater tank, the community, as a whole, would conservatively save $67m over the scenario where no rainwater tanks were installed in new allotments. Furthermore, use of rainwater tanks could delay construction of new water supply dams and pipes by up to 34 years.

In another case study involving the Gosford/Wyong water supply system it was shown that, despite a population growth rate of 1.4% p.a., use of rainwater tanks could delay augmentation of the headworks system by over 100 years and produce cost savings up to $50m.

Finding 2: Rainwater tank water quality
Our studies have shown that 100% of samples from hot water systems connected to rainwater tanks were compliant with the Australian drinking water guidelines. Even samples from rainwater tanks contaminated with soil and roof debris were largely compliant. The evidence suggests that hot water sourced from rainwater tanks is of mains water quality.

Finding 3: Source controls in subdivisions

Figure 1. Flood frequency curves at subdivision outlet for different drainage options.

A case study involving a 250-lot subdivision located near Newcastle compared several stormwater drainage options involving traditional pipe-based drainage, rainwater tanks, allotment landscaping and full water-sensitive design utilizing source and conveyance controls. Figure 1 shows flood frequency curves at the outlet. Rainwater tanks with allotment landscaping makes runoff from the subdivision mimic the natural regime. This has significant environmental benefits, namely reduced sediment and nutrient load, and reduced frequency of high velocity flow events. Significantly, in this case study the comprehensive watep?r-sensitive design approach reduced the cost of stormwater infrastructure by about 50% when compared with the pipe-based system. Similar savings have been obtained in subsequent case studies.

1.2.2 Other Australian research
While there has been considerable research into source control technologies, largely pioneered by Argue [1986], little work has focused on detailed assessment of the economic and environmental benefits. This partly reflects the historical development of water supply systems and community perceptions.

Authors such as Mitchell et al. [1997], Clarke [1990] and Hopkins and Argue [1993] state that management of urban water supply and wastewater disposal is highly disjointed and call for a holistic view of the urban water cycle. They suggest the adoption of source control measures to reduce the infrastructure costs and environmental impacts. To achieve optimum benefits for the community and the environment a total urban water cycle systems approach that includes cooperation between local government, water authorities and the community is required [Young, 2000].

Bogeholz [2000] argues that the lack of competitive market forces brought about by price control, legal and regulatory settings designed to protect customers from urban water monopolies excesses are limiting the development of source control technologies. He recommends a system of water service credits to encourage rainwater harvesting and reduced stormwater discharge from urban allotments.

Less than 1% of urban water consumption is used for drinking. However, all mains water supply is treated to potable quality [Mitchell et al., 1997]. We currently do not have water quality standards for second-quality uses (toilet flushing, outdoor, laundry and hot water). Rainwater tanks provide a matrix for the development of biofilms at the water-interfaces with the containment walls. There is no literature reporting the roles of these biofilms in affecting water quality or trapping potentially hazardous microorganisms.

1.2.3 Overseas research
The traditional urban drainage paradigm involving use of more and bigger capacity pipes to discharge stormwater runoff as quickly as possible results in costly solutions. Andoh and Declerck [1999] show that use of source control measures can result in cost savings of 30 to 80% over traditional stormwater drainage measures.

Schilling and Mantoglou [1999] report that in Germany rainwater tanks are subsidised and are used to supply water for toilet flushing and irrigation to avoid the development of new water resources. They argue that the challenge is to find the optimum balance of technical, economic and institutional measures that ensures satisfaction of societal needs with minimum consumption of available water and environmental resources. They argue that to achieve sustainability greater efficiency in design and operation is required and that optimum management of the entire urban water cycle be pursued.

The price and availability of urban water cycle services has an important impact on urban development and the environment. Many authors including Niemczynowicz [1995], Hawken et al. [1999] and Schilling and Mantoglou [1999] acknowledge that the relationship between urban development, the price of water cycle services and environmental impact is poorly understood and call for focussed and integrated research projects. This is the rationale for this research program.

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2. AIMS, SIGNIFICANCE, INNOVATION AND METHODOLOGY

Source control technologies are relatively mature. What is lacking is the knowledge on how to implement source control technologies to the best advantage for the community.

The primary aim of this research program is focused on the best use of source control technologies. Community values require infrastructure lifecycle costs and all environ-mental demands, provided by ecosystem services, should be minimised subject to the maintenance of the high public health standards. This causes a fundamental problem because there is nop? common way of valuing lifecycle costs and ecosystem services. A major innovation of this research program is the use of shadow pricing to value ecosystem services.

The research program is organised as four interrelated projects. Each project is described below. The first two projects underpin the third which optimises urban water cycle management from the regional or community perspective. The fourth project deals with public health issues and is essentially independent of the first three projects. For each project an overview of its key ideas and contributions is presented followed by a more detailed description of methods.

2.1 Project 1: Water Cycle Optimisation at Allotment Scale

2.1.1 Aims, significance and innovation
The aim of this project is to develop and apply methodologies that optimise water cycle management at the allotment scale for a given climate and allotment scenario.

In an optimisation problem it is necessary to define an objective, the constraints and a decision space within which the optimal decision is to be found.

The objective is to minimize the allotment owner's lifecycle costs associated with the provision of potable water supply and the disposal of storm and wastewater collectively referred to as water cycle services. The need for provision of external water cycle services, namely mains water and off-site disposal of storm and wastewater, can be reduced by using source control technologies.

External water cycle services have a unit price ($/kL) payable to the agency responsible for providing the service. This price will be referred to as a shadow price, which represents the cost to community and environment for provision of water cycle services. In Australia unit pricing has been widely adopted in urban areas for mains water and sewage disposal. However, there are no similar pricing schemes for stormwater disposal, though it is noted such schemes have long been used in Germany.

To minimize lifecyclp?e costs on the allotment it is necessary to develop a simulation model of inhouse and exhouse water consumption, storm and wastewater disposal and all available source control technologies. To be useful the model must be able to simulate a long (~100 year) rainfall history with 5-minute time steps. Unfortunately such long rainfall records are typically unavailable.

This data limitation will be overcome in an innovative way by use of the stochastic point rainfall model called DRIP [Heneker et al., 2001]. DRIP can generate synthetic rainfall data at 5-minute resolution that is statistically indistinguishable from observed rainfall data. It can be applied to sites with little or no pluviograph data provided there is a daily rainfall record - see the accompanying ARC progress report for further details.

The purpose of the optimisation is to search for the mix of source control measures (type and size) and external water cycle services that minimizes allotment lifecycle costs. The search will be conducted using a genetic algorithm (GA), a robust probabilistic search method that is widely used in many disciplines.

Figure 2. Schematic of domestic allotment water balance (DAWB) model.

The expected outcome will be a methodology that defines an optimum water management solution at the allotment scale for particular climate and site conditions. Case studies in the major urban centres of the Lower Hunter and Central Coast regions will be used to demonstrate the benefits of the methodology.

This outcome is significant for two reasons. First, it provides an unambiguous basis for defining best practice. Second, it provides a key input to the third project which optimises at the regional scale.

2.1.2 Methodology
The core of the optimisation will be the domestic allotment water balance (DAWB) model schematised in Figure 2. A detailed hydraulic model of the entire allotment water cycle will be developed. p?The model will simulate allotment water use and all the source control technologies that affect mains water use as well as storm and wastewater discharge. Inhouse water use is relatively well understood, whereas exhouse use is highly variable. DAWB will use the probabilistic behavioural model of exhouse water use, developed by Coombes et al. [2000c], which has significantly better predictive abilities than established models. Allotment configuration details (eg occupancy, roof area, soil types, slope,..) and socio-economic data will be inputs to the model thereby making DAWB a generic model.

About 100 years of rainfall at 5-minute resolution, generated by the stochastic point rainfall model DRIP, will be routed through DAWB. Computation efficiency will be enhanced by the use of a variable size time step, with resolution of down to 10 seconds during storm events to enable modelling of rapidly changing tank levels, and up to 1 day between storm events. The design storm approach is considered unsuitable because of the difficulty in specifying antecedent conditions - for example, how full is the on-site storage at the start of a design storm event?

The primary output from DAWB will be the demand on external water cycle services and the charges paid by the allotment owner for use of these services. The lifecycle cost for the allotment is then calculated as the sum of the present worth of the average annual water cycle service charges and the present worth of capital, operation and maintenance costs for the selected mix of source control technologies.

A genetic algorithm will be used to optimise the mix of source control technologies. The decision space consists of a discrete number of choices for each source control technology. For example, the rainwater tank may be available in several commercially available sizes, say 0, 2.5, 5, 7.5 and 10kL. If the GA selected a tank with zero volume then DAWB would ignore the rainwater tank circuit and satisfy all potable water demand using mains water.

Apart from selep?cting tank size the GA will need to subdivide the tank into zones to manage mains water use, provide stormwater detention and reduce peak-day mains water demand. Peak-day demand is a key variable affecting the sizing of mains water distribution infrastructure. Use of distributed storage can delay augmentation of this infrastructure

Other decision variables would include the dimensions and specifications for on-site detention, infiltration devices, first-flush treatment and wastewater storage and treatment.

2.2 Project 2: Water Cycle Optimisation at Subdivision Scale

2.2.1 Aims, significance and innovation
The aim of this project is to optimise water cycle management at the larger subdivision scale. At this scale new opportunities arise. Larger storages can be used to retain excess stormwater. Use of allotment source controls results in lower flow volumes that enable the use of water-sensitive conveyance measures in lieu of pipes. This further reduces both stormwater infrastructure costs and downstream environmental impacts.

The computational demands of the optimisation problem at the subdivision scale are huge. A subdivision with say 1000 allotments provides an enormous number of choices for allotment and subdivisional storages. A search using genetic algorithms will likely require tens of thousands of simulations. Although computationally feasible at the allotment scale such a task is considered beyond the capabilities of present-day PCs at the subdivision scale.

To overcome this problem two innovations are proposed. The fact that GAs lend themselves to parallel computation will be utilised. We have built and are using [see Cui and Kuczera, 2001] a small parallel virtual machine (PVM) using PC technology and public-domain PVM software. A major upgrade to the PVM will be required to support this project (and Project 1).

To further reduce computation time generic decisions can be used to reduce the size of the decision space. For example, instep?ad of optimising the storage on each allotment the storage per unit roof area can be optimised.

2.2.2 Methodology
The simulation model of the subdivision water balance will be a modified version of WUFS, a public-domain event-based water-sensitive design stormwater model developed during the Figtree Place Project [Kuczera et al., 2000]. WUFS will simulate various combinations of storage at the allotment and subdivision scale as well as conveyance measures to quantify stormwater export from the subdivision as well as mains water consumption. To achieve this substantial modifications to WUFS are required including developing a continuous simulation capability with interface to the stochastic rainfall model DRIP and adding a simplified version of the DAWB model.

The interfacing of WUFS with the genetic algorithm in a parallel computing environment using PVM software will be challenging. Careful program and graphical user interface design will be necessary to achieve a generic capability.

2.3 Project 3: Water Cycle Optimisation at the Regional Scale

2.3.1 Aims, significance and innovation
Optimisation at the allotment and subdivision scale (Projects 1 and 2) minimises developer and resident owner lifecycle costs for a given set of shadow prices. These optima may not achieve optimal outcomes for the wider community and/or the ecosystem.

Figure 3. Flowchart for constructing demand/sustainability versus shadow price curves.

This project will develop and demonstrate a methodology for setting shadow prices that will favour sustainable use of ecosystem services. The use of shadow prices is not new. For example, in the 1960s the Harvard Water Program investigated shadow pricing for pollution abatement [Kneese and Bower, 1972]. By incorporating (or internalising) the cost of pollution in a producer's accounting, a profit-maximizing producer is encp?ouraged to be environmentally responsible. Shadow pricing has seen little practical implementation in urban water cycle management until now.

If the shadow price for external services is low it is not economical for allotment owners to utilise source control measures, thereby putting maximum demand on ecosystem services. As the shadow price for external services increases source control measures become economically attractive thus reducing the demand on ecosystem services.

Figure 3 illustrates the role played by shadow prices in the quest for optimal community and environmental outcomes. The shadow price incorporates two components: One to cover the cost of the external water service infrastructure, and the second to pay for use of ecosystem services. It is the latter component which is the subject of this project.

To ascertain the optimal installation of water supply infrastructure and source control devices this project will use the iterative approach described by the flowchart in Figure 3a. Initial shadow prices for external water services are assigned. The next step in the flowchart is to find the best source control solutions at the allotment and subdivision scales by minimising lifecycle costs given the shadow prices for external water cycle services - this is the task of Projects 1 and 2. These source control solutions place a demand on external water cycle services and in turn on ecosystem services.

The next step in the flowchart is assessment of the community infrastructure necessary to provide the external water cycle services. Such infrastructure may include new dams for water supply, extensions to distribution networks, new stormwater drainage and treatment facilities and so on. The new and existing infrastructure puts a "demand" on ecosystem services: Rivers provide water supply; receiving waters assimilate urban pollutant loads; natural streams within urban catchments convey stormwater and so on. In providing these services the natural regime of ecosystems is modified: Rivers are dammed;p? receiving waters assimilate urban pollutant loads in excess of natural loads; streams receive frequent stormwater discharges; and so on. These changes to the ecosystem affect its sustainability and are characterised by a sustainability index worked out in the third step of the flowchart.

Cycling through the flowchart of Figure 3a using different shadow prices enables construction of the curves, shown in Figure 3b, relating shadow price to demand and sustainability.

There is no objective way of deciding what is an acceptable level for the sustainability index. It is a value judgement reflecting community values on modification and degradation of natural ecosystems and inter-generational equity. Once an acceptable index level is specified, the appropriate shadow price p* is defined and, in turn, the "optimal" solutions for water cycle management can be found.

One of the curves in Figure 3b represents community lifecycle costs as a function of shadow price. In this example, the shadow price that minimises community lifecycle costs is not the same as the shadow price that provides acceptable environmental outcomes. Without this type of investigation, it is likely that the actual shadow price charged, for example po, is neither economic nor sustainable.

The significance of this project is that it provides a rational framework for the community to assess its water cycle management requirements at all three scales. The analytical method also provides an effective tool for government to set policy objectives. This approach, along with the optimisation of source controls at the allotment and subdivision scale, represents the major innovation of the research program.

2.3.2 Methodology
The key challenge is to develop models at the regional scale that simulate the operation and performance of the external water cycle service infrastructure responding to the demands imposed at the allotment scale. The objective is to evaluate community lifecycle costs and demands on ecosystem services. Regional models of the water supply headworks system using the generic network linear programming model WATHNET [Kuczera, 1992] have been used by Coombes et al. [2000b, 2001] to evaluate the impact of source control measures on operation and augmentation of water supply infrastructure.

On-site storage reserved for peak-day demand can reduce the load on the mains water distribution system and hence delay augmentation of the distribution system. Use of industry-partner water distribution simulation software will enable costing of the savings arising from different source control solutions.

Reduced stormwater runoff from allotments using source control has three downstream potential benefits:

The frequency and severity of downstream flooding will be reduced. The reduction in expected flood damage can be assessed using existing rainfall-runoff, hydraulic and economic modelling techniques.
Sediment and nutrient loads into streams and receiving waters will be reduced. Current technology for evaluating the impacts of reduced loads is evolving but will suffice in the evaluation of sustainability indices for affected streams and receiving waters.
The incidence of stormwater entering sewers and the consequent overloading and surcharging of downstream sewers will reduced. The economic and environmental impacts of reduced source runoff can be evaluated using industry-partner dynamic hydraulic models such as MOUSE.

Reduced disposal of wastewater to the sewer system will reduce dry weather flows and hence the base load on existing treatment plants and effluent loads on receiving waters. The ensuing economic impacts can be readily evaluated.

Sustainability is usually defined as a characteristic of a condition in which economic and environmental systems are operating to meet the needs of the current population while maintaining or increasing the resources and productive capacities to be passed onto future generations. A fundamental concept of eco-logical sustainability is that communities mp?ust live within the carrying capacity afforded them by the ecosystems of which they are part [Rees, 1990, 1992]. Thus sustainability requires that the use of ecosystem services should not exceed the capacity of the ecosystem to produce those services without being degraded or put at risk.

A key task will be to define appropriate indices of ecological sustainability for use in a number of regional case studies. In recent years numerous studies have proposed environmental indicators of sustainability (see for example the website of the US Interagency Working Group on Sustainable Development at www.sdi.gov). In this project we will explore first the usefulness of such indicators in the context of water cycle ecosystem services. A range of key indicators will then be combined in a sustainability index following recent studies on sustainable urban development [e.g. Boyd and Deelstra, 1998; Mega and Pedersen, 1998]. In a number of regional studies we will then explore how such a sustainability index reflects the environmental impact of demand on ecosystem services associated with water supply, and the disposal of storm and wastewater.

2.4 Project 4: Public Health Implications of Distributed Storage

2.4.1 Aims, significance and innovation
A major aspect of source control involves on-site storage of water that raises public health questions. Because all urban water supplies are treated to drinking water quality there has been no requirement for water standards for uses that could be sourced from rainwater tanks.

The Figtree Place Project has shown that there exists a treatment train for rainwater involving gutters, first-flush separation devices and hot water systems as well as the rainwater tank itself. However, there is little scientific understanding of the microbial and biochemical processes involved in this treatment train.

Air-borne microbes and chemicals can enter rainwater tanks via the water collection pp?rocess during periods of rain either directly from the atmosphere or indirectly by leaching of materials from water collection surfaces. Organic materials and microbes may also be derived from accumulated debris and excreta from animals and organisms colonizing or traversing the water collection surfaces.

When the concentration of dissolved organics falls below 25mg/L, there is an advantage for microorganisms to form attachments to the containment surfaces leading to the formation of biofilms. These biofilms have been extensively investigated in conduit systems for their impact on drinking water quality, by removal of chlorine and contribution to bacterial counts. However, literature searches did not reveal any research on biofilm activity in rainwater storage systems.

Biofilms develop in complexity with time and deposit aggregates as part of a physical support and protection structure. As a consequence, these biofilms can become extremely efficient at removal of dissolved organics and can also remove potential contaminating metal ions. Rainwater storage tanks may therefore provide an effective mechanism for removal of dissolved organic and inorganic molecules. The low dissolved nutrient content would ensure that bacterial numbers do not proliferate in the water column.

The aim of this project is to gain sufficient understanding of the distributions and functions of the microbial flora as well as the associated chemical dynamics in situ, which both affect water quality. Developing this understanding represents the project's original contribution.

This project is significant because it will provide the necessary information to facilitate the development of guidelines to ensure appropriate public health standards are main-tained with the introduction of source control technologies. Without such guidelines the use of source control technology cannot go ahead.

2.4.2 Methodology
Five new rainwater tanks located in representative regions of Newcastle will provide the in-situ facilities for thp?e two subprojects investigating microbial and biochemical behaviour. The tanks, fitted with first flush devices, will be instrumented to provide a continuous log of water levels and rainfall.

Subproject 4.1: Microbiology of rainwater tank treatment train

The aim is to identify the microorganisms in the rainwater tank treatment train and understand their ecology. This subproject will use conventional techniques to assess bacterial content in water and will also endeavour to develop Polymerase Chain Reaction (PCR) based techniques to scan for very low levels of selected bacteria, viruses and protozoa. This has the added attraction of identifying bacteria which may not be readily cultured in the laboratory. General probes will be used to scan for all species of bacteria (including mycoplasma) and any detected organisms will be identified by cross matching with sequences in reference databases.

The following specific tasks will be pursued:

Study seasonal variations in microbe content in rainfall, collected surface runoff, stratified layers of the stored water and biofilms;
Confirm the efficacy of hot water systems in reducing bacterial counts;
Understand the role of biofilms; and
Develop guidelines for microbiological water quality in stormwater systems.

Subproject 4.2: Biochemistry of rainwater tank treatment train

The organic and inorganic material entering a rainwater tank would comprise a nutrient source to support the growth of certain microorganisms and biofilms that form on the tank surface. These biological matrices may provide a mechanism for removal of contaminants in the rainwater.

This subproject will use gas chromatography mass spectrometry to assess organic chemical composition of samples. Elemental analysis will also be performed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) which will be available to the University in 2002. Inorganic composition will be investigated by appropriate techniques following an indication of likely spep?cies identified by the elemental evaluation. HPLC-diode array detection will be utilized to assess for higher molecular weight molecules such as glycoproteins in samples.

The following specific tasks will be pursued:

Identify the major chemical species in rainfall and on collection surfaces which may contaminate the tank water;
Develop a conceptual model for nutrient cycling, contaminant removal, and biofilm deposition in the rainwater tank train; and
Develop guidelines for chemical water quality in rainwater tank systems.

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3. TRAINING

Projects 1, 2 and 4 are relatively self-contained and present suitable topics for PhD scholars. Projects 1 and 2 will each require one PhD scholar - the scholars will have to learn and apply state-of-art skills in urban hydrology and hydraulics, operations research and programming. Project 4 will require two PhD scholars to master state-of-the-art techniques in microbiology and analytical chemistry to elicit the ecology of the little studied rainwater treatment train.

Project 3 builds on Projects 1 and 2 and requires skills to develop and apply regional scale models of the urban water cycle. This is considered to be too ambitious for PhD scholars and will be the responsibility of the APDI who will have to work very closely with the industry partners.

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4. INDUSTRY PARTNER COMMITMENT AND COLLABORATION

The industry partners are Hunter Water Corporation (HWC), Gosford-Wyong Councils' Water Authority (GWCWA), Hunter Region Organisation of Councils (HROC) and the Public Health Unit (PHU) of the Hunter Area Health Service. These partners will be members of a steering committee which will oversee the research program.

HWC and GWCWA provide water, wastewater and associated services to 460,000 people in the Lower Hunter Region and to 290,000 people in the NSW Central Coast Region, respectively. HWC and GWCWA are regulated by the State Government through an operating license which sets sp?tandards of service, by the Department of Land and Water Conservation which provides licenses to extract water, by the Environmental Protection Authority which licenses effluent discharge and by the Independent Pricing and Regulatory Tribunal which sets prices. In pursuance of their corporate charters, HWC and GWCWA have assigned a high priority to finding the combination of local government development standards, source controls and catchment management practices that will minimise infrastructure development costs and environmental impact. They have a strong commitment to research and development and continue to implement new improved methods and procedures for water supply and water resources management. They also make financial contributions to the industry's national research body, the Water Services Association of Australia.

The proposed research program will strengthen the alliance between the University's Environmental Engineering group, HWC and GWCWA. In addition, the program forms strong multidisciplinary links with the School of Biological and Chemical Sciences which is necessary to achieve the desired research outcomes. HWC already has a long established collaborative relationship with the group, having last year approved for a further five years support for the Chair of Environmental Engineering. GWCWA has been involved in the Figtree Place project.

HWC and GWCWA have nominated PIs Berghout and Grimster who will work closely with APDI Coombes on Project 3 to develop the regional water cycle models. In addition they will provide extensive data on urban water to support Projects 1 and 2.

HROC was established in 1995 to represent inter alia the environmental interests of local government councils from the Hunter and Central Coast region as well as several catchment management committees. Part of HROC's charter is to develop regional strategies for biodiversity, stormwater management, state of the environment reporting, erosion and sediment control and environmental accounting. The stormwp?ater management strategy seeks to increase the capacity of catchment managers, local government, the development industry and the community for best practice urban water cycle management by providing policies, education, guidelines and case studies.

Although HROC has not nominated a PI, it will provide the greatest in-kind support. In line with its charter it will play the key role in transferring the results of the research program to its member and to the wider industry. As stated in its letter of commitment, it will organise workshops for industry and community representatives and researchers to refine program objectives and to transfer the results. It will facilitate the policy development process by developing guidelines and standards resulting from the research.

HROC will also play a key role in Project 3. It has expertise in assessing community environmental values and developing ecological sustainability indicators and indices. It will use this expertise to marshal the resources of participating local government councils and catchment management committees to assist in the development of sustainability indices. These indices will guide the setting of shadow prices consistent with sustainable demands on ecosystem services.

The Public Health Unit's role will be to oversee the research, particularly with regard to Project 4, to ensure that the research is consistent with the objective of maintaining high public health standards. This will be achieved by the PHU having membership on the steering committee which will oversee the research program.

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5. NATIONAL BENEFIT

The replacement value of Australia's urban water cycle infrastructure is of the order of $50 billion [Johnson and Rix, 1993]. A considerable fraction of this infrastructure is old and overloaded. The proposed research program provides an innovative way forward. There are multiple and significant benefits to the Nation:

The community can make huge savings by optimising the use of source controls p?whilst maintaining current high public health standards. Section 1.2.1 showed that use of 10 kL rainwater tanks for new allotments produced savings of the order of $117 million for the Lower Hunter and Central Coast which have a combined population of about 0.75 million. Scaling these results to a population of say 12 million living in major urban centres could yield national savings of order of $1.8 billion.
It is noted that these savings are conservative because the solutions have not been optimised and the costings have underestimated savings in new stormwater infrastructure, disregarded the benefits of reduced load on existing infrastructure and disregarded any benefits to the environment.
The industry partners benefit directly because the case studies will focus on their systems.
The water industry benefits indirectly because a general methodology and tools will be available for application to other systems.
Source controls are decentralised infra-structure solutions that will create new industries and job opportunities.

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6. DESCRIPTION OF PERSONNEL

The steering committee consisting of the CIs, APDI Coombes, and partner representatives, Pascoe and Berghout (HWC), Laing (HROC), Grimster (GWCWA) and James (PHU) will oversee management of the program. It will meet at least quarterly.

CIs Kuczera and Kalma will provide detailed supervision and training for the PhD scholars for Projects 1 and 2, while CI Dunstan will do likewise for Project 4. APDI Coombes will work on Project 3, assist in supervising the other three projects, and liase with industry, community and government. PIs Berghout and Grimster will primarily focus on Project 3 and collaborate with APDI Coombes.

Laing from HROC will play a key role coordinating technology transfer and overseeing the marshalling of resources to evaluate sustainability indices.

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7. COMMUNICATION OF RESULTS

This program has major policy implications for the water industry. It ip?s also expected to attract wide community interest. We, therefore, plan to use a communication strategy similar to that used in the Figtree Place Project, but on a larger scale. This includes: publication in refereed journals; conference presentations; workshops, seminars and meetings for the industry and government and general public (over 30 presentations took place during the Figtree Place Project including presentations to parliamentary and government committees); maintenance of a web site; development of industry guidelines; and release of software.

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8. REFERENCES
Andoh, R.G.H., and Declerck C., Source control and distributed storage - A cost effective approach to urban drainage for the new millennium? 8th Int'l Conf. on Urban Storm Drainage, 1997-2005, Sydney, 1999.

Argue, J. R., Storm drainage design in small urban catchments: a handbook for Australian practice. Special Report No. 34, Australian Road Research Board, Vermont South, 1986.

Bogeholz, S., Water services credits: towards a growing sustainable, competitive, reformed urban water industry, Xth World Water Conf., Melbourne, 2000.

Boyd, D., and Deelstra, T. (Eds.) Indicators for sustainable urban development, Proc. of the Advanced Study Course, DGXII European Commission, Int'l Institute for Urban Environment, Delft, 1998

Clarke, R.D.S., Asset replacement: Can we get it right? Water, 22-24, Feb, 1990.

Coombes, P.J., Kuczera, G., Argue, J.J. and Argue, J.R. Water sensitive urban redevelopment: The Figtree Place Experiment, HydraStorm 98, Int'l Symp. on Stormwater Management, I.E.Aust., 195-203, 1998.

Coombes, P.J., Kuczera, G., Argue, J.R., Cosgrove, F., Arthur, D., Bridgman, H. and Enright, K., Design, monitoring and performance of the water sensitive urban redevelopment at Figtree Place in Newcastle, 8th Int'l Conf. Urban Drainage, Sydney, 1319-1326, 1999.

Coombes, P.J., Argue, J.R. and Kuczera, G., Figtree Place: A case study in water sensitive urban developmenp?t, Urban Water, 1(4), 2000a.

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