A fresh approach to water practices
Science is meeting the challenge of finding ways to reduce Australia's wasteful water practices and improve the way we use and manage this finite resource. In the regional NSW town of Goulburn, just down the road from Australia’s national capital, water supplies earlier this year fell to less than 10 per cent of capacity. In most of Australia’s major cities demand is close to or equalling supply availability. To tackle this worsening problem, CSIRO has established its Water for a Healthy Country Flagship, which has the job of delivering the science needed to underpin various state and Australian government water resource strategies. 'The challenge is how to provide an appropriate balance between water supply and demand to accomodate population growth, climate change and environmental needs while maintaining people’s quality of life,” says Dr Shiroma Maheepala, who leads the Flagship’s Water Smart City Systems program.
The program uses Integrated Water Resource Management – an emerging approach that looks at a range of demand management and supply alternatives to meet future water supply needs. And it is developing tools that assist decision makers understand city-wide environmental, economic and social implications of choices about these alternatives.
One part of the program involves scientists and engineers studying consumption habits, understanding community attitudes, predicting urban water needs and how these might be met and assessing opportunities for recovering and recycling stormwater and wastewater.
This approach to water planning reflects a basic principle that consumers want the outcomes provided by water, not necessarily a specific quantity or quality of water, Dr Maheepala says.
“For example, if we can clean our clothes in a washing machine that uses half the water, this has to be a smarter approach. Similarly, we can keep our gardens healthy but use far less water through efficient irrigation methods, and substitute the use of drinking water with ‘fit for purpose’ water captured from our roofs or from recycled wastewater.
“We know we are reaching the limits of our fresh water supplies. We also know that with the application of smarter technologies, to reduce water use and reuse and recycle water, combined with some changes to water use, behaviour and attitudes, we can meet this water challenge. However, we don’t yet understand the full implications and the sustainability of applying these alternatives.”
Initially, researchers are developing tools and processes to help water managers better understand the urban water system. Identifying the changes needed to make the current system more sustainable will be the next step.
In collaboration with Melbourne’s water companies and the Institute for Sustainable Futures, the CSIRO team has enhanced a Sydney Water Corporation model to help water companies assess the cost-effectiveness of demand-management and alternative supply options. This information is being used to develop the city’s next supply/demand strategy. The model includes data from the Australian Bureau of Statistics, manufacturers’ specifications and energy ratings and consumption research undertaken by water utilities.
This information can help shape questions such as: what should be the target group for demand-management programs? Can you save more water by replacing standard showers with AAA-rated showers or should you be targeting something else?
“For example, if you want to see the effect of replacing top-loading washing machines with AAAA-rated machines or front-loading models, the model will incorporate information about the uptake rate of new washing machines; and information on the water-use of different machines to give an idea of the water savings you could expect,” explains Dr Maheepala.
Another management tool in development, Hydro Planner, will help urban planners and water resource managers assess environmental outcomes. It will answer the following: how will climate change affect the urban water cycle? What are the implications of population growth on water use and wastewater and stormwater volumes and contaminant loads? What would be the most desirable urban development pattern from the water point of view?
Dr Maheepala says Hydro Planner is built on the Cooperative Research Centre for Catchment Hydrology’s E2 modelling framework. “It has the capacity to provide a system-wide water and contaminant-balance picture. Hydro Planner can be used to determine how much water is available at a particular location and includes not only conventional sources such as surface water and groundwater, but also non-conventional sources such as stormwater, greywater and wastewater.
“Once the Hydro Planner is calibrated to a city it can be used to help us understand the impacts of various water management and land development options on these water systems.”
Linked into a Social Attitudinal Evaluation model, levels of community acceptance to different options can also be measured.
The CSIRO team’s own attitudinal model is currently being applied in Melbourne to study factors that determine community acceptance for a selected set of demand management and alternative supply options.
It is also being used in Perth where CSIRO is working with Western Australia’s Water Corporation to better understand community attitudes to reuse.
Assessing attitudes to wastewater treatment and reuse via recharge to groundwater is an important issue for future water needs, especially in Perth, where groundwater accounts for about 50 per cent of the city’s water supply, making research into groundwater recharge vital.
Other tools and processes being developed by researchers working in the Water Smart City Systems program include a ‘stocks and flows’ model which can be used to examine physical interactions between water systems and other economic sectors. It can measure the flow-on effects of water management decisions, such as energy use and greenhouse gas emissions under a particular scenario.
Economic models are also being developed to help understand the ‘true’ value of water, which includes the cost of providing infrastructure and maintaining it, as well as environmental and community impacts. “It is important to understand both the direct and indirect costs and benefits of water management alternatives. This helps to ensure water pricing reflects the true, long-term cost of service provision and doesn’t create future environmental or economic dilemmas.”
One model, called TERM, is able to quantify externalities, investigate economic implications of decision making, and the impacts these decisions have on other parts of the economy. TERM – a joint activity between CSIRO and Monash University – can be used to answer questions such as: what would be the effect on urban and rural sectors if competitive water trading was introduced?
Economic analysis will also explore alternative ways to provide and manage urban water services, including alternative pricing and behavioural mechanisms, investment approaches and transition options to ease the impacts of change on households and industries.
Ross Young, executive director of the Water Services Association of Australia, says the Water Smart City Systems program will give urban water managers a better understanding of how water is used, especially in domestic situations. “This is essential information to target water conservation programs and the type of water conservation messages we need to deliver,” he says.
The program should also increase understanding of the whole water and contaminant-balance position in urban areas, and provides a more accurate handle on the economics of urban water management.
“Australian capital cities have grown tremendously over the past 20 years and no new urban water supplies have been built except in Perth. So any increases in water supply have been made available through water conservation measures.”
Mr Young says research like that being done through the Water Smart City Systems program is essential for helping urban planners make decisions now and define options for the Australian cities into the future.