As demand for water in Western Australia (WA) increases and supply decreases, an innovative model is helping both government and industry make long-term plans for sustainable development.
Water use in WA has more than doubled in the past 30 years, driven by population growth and an increase in mining, which now accounts for one-third of the state’s total water use. At the same time, records were being set for the driest and hottest years in the south-west, with historically low inflows to dams and recharge to aquifers.
Ensuring water security in the face of these competing forces requires a clear picture of the state’s water challenges, WA Department of Water and Environmental Regulation (DWER) Principal Water Planner Daniel Ferguson said ahead of his presentation at Ozwater’19 in May.
“A combination of declining water supplies due to climate change and increasing demand requires careful management of existing water resources, and adaptive approaches to balance future water supply and demand,” Ferguson said. “A shared understanding of WA’s future water needs provides government and the private sector with time to innovate and adapt to the best water source options.”
This understanding comes in the form of the DWER’s Water Supply-Demand Model (WSDM), which projects the demand for water resources and water uses to 2060. It does this by applying economic and population growth forecasts to current water abstraction from WA’s 1300 water resources by 75 types of water use.
Ferguson said it is this broad scope that makes the WSDM unique.
“The WSDM is the only model known to project water demand and supply for all types of water use from all water resources, across an entire state jurisdiction,” he said. “Sharing this data is fundamental to the Department’s management of WA’s water and environmental systems.”
The WSDM is used by the State Government and industry for major project proposals, water efficiency scenarios and to raise awareness of water resource management and supply challenges across the state.
For example, with Perth’s population expected to grow by 1.4 million over the next 30 years, the WSDM has highlighted the need for increased water-use efficiency and the development of alternative water supplies. Ferguson said the information available through the WSDM has helped the government and private sector collaborate on the direction WA’s water future should take.
“Modelling future water supplies and demand supports government and industry to undertake coordinated, long-term water supply planning for the sustainable development across WA,” he said. “This planning helps identify potential shortfalls in groundwater and surface water, so demand management and alternative, cost-effective water supplies can be determined ahead of time.”