Total water cycle management

The Queensland Water Commission operates under the guiding principles of the Water Act 2000. One such principle is that regional planning should consider environmental, social and economic factors and include 'least cost planning' to ensure proper economic comparison of all supply and demand options.

Total water cycle management (TWCM) recognises the finite limit of the regions surface and groundwater resources. It responds to the inter-relationships between human uses of water and the health of the natural environment arising from changes to natural water quality and quantity patterns.

Total water cycle planning considers all aspects of the natural and urban-rural water cycles. Key features of total water cycle planning include water efficiency and recycling, water sensitive urban design in development, stormwater management to improve water quality and water supply, and a focus on catchment management to protect drinking water supplies and waterways from pollution.

The Water Savings Target under the Queensland Development Code requires the substitution of town water supplies by alternative sources which provide 70,000 litres per year per house and 42,000 litres per year per townhouse. Alternative sources include rainwater, treated grey water, stormwater, and recycled wastewater.

Source substitution has generally been achieved through rainwater tanks due to the lack of basic information on stormwater harvesting such as:

• What infrastructure is needed to meet the water savings target?
• Is integrating stormwater supply infrastructure into greenfield developments cost effective compared to other options?
• Can other requirements for stormwater, such as water quality and flow, be cost effectively be built into harvesting infrastructure?

The Commission commissioned the following report to address these questions and provide some guidance on the potential application of stormwater harvesting as a local water supply solution:

• Executive summary (PDF, 203K)*
• Full report (PDF, 3.5M)*.

The Environmental Protection (Water) Policy 2009 requires all local governments to prepare total water cycle management plans. Details can be found on on the Department of Environment and Resource Management website.

In addition, the SEQ Regional Plan 2009-14 requires the Commission to prepare sub-regional total water cycle management plans where large-scale development and significant infrastructure is to be developed. Plan development has commenced in Caboolture West, Ripley and Caloundra South/Palmview for completion in 2012.

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