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With increasing awareness of stormwater quality issues, a new approach to stormwater management has developed throughout Australia as well as overseas. This approach has resulted in a number of different management ideas with the underlying principle of treating stormwater to a suitable standard before either release into the environment or use as an alternative supply source.

Best Management Practice (BMP), Water Sensitive Urban Design (WSUD) and Integrated Water Management have been developed to manage stormwater prior to disposal to the environment and improve water quality. These practices are also aimed at examining stormwater in terms of the total urban water cycle and developing sustainable practices. In line with the push to examine quality as well as quantity, a draft

version of Australian Runoff Quality was launched in June 2003 as a complimentary guide to Australian Rainfall and Runoff (Wong, 2003).

In more recent times stormwater Best Management Practices (BMPs) have been in use around the world including Australia, the United States and Europe. Structural and non- structural treatment methods are applied to reduce the impacts of stormwater on receiving bodies. Stormwater BMPs were initially developed as a method to improve the stormwater quality prior to disposal rather than prior to use. Urbonas (1994) provides a good summary of the removal efficiencies of stormwater BMPs, as well as describing the range of measures available. These range from public education programs to raise awareness and reduce pollutants such as litter and oils from industrial sources, to structural measures to capture or treat the stormwater before disposal into the receiving water body. Andoh and Declerck (1997) state that it can be advantageous to control pollutants at the source using BMPs. This is because source control results in minimised costs compared to large stormwater treatment measures applied at the end of the line. While BMPs can be adapted to stormwater use schemes, the focus of past, current and proposed BMP research is on stormwater quality improvement prior to disposal to the environment rather than use as an alternative supply source.

The concept of Water Sensitive Urban Design(WSUD) began in Western Australia in the late eighties and is based on minimising the impact of urban developments on the natural environment and water system, and managing the total urban water cycle. Hedgecock and Mouritz (1993) state that a group of interested individuals set up a group in Perth, Australia, that initiated the ideas and basis of WSUD. This group discussed and researched the benefits and practicalities of implementing WSUD. While the basic principles of WSUD are about management of the entire water cycle including water, sewage and stormwater, the Victorian Stormwater Committee (1999) have shown the focus for implementation of WSUD in Melbourne has been on stormwater design to minimise impacts on receiving water bodies, rather than on the whole water cycle and the interaction between all of the water areas. A limitation of these guidelines is that solutions to manage stormwater have been developed without examining solutions to manage water supply shortages. Thus using stormwater as an alternative supply source has been overlooked.

WSUD principles when applied to stormwater management, focus on integrating stormwater management into the landscape; minimising impervious areas to increase infiltration; maximising local on-site retention; efficient stormwater treatment to protect the receiving water bodies; (re)use of stormwater; and using stormwater beneficially for environmental and cultural benefits. The practicalities and effectiveness of implementing WSUD has been demonstrated at Lynbrook Estate in Melbourne (Lloyd et al., 2002). A shortcoming of this study was that the potential for using stormwater as a resource was minimal, although there has been small-scale irrigation of local red gums. Instead, the focus of the project was on stormwater quality improvement. While demonstrating the effectiveness of WSUD is very important, future demonstration projects should include larger scale use of stormwater as a resource.

As well as providing a comprehensive review of WSUD projects around Australia and overseas, Shipton and Mitchell (2002) examine WSUD technologies, including a number of technologies whose main or secondary purpose is to use stormwater as a water supply source. This study is useful in that the entire water cycle is examined and the application of WSUD as a design tool for stormwater use schemes is clearly demonstrated. In particular, the authors list the issues that need to be considered for selecting a water service. These issues are very relevant to stormwater use schemes and can be included in the decision making process for selecting a stormwater use scheme. The emerging stormwater management practice has required a new approach to management of all of the water systems. Integrated stormwater, wastewater and water supply management systems are being developed in order to explore ways to use and effectively manage all of these water resources (Mouritz, 2000). Integrated Water Management is similar to WUSD in that it examines the multiple functions of water resources as a whole, including natural functions, in-situ uses and withdrawals of water. Stormwater, sewage, groundwater and fresh water are managed in an integrated manner. When stormwater management is examined in terms of the total urban water cycle, the focus shifts from examining only flood protection measures to also examine the impact of stormwater on the surrounding environment and opportunities to use stormwater as a substitute for non-potable uses of water (Apostolidis, 2004; Lawrence et al., 1999; Marsalek, 1990; Palmer et al., 2000; Phillips et al., 2002; Schmitt, 1996).

Many of the abovementioned studies examining BMPs, WSUD and Integrated Water Management did not focus on using stormwater as an alternative supply source. The potential for using stormwater as a resource was not fully developed or realised. However, the management practices and tools developed as part of these new approaches can be adapted for stormwater use schemes, in particular treatment of the stormwater prior to use. Additionally, examination of stormwater in the context of the total urban water cycle has produced new opportunities for using stormwater.