Stormwater reuse project

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The Stormwater Management, Harvesting and Reuse Efficiency Project (Stormwater reuse project) was focused on stormwater harvesting and reuse for social, economic and environmental benefits in Western Australia's wheatbelt towns.

The project was supported with $2 million from the State Government's Royalties for Regions program, and received substantial support from the Department of Agriculture and Food, Western Australia (DAFWA). The project operated from 2012 to 2015.

Project overview

DAFWA, with partner Wheatbelt NRM, provided resources to regional local government authorities to plan and implement best practice stormwater management infrastructure in wheatbelt towns.

DAFWA led the project based on its experience and expertise in assisting regional towns to use locally sourced water, such as through the Rural Towns Program. Wheatbelt NRM coordinated delivery of the project and wrote the final report.

Many rural communities are faced with an annual dilemma — they cannot afford to use expensive, drinking-quality scheme water for irrigation over summer, nor do they want to allow their well-utilised and highly valued community sports grounds to die.

The community and environment benefit by harvesting stormwater, and using this resource to keep public open spaces irrigated, and to reduce the use of drinking-quality water supplies.

Climate projections for the south-west of Western australia are for higher temperatures and lower rainfall. Wheatbelt towns will suffer from those conditions, and will need improved water management to maintain their communities. Stormwater reuse is one strategy to provide an efficient, reliable and safe water supply for communal use.

What is stormwater harvesting?

Stormwater harvesting is the collection and reuse of runoff from urban areas that would otherwise end up in natural drainage systems. While the approach to stormwater harvesting differs between locations, the elements include:

  • collection of rainwater from roofs, hardstands, sports areas, road surfaces, town drains or creeklines
  • temporary storage of runoff water in excavated sumps or tanks (above or below ground)
  • water transfer to larger storage units, a process known as 'bulking up'
  • passive infiltration or injection of stormwater into a suitable groundwater aquifer (this option is limited by the site)
  • reticulation to distribution locations, most commonly irrigation points or to a standpipe.

An example of an effective stormwater harvesting and reuse scheme is in the town of Wagin. DAFWA has helped the Shire of Wagin design and implement a whole townsite water management scheme for water conservation and salinity control. Stormwater capture and reuse is an important component of that scheme.

In places like Wagin affected by salinity, rising groundwater and waterlogging in the townsite is being managed with a comprehensive borefield installed to dewater the local aquifer. The shire is also capturing most of its stormwater and much of the town catchment runoff with a 6000 cubic metre weir across one of the main town drains. The high quality surface water is then pumped back up-slope to the 25 000 cubic metre ‘Brown’ dam (see photo below), from which the town sports oval and other recreational sites are irrigated.

Stormwater reuse can convert townsite runoff, that may be considered a nuisance or threat, into a productive resource that sustains a community’s wellbeing by maintaining a sports ground that is a source of local identity and pride.

25000m3 four sided excavated earthern tank located above Wagin storing stormwater harvested from the townsite

Benefits of stormwater reuse project

This project aimed to improve the capture, storage and distribution of stormwater runoff in selected wheatbelt towns by implementing well-conceived and well-designed runoff harvesting systems.

Stormwater reuse is one way to assist local governments to meet conflicting pressures from rate-payers to reduce budget excesses and also keep the town’s sports grounds and parks green. A 'fit for purpose' approach can be adopted, using good quality but not drinking-quality water to meet the town's irrigation needs.

Economic benefits include:

  • reduced scheme water costs
  • community use of amenities requiring irrigation.

Based on 2013 charges of $1.85 per kilolitre for scheme water, Wagin Shire estimated their stormwater reuse system would save them an average $129 000 per year in Water Corporation charges (Source: Allen Hicks, Shire works manager, pers com. 2013).

Outcomes of stormwater project

The expected benefits are:

  • reduced demand on drinking-quality town water supplies.
  • increased community amenity using fit-for-purpose water supplies for community benefit, for example sports grounds, parks, public gardens and street-scaping
  • reduced financial cost of scheme water supplies.

Some principles

Whether large or small, the ideal townsite water management plan can be achieved by applying some water sensitive urban design principles:

  • Maximise water use efficiency, reduce potable water demand, and maximise the use of wastewater and harvested water including stormwater.
  • Provide 'fit-for-purpose' water for specific uses. Provision of potable quality water for human use under these schemes is not recommended by DAFWA.
  • Manage runoff in the catchment above the townsite. Use runoff control measures to reduce runoff volumes and peak flows.
  • Retain, restore and enhance existing elements of the natural drainage system, including waterways, wetlands and groundwater features, regimes and processes, and integrate these elements in the town and surrounding rural landscape.
  • Minimise pollutant inputs to surface water and groundwater systems.
  • Provide protection from flooding that could occur during major runoff.
  • Enhance social amenity through multiple use corridors, lot landscaping and integrating water management measures in the landscape to improve visual, recreational, cultural and ecological values.
  • Design water-sensitive systems and landscapes which are more resilient to climate change  (Source: modified from Department of Water’s Stormwater Management Manual for Western Australia, 2004–07).

DAFWA recommends stormwater reuse schemes be part of a whole townsite water management plan. The illustration below shows the linkages between water uses, such as community, industry and agriculture, and available water sources, such as groundwater, recycling and catchment.

A management plan recognises that water demands, stormwater sources, groundwater reserves, and wastewater contributions are interrelated components of a town water management system. These components could be many and varied, or they may be less complex than those depicted below in the stylised urban illustration from the State Water Plan (Government of Western Australia 2007).

Town site schematic showing the water cycle in the built environment

Royalties for Regions support and partnerships

This project has received strong support from the State Government’s Royalties for Regions program.

Funding was allocated from the Royalties for Regions $78.2 million Regional Development — Water and Natural Resource Management initiative, which aims to capitalise on water availability opportunities and support regional development in WA. DAFWA is working as the lead agency with the Department of Regional Development and Department of Water to deliver this initiative.

Through Royalties for Regions, the equivalent of 25% of the state's mining and onshore petroleum royalties is being returned to regional areas each year as an additional investment in projects, infrastructure and community services.

The project builds on previous work led by the Department of Agriculture and Food, Western Australia under the Rural Towns — Liquid Assets Project.

Contact information

Jamie Bowyer
+61 (0)8 9368 3135