Stormwater management

It is important that we use all water resources as effectively as possible, including stormwater. Stormwater is rainwater that flows across surfaces and into drains and gutters in the street. Traditionally, this water is not treated and flows into creeks, rivers, lakes and oceans.

Stormwater management is the treatment and reuse of this water. There are two benefits. Firstly, stormwater is an important water resource that can be used in place of other water resources. Treated appropriately, stormwater can be used for a variety of purposes, including irrigating gardens and parks. In the SA Murray-Darling Basin region, stormwater reuse schemes have been implemented in Karoonda, Lameroo, Loxton, Murray Bridge and Pinnaroo. A second benefit of stormwater management is that treating stormwater before it enters creeks, rivers, lakes and oceans helps protect the native plants and animals that live in and rely on these ecosystems.

How you can help

A significant issue with stormwater is the pollutants that it can collect as it runs across surfaces. Some of these are heavy metals, hydrocarbons, pathogens, sediment, litter and industrial, domestic and agricultural chemicals. You can help reduce these pollutants.

• Vehicle maintenance: leaking oil and brake fluids are extremely toxic to aquatic plants and animals. You can prevent polluting stormwater by fixing these leaks promptly, cleaning up leaks with rags, and never disposing of oil or other engine fluids into gutters and drains.
• Car washing: washing your car on the street or driveway results in detergents entering stormwater and polluting waterways. You can prevent this pollution by ensuring you wash your car on lawn, gravel or at a commercial car wash, using biodegradable detergents, and using hoses with nozzles that turn off when unattended.
• Leaf litter: leaves can increase the organic content of stormwater, which can be unsuitable for native plants and animals and can potentially cause algal blooms. You can prevent this by removing leaf litter from streets, using this litter for compost or mulch, and avoiding mowing lawns in the days before heavy rain.
• Garden fertilisers and pesticides: fertilisers significantly increase nutrient levels in stormwater which can lead to algal blooms and native plant suffocation. Pesticides kill native plants and animals in waterways. You can prevent fertilisers and pesticides polluting stormwater by limiting their use, not using them before heavy rain, and avoiding over watering of treated areas.
• Introduced plants: compared to native plants, introduced plants can impact stormwater by producing large quantities of organic litter through an annual dump of leaves and have the potential to become weeds if spread by water runoff. To help prevent this, you can plant native vegetation where possible and prevent plant litter from entering stormwater gutters.

Stormwater and water sensitive urban design

Water sensitive urban design (WSUD) is an approach to the planning and design of urban developments that integrates the management of the total water cycle. WSUD is important because urban development can significantly change the local water cycle, creating much greater surface water runoff from roofs, driveways and other solid ground coverings. This can increase the risks of flooding, erosion and pollutants entering stormwater, and reduce the replenishment of underground water.

WSUD includes the:

• integrated management of groundwater, surface runoff including stormwater, drinking water and wastewater
• storage, treatment and beneficial use of stormwater
• treatment and reuse of wastewater
• using vegetation for treatment purposes, water efficient landscaping and enhancing biodiversity
• utilising water saving measures to minimise requirements for water.

WSUD is implemented through development plans. Each council has its own development plan that sets out the rules for developing land. These can be accessed via:

• country council development plans
• outer metropolitan council development plans

When an application for development is made, it is reviewed against the relevant development plan and the Development Act 1993 by Council Planners and Development Assessment Panel members. It may also be referred to internal and external experts to ensure it meets WSUD principles and to the state government if there is the potential for the development to impact on the natural resources in the region. More information about this process is available at the Department of Planning and Local Government website.