Stormwater is rainwater plus anything the rain carries along with it. In urban areas, rain that falls on the roof of your house, or collects on paved areas like driveways, roads and footpaths is carried away through a system of pipes that is separate from the sewerage system. Unlike sewage, traditionally, stormwater has not been treated. In some cases it's filtered through stormwater treatment measures, usually located at the end of the pipe system, but it still flows directly from streets and gutters into waterways inhabited by fish, frogs and other aquatic animals and plants.
If you live near a waterway or often spend time in or near the water you are probably familiar with what happens after rain. Polluted stormwater spreading out into the surrounding clean water can be clearly seen because it's a muddy colour, and often carries litter with it. You may be advised not to swim for a couple of days, because the pollution carried along with the rainwater may pose a significant health risk.
Stormwater pollution can be controlled if everyone plays a part in managing the drains in the streets where they live and work. In other words, if you look after your local drains, you can dramatically improve what happens in the harbours, on the beaches and in the rivers. The most effective way to reduce stormwater pollution is to stop it entering the system by capturing it at the source.
In recent years, new developments have incorporated stormwater treatment techniques at the source of the pollutant, such as rainwater harvesting, bio-filtration systems and wetlands. In addition, there has also been a steady increase in retrofitting stormwater treatment systems in developed areas, where this is practical, such as council constructing a wetland at the discharge point of the catchment or household owners installing a rainwater tank.
According to the principles of best practice management, urban stormwater should be managed to minimise impacts on waterway health, minimise stormwater flooding and provide an alternate water source. Stormwater management aims to achieve the long term goals of:
OEH and other agencies have prepared a series of publications to help stormwater managers improve their stormwater management practices and technical notes to assist professionals. These documents address topics including stormwater harvesting and reuse, erosion and sediment control on construction sites, stormwater education and environmental management on the urban fringe. This stormwater website also provides information for teachers, parents and children on the effect of stormwater and how we can prevent stormwater from further deteriorating the receiving waters.
Page last updated: 19 October 2012