What is urban storm water?

Stormwater is pure 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, stormwater is not treated. In some cases it’s filtered through traps, usually located at the end of the pipe system, but it still flows directly from streets and gutters into our rivers, the harbor and the ocean. Straight from your street to 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 color 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 harbors, on the beaches and in the rivers. The most effective way to reduce stormwater pollution is to stop it entering the system in the first place

What causes stormwater pollution?

Types of stormwater pollution

There are three main types of stormwater pollution:

This ends up discharging into waterways as sediment, sludge and solids. These can be caught in pollution traps, but the most effective way to reduce this problem is to prevent pollution entering the stormwater system in the first place. The traps don’t catch all the silt or litter, and they don’t stop chemicals.

Who’s responsible?

Everyone has a part to play. Reducing the pollution depends on every person preventing harmful natural or chemical substances entering the drains.

Council is responsible for controlling and maintaining stormwater systems. However, it is everyone’s responsibility to reduce the amount of rubbish and pollution that is carried into the drains. Local councils and rate-payers have to foot the bill for cleaning out pollution traps, and it’s much more cost-effective to stop the problem at the top of the pipe than further downstream.

Factors affecting stormwater pollution

The quantity and severity of stormwater pollution are affected by:

when it last rained and the intensity of the rain

building density and other land uses in the catchment area

level of vegetation cover

the cleanliness of the streets

local practices, such as street sweeping, pet control, garden watering, or use of chemicals.

Pollution at home and in your street

Typical activities that can cause stormwater pollution are:

disposing of garden waste: letting leaves or garden clippings accumulate in gutters or driveways where they can end up in the street drain f  dropping litter: clopping litter where it will be swept into the street drains next time it rains

Pollution at work

Typical activities at work that can cause stormwater pollution are:

Effects on plants and animals

Stormwater pollution can kill plants and animals that live in the water. For example:

How does stormwater pollution affect us?

Effects on plants and animals

Stormwater pollution can kill plants and animals that live in the water. For example:

Effects on humans

Stormwater eventually feeds into our waterways. Healthy waterways mean a healthy future for the environment and the economy and-for us. For example:

People do care about water pollution

Water pollution is the single most important environmental issue in NSW, according to the EPA’s 1997 benchmark survey ‘Who Cares About the Environment?’.

There is enormous consumer awareness of this issue and people are prepared to change their behavior from say, washing their car in the street, to washing it on the lawn. They understand their polluting behavior is having a direct and harmful effect on our waterways.

According to an EPA survey, 85% of people in NSW hold ‘a great deal of concern’ or a ‘fair amount’ of concern about the environment. People ranked the environment as the second most important issue for government action over the next decade. They identified water pollution as the single most important environmental issue in NSW.

What can we do about stormwater pollution

Everyone can do something to reduce stormwater pollution

Some people are quick to complain about water pollution, especially when it affects their favorite river, lake or beach. They may not realize that they may be contributing to this pollution when they tip harmful materials down the drain or carelessly drop litter on the road. The reality is that we all have an impact on stormwater quality, and we can all take steps to make a difference. You could make a difference just by changing the way you do something, like washing your car or walking your dog.

Activities which seem harmless or insignificant on a small scale can have an enormous cumulative impact on our waterways. Imagine thousands of people in the streets around you dropping a cigarette butt from their cars, sweeping dirt off their driveways or washing detergent off their cars down the street drains. It all ends up in the water.

Benefits for everyone

Whether you live close to the water, or only visit lakes, rivers, the harbor or beaches occasionally, reduced stormwater pollution will lead to many ongoing benefits for the environment and for all of us:

the environment will be healthier for plants and animals

What we can do at home and in the garden

   DO     Don’t


Pick up litter in the park or on the       • drop packaging or cigarette butts
street on the ground