Stormwater Management

What is stormwater?

Stormwater is the rainwater that does not soak into the ground, but travels over the land and into the drains, pipes and creeks.

On hard surfaces such as driveways, paths and roofs the water collects and is passed into small pipes that enter our road gutters. This water enters one of Councils 19,000 drainage pits before being conveyed underground along some of the 438km of piped drains within the Local Government area.

This water, along with the pollutants it has picked up, is eventually transported into the 65km of natural creeks or 13.4km of open channel that form the lifeblood of our catchment. From here, the majority ends up in Parramatta River, and then Sydney Harbour.

What is the problem with stormwater?

Along its journey, stormwater picks up pollutants such as fertilisers from gardens, oils from driveways, sediment and leaves from paths and litter from the road and carparks. Unlike sewage from your toilet or shower, stormwater does not pass through any treatment plant to clean the water. So, whatever pollutants are deposited or blown into our stormwater ultimately end up in our creeks and rivers.

The amount and quality of water that enters our creeks and rivers depends on how impervious the land is. The greater the impervious nature of the land (ie more hard surfaces) the greater the following problems are:

• Increased chance of flooding
• Increased chance of erosion from higher flow rates
• Less water for plant life at source
• Less water to enter and re-charge groundwater reserves
• Greater pollution transported with the water from hard surfaces

Stormwater Management Planning

For Council to determine what actions are needed to reduce the impact of stormwater pollution the following plans have been prepared:

• Central Business District Stormwater Asset Plan
• Commercial and Industrial Stormwater Asset Plan
• Combined Parramatta City Council Stormwater Management Plan

Water Quality Improvement

There are many things we can do to stop pollution, and ideally pollutants should be prevented from entering our waterways. However, this is not always possible, so Council has installed ‘pollution control devices’ to help reduce the amount of litter, sediment and organic pollution entering our waterways.

Some pollution control devices (or gross pollutant traps) installed in Parramatta City include underground proprietary units, end-of-pipe net and cage traps, in-stream trash racks and litter booms and road side gully pit traps. While these can assist in minimising the amount of pollution entering our waterways they can not control all pollution. Council has a total of 81 stormwater pollutant traps across the City.

Caption: A floating litter boom in DuckRiver