Stormwater network

Rain's too valuable to go down the drain

Managed properly, stormwater is a valuable resource that can enhance the liveability, sustainability and resilience of cities. We achieve this for Greater Sydney by working with councils to improve the health of our waterways, provide opportunities for stormwater re-use, and protect people and properties from flooding. So how do we manage stormwater, and how do we redirect it?

Our stormwater system

Urban environments are packed with hard surfaces such as roofs, roads and footpaths that prevent rain from soaking into the ground. Stormwater is the water that flows on those surfaces after rain. Often it flows from property drains to street gutters operated by local councils, and these drains may connect to our large channels, pipes and creeks. This is what forms our stormwater trunk drainage system

Our stormwater network provides services to about 627,300 properties. It consists of:

  • 73 catchments
  • 456 kilometres of channels and pipes
  • over 70 stormwater quality improvement devices.


Are you in one of our stormwater catchment areas?

We also manage flood-prone areas and trunk drainage in the Rouse Hill area. Find out more about:

Download Stormwater - Our role in managing floods.

Stormwater safety

Only authorised maintenance crews can enter our stormwater system. Stormwater systems includes open channels, drains and underground tunnels. They're dangerous because:

  • water in drains can rise quickly and unexpectedly, even when it's not raining in the immediate area
  • flowing water is powerful and can knock people over, even when it's shallow
  • stormwater contains pollutants, including dangerous chemicals and disease-causing bacteria. 

Report unauthorised access to the stormwater system
If you see anyone entering a stormwater drain, channel, tunnel or maintenance hole, call us on 13 20 90, 24/7. We'll keep your contact details confidential and you may prevent an accident or death. We'll investigate all reports of entry to our stormwater systems and refer reports of entry to the relevant council or NSW Police.

Stormwater quality

Stormwater can carry pollution like litter, sediment, grease, oil and metals that are picked up from roads and properties. This pollution affects the quality of our local waterways. We've installed over 70 Stormwater Quality Improvement Devices to help clean stormwater. These include trash racks, sediment traps and litter booms.

If you're connecting to our stormwater pipes or developing your property, you must meet our stormwater quality targets.

Stormwater harvesting

About 70 projects across the Sydney region are collecting and re-using stormwater, a practice known as stormwater harvesting. These projects include using stormwater to:

  • water local parks, gardens and sports fields
  • flush public toilets.

Together, these projects collect over 1.3 billion litres of water each year. This is about the same as 520 Olympic swimming pools.