Stormwater network

What is stormwater?

In urban environments there are many hard surfaces such as roofs, roads and footpaths that prevent rain from soaking into the ground. Stormwater is the water that flows on surfaces after rain.

Stormwater often flows from property drains to street gutters operated by local councils. Sometimes these drains connect to our large channels, pipes and creeks. This forms the stormwater trunk drainage system.

Stormwater is a highly valuable resource that can enhance the liveability, sustainability and resilience of cities. We work with councils to:

  • improve the health of our waterways
  • provide opportunities for stormwater re-use
  • protect people and properties from flooding.

Learn more about how we're managing stormwater and improving waterway health.

Where are our stormwater catchment areas?

Look at our Stormwater catchment map to find out if your property is in one of our stormwater catchment areas.

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

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

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

Only authorised maintenance crews can enter our stormwater system.

Stormwater systems are 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. 

What can you do if you see someone entering the stormwater system?

Report unauthorised access to the stormwater system immediately
Call us on 13 20 90 (24 hours) if you see anyone entering a stormwater drain, channel, tunnel or maintenance hole. We'll keep your contact details confidential.

Your help may prevent accidents and deaths.

We'll investigate all reports of entry to our stormwater systems and refer reports of entry to council stormwater drains to the relevant council or NSW Police.

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 (SQIDs) to help clean stormwater. These include trash racks, sediment traps and litter booms.

Learn more about SQIDs and how they're helping protect the Whites seahorses in Rose Bay in the Woollahra Golf Course SQID fact sheet.

To find out more about how we minimise pollution in our waterways, read our Stormwater pollution fact sheet.

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

About 70 projects across the Sydney region are collecting and re-using stormwater. This is known as stormwater harvesting. 

These projects include using stormwater to:

  • water local parks, gardens and sportsfields
  • 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.


Learn more