Stormwater

Being safe around stormwater

Stormwater drains can be very dangerous places. This is why stormwater drains are often fenced and have warning signs telling people to stay out.

It's important that you don't go into drains – even during fine weather. It's also a good idea to keep pets away from drains.

Stormwater drains can be open channels or underground tunnels. They are dangerous because:

• water in drains can rise quickly and unexpectedly, even when it's not raining in the local area
• huge amounts of water can suddenly wash into the drain when it rains
• you may not be able to get out of a stormwater drain if you're swept away by water – you could even drown
• even shallow water can be very powerful and could knock you over
• drains can contain pollution like broken glass, dangerous chemicals and disease-causing bacteria.

Don’t try to lift stormwater grates near footpaths and roads, even if something has accidentally dropped down. These grates can be very heavy.

If you're in a flooded area, stay away from roads, footpaths and areas where you can’t clearly see where you're walking.

What's in stormwater?

Water is a solvent, which means it dissolves things. Wherever it travels, water carries chemicals, minerals and nutrients with it. 

Stormwater carries all the things that collect on hard surfaces, like roads, footpaths, driveways and roofs. Some examples of things in stormwater are:

• litter, like plastic bottles, food packaging and cigarette butts that people leave on the street
• oil and grease from cars
• dirt, leaves and twigs
• animal and bird droppings
• chemicals, including nutrients, from washing the car on the driveway or road.

How is stormwater quality managed?

Unlike wastewater, stormwater isn't treated before flowing into creeks, rivers and oceans. We (and many councils) manage stormwater using stormwater quality improvement devices (SQIDs).

SQIDs are designed to catch solids so they can be removed from the water, such as:

• trash racks
• sediment traps
• litter booms
• constructed wetlands.

In the past 20 years, we've installed 70 SQIDs. These devices have helped remove over 35,000 cubic metres of litter and organic waste as well as 39,000 tonnes of sediment from stormwater before it reaches Sydney’s waterways.

Learn more about what we're doing to manage stormwater.

What is water-sensitive urban design?

It's important to consider the water cycle as part of our built environment. When the water cycle is included in planning, designing and constructing our built environment it's called water-sensitive urban design (WSUD).

Our built environment often includes hard surfaces, like roofs and roads, that interrupt the natural water cycle processes of run-off, infiltration and percolation. WSUD concentrates on making sure these processes can still happen.

When using WSUD, we have to take lots of things into consideration. Learn more about water-sensitive urban design (553KB).

Safety – Can we use design to reduce dangers like drowning?

Maintenance – Who will maintain the area after it's built? How?

Water quality and quantity – What quality and how much water is flowing in? What quality is the receiving environment?

Available space – How much land does the design use? What habitat or land features will be impacted?

Climate – What are the rain patterns? Will the design need to cope with high volume, infrequent rain events or low levels of rain over a long period of time?

Landscape – What is the topography and slope of the land? What type of soil is in the area? Different soils have different percolation rates.

Community – How will the area be used by community?

Water-sensitive urban design – case studies

Creating a green, cool, resilient city requires a shift towards water-sensitive planning and design.

By improving the flow of water through the natural and built environment and using and reusing water more wisely, we can achieve these outcomes:

• cooler temperatures and reduced energy demands
• improved waterway health and habitat
• increased canopy cover and retain vegetation
• increased open spaces
• less money spent on infrastructure to capture and treat run-off
• reduced impact of flooding.

How can stormwater enter our wastewater system?

When a stormwater pipe is connected incorrectly or rain can enter the wastewater system it can cause overflows, impacting the community and the environment. 

The condition of stormwater connections can be checked using a couple of methods:

• smoke testing – a small amount of environmentally safe, non-hazardous smoke pumped into wastewater pipes to identify possible leaks and incorrect connections. 
• visual inspection – a visual check of external downpipe connections and outdoor drains

Did you know as a property owner, you have a role in maintaining the wastewater pipes and stormwater downpipes on your property.

Harvesting stormwater for recycling

Collecting and treating stormwater so it can be recycled is called stormwater harvesting.

Stormwater harvesting can help reduce demand on drinking water supplies by providing another water source for things like:

• watering sports fields and gardens
• flushing toilets
• washing machines (in some cases).

These activities don't require water to be treated to a drinking water standard.

Sydney has a variable climate. We can’t always predict when it will be dry or it will rain.

Heavy rain can cause urban waterways to rise quickly. It may take only minutes for fast-moving floodwater to fill a waterway.

We work closely with local councils and other agencies to improve the health of our stormwater system and protect people and properties from flooding.

Our current projects will help protect people and their property from flooding during storms and heavy rain.

To be active in what is happening in your local community, we have Sydney Water Talk. Customers get to share their opinions about projects, so you can help us shape and create liveable communities.

Learn more about how to minimise your flood risk with SES NSW education programs.