Water Sources: Storm Water

storm drain

By Robert Lawton (Robert Lawton) [CC-BY-SA-2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons

Now that we have taken a look at rainwater in our water sources series, it’s a good time for us to turn to storm water.

What is storm water?

Storm water and rainwater are terms that are often used interchangeably, however, when talking about water sources rainwater usually refers to water that falls on roofs or other surfaces that can be captured in a tank.

Storm water is also from rainfall but has flowed off your property, or landed on roads and footpaths. The overflow from your rainwater tank is also classified as storm water. While rainwater is relatively clean, storm water will often carry debris such as soil, organic matter and litter as well as oils and other pollution.

Storm water has often been a problem for water providers and local councils, as they have to build drains and other infrastructure to prevent flash flooding.

What can storm water be used for?

The traditional method of dealing with storm water was to redirect it as quickly as possible to streams, rivers or the ocean. Today, there are new and innovative ways to capture, treat and use storm water.

Depending on how clean the water is, and the amount of treatment required, storm water can be used for a wide variety of purposes including industrial, sporting grounds, parks and wetlands or even as potable water.

The following video from the United Kingdom gives a good overview of storm water.

How is storm water used?

There are a number of great examples of how storm water is being used, from local rain gardens to treat and slow down storm water, to large scale harvesting and treatment projects.

Rain gardens have become a popular way to use and treat storm water, both on a residential level, using the runoff from your roof, or on a larger scale, filtering the runoff from roads before the water reaches the drain.

Scotch College in Melbourne’s Eastern suburbs has invested in storm water harvesting, using it to water all of it’s sporting grounds and gardens.

Orange City Council in NSW has developed a storm water harvesting project which captures water from Blackmans Swamp Creek during storm events to augment local water supply.

Wannon Water is also reusing storm water for drinking water supply in Victoria’s South West. In this instance, water is captured from roofs in a residential subdivision and diverted to an untreated storage before making its way to an existing water treatment plant.

storm water drain and rain garden

What are some of the benefits of harvesting storm water?

There are a number of great benefits from harvesting storm water:

  • Reducing flash flooding by slowing storm surges down
  • Keeping waterways cleaner by providing filtering through rain gardens and wetlands
  • Reducing our reliance on traditional water sources by providing an alternative water source
  • Reducing costs in building and maintaining traditional infrastructure

What are some of the issues with using storm water?

There are some hurdles that need to be overcome when implementing a storm water reuse scheme. They include:

  • The cost of additional treatment to remove oil and other debris
  • Finding storage locations in built up urban areas can be difficult
  • The cost of converting traditional infrastructure

Despite these issues, storm water remains an attractive and affordable option for water supply. At the very least, each household can make the most of local stormwater through a rain garden.

Further resources

How do you use storm water as a resource in your community?