Bankstown's biggest stormwater management project has just been completed by Bankstown City Council at the Crest Sporting complex in Georges Hall.

A Bankstown City Council spokesperson said the project at the Crest is part of Council's commitment to a sustainable Bankstown by significantly reducing the water use of the city's largest water using site.

"The Crest Sustainable Water Management Project will save at least 20 millions litres of drinking water each year and ensure Council can better manage the playing fields at the complex.

"Urban runoff from the houses around the Crest and rainwater from the Dunc Grey Velodrome roof will now be captured and treated using a natural rain garden.

"The water will then be used to irrigate all of the playing fields in the area throughout the year, including in tough drought conditions."

In addition to supplying more than 80 per cent of the irrigation demands for the area, the project will also improve stormwater quality in the Prospect Creek catchment, which in return will increase biodiversity and help mitigate floods downstream.

The Crest Stormwater Management Project was jointly funded by Bankstown City Council and the Australian Government through the Sydney Metropolitan CMA's Botany Bay Water Quality Improvement Program.

Bankstown Council is currently investigating similar stormwater and reuse projects for Jim Ring Reserve, the Kelso Sporting complex and Sefton Golf Course.