Stormwater Treatment Project: More Than Meets the Eye at Unity Park

Along the meanderings of Dry Creek, the City of Salisbury is embarking on a unique water security project that will also embrace historic, cultural and artistic elements of life in the region.

A central feature of the project is a series of underground biofiltration cells that will cleanse harvested stormwater at significantly less cost than wetlands and with a much smaller development ‘footprint’.

The biofiltration technology is being installed in picturesque Unity Park at Pooraka to further refine stormwater collected in reconfigured wetland basins in the expansive recreational area along South Terrace.

A key objective of the project is to demonstrate the efficiency of vertical flow biofiltration for application in other places where available space for wetlands is limited.

Bruce Naumann, Manager of Water Systems for the City of Salisbury, explained that biofiltration cleanses stormwater of pollutants by allowing the stormwater to drain through a layer of vegetation, porous soil and deeper layers of filtration media, before it finally seeps into a slotted recovery pipe.

An initial six biofiltration cells will operate with the conventional wetlands at Unity Park. The cleansed water is transferred by pipeline to a series of nine Aquifer Storage and Recovery (ASR) wells at Cavan.

The Unity Park Biofiltration and Reuse Project – funded by the Federal Government ($7 million), State Government ($2 million) and the City of Salisbury ($5 million) – will harvest an estimated 1.3 million litres of stormwater each year.

  • Apart from creating new landscaped features and amenities at Unity Park between Main North Road and Briens Road, the project will provide:
  • Fit-for-purpose water for local industries;
  • Irrigation of open space, school ovals and sports facilities; and
  • An alternative supply for watering gardens, flushing toilets and washing cars in new residential developments where the developers install a ‘purple pipe’ network to new homes.