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City Holden is proud to be teaming up with Landcare Australia to help the River Torrens maintain a healthy balance and promote bird life in the area.

Torrens Lake Floating Island Installation Adelaide Background: The Torrens Lake at the centre of Adelaide is a South Australian icon, and the recreational heart of the city. It is a haven for wildlife and humans alike but has struggled with water quality issues, including regular blue green algal blooms.

Actions: To help combat the high levels of nutrients in the water floating islands of natural vegetation will be installed in the lake. These islands will have an area of almost two square meters and will be planted with dozens of wetland plants such as reed and sedge. The islands are being made by Floating Islands Australasia. The plants will feed off the heavy nutrient load in the water to help the purification process, as well as become a haven for birds. The plants will grow hydroponically when launched into the Torrens Lake. The plants and island itself become populated by bacteria that occur in the ecosystem. The combination of plants and bacteria operate to remove nitrogen and phosphorus from the water column, which are normally present as excess nutrients from urban and agricultural run-off. Bacteria also remove organic matter from the water and assists in settling suspended matter, thereby reducing cloudiness. Therefore the water cleanup is achieved by completely natural processes with no consumption of chemicals or energy.

Outcomes: The highly visible project will help to return the Torrens Lake back to its ecological best through improving the water quality, and reducing the frequency of issues such as algal blooms.