THE NSW Government has implemented innovative ultrasonic technology and a stormwater diversion system to improve water quality and help tackle blue-green algae at one of Sydney’s most significant aquatic recreation and sporting sites at Penrith Lakes. Spanning 1,940 hectares, Penrith Lakes includes 750 hectares of freshwater lakes and features the Sydney International Regatta Centre and Penrith Whitewater Stadium which attract over half a million visitors and host approximately 1,700 sporting and community events each year. New water quality measures were implemented ahead of the International Canoe Federation’s Slalom World Championships at Penrith Whitewater Stadium from 29 September to 4 October, which attracted more than more than 230 athletes from 41 countries. The Penrith Lakes Scheme was developed through the rehabilitation of sand and gravel quarries on the Nepean River floodplain creating a series of lakes, wetlands, and public recreation spaces. However, recent years have seen these sites challenged by flooding and runoff from surrounding urban catchments. Stormwater inflows have contributed to a nutrient-rich environment where blue-green algae and other nutrient-loving bacteria are able to grow. The NSW Government allocated $3.95 million in its 2025-26 budget to undertake new water quality improvement measures at the Regatta Centre and Whitewater Stadium areas including:

• The use of ultrasonic technology that uses low-power ultrasound waves to inhibit blue-green algae’s ability to regulate buoyancy causing it to sink to the bottom of the lake where, deprived of sunlight, it cannot photosynthesise and reproduce.

• Installing a 1 kilometre pumping system to divert stormwater entering the Sydney International Regatta Centre into a wetland system to promote natural filtration of water prior to it flowing into the Penrith Lakes system.

A dedicated working group comprising senior personnel from the Department of Planning, Housing Infrastructure, Office of Sport and NSW Health was established to monitor and respond to prevailing lake conditions.

For further information on Penrith Lakes visit: www.westernsydneylakes.com.au/

Member for Penrith, Karen McKeown OAM said, “Maintaining water quality in the lakes is an essential focus for the continued enjoyment and safety by our community. These iconic locations which were prominent during the Sydney 2000 Olympics and recent ICF
World Championships. “It is important that ongoing water quality measures at Penrith Lakes are being supported through agencies including Western Sydney Lakes, the NSW Office of Strategic Lands, the Waste Assets Management Corporation, and the NSW Office of Sport.”

Leon Walker, Deputy Secretary of Property, Workplace and Development at the Department of Planning, Housing and Infrastructure said, “Penrith Lakes is a key community and environmental asset for Western Sydney that balances environmental rehabilitation, recreation, cultural heritage, sustainable urban planning and water management. “The lakes support a range of activities including boating, rowing, swimming, birdwatching and sporting events, so we want to do all we can to keep them healthy and functional. “Keeping these rehabilitated lands and waterways in good shape will make sure they continue to prosper as a recreation and tourism hub that can help expand our visitor economy through adventure, sports and outdoor offerings.”