The Narrows WA Oct 2024

In late September/early October 2024 some 22 tonnes of Phoslock granules were applied to the Narrows lakes, which are the waterbodies located within the Interchange parkland as one approaches the Narrows Bridge over the Swan River in Perth. Managed by the Department of Main Roads, the area of water is 19 hectares.

The decision to apply Phoslock was based on recommendations made by West Australia Department of Water and Environmental Regulation (DWER). The aim was to reduce the internal phosphorus load in the lakes and provide a ‘top-up layer of active Phoslock to the sediment. It followed on from applications made in earlier years, the last one being in 2022.

The application was undertaken by a contractor using our equipment and overseen by Limnological Services International. The phoslock was applied as a slurry, most of it using a pontoon boat with a hopper, mixing tank and boom. In the narrower portions of the water bodies the application was undertaken from shore. The product was supplied in 1.05 tonne bulk bags and to a much lesser extent in 25 kg bags.

Pre and post the application, water sampling and testing was conducted by officers from DWER.