A MANMADE floating wetlands was kayaked into the middle of Brickworks Lake this week, a trial to restore the health of the plagued Maylands lakes.
The Friends of Maylands Lakes successfully lobbied the City of Bayswater to address poor water quality and algal blooms at Bungana, Brearley and Brickworks lakes and $1.7 million worth of management options will start to be rolled out in the next financial year.
Ahead of this, Ecocraft Environmental has installed a free trial floating nutrient-stripping reed bed in Brickworks Lake, kayaked it out and anchored it to the lake floor with mooring blocks.
The Brickworks Lake had a sudden influx of nutrients after the February storms and the floating wetlands would aim to fix this.
Mayor Barry McKenna said the “innovative” approach was cost effective and had a minimal impact on the environment during installation.
“The City will continue to monitor the nutrient levels to assess the effectiveness of the floating wetlands during the trial,” he said.
“In addressing the water quality of the Maylands Lakes the proposed management plan includes a range of methods to strip nutrients from the water including pollutant traps on stormwater drains, revegetation, sediment removal, installation of solar pumps and community education.”
City catchment management officer Rebecca Ferguson said the City had also recently repaired Brickworks’ fountain, added sub-aerators and completed weeding with a steam wand and put in a new natured bed.
She said the first step of the $1.7 million management options, if approved in the 2017-18 budget, likely to be rolled out was gross pollutant taps on drains.
Ecocraft Environmental consultant Michael Mac Shane said the plants will grow through the mesh and the roots go down 1m to 1.5m into the water column, 1m to 1.5m.
“Because the enormous amount of roots, it means there’s a large surface area; the roots gets covered in microbes and it’s those that do the actual nitrate and nutrient conversion,” he said.
“You can remove the installation eventually once the lake has been returned to a nutrient balance.”
Mr Mac Shane said the floating wetlands were reactive to storm events and extra modules could be added to cover a larger area.
Friends of Maylands Lakes chairman Geoff Trott said the raft was an “excellent pilot” and if effective, it could be rolled out on larger scale.
He said the stench from Brickworks Lake in recent months had been strong.