Council trials ‘floating wetland’ to treat water in Wellington Point lake


Redland City Council is trialling a new water treatment system, known as a ‘floating wetland’, at Sovereign Waters Lake in Wellington Point.

Mayor Karen Williams said, if the trial was successful, the floating wetland concept could be used to help improve and protect aquatic environments across Redlands Coast.

“Floating wetlands are small artificial platforms that incorporate wetland plants on a suspended matrix that floats on the surface of the water,” she said.

“In December 2020, two floating wetland islands were installed at the southern end of Sovereign Waters Lake to reduce turbidity levels, absorb excess nutrients and settle sediment particles.

Mayor Karen Williams and Cr Wendy Boglary view one of the ‘floating wetlands’ at Sovereign Waters Lake.

“Over the next 10 months Council will monitor water quality levels, the growth rate of the wetland plants, plant root density, and the floating wetland’s ability to cope with changing water levels.

“At the end of the year officers will review the effectiveness of the trial and decide whether to permanently install floating wetlands at the lake and possibly other waterways across the city.”

Cr Williams said floating wetlands were not only visually appealing, but research showed benefits for the environment and wildlife.

“As the plants’ roots grow through the platform and down into the water, thick root columns absorb nutrients and other contaminants to help maintain high water quality.

“The floating islands also provide habitat and a food source for aquatic species and water birds.”

Division 1 Councillor Wendy Boglary said she hoped the trial would be successful in improving the lake’s water quality.

“As well as being a complex ecosystem of aquatic plants, animals and micro-organisms, Sovereign Waters Lake is a tranquil open space for the community,” Cr Boglary said.

“Success with this floating wetland trial could pave the way for more of these water treatment systems in other well-loved areas across Redlands Coast.”