Bio-retention basin improves stormwater quality from recycling and waste centre

A new bio-retention basin has been constructed alongside Birkdale Recycling and Waste Centre to improve the quality of stormwater discharged into nearby waterways.

Redland City Mayor Karen Williams said as well as the environmental benefits, the basin would also reduce maintenance and operational costs associated with managing stormwater and stormwater infrastructure.

“The construction of the bio-retention basin is part of a wider scope of works at the site following the remediation of the landfill in 2017, and construction of the asphalt hardstand for stockpiled materials in 2020.

“Stormwater runoff from the Recycling and Waste Centre has the potential to cause water contamination or environmental harm in the areas where it is discharged, namely Tarradarrapin Creek which in turn flows into Waterloo Bay.

“However, the water treated through the bio-retention basin will be of a higher quality than previously managed through the stormwater pond it is replacing.”

Playing a pivotal role in that improved water quality are almost 3000 native grasses and plants which cover about 425 sq m of the basin.

“The stormwater quality onsite improved significantly following the completion of the asphalt hardstand,” Cr Williams said.

“Now the bio-retention basin is complete, the stormwater will meet quality standards without the requirement for treatment before being discharged, as any sediment or nutrients in the stormwater will be filtered by the plant and filtration media (a combination of soil, sand and gravel).”

Cr Williams said Council saved time and a lot of money on the basin’s construction by using a new product to transform a large amount of silt and contaminated sludge at the bottom of the previous stormwater pond.

“This innovative mud stabilisation product transformed the sludge into a usable material which was then incorporated with other materials to construct the bio-retention basin,” she said.

“The use of this product saved more than $275,000 and reduced construction time by three weeks, achieving a great environmental and financial outcome for the city.”

Division 8 Councillor Tracey Huges said the bio-retention basin met the expectations and compliance standards set by the Department of Environment and Science and modern environmental standards required for an operating waste facility.

“Last year Council resurfaced the gravel area on top of the hill with an innovative bitumen seal that used recycled tyres,” Cr Huges said.

“Earlier this year Council repaired a stormwater drain which had been damaged following heavy rain.

“Now, with the completion of the bio-retention basin on the western perimeter of the Birkdale Recycling and Waste Centre, Council has ensured there is modern and best practice stormwater management infrastructure in place to capture any fine particles or sediment generated through operations onsite.”