Wetland to boost Swan River water quality

WA Environment Minister Albert Jacob has announced the construction of one of Western Australia’s largest constructed wetlands - the Ellen Brook Wetland project.

Jacob said the project aims to reduce phosphorus and nitrogen loads entering the Swan River from the Ellen Brook catchment - a significant source of nutrients to the waterway.

“It is estimated that the first stage of the wetland will remove 270 kg of phosphorus and 330 kg of nitrogen each year,” he said. “Further stages of work will further increase the quantity of nutrients removed from the Ellen Brook before it flows into the Swan River.

“The result will be an improvement in water quality which will help reduce the likelihood of toxic algal blooms.”

Stage one of the project, which is expected to be completed in late May, will involve planting almost 50,000 native plants. It will also see the creation of a wetland basin on the site’s floodplain, about 800 m² of bank stabilisation works and the installation of an access path and a pumping system.

“The wetland has been designed as a compartmentalised system, allowing up to seven wetland basins to be constructed in stages,” Jacob said. “Once fully constructed, these innovative offline basins will treat water before returning it to the Ellen Brook.”

Initial works, including the application of phosphorus removal technology Phoslock in late 2013, are already making a difference to the quality of water entering the Swan River from the brook.

“Water quality monitoring has clearly shown that a reduction in phosphorus, one of the main nutrients contributing to algal blooms in the Swan Canning river system, occurred following the application of Phoslock,” Jacob said.

The state government has committed $2.52 million to the project, with $1.53 million from the federal government.