Maylands Lakes is a combined lake system that began as clay extraction pits used to supply a former brickworks on the Maylands Peninsula in Perth, Western Australia. The pits filled naturally from groundwater seepage and provided significant wetland and open water habitat for fauna and flora. In the late 1990s, the lakes, covering an area of nearly 15 ha were formalised into aesthetic water bodies as part an urban development of the area. Since being reshaped and modified, the lake system has been developing a number of issues, largely associated with poor flushing and continued nutrient inputs. Harmful algal blooms, particularly of toxin producing Microcystis aeruginosa and Raphidiopsis raciborskii species have been reoccurring in warmer months for a number of years with chironomid (non-biting midge) swarms also regularly prevalent.
A restoration approach was developed by considering a number of lines of evidence, including water quality data, previous modelling, groundwater studies and historical information, with a series of concept approaches to address the issues proposed. The high level of community interest in these lakes, given that there are properties immediately adjoining the lakes’ edges, has meant considerable engagement throughout the development of the restoration masterplan, with challenges of addressing a wide range of opinions and community advocacy throughout the process. Developing a logical evidence-based response has been central to providing the community, local government officers and elected officials with sufficient confidence that the problems at Maylands Lakes can be effectively dealt with by the masterplan approach.
The resulting final masterplan concept design resulting from this is an approach to restore ecosystem functions back into the system, including significant revegetation, recirculation through treatment wetlands, biofiltration to address nutrient inputs, habitat restoration and nutrient fixation. This restoration approach focused on reducing nutrient availability in the water column, reducing residence time in any one part of the lake system, and reducing nutrient inputs from surface and groundwater inflows and avian fauna prevalent on the habitat islands created around the two main lakes. Producing high quality concept designs of the proposed restoration elements that are fully justified in a logical process has been central to engaging the community and local government stakeholders to demonstrate the potential pathway needed to restore Maylands Lakes into a sustainable lake system.