FAQs
Maylands Lakes - General Information
- the large size of the lakes
- the presence of hard walls
- their location near residential areas
- their unusual shape
- their significant depth
- a shallow layer of sediment
- The urgent need to address midge levels and water quality
- The need to have a sustainable solution
- Mixed views on dredging, although support for dredging as a quicker fix
- Recognition of the value of the flora, fauna and amenity
What are the Maylands Lakes?
Maylands Lakes are former clay mines that were decommissioned in 1986 and then allowed to naturally fill, resulting in the forming of the lakes. Some of the old brickworks structures were demolished and rubble was placed in the claypits, as well as inert rubbish, including construction rubble, scrap metal, plastics, sand, bricks and old electrical equipment. The pits were classified as ‘modified wetlands’ by the Environmental Protection Agency (EPA), whereby the existing wetland function of the lakes was to be retained. The lakes are not classified as geomorphic wetlands.
The lakes were modified into their current shape as a result of the Satterley Peninsula Estate Development, which was approved and constructed when the area was under the control of the City of Stirling. The estate was completed in 2000.
What is the problem at Maylands Lakes and why is it so complex to solve?
The man-made lakes at the Brickworks, Lake Bungana and Lake Brearley were built in the late 1990s in former clay pits, with a traditional 'pit and pipe' stormwater system. Water quality issues have led to the occurrence of persistent algal blooms, increased midge breeding and significant community concern.
The complexity and challenging nature of poor water quality and high midge levels is compounded at Maylands Lakes by:
How has the community been consulted?
The City has been liaising with various groups and residents over the past five years.
A community information session on 14 October 2020 with 90 attendees provided feedback, including:
Visit this page again to find out future opportunities to have your say.
Improving the Water Quality of Maylands Lakes
- The City has engaged a consultant to prepare a masterplan under the guidance of a Scientific Advisory Panel of experts in the fields of Applied Ecology, Environmental Engineering, Environmental Science and Environmental Biology, which will guide the City in delivering a solution based on scientific information and advice.
- Present the masterplan to Council for approval.
- Seek tenders for the pumping and filtration of the lakes.
- Continue advocacy at State and Federal Government levels for Maylands Lakes, and explore other avenues of assistance such as the State’s Mining Rehabilitation Fund.
- Installed mechanical mixers to reduce stratification and improve oxygen levels in the bottom waters of Lake Brearley and Lake Bungana
- Dredged Lake Brearley in shallow midge breeding areas
- Undertaken 3D modelling to see how the water moves around the lakes and determine the best location for the mixers
- Complete a fauna study of the lakes and surrounds
- Monitor the health of the water
- Provide opportunities for community education and involvement
- Develop a plan to progressively transform stormwater inlets near the lakes i.e. rain gardens
- Prioritise the restoration of lake foreshores by planting species endemic to the area, and maintain and replace infrastructure
- A program of works at Brickworks Lake included weed removal, a new nutrient barrier between this lake and Lake Bungana, installation of an aerator, and planting of sedges.
- Algal treatment and addition of floating wetlands at all three lakes.
- Replacement and repositioning of water fountains on Lake Brearley and Lake Bungana.
- Planting of 15,000 sedges in the shallows of Bungana and Brearley lakes.
- Dredging of Lake Bungana.
- Further algal treatments of the three lakes.
- An additional 10,000 plants including revegetation of Brickworks stream.
- Installation of two solar-powered ultrasonic devices in Lake Brearley as part of a 12-month trial.
- Installation of large mechanical mixers in both lakes.
What will the City do to improve the quality of the water in the lakes into the future?
What is the City currently doing to improve the water quality of the lakes?
What action has the City and community taken so far?
What trees are being managed within Maylands Lakes?
Two introduced invasive tree species will be managed:
The revegetation area in question is classified as completely degraded and dominated by these species, which have been identified as requiring management by the Department of Biodiversity Conservations and attractions (DBCA).
As part of the Maylands Lakes Restoration Plan, the City is seeking to increase riverbank vegetation to assist with nutrient stripping and create a more diverse habitat reflective of a naturally occurring environment to provide habitat for fauna.
The invasive species have formed a root shelf preventing the establishment of riverbank vegetation and turtle nesting at the site. Works are being undertaken in collaboration with the friends of Maylands Lakes who successfully obtained grant funding to support the restoration.
Eucalyptus species in the area will be retained and several thousand species endemic to the area will be planted as part for the revegetation. This methodology has been highly effective at previous rehabilitation sites on Lake Brearley and Brickworks Stream.
Water Quality Sampling & Bacteria Levels
How often is the water at Maylands Lakes sampled?
Water quality monitoring at Maylands Lakes is generally completed quarterly – i.e. once every three months. The City is looking to increase this to monthly sampling from 2024 onwards.
What does the City do with the analysis data from the collected samples?
Water quality reports that summarise the data and evaluate trends with time are prepared and made available to the public via Engage Bayswater. These reports are also used to inform next steps in the environmental management of the Lakes.
Are the levels of cyanobacteria in Maylands Lakes safe?
The City regularly monitors water quality at Maylands Lakes and has recently provided water sampling results to the WA Health Department for analysis.
The Department has assessed the results and noted there are high levels of cyanobacteria present in Lake Brearley and Lake Bungana which are not suitable for activities where there is direct contact with the water or the risk of ingestion.
Signage exists around the perimeter of the lakes advising the community to avoid contact with the water. View the location of the signs below.
The fountain in Lake Brearley, which is connected to an automatic shut-off during windy conditions, has also been completely shut off.
The WA Health Department has not required the City to take any further action.
Health Warning signage at Maylands Lakes
What guidelines are in place to protect the community from dangerous cyanobacteria levels?
The WA Health Department has guidelines in place for drinking water and recreational water bodies where users come into direct contact with water and potentially swallow it. These do not apply to Maylands Lakes which are used for passive enjoyment.
Treating the Midge Population at Maylands Lakes
- Regularly treating midge harbourage areas with residual insecticide.
- Regularly treating known breeding sites.
- Lake Brearley specifically is treated with a hybrid larvicide on a constant 14-day cycle during the midge breeding cycles, this treatment forms the City's ongoing mosquito control of the lake.
- Trapping and monitoring.
- Sampling to determine the effectiveness of treatments and extent of breeding.
- Providing advice and free residual insecticide to impacted homeowners.
- Using temporary mobile light towers to attract midge and keep them in the treated areas away from residential properties.
- Deploying multiple large mobile solar powered traps around the lakes.
What is being done to manage non-biting midge populations associated with Lake Brearley?
To help control midge nuisance experienced by residents living near Lakes Brearley and Lake Bungana, the City in accordance with its management plan, is:
The City is researching and trialling additional midge control measures, including:
How does the presence of vegetation affect the midge population at Maylands Lakes?
Nuisance populations of non-biting midges are unfortunately a very common issue for modified urban wetlands within the Perth coastal plain, with nutrient enrichment and wetland degradation believed to be a major factor in high larval densities.
Modified wetlands with cleared water bank vegetation and high nutrient levels are linked to frequent cyanobacterial blooms that, as they decay, form a key food source for midge larvae. The larvae themselves then undergo a population explosion that is not kept in check, because the presence and efficiency of higher-level grazers (which would normally eat the midge) are negatively affected by the cyanobacterial bloom.
Reduced aquatic vegetation also results in less habitat for midge predators, further improving conditions for the midge.