Lake Illawarra’s latest annual report card brought mixed results, with seven sampling sites rated ‘good’ or ‘very good’ and two rated ‘poor’ for water quality.
Key points:
- Lake Illawarra earned a ‘fair’ rating in the latest Estuary Health and Water Quality Report Card.
- Seven sampling sites rated ‘good’ or ‘very good’ and two rated ‘poor’ for water quality.
- A significant rainfall event during the monitoring period contributed to elevated nutrient levels and reduced water clarity.
Overall, the 2025-26 Estuary Health and Water Quality Report Card gave the lake a ‘fair’ rating, representing a decline from the ‘good’ rating achieved in previous years.
The annual report assesses estuary health on key indicators outlined by the NSW Government — including water clarity, nutrient levels and algal growth — to provide a long-term picture of conditions across the lake.
City of Wollongong Lord Mayor Councillor Tania Brown said the report highlighted both the strengths of the lake and the importance of ongoing management.
“Seven of the nine sites achieving good or very good ratings is an encouraging result and shows much of Lake Illawarra continues to support a healthy aquatic environment,” Cr Brown said.
“This report isn’t just a health check; it’s a road map. It highlights what’s working, where the pressure points are and how we can target future investment to achieve the greatest benefit for Lake Illawarra.”
“A risk-based stormwater management framework introduced in 2025 is helping protect Lake Illawarra as West Dapto grows. Council is also auditing existing stormwater treatment devices and requires new developments to include measures that improve water quality.”
“The lake is one of our region’s defining natural assets, and we’re committed to working together to protect it.”
The report found water quality was generally strongest in the central basin, while some foreshore areas were more vulnerable to nutrient and sediment run-off from surrounding catchments.
A significant rainfall event during the monitoring period contributed to elevated nutrient levels and reduced water clarity, particularly at the north-east and south-west tips of the lake. Griffins Bay, Warrawong, and Burroo Bay, Oak Flats, both experienced elevated chlorophyll-a and turbidity levels during summer.
Shellharbour Mayor Chris Homer said protecting the lake is everyone’s responsibility.
“Lake Illawarra doesn’t stop at a council boundary, which is why collaboration between councils and our partners is so important,” he said.
“These results show the work we’re doing across the catchment is making a difference but also underscore that protecting the lake requires a sustained, long-term commitment.”
Under the 10-year Lake Illawarra Coastal Management Program, Wollongong City Council and Shellharbour City Council continue to work with the NSW Government and local stakeholders on catchment restoration, revegetation and water quality improvement projects aimed at reducing pollutants entering the lake.
“One way residents can help is keeping litter and pollutants out of the drains, which feed out into our waterways. The drain is just for rain!”
Find all report cards and technical reports on the Lake Illawarra webpage.
For regular updates on planet-friendly projects, programs and events, subscribe to the Sustainable Wollongong and Sustainable Shellharbour enewsletters.
Wollongong City Council hosts monthly community clean-ups on the lake foreshore. The next events will be held at Berkeley on 30 October and Kanahooka on 20 November.
The Lake Illawarra Estuary Monitoring Program is supported by the NSW Government’s Coastal and Estuary Management Program.
