Port Phillip Bay, Western Port Bay and the Gippsland Lakes are Victoria’s largest coastal waterbodies.  

EPA, Melbourne Water and Department of Energy, Environment and Climate Action monitor water quality for these bays and lakes. 

Report Card 2021-22 looks at water quality between July 2021 and June 2022. We compare results to data from the past 20 years, dating back to 2000.  

The Report Card uses the monitoring data, to calculate an annual Water Quality Index (WQI) – ‘Very Poor’, ‘Poor’, ‘Fair’, ‘Good’ or ‘Very Good’. These refer to the Environmental Reference Standards (2021). 

In 2021-22, water quality in the bays, lakes and waterways was generally the same as in previous years. East Gippsland Lakes was an exception where water quality declined from Good to Poor. Heavy rain in this region, during 2021, delivered nutrients to the Gippsland Lakes. With warmer than average summer temperatures, this triggered a blue-green algal bloom. The bloom persisted in the Gippsland Lakes from February to May 2022.   

In general, water quality was Very Good or Good in the elevated areas where most rivers originate. Water quality declined to Poor or Very Poor, as the rivers moved through rural, and urban low-lying areas.  In the bays and lakes, water quality was Very Good or Good for areas that mix with the open ocean. Water quality was generally worse in rivers polluted by urban and industrial areas.  

EPA also forecasts water quality for recreation. These forecasts use microbiological indicators which are not reported here. For more information, see our Yarra Watch and Beach Report programs. 

Read more about EPA’s annual Report Card and the work we are doing to improve Victoria’s water quality.