Long-term microbial water quality

The Environment Protection Authority Victoria (EPA) monitors recreational water quality each summer and assesses it against long-term standards that are outlined in the Environment Reference Standard (ERS). EPA also works with partners and stakeholders to understand and improve recreational water quality.

Long-term trends in microbial water quality are reported as the percentage of all Port Phillip Bay beaches and Yarra River sites that meet long-term microbial water quality standards for primary contact recreation (swimming). Trends are calculated using a 5-year rolling dataset.

Port Phillip Bay beaches and Yarra River sites were all suitable for secondary contact recreation (for example rowing and boating) during the 2018-2023 reporting period.

Many beaches in Port Phillip Bay met long-term water quality standards for primary contact recreation during dry weather.

Data Source: EPA

Of the 4 Yarra River sites, only Warrandyte met long-term standards during dry weather for the 2018-2023 reporting period and remains the most suitable swimming site on the Yarra River. Launching Place, Healesville and Kew reaches consistently do not meet standards for swimming, with these reaches graded Poor or Very Poor across all weather conditions in recent years.

The Yarra River is highly susceptible to stormwater pollution during and after rain. EPA advice is to avoid any contact with water for 24-48 hours following rainfall.

Data Source: EPA

For more detail on how long-term microbial water quality grades are calculated view the methodology section.

Trends of long-term microbial water quality

Data Source: EPA

As expected, more beaches meet standards during dry weather, due to the impact rainfall (and associated stormwater) has on microbial water quality. The percentage of beaches meeting all weather standards has been variable over time, likely due to changing rainfall patterns at individual beaches.

Launching Place, Healesville and Kew reaches consistently do not meet standards for primary contact recreation. The trend in microbial water quality during dry weather at Warrandyte reach is an exception. Long-term microbial water quality is variable over time at Warrandyte but has met standards during dry weather in 3 out of the last 5 reporting periods.

EPA is actively working with Melbourne Water on a Quantitative Microbial Risk Assessment (QMRA) and Microbial Source Tracking (MST) to better understand health risk and faecal sources in the Yarra River. These studies will be used to determine if site-specific standards can be developed. Site-specific standards would more accurately estimate the risk of illness at Port Phillip Bay beaches and the Yarra River, informing targeted pollution mitigation and communication approaches to recreational users.

The Victorian Government, community and other groups work to improve water quality through developing and applying effective policies and projects, including:

Page last updated: 17/04/24