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). The trend is shown using 5-year rolling datasets between 2013-2018 and 2019-2024.
Port Phillip Bay beaches and Yarra River sites were all suitable for secondary contact recreation (for example rowing and boating) during the 2019-2024 reporting period.
Fourteen beaches in Port Phillip Bay met long-term water quality standards for primary contact recreation during dry weather.
Launching Place, Healesville, Warrandyte and Kew reaches did not meet standards for swimming, with these reaches graded Poor or Very Poor across all weather and dry weather conditions. However, Warrandyte can meet long-term standards during dry weather (for example - 2018-2023) and remains the most suitable swimming site on the Yarra River with short-term microbial water quality generally suitable for swimming.
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.
For more detail on how long-term microbial water quality grades are calculated view the methodology section.
Trends of long-term microbial water quality
As expected, fewer beaches meet standards during wet weather (as represented by 'all weather' conditions), due to the impact rainfall (and associated stormwater) has on microbial water quality. The percentage of beaches meeting standards during all weather and dry weather conditions has been relatively low over recent reporting periods. This is likely due to the impacts of stormwater pollution from 2022 Victorian floods and recent summers having higher-than-average rainfall. Wetter summers may reduce the percentage of beaches meeting standards during dry weather as the impacts to microbial water quality may persist for longer than advised (24-48 hours).
Launching Place, Healesville and Kew reaches consistently do not meet standards for primary contact recreation, for all weather and dry weather conditions. The trend in microbial water quality during dry weather at Warrandyte reach is an exception. Long-term microbial water quality has been variable over time at Warrandyte (for example - Warrandyte met long-term standards for the 2018-2023 reporting period, however was slightly below standards for the 2019-2024 period).
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 could 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:
- DEECA's Water for Victoria Water Plan, and Integrated Water Management Framework.
- The Port Phillip Bay Environmental Management Plan 2017-2027.
- Melbourne Water's Health Waterways Strategy 2018-2028.
- EPA stormwater inspections with businesses across Victoria to check they are preventing stormwater pollution risks. (EPA inspections keeping chemicals out of Creeks).
- EPA guidance on planning, designing and managing urban stormwater systems. (Urban stormwater management guidance).
Page last updated: 30/10/25