Map of Yarra River system: click to enlarge.
Overview of 2025/26
The delivery program operated to the dry scenario (Seasonal Watering Plan 2025-26) during winter/spring and early summer/autumn to present. This was due to flow conditions reflecting rainfall and streamflow deficits accumulated from summer/autumn in the previous water year.
Dry conditions experienced in summer/autumn 2025 continued into winter and early spring. During winter, mean maximum temperatures were above average across the catchment, with rainfall and streamflow below average (Melbourne in Winter 2025).
Above-average monthly rainfall totals were accumulated at the end of October through November, leading to the spring season ending with above-average rainfall totals (Melbourne in Spring 2025). However, this masked underlying rainfall and streamflow deficits experienced throughout most of the season, which aligned with the dry operating scenario.
Environmental water delivered in 2025/26
The environmental entitlement was used to deliver water to:
- Yering Back Swamp and Bolin Bolin Billabong
- 1 winter/spring fresh for reach 5
- a period of summer/autumn low flow supplementation for reach 5/6 in January.
Two further summer/autumn freshes are planned for the upper and lower reaches, along with a possible autumn high.
Further low flow supplementation for reaches 5 and 6 may be required if dry conditions persist.
Unregulated streamflows and an operational water transfer from Upper Yarra Reservoir met a number of environmental watering targets for the Yarra River (Birrarung).
This included:
- most of the seasons winter/spring baseflow and early summer baseflow
- 3 spring freshes in reach 2
- 1 summer fresh in reach 2
- 2 summer freshes in reach 5.
Vegetation and frog responses to billabong watering and natural inundation continue to be monitored by the Wurundjeri Narrap Rangers in a partnership with Melbourne University and Melbourne Water.
Eel capture and tagging to help understand flow regime requirements was also undertaken with Arthur Rylah Insitute and the Wurundjeri Narrap Rangers.
Wurundjeri Narrap Rangers and Melbourne Water planned and delivered collaborative watering event to reconnect Bolin Bolin Billabong with the Yarra River in late 2025 to allow eels to escape back to the main river channel.
Key environmental values
In the Yarra River system, water for the environment supports the following key environmental values:
Opportunities for shared benefits are also incorporated into planning and watering decisions, if they do not compromise environmental outcomes.
Potential watering actions
We estimate there will be approximately 31,000ML of water in the Environmental Entitlement for the Yarra River.
We plan for all climatic scenarios. Below are the proposed environmental watering actions for the Yarra River (Birrarung) in 2026/27 under an ‘average’ scenario:
- Summer/autumn low flows
- Summer/autumn freshes
- Autumn high
- Winter/spring low flows
- Winter/spring freshes
- Targeted billabong watering
