The purchase of water for the environment by the VEWH in the Maribyrnong catchment to help support critical environmental needs, demonstrates how partnerships and forward planning can support river health in a changing climate.
As part of implementing the Victorian Environmental Water Holder's (VEWH) Allocation Water Trading Strategy 2025-26, the VEWH Commission approved the purchase of 302 megalitres of allocation water to help address environmental water shortfalls in the Maribyrnong system.
In conjunction with Melbourne Water, the VEWH lead an expression of interest process to acquire a small volume of water from local licence holders, helping ensure water was available to support critical environmental needs.
The purchase builds on a longstanding partnership between Melbourne Water and diversion licence holders in the Keilor irrigation district. Since 2013, licence holders have voluntarily traded unused water to the VEWH, allowing water for the environment to be delivered when the river’s ecosystems need it most.
The initiative highlights the growing importance of adaptive water management as climate variability and competing demands place increasing pressure on Victoria's waterways.
"A planned allocation water purchase helped ensure water for the environment was available to support critical environmental needs in the Maribyrnong system when it was needed most due to the dry conditions in 2025-26," VEWH CEO Sarina Loo said.
Below-average rainfall and streamflows, combined with warmer-than-average temperatures, meant the system operated under a dry seasonal watering scenario throughout the year.
Water for the environment and coordinated irrigation releases helped maintain important flow patterns in Jacksons Creek during summer and autumn, when waterways are often under the greatest stress.
Five targeted freshes were achieved in Jacksons Creek Reach 6, helping maintain habitat quality and flow variability for aquatic species. Water deliveries also supported low-flow objectives through much of the warmer months, with monitoring showing no sustained periods of flow stress-related water quality issues.
Deliveries of water for the environment were coordinated with irrigation releases from Rosslynne Reservoir, creating shared benefits for both river health and local water users.
“Successful deliveries of water for the environment in 2025-26, in the face of prolonged dry conditions, highlight the value of working with local licence holders to manage water strategically and achieve positive environmental outcomes in Jacksons Creek,” Melbourne Water Environmental Water Resources Delivery Lead James Frazer said.
While environmental flows continue to play an important role in supporting river health, long-term monitoring highlights the need for a broader range of actions to improve ecological outcomes in the catchment.
Monitoring in Jacksons and Riddells creeks shows native fish populations continue to face challenges, including reduced recruitment of ornate galaxias downstream of Rosslynne Reservoir.
Water for the environment is one part of improving conditions for native fish populations. Complementary actions identified through the Central and Gippsland Sustainable Water Strategy, including upgrading Rosslynne Reservoir outlet capacity, improving fish passage and undertaking weed management works, will also help improve conditions for native species and waterways over time.
A further purchase of approximately 300 ML of allocation water is planned for 2026-27 as a short-term measure by the VEWH in the interim period until a secure environmental entitlement is created in the system.
The story of the Maribyrnong in 2025-26 is one of collaboration, adaptability and planning ahead. Through partnerships with local water users, strategic use of water markets and targeted delivery of water for the environment, water managers are helping build a more resilient future for the river and the communities and ecosystems that depend on it.
Page last updated: 28/09/26