The lower Darling/Baaka River supports a rich and important native fish community. It once held the largest population of Murray cod in the entire Murray-Darling Basin. Today, that picture looks very different.
Over the past decade, the river has faced repeated challenges. Flow has stopped completely. At times for more than a year. There have been major fish kills, and water quality has been poor. These events have caused a sharp drop in native fish numbers. In particular, Murray cod populations have not bounced back and are still fragile.
Recent scientific monitoring provides some positive signs. Surveys have detected juvenile, sub-adult and adult Murray cod in parts of the river. Good numbers of golden perch have also been recorded, along with endangered silver perch and other native species.
To help these native fish recover and to build their resilience to cope with drier conditions, environmental water holders plan to increase winter flows from Menindee Lakes. The current minimum flow is 200 megalitres per day (ML/day). The environmental flow will lift this to about 400 ML/day.
Fish scientists describe this higher flow as a "recovery baseflow." It is designed to:
- support the survival of young fish, especially Murray cod
- provide access to important habitats like river benches and snags
- maintain connectivity so fish can move freely.
Winter is a key time for fish survival. Juvenile fish face high risks during their first year. Without adequate flows to provide food and habitat to shelter and hide from predators, many do not survive to join the breeding population.
Flow decisions in the Darling/Baaka system affect the environment, water supply and local communities. The region has experienced droughts, floods, poor water quality and large-scale fish deaths over the past decade. Our decision to release water has been made with this in mind - our aim is to support a healthy Darling River.
The water for this winter flow will come from the Menindee Lakes system, including the drought reserve. It is important to note that the water being released is flow that has been protected from environmental water decisions in the northern basin. The water is additional water, that would have previously been extracted upstream and not made it to the Menindee Lakes.
Trial arrangements established by the state governments allow this water to now support outcomes downstream of the lakes. This includes water orders placed by:
- the NSW government
- the Commonwealth Environmental Water Holder
- the Victorian Environmental Water Holder for the Victorian share of inflows.
Environmental water managers recognise the need to balance immediate ecological needs with long-term water availability. This has been considered when planning this flow.
The release is for a critical environmental purpose. Increasing flows to 400 ML/day can help young fish survive, strengthen populations, and build resilience for drier conditions ahead. This approach aims to restore river health while carefully managing water for the future.
