Upper Murrumbidgee River environmental release

Upper Murrumbidgee River communities are being advised that due to low water allocations reflecting dry climate conditions, this water year there will be no high-flow releases exceeding 1,400 ML/d from Tantangara dam.

Smaller environmental flows will continue to be released, including smaller pulses to help provide flow variability and support the health of the river.

The environmental flow regime has been designed by NSW Department of Climate Change, Energy, the Environment and Water (DCCEEW) in close consultation with the Snowy Advisory Committee and Snowy Hydro to maximise environmental outcomes from the available water.

The flow regime includes five small flow pulses ranging in size from 150 to 450 ML/d that will be released in winter and spring, reflecting the natural timing of expected peak events to provide flow variation. Smaller releases are planned throughout the year.

The largest flow of the year will be 450 ML/d on 25 September 2026. This is a flexible release event and may be bought forward to earlier in the month to respond to natural cues.

There will be periods throughout the year where no environmental flows will be released from Tantangara Dam because there is insufficient water available to maintain a variable flow regime for every day of the year.

During this time, Snowy Hydro may be required to make releases to maintain flows at or above 32 ML/d at Mittagang Crossing if tributary flows do not provide this level of flow, subject to the rules of the Snowy Water Licence.

This planned flow regime aims to improve the health of the upper Murrumbidgee River, a key objective of the Snowy Water Inquiry Outcomes Implementation Deed 2002, a tri-government agreement between the Australian, New South Wales and Victorian Governments.

As an outcome of the Snowy Water Licence Review, flexible delivery of smaller flows will also continue, enabling the volume and timing of releases under 1,400 ML per day to quickly change to respond to natural cues such as rainfall events.

It is also important to note that the planned flow regime is subject to change, depending on weather, operational and environmental conditions.

The NSW Government is committed to keeping the public informed. Please check the DCCEEW website for further information at: Snowy Montane River increased flows.

NSW Department of Climate Change, Energy, the Environment and Water Director Murray Darling Basin & Intergovernmental, Samatha McCallum said:

“This year, water allocated to all entitlements is low due to dry conditions in the Murray Darling Basin, in which the Snowy Montane River Increased Flows (SMRIF) entitlement sits. This means that there is considerably less water available for SMRIF than in 2025-26.

“Where possible with available water, environmental releases are designed to mimic the natural flow characteristics that are seen in Snowy Mountain rivers with the aim of improving the long-term health of these river systems.

“This year the largest release planned is 450 ML/day.

“Natural inflows below the dam may combine with released flows, creating higher-than-expected river levels in some areas.

“Downstream landholders remain encouraged to make appropriate plans ahead of any water release, including securing watercraft and moving stock, pumps and infrastructure to higher ground.”