Upper Murrumbidgee high-flow environmental releases

Environmental water releases from Tantangara Dam into the upper Murrumbidgee River for the 2024/25 water year have been organised by NSW Department of Climate Change, Energy, the Environment and Water in close consultation with the Snowy Advisory Committee and Snowy Hydro.

The plan includes frequent small releases, two moderate releases in excess of 1,000ML/day and one large high flow release of 1,500ML/day on 24 September 2024 starting at midday.

Whilst the department works hard to inform the public of high-flow releases ahead of time, the plan may change subject to weather, operational and environmental conditions.

Further information about the upper Murrumbidgee River environmental releases is available at:

• Snowy and Montane Rivers | NSW Department of Climate Change, Energy, the Environment and Water
• Snowy and Montane Rivers | Environment and Heritage
• Temporary water restrictions

QUOTES ATTRIBUTABLE TO: Director Asset Management and Performance at DCCEEW, Aurelio Lindaya:

“The planned high-flow release from Tantangara Dam into the upper Murrumbidgee River will be in the order of 1,500 megalitres per day.

“This high-flow event is designed to maximise the ecological benefits for the river.

“The release of environmental water into the upper Murrumbidgee via a series of high-flow events has been successfully trialled in previous years.

“The timing and duration of high-flow events varies from year to year, based on inflow sequences to the upper Murrumbidgee catchment.

“This year there will be two moderate winter releases and one large spring water release, reflecting the natural timing of expected high-flow events.

“The high-flow release will have the greatest impact on river levels from immediately below Tantangara Dam wall to Yaouk. The river will be higher than normal on either side of the release. "Natural system inflows downstream of the dam may also contribute to flows, resulting in higher river levels than predicted.

“Downstream landholders and visitors to the area are being encouraged to make appropriate plans ahead of the water release, including moving stock or pumps and infrastructure to higher ground and being aware of flows.

“Whilst we endeavour to make release consistent with the planned date, it may be necessary to modify or cancel flow in the lead up to the event because of environmental, weather or operational conditions.

“We encourage the public to check our website for any changes closer to the event.”

“In addition to the large flow release, frequent moderate and smaller releases will be made throughout the year.

“The planned flow pattern includes a high degree of daily and seasonal flow variability which assists the river to re-establish stream function, including flushing fine sediment and improve in-stream habitat.

“High-flow environmental water releases improve the health of the upper Murrumbidgee River by flushing sediment, clearing vegetation that encroaches into the channel, providing opportunities for fish and other native animals to move and wetting and filling riverside wetland areas.

“Extraction of water during environmental flow events may be subject to temporary water restriction orders which is why I encourage unregulated licence holders in the Murrumbidgee I and II water sources to check our website for further details.

“The results from previous studies show that Snowy montane rivers respond well to these seasonal high-flow events and this continuing approach has received input and support this year from the Snowy Advisory Committee and ecological experts.”