Snowy River high-flows to commence in late May

Media release | 2 May 2022

The first of nine planned high-flow environmental water releases to the Snowy River will begin on Tuesday 31 May and will continue through until early December 2022.

NSW Department of Planning and Environment Director Asset Management and Performance, Aurelio Lindaya, said the first release will have a daily peak flow of 2,061 megalitres per day (ML/d), with equivalent peak flows of 3,715 ML/d for eight hours.

“The nine planned high-flow events, that will take place over the next seven months, are releases into the

Snowy River that will be above 2,000 megalitres per day on 14 separate days,” Mr Lindaya said.

“In September and October, there are multiple daily high-flow events that will have flows larger than 2,000 megalitres per day to maximise the ecological benefits for the river.

“The largest event planned in this year’s series will take place on Wednesday 12 October 2022, which will

have a daily peak flow of 4,339 ML/d, with an equivalent peak flow 5,000 ML/d for eight hours.”

Currently the schedule does not include a flushing flow. If wet conditions continue this will be reconsidered for October and landholders and stakeholders will be notified in advance.

Mr Lindaya said the release of environmental water into the Snowy River via a series of high-flow events has been successfully trialled over a number of years.

“The timing and duration of high-flow events varies from year to year, based on inflow sequences to the Snowy catchment,” he said

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

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

The planned 2022 high-flow releases are:

Table 1. Release schedule
DateVolume
Tuesday 31 May 2022 Daily peak flow of 2,061 megalitres per day (ML/d), with equivalent peak flow 3,715 ML/d for eight hours
Thursday 14 July 2022 Daily peak flow of 3,004 ML/d, with equivalent peak flow 4,504 ML/d for eight hours
Monday 5 September 2022 Daily peak flow of 3,179 ML/d, with equivalent peak flow 4,979 ML/d for eight hours
Tuesday 6 September 2022 Daily peak flow of 2,090 ML/d over 24 hours
Wednesday 7 September 2022 Daily peak flow of 2,678 ML/d over 24 hours
Tuesday 11 October 2022 Daily peak flow of 3,059 ML/d over 24 hours
Wednesday 12 October 2022 Daily peak flow of 4,339 ML/d, with equivalent peak flow 5,000 ML/d for eight hours (Largest flow)
Thursday 13 October 2022 Daily peak flow of 2,925 ML/d over 24 hours
Friday 14 October 2022 Daily peak flow of 2,248 ML/d over 24 hours
Monday 24 October 2022 Daily peak flow of 2,143 ML/d over 24 hours
Monday 31 October 2022 Daily peak flow of 3,910 ML/d over 24 hours
Monday 14 November 2022 Daily peak flow of 2,384 ML/d, with equivalent peak flow 4,189 ML/d for eight hours
Thursday 1 December 2022 Daily peak flow of 2,832 ML/d over 24 hours
Friday 9 December 2022 Daily peak flow of 3,705 ML/d over 24 hours

“This flow pattern includes a higher degree of daily and seasonal flow variability which assists the river to re-establish stream function, including scouring of sediment and improve in-stream habitat,” Mr Lindaya said.

“The results from previous studies show the Snowy River is responding well to these seasonal high-flow events and this continuing approach has received input and support this year from the Snowy Advisory Committee.

“The high-flow releases help promote channel function within the remnant bed of the Snowy River, wet the riparian zone and promote the establishment of aquatic and riparian vegetation and provide important habitat for water dependant reptiles and animals including native fish, waterbugs, frogs and platypus.

Environmental water releases to the Snowy River are mandated under the Snowy Water Inquiry Outcomes Implementation Deed 2002, a tri-government agreement between the Australian, New South Wales and Victorian Governments, to achieve improvements in Snowy River health.

The Snowy Advisory Committee brings together local knowledge and expert advice to provide advice each year on the timing and annual pattern of release of environmental water to the Snowy River.

Further information about the Snowy River environmental releases is available at increased flows or the Snowy and Montane rivers webpages.

Planned high-flow environmental water releases to the Snowy River will begin on Tuesday 31 May.Planned high-flow environmental water releases to the Snowy River will begin on Tuesday 31 May.