Snowy River high-flows to commence in mid May
The first of eight planned high-flow environmental water releases to the Snowy River will commence on 18 May and will be rolled out until early November 2023.
“Over the eight planned high-flow events there will be 8 separate days where releases into the Snowy River will be above 2,500 megalitres per day,” NSW Department of Planning and Environment Director Asset Management and Performance Aurelio Lindaya said.
“The first in the series of this year’s high-flow events will happen on Thursday 18 May and will have a daily flow of 5,000 megalitres, which will include an eight-hour peak flow of 8,864 ML/d from 8am to 4pm if water levels are sufficiently high in Jindabyne Dam to enable deliveries above 5,000 ML/day via the spill way.
“The largest event will take place on Wednesday 18 October 2023 with a daily flow of 5,000 megalitres and a planned eight-hour peak flow of 10,362 ML/d from 8 am to 4 pm.
“Smaller flow releases, below 2,500 ML/d will also be made throughout the year”.
Mr Lindaya said the release of environmental water into the Snowy River over a series of high-flow events has been successfully trialled across 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.
“This year’s high-flow water releases are being spread throughout autumn, winter and spring, reflecting the natural timing of likely high-flow events.
“It includes daily and seasonal flow variability which assists the river to re-establish stream function, including scouring of sediment and improve in-stream habitat.
“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 from the Snowy Advisory Committee.”
The high-flow releases will help to improve channel function within the remnant bed of the Snowy River, wet the riparian zone and promote the establishment of aquatic and riparian vegetation. It will also provide important habitat for water dependant animals including native fish, waterbugs, frogs and platypus.
Mr Lindaya said the high-flow releases will have the greatest impact on river levels immediately below the Jindabyne Dam wall but could be observed along the full length of the Snowy River.
“The river level will also be higher than normal on either side of the planned releases, while natural system inflows downstream of the dam may result in higher river levels than predicted,” he said.
“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.”
Whilst we endeavour to stick with the planned release dates, it may be necessary to modify or cancel flows in the lead up to the event because of environmental, climatic or operational conditions.
For more information, please visit our website for any changes closer to each of the planned events.
The planned 2023 high-flow releases (subject to environmental, climatic and operational conditions) are:
Thursday 18 May 2023 | Daily flow of 5,000 megalitres per day (ML/d) over 24 hours, with equivalent peak flow 8,864 ML/d for eight hours from 8am to 4pm if Jindabyne Dam levels are high enough to enable delivery |
|---|---|
Wednesday 21 June 2023 | Daily flow of 2,931 ML/d over 24 hours, with equivalent peak flow 4,507 ML/d for 8 hours |
Thursday 6 July 2023 | Daily peak flow of 4,099 ML/d over 24 hours |
Tuesday 22 August 2023 | Daily flow of 3,919 ML/d, with equivalent peak flow 5,000 ML/d for 8 hours |
Wednesday 20 September 2023 | Daily flow of 3,827 ML/d over 24 hours with equivalent peak flow 4,699 ML/d for 8 hours |
Friday 6 October 2023 | Daily peak flow of 2,743 ML/d over 24 hours |
Wednesday 18 October 2023 | Daily flow of 5,000 ML/d over 24 hours with equivalent peak flow 10,362 ML/d for eight hours from 8am to 4pm if Jindabyne Dam levels are high enough to enable delivery |
Friday 10 November 2023 | Daily flow of 2,832 ML/d over 24 hours, with equivalent peak flow 4,236 ML/d for 8 hours |
The 8-hour peak flow releases will occur during daytime hours from 8am to 4pm Australian Eastern Standard Time.
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 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:
