Snowy and montane rivers environmental flow priorities 2021–22

In 2021–22 environmental flows will continue to build on the outcomes of previous years to improve the health of the Snowy and montane rivers.

2021–22 environmental water availability

The 2021–22 water year runs from 1 May 2021 to 30 April 2022. This water year 209,800 megalitres (ML) of water for the environment is available for the Snowy River below Jindabyne and 88,800 ML (142.272 GWh electricity value) for the montane streams, including 31,600 ML for the upper Murrumbidgee River. With wetter conditions in the southern Murray-Darling Basin, the environmental water allocation is significantly higher than the 91,400 ML that was available in the previous water year. 

Snowy River environmental flow priorities

There are planned environmental flow releases to the Snowy River for every day of the year. The flows have daily variability with higher release rates during winter and spring that are typical of a local snowmelt river. With high environmental water allocations available this water year, there will be an opportunity to provide 5 peak events of 8 hours each including a spring flushing flow to the Snowy River. The high flow events are required to clean riffles and to mobilise and flush sediment to improve the condition of the river channel. These events will help to return the Snowy River to a smaller but healthy river while providing important habitat for water-dependent animals.

The Snowy River daily flows can be found in the Snowyhydro’s 2021–22 water year Snowy River daily release targets calendar (PDF 66KB).

Montane rivers environmental flow priorities

There is adequate water for the environmental for 2021–22 to maintain flows in all the targeted montane streams, including the upper Murrumbidgee, upper Snowy River, Goodradigbee River, Middle Creek, Diggers Creek and the Geehi River. These daily flows aim to provide essential habitat for water-dependent animals including water bugs, frogs, native fish and platypus.

Environmental flows delivered to the upper Murrumbidgee River from Tantangara Dam will provide some natural flow seasonality and flow variability. The upper Murrumbidgee supports the largest of only 3 remaining natural NSW populations of Macquarie perch, listed as endangered both in New South Wales and nationally. Three high flow events of 1000 ML per day or more aim to improve the health of riffles to provide suitable habitat for Macquarie perch to lay their eggs.

The Upper Murrumbidgee daily flows can be found in the Snowyhydro’s Tantangara Daily Montane Release Targets for 2021-22 Water Year document (PDF 33KB)

Snowy and montane 2021–22 watering plan

Further details on the 2021–22 Snowy and montane rivers water for the environment priorities can be found in the Annual plan for the Snowy and montane rivers increased flows 2021–22.