Snowy, Montane rivers and environmental flow patterns

THE NSW Office of Water has finalised the 2013/14 environmental release patterns to the Snowy River below Jindabyne and the Snowy Montane Rivers.

A return to drier conditions across the Snowy catchment has seen a drop in the level of Lake Jindabyne compared to 2012, however levels are still expected to remain above average in the coming months in order to ensure that the required volume of water for the full environmental release program is available.

As Snowy Hydro is legally obligated to meet the release requirements, the company works hard to ensure sufficient water remains available to meet all of its release requirements whilst balancing the risk of Lake Jindabyne once again reaching full supply level and spilling as it did in 2012.

The 2013 pattern of daily releases from Lake Jindabyne down the Snowy River is much more varied than previous years and seeks to emulate flows in a natural un-regulated snow melt river system. This means that the operation of the release valves will be a regular feature during winter and spring as a number of high flow events will be delivered.

A flushing flow, which will peak at 10,083 megalitres per day, is tentatively scheduled for early October, although the exact release date will be dependent on inflows during spring. The NSW Office of Water will advise downstream residents and other stakeholders 14 days ahead of the confirmed release date.

The NSW Office of Water will again be responsible for advising downstream landholders and other stakeholders of the flushing flow details and river heights. It is again expected that the Snowy River will likely rise downstream of Jindabyne Dam between approximately 1.8 to 3.6 metres in height during this time dependant on location and local inflow conditions. Snowy Hydro will again assist the NSW Office of Water in preparing a detailed communications plan in order to raise awareness of the planned releases and to ensure public safety.

As of May 1st environmental flow releases have also commenced into the Snowy River below Island Bend as part of the Montane Rivers environmental flows program. This year approximately 19 gigalitres will be targeted for release from a total turn out of Tolbar and Diggers Creek Aqueduct Intake Structures. Recreational users are advised to maintain vigilance when undertaking activities in and around the Snowy River in this area as river flows are likely to be much higher and more variable compared to previous years, especially during the winter and spring period.

As with previous years the Montane Environmental Program will also deliver additional water to the Murrumbidgee River below Tantangara, the Goodradigbee River and the Geehi River below Geehi Reservoir. The total volumes targeted and the apportionment of water between all of the Montane catchments is determined by the NSW Office of Water.

For more information about the targets and release patterns for the Snowy and Montane Rivers environmental release programs contact the NSW Office of Water:

This article was submitted by Snowy Hydro

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