The NSW Department of Planning and Environment has today issued a ‘rising river alert’ for the Upper Murrumbidgee River between Tantangara Dam and Yaouk in Southern NSW for Tuesday 26 July 2022.
The river will rise due to the second high-flow event in a series of three planned environmental releases from Tantangara Dam to the Upper Murrumbidgee River during 2022.
The highest flow rate for this event will occur at Tantangara Dam from midday on Tuesday 26 July and will be equivalent to 1,300 megalitres per day for a 24 hour period.
As a result of the release, it is expected we will see the river level at Yaouk rise to at least 1.33 metres. This does not account for the effect of tributary inflows or rainfall in the catchment, which may increase these heights.
For the remainder of Wednesday 27 July, the flow rate at Tantangara Dam will be about 525 megalitres per day. The flow rate will then drop back to 475 megalitres per day on Thursday 28 and back to about 325 megalitres per day on Friday 29 July.
The environmental benefits from this release are expected to be greatest between the dam wall and Yaouk. However, the flow pulse will be noticeable well downstream towards the ACT.
Water released from Tantangara Dam will take about 11 hours to reach Yaouk at this flow rate and around 2.5 days for the flow to arrive at the ACT border.
Landholders downstream of the Tantangara Dam are advised to take all necessary precautions with stock, fencing and property in proximity to the river. As the release flows through the system, people should refrain from entering or crossing swollen waterways.
The department will work with the NSW State Emergency Service and the Bureau of Meteorology to provide up-to-date information to the community regarding the management of this release should weather conditions warrant.
Conditions will be closely monitored in the lead up to the release. If heavy rainfall appears likely, the release will be reduced or postponed to avoid adverse effects on river levels. If this happens, we will inform the community.
More information can be found at Snowy montane rivers.