WaterNSW managing major inflow event at Wyangala Dam

WaterNSW managing major inflow event at Wyangala Dam

12 November 2021

WaterNSW is managing a significant inflow event at Wyangala Dam on the Lachlan River, which could peak at a rate of 100 gigalitres per day (GL/day), after multiple rain events over the catchment.

Inflows generated by heavy rains in the previous 24 hours re-filled Wyangala dam overnight Thursday (11 November), with inflows reaching 80GL/day by midday and expected to peak at 100 GL/day by the afternoon.

As a result of the inflows the dam is spilling at a rate of 40 GL/day and that is expected to increase, with more storms and showers predicted.

WaterNSW is working with the Bureau of Meteorology and the NSW State Emergency Service to monitor the situation.

WaterNSW has been making repeated airspace releases from Wyangala dam in recent months, in consultation with the local community and the regional airspace reference panel.

Rain across the Lachlan catchment last weekend had re-filled the dam and in the days between rain events WaterNSW reduced the storage to 99.6% before cutting releases in preparation for more rain.

WaterNSW teams at other key dams are also monitoring inflows, with Keepit (95%) on the Namoi River and Burrinjuck (92%) on the Murrumbidgee now considered to have sufficient storage capacity to capture inflows and unlikely to spill.

The majority of dams across regional NSW are expected to experience inflows before the weather system moves to the Greater Sydney catchment in the days ahead.

WaterNSW Executive Manager of System Operations, Adrian Langdon said based on weather forecasts from the Bureau of Meteorology and in consultation with local airspace advisory panels, WaterNSW has already released large volumes from dams in flood-prone river valleys.

With the Bureau of Meteorology continuing to forecast a climate outlook that “indicates rainfall over the coming months is likely to be above average” WaterNSW will continue to make airspace releases as required.

For more information on WaterNSW storages visit our Regional NSW Dams page.

To access information on river heights and flow data visit: WaterInsights




Bureau of Meteorology (BOM)

Weather forecasts and warnings


NSW State Emergency Service (SES)

Flooding and severe weather warnings and advice



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