A major NSW dam is below its flood mitigation level for the first time in almost two years. 

The level of Burrendong Dam on the Macquarie River has dropped below its Flood Mitigation Zone following 15 months of exceptional weather conditions and high inflows.

The storage, upstream of Dubbo on the Macquarie River, currently sits at 99 per cent, the first time the dam has been below its Full Supply level since November 2021.

This milestone follows a two-year period of extreme wet weather in the region.

In March 2021, the storage sat at 39 per cent, by September 2021, the storage reached 100 per cent, and from November 2021 to present, the storage (1,189 gigalitres at full supply level) received over four times its capacity in inflows and remained in the Flood Mitigation Zone.

Unlike many other dams, Burrendong has a Flood Mitigation Zone, a designated airspace to capture excess water for the purposes of flood mitigation, meaning water can be held above full supply level and then released when downstream tributaries have reduced.

This allows dam operator WaterNSW to temporarily hold water back and, where possible, limit the impact on communities downstream.

WaterNSW Executive Manager of Operations, Ronan Magaharan, praised dam operators during the period.

“The news of the dam falling below full supply level follows a difficult period in the Macquarie Valley,” he said.

“WaterNSW operational staff have been centred on flood operations for many months now, with our expert planners working to manage unprecedented volumes of water.

“The design of Burrendong Dam has meant WaterNSW can hold back water in the flood mitigation zone and plan our releases in windows to minimise the impact on downstream communities.

“I’m incredibly proud of the WaterNSW staff who have worked closely with local communities over this testing period.

“With the storage moving out of the FMZ our dam operators are now focused on maximising the resource available for customers and the environment.”