Menindee releases to rise as upstream flood risk rises
9 NOVEMBER 2022WaterNSW is advising the community that it will gradually increase releases from Menindee lakes in preparation for increasing volumes of water expected in coming weeks due to heavy rain and flooding in the northern basin.
The lakes – which hold 1731 gigalitres (GL) at 100% - are currently 106.75% of storage capacity, having been surcharged above 100% since February due to high inflows resulting from the La Nina weather pattern.
On current modelling WaterNSW is expecting at least a further 2300-2700 GL to arrive between now and the end of December, increasing the risk of flooding in the Menindee area and downstream.
On current projections to peak flow rate expected at Wilcannia in coming weeks (~46 GL/day) would be the highest in decades. The lakes have received almost 7,060 GL of inflow this year, representing the equivalent of four times the storage capacity of the lakes.
WaterNSW informed a multi-agency community meeting on Friday, convened by the Local Emergency Management Committee - and advised stakeholders via an operational update - that releases would increase gradually from the main weir to eventually target 9.6 metres at Menindee and a flow rate of about 36 GL/day at Weir 32.
WaterNSW maintained releases within the minor flood level from May to early October, successfully passing multiple large flow surges without impacting property, and has now generated 203 GL of capacity within the lakes to receive increasing inflows.
The intention is to create/maintain this storage capacity now to capture the higher peak later in December to minimise downstream flooding impacts. Planning will also consider uncertainty about volumes of water on the northern flood plain and the contribution of the Tallywalka into the Lower Darling.
As the water levels continue to rise above the minor flood level, under the State Flood Plan, the Bureau of Meteorology is responsible for providing information of river heights and flood warnings, while the NSW State Emergency Service is the lead flood response agency.
More information:
- Register for the Early Warning Network (EWN)
- Visit WaterInsights for dam levels and releases
- View the BoM website for weather and flood updates
- For emergency information, contact the NSW SES or phone 132 500