WaterNSW could start pumping water from Lake Tandure into Lake Wetherell as soon as March 2018 if the drought conditions continue to dry the Darling River.
The Darling has stopped flowing from Walgett, and the Menindee lakes total storage is approaching 21.6 per cent of capacity.
Under the WaterNSW Lower Darling Annual Operations Plan, the next step to conserve water in the absence of inflows is to pump water from Tandure to Wetherell.
Under a worst-case scenario of zero inflows, the WaterNSW Operations Plan ensures the Menindee lakes would still provide water for Lower Darling landholders and environment until at December 2018, and provide supply to Broken Hill until at least August 2019.
Transferring water from the shallow Lake Tandure to the comparatively deeper Wetherell reduces the surface area of the water storage and thereby cuts evaporation losses.
Without significant inflows, the plan’s next major action would be transferring water from Lake Pamamaroo to Copi Hollow, with the construction of an earthen block bank to separate the two bodies of water.
WaterNSW has implemented a reduced release regime from the lakes to maximise supply to both the Lower Darling and Broken Hill.
Releases into the Lower Darling continue at a rate of around 200ML/day with flows at Burtundy of 50ML/day.
The operations plan will endeavour to maintain at least 20ML/day at Burtundy should drought conditions persevere over summer and beyond.
WaterNSW is in constant contact with the key Lower Darling advisory group of landholders to ensure that a minimal flow is maintained without exceeding the agreed target flow.
Ensuring water quality and maintaining acceptable salinity levels are also integral components of the operations plan.