WaterNSW is to transfer water from Windamere to Burrendong dam via the Cudgegong River to secure vital supply in the Macquarie valley.
Burrendong Dam is currently at 1.8 per cent of capacity and experiencing acute drought conditions, with chronically low inflows in the past 12 months and a predicted storage capacity of 1.2 per cent by the end of January.
At this stage, it is intended that the bulk water transfer will occur in early February, with the volume expected to be up to 25GL.
Under the existing bulk water transfer protocol – and the terms of the Macquarie-Cudgegong water sharing plan – at least 70GL must be retained in Windamere Dam, which currently sits at 27 per cent of capacity.
WaterNSW modelling indicates 70GL will provide at least five years of water security to Cudgegong water users.
The Windamere transfer is one of the final measures in a drought response strategy that involved gradually restricting access to users and suspending environmental releases and carryover as unprecedented drought conditions impacted dam inflows.
The Macquarie River’s long term annual average inflow is 1450GL. In the five months from 1 July it received just 5GL.
Other measures have included preparing to pump remnant storage once Burrendong’s water level falls below 0 per cent, as well as cutting flows to creeks in the lower reaches of the system. As part of the latest initiative, the flows past the Gunningbar Weir ceased from 10 December 2019.
WaterNSW has been regularly updating Mid-western Regional Council and the Cudgegong valley water security committee on the drought operation of Cudgegong and Macquarie Rivers. It will meet with stakeholders in the Cudgegong valley on 16 January to keep them abreast of plans.
The last bulk water transfer between the two dams occurred in January 2019, with the intended delivery of 35GL being stopped at 10GL after a rain event resulted in inflows to Burrendong.
WaterNSW will continue to review the need for any further bulk water transfers and keep the communities informed.