A new network of pumps at Burrendong Dam will be used the next time its water falls to "critically low levels".
The pumps will get 16 gigalitres (GL) of remnant storage water out of the dam, an exercise never before undertaken.
The water would be made drinkable in Macquarie Valley communities such as Dubbo.
On Thursday the NSW government advised that the pump network and associated operational apparatus had been constructed and commissioned as part of a $6.7million project.
Member for the Dubbo electorate Dugald Saunders said the "pump pontoon project" would not only safeguard town supplies at a critical time, but it would be on hand to help drought-proof the region should it be required.
"I commend WaterNSW for the timely manner in which it has managed this project, which has also confirmed its ability to reliably deliver urgent drought infrastructure projects," he said.
"While the need to extract the last of Burrendong's storage is thankfully not required for the time being, the fact that the pumps will be ready for immediate service in the future adds to the drought resilience of the local communities dependent on the dam."
Mr Saunders said work on a coffer dam to help access water below the level of the dam wall's outlet valve would resume if the dam storage fell below 1.5 per cent of capacity and the pumping network was installed.
"While rain and dam inflows have been well received and offered a temporary reprieve, it is most important that we remember that the impacts of the drought are very much still with us," he said.
Rain across February, March and April has seen 119GL of water flow into the dam, lifting its storage capacity from a low 1.47 per cent in February to more than 12 per cent in April.
Minister for Water, Property and Housing Melinda Pavey said the project was among $65 million in urgent drought measures across regional NSW announced in August last year.
She welcomed widespread rainfall in 2020 and inflows into Burrendong Dam but declared "this is by no means an end to the drought here and elsewhere in regional NSW".
"As a government facing growing water insecurity ..we acted decisively and on a scale that brought immediate results in extending the availability of surface water from dams such as Burrendong," Ms Pavey said.
"This enabled local communities sufficient time to implement strategies to shore up their town water supply."
Dubbo Regional Council received $30 million "in additional government funding to extend its groundwater network".