New South Wales is experiencing a "critical" water situation that could see some towns completely run out of water within a few weeks.

Parts of the state could run out of water as early as November if the government does not intervene.

Projections from NSW's river operator and bulk water supplier WaterNSW show that, unless it rains significantly in the next few weeks, the towns of Dubbo, Cobar, Nyngan and Narromine will be out of water by November.

The Macquarie River, which usually experiences an average inflow of 1448GL annually, has seen only 97GL enter the system in the last two years.


NSW Water Minister Melinda Pavey has described the situation as "critical".

The lakes which sit within the town of Menindee and run along the Darling River, experienced mass fish deaths last summer.

The deaths are blamed largely on the water levels of the lakes.

Under a projected worst-case scenario, the Lachlan River will run dry by March 2020. If that happens, it will leave the towns of Forbes, Cowra and Parkes without water supply.

The state's northwest, including the small towns of Manilla and Boggabri, could also run out of water by the same date if there is no significant rainfall.

WaterNSW also predicts the Border rivers will run dry by September 2020 if the situation does not change.

Water is projected to stop flowing from taps in the town of Inverell in March 2021.

Most of Sydney's tap water supply should remain flowing until October 2021 but, under a worst case scenario, the upper Nepean River will be dry by then and affect the city.