‘Critical’ drought are putting water supplies at risk across New South Wales.

Forecasters say the Menindee River will run dry in November, leading to a water shortage in several parts of regional New South Wales if there is no assistance from the government.

The water entering the river system has decreased over 12 months, triggering a massive spike in fish deaths.

Dubbo, Cobar, Nyngan and Narromine will be the first towns affected.