The drought gripping much of NSW is tightening, forcing authorities to prepare to cut flows along a major river in the north west, while job losses loom as towns in the Northern Tablelands start to dry.

WaterNSW on Monday will announce that unless conditions improve, regulated flows along the Macquarie River below the town of Warren will cease from early spring to prioritise water supplies for towns and key users.

Steven Gibbs walks in a dry section of Lake Burrendong in western NSW as plunging reservoir levels trigger limited water flows along the Macquarie River. Credit:Nick Moir

Even those users - such as the Western Plains Zoo, Cobar mines and Dubbo's abattoirs and golf club - are "at risk of having reduced access to water" without fresh inflows.

Pressure is likely to mount on Dubbo to introduce water restrictions as the main dam supplying the regional centre of about 40,000 sinks to just 6 per cent full.