The Kelly's once profitable farm at Werrimull has become a desert.

Werrimull family say they're in the 'worst drought in the region's history'

Parts of regional NSW could run out of water as early as November with data showing the worst-case scenario for the state if there’s no rain or government intervention.

The projections from NSW’s river operator and bulk water supplier WaterNSW show without significant rain the first towns to lose water supply will be Dubbo, Cobar, Nyngan and Narromine with the Macquarie River forecast to run dry by November.

The Macquarie River experiences an average inflow of 1448GL annually but in the past two years has seen just 97GL enter the river system, the data, seen by AAP shows.

It’s been described as a “critical” situation by NSW Water Minster Melinda Pavey with the government insisting it’s doing everything it can to make sure the state gets through this devastating drought.

Australia’s longest river - the Murray - has been severely affected with 901GL of water entering the system in the past 12 months compared to its annual average of 5000GL.

The data shows that Menindee Lakes - which is a source of flows for the Lower Darling and is a vital fish nursery - received just six gigalitres of water in the past year.

It’s annual inflow average is 1387GL.

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

Residents have questioned the drainage of the lakes twice in 2017 with some suggesting the fish carnage wouldn’t have happened if the lakes were full.

The WaterNSW data shows the lakes received 2100GL of water in 2016/17 followed by just 52GL of water in 2017/18.

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Under the worst-case scenario, the Lachlan River, which runs through the state’s central west, is projected to run dry by March 2020 leaving the towns of Forbes, Cowra and Parkes without water supply.

The river is the fourth longest in Australia and annually receives an average of 1212GL of water but in the last year recorded inflows of just 107GL.

The state’s northwest including the small towns of Manilla and Boggabri could also run out of water by the same date if the upper Namoi River doesn’t receive any rainfall.

A group of rivers which straddle the NSW and Queensland border and supply water to the towns of Boggabilla, Ashford and Goondiwindi, received just 17GL of inflows in the past year compared to an annual average of 1000GL.

WaterNSW predicts the Border rivers will run dry by September 2020 without government intervention and rain.

Water is projected to stop flowing from taps in the northern NSW town of Inverell in March 2021 where the Gwydir River, which usually receives 1141GL of rain a year, will dry up after just 19GL entered the system last year.

The data predicts that most of Sydney’s water supply will remain flowing until at least October 2021 when, under the worst-case scenario, the upper Nepean River will run dry.

Australia’s largest urban water supply dam - Warragamba Dam - is projected to stop flowing by January 2022, according to the data.

Warragamba Dam received 105GL of water in the last year compared to its annual average of 1069GL.