Drilling work has started in Broken Hill in far west New South Wales to find an emergency water supply for the drought-stricken town.

The iconic mining city is due to run out of good quality water by August 2015 due to the dwindling level of the Menindee Lakes.

The lakes have been steadily drying out because of the drought.

Darryn Clifton from the Broken Hill-Menindee Lakes We Want Action Group said mismanagement was also to blame.

"It's only through over extraction of water upstream in the Barwon-Darling River system that we're not getting the flows down," he said.

The NSW Government has started drilling for groundwater to provide an emergency bore water supply for Broken Hill.

Water Minister Kevin Humphries said the current supply of surface water was not sustainable.

"We're in a once-in-a-lifetime opportunity to resolve this issue of securing up Broken Hill's water supply," Mr Humphries said.

"The Darling River is not reliable enough."

Some people within the Broken Hill community have raised concerns that the drilling program is part of a larger plan to decommission the lakes.

"This is not to replace surface water supply at all," Mr Humphries said.

The Action Group has suggested extending a pipeline which draws from the Murray River to connect to Menindee so it can be pumped to Broken Hill.

But Mayor Wincen Cuy said this was not feasible.

"That is not going to help us in the short term," Mr Cuy said.

"The short-term solution at this point looks like the bore or rain in Queensland."

The NSW Office of Water has also ruled out trucking water to Broken Hill, saying it would require 500 road trains a day from Mildura.

The drilling program is due to finish in early 2015.