The construction of a $500 million water pipeline from the Murray River to Broken Hill should be postponed until all inquiries into allegations of water theft and corruption have wrapped up, local NSW residents say.

Residents of Broken Hill will present the NSW Government with a petition of 13,300 signatures in Sydney on Tuesday, demanding a moratorium on the construction of the 270-kilometre pipeline.

The petitioners argue the pipeline makes “no economic sense” and the government should prioritise cleaning up alleged water theft upstream.

The outback residents say the health of the Darling River and communities along the waterway are being impacted by irrigation schemes and the proposed pipeline will worsen the problem.

They say upgrading the current 114km pipeline to nearby Lake Menindee makes more sense.

The delegation, including the Broken Hill mayor Darriea Turley, grazier Katherine McBride and Barkandji man Uncle Badger Bates have travelled 1100km to Sydney to hand the petition to the Berejiklian government.

They say the community has received “negligible” consultation and the government is yet to present a full business case or environmental impact statement to the public.

Opposition water spokesman Chris Minns says the government has to cough up a business case to justify the project’s half a billion dollar price tag.

“No other project of this scale would be allowed to continue without a business case,” Mr Minns said in a statement on Sunday.

“The only explanation for the secrecy behind this development is that it doesn’t add up, and the NSW government might just have a $500 million blunder on their hands.”

A spokeswoman for Water Minister Niall Blair says the pipeline has been identified as the best solution for the current problem.

“Projections show there is enough water to sustain Broken Hill without significant inflows until April 2019, and the more Labor and the Greens delay, the more likely it is that Broken Hill will run out of water,” the spokeswoman said in a statement.

Several state and national reviews of compliance were ordered following revelations of water theft in the Murray Darling Basin by the ABC’s Four Corners program last year.

Both NSW and Queensland were slammed by a Murray-Darling Basin Authority review into water theft and regulation in November.

That inquiry found both states regularly failed to make sure irrigators complied with the Murray-Darling Basin Plan, and weren’t transparent about their failures.

South Australian Premier Jay Weatherill also announced a royal commission in late 2017 into water theft in the basin.