According to the NSW Auditor General water security in rural and regional NSW is at dire risk without urgent investment.

The Auditor General said in the Auditor General report that $1 billion needs to be invested in water infrastructure, a stark warning that has been echoed by Local Government NSW.

LGNSW president Mayor Darcy Byrne said the Auditor General's report sounds a warning bell about the financial sustainability of locally managed water utilities.

"Access to safe drinking water is a basic human right," Mayor Byrne said.

"Anything less than that is unacceptable for any Australian community, but without urgent investment in water infrastructure in rural and regional NSW we risk these communities being left to wither away."

According to Mr Byrne the response should be simple.

"The Auditor General's report shows in black and white that major investment is needed in water infrastructure in rural and regional communities, or their access to safe drinking water and wastewater processing will be threatened," he said.

The Auditor General's report also showcased that two regional and 13 rural councils across the state that supply water to their communities, recorded operating losses for their local water utilities, and that even where operating costs were covered, essential infrastructure upgrades were not guaranteed.

Mayor Byrne is continuing to call on the State Government to invest in water management infrastructure and the lack of ongoing investment is having real-world impacts on communities.

"This is not some theoretical argument," Mr Byrne said.

"Council owned water utilities serve almost two million people in NSW, and without appropriate funding and support to deliver this basic service of safe drinking water - we are going to start seeing increasing disruption to essential water and sewer services for those communities.

"The upcoming State Budget is the perfect opportunity for the NSW Government to renew funding for the fully allocated $1.1 billion Safe and Secure Water Program, or a replacement program to meet this critical need."