This is part of a $12 million program funded by the state government allowing the NSW Crown Holiday and Parks Trust to provide a significant upgrade of sewerage, water and electricity at eight of the inland parks across NSW.

Member for Dubbo and deputy premier Troy Grant said he expected it to bring a boost to both the Wellington and Dubbo economies and said it was long overdue.

"We have got to be on top of the game all the time across Australia," chief executive officer of NSW Crown Holiday and Parks Trust, Steve Edmonds said.

"Over the last 20 years there's been 462 holiday parks that are no longer in business."

"With fewer parks than 20 years ago we see our role as critical."

Now their water treatment facilities are complete, their next step will be to look at the site and take a development concept to stakeholders, local council and members of the community.

Mr Edmonds said it was a 10-year plan to maximise visitors' enjoyment of the park, adding that it could mean big things for Wellington.

"When someone spends $1 in the park, $1.38 is added into the local economy," he said.

Burrendong State Park manager Jason Kirk said previously the biggest complaints among visitors had been about dirty water.

"We were relying on Mother Nature and sometimes we had clean water, sometimes we didn't," he said.

Mookerawa Waters park manager Richard Vernon was also excited with the state of the art technology constructed by CRS Industrial Water Treatment Systems.

"It is a beautiful system to run," he said.

Next in line to receive fresh drinking water is Lake Glenbawn, Burrinjuck Waters and Copeton Waters. The power upgrades and installation of the water treatment plants are being managed by the NSW Department of Trade and Investment and the NSW Crown Holiday Parks Trust.

NSW CHPT was formed to consolidate the operations of 26 coastal and nine inland holiday parks and reserves located on Crown Land throughout NSW in some of the state's most iconic locations.