Sustainability factored into several of the presentations on the first day of the Australian Water Association's state conference, held at Orange Ex-Services' Club on Thursday.

Ian Law from IBL Solutions spoke about the difficulties regional areas faced in planning water infrastructure, given the state government's Assuring Future Urban Water Security document was still in draft form despite being released in December 2013.

"How is that so? Is the document useless?" he said.

"People are using it, in fact [Orange] have used it and have been very successful in coming up with a water security plan and they spent a lot of money on it."

He said the study, which included 15 climate change models, predicted significant impacts for inland areas by 2030, but to finalise the document would cost money and better engagement was needed with state agencies.

"What they are aiming for in Singapore is if they can get a 50 per cent recycle, they have doubled the amount of water they've got available - that is creating security," he said.

"Their aim is to reach 55 per cent by 2060 - that is a long-term plan, not a short-term, knee jerk, let's put a bore hole down or put a pipeline across, and we don't seem to have that."

Mr Law said a study for Armidale showed direct potable reuse could add 5800 megalitres a year to the water supply.

"It is an option that really needs to be looked at," he said.

University of NSW Professor Stuart Khan spoke about international examples of water reuse.

He highlighted California, which used treated water for decades to recharge the aquifers communities relied on for their drinking water.

He also pointed to Perth, which is expanding its system, and Brisbane, which has build three treatment plants.

Professor Khan said recycled water would not be suitable in all areas, but it would become more common because it was climate resistant and communities needed to be included in the discussion.

"It's a source of water that's relatively reliable, it's lower cost compared to some of the other alternatives such as ... pumping water very long distances [which carries] huge energy costs," he said.

"Customer engagement needs to start early, it can't be left to the last minute."