Hunter Water will be required to provide the NSW Parliament with more documents relating to its plans to build a new Lower Hunter dam.
It follows a successful Standing Order 52 (also known as a call for papers) motion by independent Upper House MLC Justin Field.
Mr Field is specially seeking access to information about planning for new dams at Limeburners Creek and Upper Chichester.
While Hunter Water argues that it must consider all options as part of the plan, the suggestion of new dams has been vehemently opposed by communities that would be affected by them.
The wider community has also indicated a clear preference for increased water conservation.
"The evidence continues to show that the public want to see water efficiency and recycling prioritised and are most opposed to new dams, but the dam options continue to be pursued by Hunter Water," Mr Field said.
"New dams will be a huge hit to local water bills and have significant environmental impacts on the affected rivers and could flood critical koala habitat. It is important that all of the documents and discussions informing these decisions are on the public record".
The latest call for papers follows a similar motion last year that produced 21 boxes of information.
In relation to the latest call for papers, a Hunter water spokesman said the corporation was committed to continued investment in water conservation and leakage reduction under the revised Lower Hunter Water Security Plan in line with what we've heard from our community.
"We have been engaging with our community openly and transparently throughout the review of the Lower Hunter Water Security Plan," he said.
"We have undertaken an 'all options' approach in our review to ensure our plan is the best fit for our region's water security. Feedback from the community has been consistently supportive of this approach."
Increased water conservation and stormwater harvesting combined with inter-regional transfers and the introduction of purified recycled drinking water were the most preferred combination of options for securing the region's water security, a Hunter Water stakeholder survey revealed.
Seventy three per cent of the 1100 participants in the Lower Hunter Water Security Plan survey, released in March supported a portfolio that favoured recycling and conservation options.
Healthy Hunter Rivers spokesman Ken Edwards said the community had consistently indicated a preference for water demand options to be included in the LHWSP.
"In all the surveys, efficient water conservation and demand options are consistently a priority over supply options," he said.
"Hunter Water even acknowledges this in the published survey results saying the community "prefer options that reduce reliance on drinking water over options that supplement our water supply" but continues with its relentless lust to want to build new dams as indicated by the fact they included two dam portfolios in the final seven to be taken forward in the final assessment."
"One of the reasons as to why the Call for Papers motion was put forward was because Hunter Water has continued to ignore the consultation process regarding water security options.
"The Deliberative forums proved conclusively that sustainable options like recycling, demand management and stormwater harvesting are what the community want.
In relation to the online Portfolio survey, Portfolio 3, which did not have dams as an option, were favoured. When will Hunter Water and the Government learn that dams are not popular in the Lower Hunter?"
Hunter Water expects to release the draft of the LHWSP for public exhibition in late July or early August.