The chairperson of a parliamentary inquiry has accused the government of using secret modelling to justify its position not to change water rules to improve town water security.
Shooters Fishers and Farmers MLC Mark Banasiak said government witnesses before his recent Upper House Industry Committee Inquiry repeatedly cited a 2014 case study conducted in the Lachlan Valley.
The modelling was used as the basis for Minister Melinda Pavey's position opposing the use of up-to-date information for developing water rules, he said.
But despite promising to provide the study to the committee, the modelling data remains "unsighted", according to the inquiry report issued on Friday.
"The current legislation in New South Wales is underpinned by this alleged document that remains unsighted," the inquiry report reads.
Mr Banasiak said he isn't even sure the survey exists, and it makes it look like the Minister has something to hide.
Tamworth Regional Council has long lobbied for the government to consider the so called 'drought of record' when creating water sharing plans like the plans for the Namoi and Peel Valleys. The new WSP was sent to the Murray Darling Basin Authority in June without the change.
The Upper House Industry Committee inquiry considered a trio of bills, one of which would reverse a 2014 law allowing government to release more water during good times. Its report recommends the bill go to the full parliament.
A spokesperson for Minister Pavey said a technical report on the Lachlan was prepared in 2013 "to inform internal policy discussion". It was not provided to the Leader on request.
"This report will be superseded by water security modelling for the regional water strategies that are now being developed by the department."
The new strategies will govern water allocation practices and assess options for improving drought security for towns and critical industry. Mr Barnasiak said the committee was not told if the data behind the new strategies would be made public.
Mr Barnasiak said the people of regional NSW would be frustrated by the government's "dodging of answers" and lack of transparency before the Inquiry.
"People in Tamworth came very close, if not some of them did, run out of water. And for them to hear answers being given like that must frustrate the hell out of them."
He said none of the government witnesses "filled me with any confidence that we're going to be somehow any better-prepared in the next drought that invariably comes around."
"All I got and heard from them was what I call word salad. You say a lot but you don't say much at all when you listen back it."
Asked what government would do to ensure there would not be a repeat of last year's horror drought crisis, a spokesperson for Minister Pavey pointed to the $40 million Chaffey Pipeline upgrade, and the new Dungowan Dam.