Healthy Rivers Dubbo president Mel Gray said the meeting on the weir was an opportunity for residents to hear from experts and experienced locals.

The Gin Gin Dam proposal to build a new dam on the Wambuul-Macquarie River has been a controversial topic among residents since it was first presented.

WaterNSW stated the structure "will contribute towards improving water access reliability and resilience for the region".

Some of the benefits listed by WaterNSW include improved long-term water security in the Macquarie Valley, improved delivery efficiency to customers downstream of Gin Gin, reduced transmission losses when transferring and delivering water through the river system and maximised available water for general security customers within the sustainable diversion limits set under the Murray-Darling Basin Plan.

But Ms Gray said the plan was "dud".

"Dr Jim Bentley, wrote to WaterNSW last year saying the plans he saw did not represent efficient, effective, prudent use of public funds, and he's right, this plan is a dud," Ms Gray said.

Dubbo Environment Group vice president Di Clifford said the questions from those who attended the meeting represented the level of concern around the proposal.

Professor Richard Kingsford led a presentation showcasing several significant impacts he believes dams have on rivers and wetlands.

He said water management in NSW was "letting us down" and government models were not reflecting the accurate water levels in the rivers.

Inland Rivers Network president Beverley Smiles raised her concerns over the rivers native fish, which she said would be "significantly impacted" by the proposed Gin Gin Structure,"'losing over 32 kilometres of habitat".

"The last thing they need is a massive dam destroying their habitat," she said.

Dubbo MP Dugald Saunders was contacted for comment following the meeting but did not respond by deadline.

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