Dubbo-based Healthy Rivers Ambassador Melissa Gray has raised concerns about damage to the river and Macquarie Marshes if more water is removed from the system.

But Macquarie River Food and Fibre executive officer Grant Tranter rejected calls for changes contained in the Northern Basin amendments to be abandoned and said four-fifths of the river’s water resource remained with the environment.

It comes after allegations were aired in an ABC Four Corners report that billions of litres earmarked for the environment have been diverted for cotton irrigation in the Barwon-Darling.

Ms Gray reported the allegations raised serious concerns in the community for the future of the Macquarie River and Macquarie Marshes if the Northern Basin amendments that are before Parliament were to go ahead.

The original Murray-Darling Basin Plan sought to deliver 3200 gigalitres to the rivers per year to ensure their survival, she said.

A public meeting about the issue will be held on September 4 from 7pm at the Garden Hotel and Ms Gray said all were welcome.

“There’s only enough water in the Macquarie River to maintain 10 per cent of the Macquarie Marshes as it is, removing a further 28 billion litres could mean they will die out,” she said. “We absolutely will lose more species of native fish from our river if the Northern Basin amendments go through.”

Mr Tranter hit back at the claims, saying calls for the Northern Basin amendments to be abandoned were “both premature and misguided”.

He also defended the industry.

“Not only has the Four Corners trial-by-media prematurely asserted guilt to the named parties, but also unfairly tarnished the wider irrigation sector,” he said.

He said it was unfortunate that groups like Healthy Rivers failed to recognise the hard-earned successes of the Commonwealth Environment Water Holder and the sacrifices of communities struggling from continual water reform.

Eighty-one per cent of the Macquarie River water resource remained with the environment, compared with 15 per cent apportioned to the irrigation community, he said.

The Murray-Darling Basin Authority last week welcomed a request from the prime minister and the deputy prime minister for it to conduct a basin-wide compliance review.

It will be delivered by December 15.