The Inland Rivers Network claims an investigation into allegations of water theft from the Macquarie Marshes wetlands in north-west NSW has uncovered evidence that irrigators deliberately and illegally siphoned-off water from a 30,000 megalitre environmental flow released from the Burrendong Dam in October 2005.

The network's report, to be issued today, contains aerial photographs – taken by NSW Government staff in 2005 – which show newly built dams, levee banks and irrigation channels diverting environmental flows to irrigate crops and pasture.

One photograph shows large volumes of tannin-stained environmental water being diverted from a river redgum forest into numerous channels and a large storage dam.

The report calls for a statewide audit of all water diversion structures on river flood plains and removal of those that allow water theft to occur.

The Macquarie Marshes, which cover 220,000ha, are one of Australia's most important breeding sites for water birds and are listed as internationally significant under the Ramsar Convention.

University of NSW ecologist Dr Richard Kingsford said the wetlands once supported 20 million breeding birds, but numbers had plummeted and were now as low as 20 birds in some areas.

Water levels were now so depleted no birds had bred in the wetlands for the past seven years, he said.

The Inland Rivers Network – a coalition of environment groups, including the Australian Conservation Foundation and Friends of the Earth – obtained government documents under Freedom of Information that show no approvals were given to build the dams, channels and levee banks used to divert water from the Macquarie River and its wetlands.

The investigation found an unlicensed channel was built to divert water illegally from a Ramsar-listed wetland on a neighbouring farm.

"Current information indicates that the channel extends some way, filling several dams and probably flooding land.

"It has been stated that the channel has a gate at the wetland end to ensure that no water can flow out of the channel and return to the wetland," the report says.

Australian Greens environment spokeswoman Senator Rachel Siewert described the report as "damning" and indicative of continuing failures in water management.

"It highlights the major problems that need to be addressed if we are to have any hope of recovering our wetlands and rivers. It goes directly to the future of water management in the Murray-Darling Basin," she said.

SOURCE: The Canberra Times.