Over $500 million … Roads Minister Duncan Gay’s projected damage bill for this year’s floods. Photo: Adam Hollingworth

THE state government’s failure to responsibly manage the thousands of weirs and levees which impede the flow of waterways has made flooding worse than it should be, says a water governance expert.

Jamie Pittock, of the Australian National University, called for urgent action to rectify or remove hundreds of dangerous, redundant or illegal weirs which he said were “pushing water out of channels and onto flood plains and so inundating areas that might not otherwise be flooding”.

The Roads Minister, Duncan Gay, has put the damage bill for this year’s floods at well over $500 million, and weather forecasts predict even worse weather for next month.

A NSW government review of weirs starting in the late 1990s found there were 3328 licenced structures built on the state’s waterways. Of the 882 inspected, one-third were assessed as in need of removal, modification or better management to reduce adverse impacts.

Applying this one-third ratio to the total number of licenced weirs (not just those inspected) suggests as many as 560 weirs might require removal, modification or better management. However, by 2008, according to Dr Pittock’s figures, only 57 had been removed or modified. These figures do not include unlicenced or illegal weirs, the number of which is not known.

The government relied largely on voluntary action by the infrastructure owners such as farmers and local councils to make improvements, Dr Pittock said, but two-thirds of the known weirs had licences without expiry dates, making intervention difficult. In addition there were legal and financial barriers to removing abandoned, ownerless and illegal weirs. A powerful regulatory system was needed to enforce the necessary improvements, said Dr Pittock, who is director of international programs for the UNESCO chair in water economics and transboundary water governance at the university.

“The fact that there are so many of these structures out there that the NSW government itself recognises are redundant or dangerous or their records are inaccurate, tells us they are not being competently regulated. You can’t manage what you can’t measure,” Dr Pittock said.

The Herald called the Office of Environment and Heritage and the Office of Water, the Environment Minister, Robyn Parker, and the Minister for Primary Industries, Katrina Hodgkinson, seeking comment. A spokeswoman for the Minister for Primary Industries said weirs were ”managed by a variety of sources, it could be State Water, it could be local councils, it could be a range of people”. A spokeswoman for the State Water Corporation said: ”All of State Water’s weirs are licenced and all of our weirs are managed under an asset management plan.”

The flood management system needed to be re-engineered to remove bottlenecks created by antiquated levee systems, Dr Pittock said. He also called for the restoration of ancient flood plains, such as those along the Danube in Europe, to be secondary channels during flooding which could catch flood peaks and release floodwater slowly. While the cost would run into hundreds of millions of dollars, it would be “less expensive than the damage from the sort of floods we are seeing”, he said.