Riverstone MP Kevin Conolly is backing three tactics - Pre-release of dam water, raising the dam wall, private sector buy up of flood prone lands.

Riverstone MP Kevin Conolly is calling for urgent ‘practical’ flood mitigation work to commence immediately and ‘undoing past planning errors’ to protect residents of the Hawkesbury-Nepean flood plain.

“After this third flood of the Hawkesbury-Nepean river in 2022, it is time for both plain speaking and practical action,” said Mr Conolly.

“No-one can stop flooding from occurring, any more than we can stop bushfires, earthquakes or cyclones. But we do have some options available to us to reduce the impacts of floods and we should be acting on these.”

Mr Conolly is backing three tactics – Pre-release of dam water, raising the dam wall, private sector buy up of flood prone lands.

“I urge the NSW Government to move on all three of these proposals and urge the Commonwealth Government to assist where it has approval responsibilities,” he said.

“The people of the Riverstone area and of the wider Hawkesbury-Nepean Valley deserve action from governments where practical options are available.”

Pre-release of water
“The first thing that can be done, and should be done without delay, is to amend the operating rules for Warragamba Dam to not just allow but require calibrated pre-release of water when the dam is full and the Bureau of Meteorology forecasts substantial rain. Controlled releases of water in the days before a rain event can reduce the dam level, enabling some more of the flood rain to be held back and reducing the peak of the flood.

“Previous studies have shown that this measure would provide only a small reduction in flood height, maybe 20 or 30cm, but nevertheless it is a reduction which is possible and which should be seized. It is something which can be done by the state government right now.

“I have written to the Premier urging that this change be implemented as soon as possible.”

Raise the wall of Warragamba Dam
“The options for providing flood mitigation in the valley have been studied, assessed and analysed many times and the best option identified each time has been the raising of the wall of Warragamba Dam. It’s time to get it done.

“Investigations after the 2021 flood showed that this measure could have reduced the peak by about three metres.

“Governments should give priority to protecting people’s lives and homes. The dam raising project must proceed as quickly as possible.”

Harness the market to undo past bad planning
“There are many thousands of homes in the Hawkesbury Nepean Valley at levels which would not be allowed today. The land was developed in the distant past before the planning schemes of the 1960s. The owners can’t afford to move unless someone buys their property.

“Governments will never be able to afford to buy them all back. But if the private sector had a financial incentive to buy these properties and hand them over to the government in return for the right to develop new dwellings on high, flood-free ground then the problem could be addressed over time.

“Starting with the lowest, most at-risk properties first, we should allow the private sector to buy the right to build extra dwellings on high ground in return for removing low, at-risk dwellings from the market.

“This would save the taxpayer millions of dollars over the years, as well as spare thousands of people the heartbreak of seeing their homes and possessions destroyed.”

Main picture: Flooding in Riverstone.