A decision to raise the wall of Sydney’s Warragamba Dam will provide vital flood protection for communities downstream, the NSW Government says, but critics have raised environmental concerns about the plan.
The State Government will set aside $58 million in next week’s budget for the project, which has a total price tag of about $690 million.
It would see the height of the dam’s wall increased by 14 metres, which Premier Mike Baird said would offer significant extra protection to communities including Windsor, Richmond and part of Penrith.
“The Hawkesbury-Nepean Valley has been identified as having the greatest flood risk in New South Wales, which poses a serious danger to life and property in Western Sydney,” Mr Baird said.
“This crucial investment is being made so we can reduce the risk to people, animals and property in the event of serious flooding.”
He said raising the dam wall was expected to reduce potential economic impacts from flood risk by about 75 per cent on average.
Concern over impact on ecosystems upstream
But environmental groups have raised concerns that the plan could damage or destroy precious ecosystems.
Andrew Cox, from the group 4Nature, said he was worried about what would happen to areas upstream.
“The raising of the dam will flood World Heritage-listed Blue Mountains national parks and it will destroy large areas of wild river, because if the water is kept behind the dam during floods, it will ruin all the vegetation in those rivers,” he said.
Mr Cox also expressed concerns that local communities would be lulled into a false sense of security if the dam wall was increased, and more homes would be built on flood-prone areas as a result.
“We’re worried that by raising the dam and providing some level of protection it will actually trigger development on the flood plain,” Mr Cox said.
The Western Sydney Leadership Council’s chairman, Christopher Brown, has already flagged developing flood-prone land as a potential funding source for the dam wall extension.
“I think there’s the capacity to use a value-capture funding method to reduce the impact on taxpayers,” he said.
“Maybe via levy on land release that was previously considered flood-prone so we might be able to do it at a cheaper rate than what the Government’s talking about.”
He suggested the wall extension could potentially be made higher than 14 metres if such a levy was charged.