Warragamba Dam: Water NSW moves to raise wall an extra 3m
An environmental group believes another 1000 hectares of national park could be inundated under new released plans to raise the Warragamba Dam an extra three metres than originally planned.
Penrith
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Water NSW has officially moved to raise the Warragamba Dam wall by 17 metres, three metres more than originally planned.
In a letter requesting to vary the proposal to raise the dam wall, project director David Harper stated that “the existing flood risk is set to increase” meaning the wall would need to be raised by 17 metres to “achieve the same benefits in 2090 as raising the dam crest by 14 metres under historical conditions”.
The letter stated the overall dam would be raised to 17 metres, but the spillway crest levels would be maintained at the levels proposed under the original 14-metre plan.
This is despite Minister for Western Sydney Stuart Ayres telling a public hearing into budget estimates for 2018-19 that 14 metres was the “preferred option”.
He told the public hearing that all environmental impact assessments and business cases were based on raising the dam by 14 metres.
Now, campaign manager at the Colong Foundation for Wilderness, Harry Burkitt, says the costs of the project would blow out.
“Given this substantial expansion to the project’s size, the costs for the dam proposal will now be ballooning well beyond $1.5 billion,” Mr Burkitt said.
“The question must be asked, what are the real economic, environmental and cultural costs of this project given the NSW parliament has likely been misled on several occasions?
“What other secrets haven’t been revealed by Stuart Ayres and Infrastructure NSW about their hidden agendas for this project?”
However, Mr Ayres said there was “no secret plan to change the flood mitigation capacity of the current proposal to raise Warragamba Dam”.
“Under the current WaterNSW proposal, the central spillway height would be increased to a maximum of 14 metres above the current full supply level,” he said.
“Sections of the proposed dam wall at 17 metres relate to abutments and the road deck ... (These) do not play a role in storing water.
“As the wall is for flood mitigation only and not storage, this project ensures temporary inundation occurs behind the dam wall rather than people’s living rooms, streets, and businesses.”
Mr Burkitt said the Colong Foundation for Wilderness believes another 1000 hectares of National Parks could be under threat on top of the 5000 hectares that would already be flooded by the 14-metre proposal.
“The assessments undertaken to date for the project have been for a 14 metre dam wall raising,” he said.
“However, this must be redone given the dramatic expansion to the size of the dam proposal to a 17 metre raising.
“The federal and state governments cannot let Stuart Ayres and Infrastructure off the hook. They must require them to re-do all cultural and biodiversity assessments before any documents go on public exhibition.”