Raising the Warragamba Dam wall by 14 metres will not stop flooding in the Hawkesbury and Nepean Valley, a full house heard at The Hub in Springwood on Monday night.
Former Greens leader Bob Brown and former NSW Environment Minister and Member for Blue Mountains Bob Debus were addressing a forum organised by the Colong Foundation to create awareness around the NSW government’s proposal and its impacts.
“It passes beyond my belief that a government should think of extending construction across a floodplain that is known to be rather dangerous,” Mr Debus said. “And on the other hand its proposals for raising the dam wall are purported to protect this new development, except that it won’t, because whatever you do to the Warragamba Dam there will only be a diminished effect on any flood that’s coming out of the dam to the floodplain around Windsor and Richmond and Wilberforce.
“But in any event only half of the floods that encroach upon the floodplain of the Hawkesbury Nepean come from the Warragamba River, they come from other parts of the catchment.”
Mr Brown agreed. “It seems unconscionable that you would be making way for thousands of people to be living in the reach of those floods and at the same time putting in a mitigation scheme.”
From the audience, Hawkesbury Liberal councillor Nathan Zamprogno argued the concerns of his community had not been considered at the forum.
“This project could potentially reduce that risk [of flooding] by 75 per cent. I haven’t heard anything from the speakers this evening that addresses the concerns of my community, the people at risk, and it’s very easy to be righteous if you don’t live in the bullseye, but we do.”
Mr Debus said: “I’m totally in favour of any measure to improve the management of the floodplain but that doesn’t include putting more houses in harms’ way on the floodplain.”
Engineering Professor Stuart Khan from the University of NSW said governments must look at diversifying water supply systems to reduce reliance on the Warragamba Dam, like cities around the world were doing.
“We need to look at a system for Sydney where one third of the supply come from the dams, a third comes from potable reuse (recycled water) and a third from seawater desalination,” he said.
Gundungurra woman Taylor Clarke from Warragamba spoke of the Aboriginal heritage which would be flooded if the proposal went ahead.
“We have sacrificed enough. When there are viable alternatives, I can’t understand why this project must go ahead. Hundreds of sacred sites are at risk and will be lost to time.”