The proposal to raise Warragamba Dam’s wall wouldn’t result in increases to its permanent storage levels, a local MP has told State Parliament.
Riverstone MP Kevin Conolly stood in Parliament on May 1 to support the State Government’s proposal to raise the dam’s wall by 14 metres.
Hawkesbury City Council voted seven to five last month to reject a motion supporting the raising of the wall, and the Colong Foundation for Wilderness launched a campaign against the proposal in in March saying Greater Blue Mountains World Heritage Area would be destroyed if the wall was raised.
But Mr Conolly said the current proposal would not alter the height of five flood gates set part-way up the wall like windows that safely store water up to that level but release extra water into the Warragamba River.
“[Under the current proposal] both the wall and the auxiliary spillway would be raised by 14 metres to ensure that even in a very rare rain event, not only would the integrity of the dam be protected but the likelihood of a massive release of water downstream would be reduced substantially,” he told Parliament. “It is important to note that as in the 1990s, the windows in the dam wall would stay exactly where they are, so no addition to the permanent storage level would occur.
“What would occur would be temporary storage of more water behind the dam for a period of up to 14 days. Over that time, water levels behind the dam would be higher, causing some environmental impact upstream.
“But without raising the wall the environmental impact caused by that water would occur downstream.
“There is no option that would see zero environmental impact when that amount of rainfall occurs. The raised wall would only alter the location of the impact that would inevitably occur.”
People living in western Sydney “need and deserve” the project to reduce damage to “homes and businesses, as well as to schools, public buildings, sewerage and electricity assets, railways and roads,” he said.