Blame game: Development, greenies, and cost blowouts stall Warragamba Dam wall raising

Supporters say it could save thousands of homes every time the Hawkesbury floods, so why is the proposal for raising the Warragamba Dam wall still in the pipeline for 30 years?

Spin and lies about the environmental and developmental impact of raising the Warragamba Dam have stalled the project which could save thousands of homes every time the Hawkesbury floods, supporters of the project say.

The proposal — which the government says is a no-brainer — has been talked about for three decades, but remains far from becoming a reality, even as the region flooded four times in 18 months.

Among the biggest barriers to approval is a view that profit-hungry councils will use a raised dam wall as a green light to build more houses on the flood plain and evacuation routes.

Opponents point to development in Brisbane which meant that despite the raising of the Wivenhoe Dam, the 2011 Queensland floods devastated the regions.

Others say raising the wall would cause “monumental damage” to both environmental and cultural heritage sites in the area.

Western Sydney Minister Stuart Ayres said many of the decisions to build on flood plains in NSW were historic ones, and current councils were much more restrictive on where property could be built.

“It’s really important to recognise that there will be no land made available in that area that isn’t already available,” Mr Ayres said. “Many of the properties that we are dealing with are historic approvals, before we had flood planning constraints.”

But Mr Ayres said green groups needed to factor in the impact on the environment in front of the dam that is obliterated every time the region floods.

“The water would only ever be held temporarily … for between one day and 14 days,” he said.

“The riverbanks themselves are often the most damaged part of the environment when a flood happens.

“You can’t really ignore the impact of the flood on the environment downstream.”

The Hawkesbury region has flooded four times in 18 months. Picture John Grainger

Former Labor Minister John Brown crossed political lines and said there had been 30 years of evidence to support the wall being raised.

“The wall should be raised, the evidence has been there from every department in government for 30 years advising them to raise the wall. Why they haven’t I cannot work it out,” he said.

“At least the present government is expressing a desire very clearly that they want to build it.

“They talk about Aboriginal artefacts being damaged. How many floods have they survived in the 60,000 years since the Aboriginal people were first here? This is a nonsense proposition that the greenies keep putting up while all those people are drowning.”

The old Windsor Bridge was submerged — again — by the overflowing Hawkesbury River on July 4. Picture: AFP

The $1.6 billion cost of the project has also been a stumbling block, with opponents saying the money could be better spent on buyback schemes.

Independent MLC Justin Field chaired a parliamentary inquiry into the proposal to raise the Warragamba Dam wall.

Mr Field said the money would be better spent on other flood mitigation strategies, including improving evacuation routes.

“I’m opposed to raising the Warragamba Dam wall for two reasons. It will not stop catastrophic floods and it will not stop the overall flood risk for the Hawkesbury-Nepean,” he said.

Mr Field also pushed back on the government’s environment defence, saying they had not provided details around the operational rules that would protect the catchment upstream.

Western Sydney Minister Stuart Ayres is the project’s biggest supporter. Picture: NCA Newswire / Gaye Gerard

“The temporary inundation, four times in two years for the maximum capacity, would kill everything,” he said.

“The dam wall raising would provide some mitigative capacity (but) it will cause monumental damage to both environmental and world heritage (listed) area, but also to cultural heritage.”

Committee for Sydney Resilience Program Director Sam Kernaghan said raising the wall would not solve the issue of flooding in the Hawkesbury-Nepean Valley.

“The Hawkesbury-Nepean flood plain is fed by rainfall from four catchments, with the Warragamba Dam reducing run-off from just one,” he said.

A slew of bureaucratic delays, including the Commonwealth ordering the states to provide more detail in its Environmental Impact Statement in 2020 and this year calling for more details on an early business case, have also stalled the project