Warragamba Dam plan stirs World Heritage Committee worry over ‘values’
By Peter Hannam
July 3, 2019
The NSW government’s plan to raise the height of the Warragamba Dam has triggered concern from the World Heritage Committee that the Blue Mountain’s “outstanding universal values” will be affected.
The committee issued its response to the proposal at a UNESCO meeting in Baku, the capital of Azerbaijan, on Wednesday. It noted the raised dam would likely increase the extent and frequency of inundation of the World Heritage area.
The committee requested the government submit the proposal’s environmental impact assessment to the World Heritage Centre “for review” by the International Union for Conservation of Nature “prior to taking any final decision regarding the project”.
Officially, Infrastructure NSW has been working on a project that would raise the dam wall of Sydney’s main reservoir by 14 metres to 144.5 metres, flooding as much as 5000 hectares of the Blue Mountains World Heritage Area.
However, as reported in the Herald in March, one document indicated construction would involve building 17-metre-high abutments that would permit a further raising with minimal additional work.
The World Heritage Committee also noted that it considered any construction of dams with large reservoirs within the boundaries of World Heritage properties “incompatible with their World Heritage status”.
It urged all governments to “ensure that the impacts from dams that could affect properties located upstream or downstream within the same river basin are rigorously assessed in order to avoid impacts on [their] outstanding universal values”.
Bob Debus, a former NSW Environment Minister who presided over the successful nomination of the Blue Mountains region for World Heritage state, told the Baku gathering that as much as 65 kilometres of wilderness rivers would be flooded if the dam wall were to be raised.
“The area proposed for inundation includes at least 300 known Gundungurra Aboriginal cultural sites, which would be damaged,” he said. “Its cultural and conservation value is exceptional even within the Blue Mountains area.”
“The government of New South Wales has in its own publications treated [outstanding universal values] as little more than an irritating afterthought.”
“[Australia’s] failure to protect World Heritage in the Blue Mountains would not be an isolated misfortune,” Mr Debus said. “It would amount to a fundamental attack on the [World Heritage] Convention itself.”
The Berejiklian government has argued that the wall must be raised to reduce the risk of catastrophic flooding in the Hawkesbury-Nepean river plain.
Much of the plain was frequently inundated during the first 150 years of European settlement although a relative dearth of floods in the past half century have prompted planning authorities to allow development of houses and other infrastructure in the flood zone.
Mr Debus said the government’s support for the project – to cost as much as $1 billion – “so far presume that the population living on the floodplain will be greatly increased”.
“It has so far demonstrated very little interest in a rigorous assessment of alternative strategies for flood mitigation, urban planning and water supply, even though strategies clearly exist.”
Stuart Ayres, the Western Sydney Minister, said the project’s environmental impact statement would be provided to the World Heritage Committee “when it is placed on public exhibition in early 2020”.
“The Hawkesbury-Nepean is a high-risk floodplain,” Mr Ayres said. “Raising the dam wall is key part of the strategy to reduce the existing risk to life and property on the floodplain.”
“The final decision to raise the wall has not yet been taken and will only take place after financial, environment and cultural assessments have concluded,” he said.
“While there will be environmental impacts from temporarily holding flood water from behind a raised dam wall, they must be measured against the social and financial impact a catastrophic flood would have on Western Sydney communities.”
Peter Hannam writes on environment issues for The Sydney Morning Herald and The Age.