Raising Warragamba Dam wall

Kowmung River. At risk of 14 metre flooding & restricted access if dam levels raised. Photo David Hufton

An existential threat to NSW National Parks

David Hufton Member, National Parks Association of NSW and Committe Member, Colong Foundation

The NSW Government has decided to raise Warragamba Dam 14 metres for flood mitigation in the Hawkesbury-Nepean Valley at a cost of over $700 million. The EIS and final ministerial sign-off is due later this year, and we urgently need your help to stop it from happening.

Raising the dam would destroy vast tracts of the Blue Mountains National Park and hundreds of Gundungurra Aboriginal heritage sites, all in the name of injecting another 130,000 people to live on western Sydney floodplains.

As many people know, an auxiliary spillway was built in 2002 to ensure the dam meets international safety regulations and mitigates the very largest of floods.

Environmental Impacts

During high rainfall events, the raised dam would inundate 4,700 hectares of pristine World Heritage listed National Parks and 65 kilometres of wild rivers upstream of the dam including the Cox, Kowmung, Kedumba, Nattai, Wollondilly and Little Rivers.

Internationally significant environments that are recognised in the Blue Mountains UNESCO listing would die from sedimentation, erosion and invasion of exotic plants.

There are 48 threatened plant and animal species which inhabit the proposed inundation area. The Camden White Gum, Kowmung Hakea and near-extinct honeyeaters are found in the upstream inundation area. If the dam were raised, many of these species would likely become extinct.

Ecologist, Roger Lembit has said, “Raising Warragamba dam wall would drown threatened, rare and restricted plant communities including dry rainforest. It would extend weed invasion and create extensive new areas of eroded banks visible from Blue Mountains vantage points. Raising Warragamba Dam would have a severe impact on World Heritage values.”

If this proposal went ahead the Blue Mountains World Heritage Listing could very easily be a risk.

Cultural Impacts to Aboriginal Historic Sites

The proposed inundation area is home to hundreds of Gundungurra Aboriginal Heritage Sites and sacred waterholes. If the valleys were flooded for a second time, some of the last remaining rock art, marker sites and sacred water holes would be once again submerged under Warragamba Dam.

Gundungurra traditional owner, Kazan Brown has said, “Our history and our stories are in the landscape that surrounds Lake Burragorang. When Warragamba Dam flooded the valley in 1960, our lands and cultural sites were flooded. We do not want to see this story repeated with the remaining sites. Each time we lose a site, we lose part of our identity.”

Economic Risks

The Blue Mountains economy is built on ecotourism. Raising Warragamba Dam wall poses a significant threat to ecotourism in the mountains, with access to areas such as the Kedumba Valley and Kowmung River becoming further restricted if dam levels were to be raised – not to mention the eye-sore of dam scarring that will be from Echo Point, Katoomba.

Risk Management in the Hawkesbury-Nepean Catchment

The core agenda for the NSW Government in raising the dam wall is to release floodplain for housing in the Hawkesbury-Nepean Valley, to house no less than an additional 130,000 people over the next twenty years on the floodplain! The proposed dam wall raising will only have marginal impacts on downstream flooding and thus housing more people on the floodplain remains highly dangerous.

Take for example the Brisbane River floods of January 2011, when a major rainfall event occurred in the foothills surrounding Brisbane. The Wivenhoe Dam opened its gates, with 15,000 homes inundated in areas where over-development had been allowed below flood planning level. The event cost Queensland $2.55 billion in insurance and many months of recovery. If the dam had collapsed, 11,000 people would have died.

The 2011 Brisbane floods shows us that dams are not always safe. Controlled flood releases from dams before extreme flooding events can prevent flooding, but the Brisbane floods demonstrated the importance of governments not allowing the building of houses on floodplains, no matter how big a dam there is upstream. Floodplains are for floods, and the Hawkesbury-Nepean Valley is no different.

The plans by Infrastructure NSW to house an additional 130,000 people on the Hawkesbury-Nepean floodplain is ridiculous and will one-day lead to the very same outcome as the tragic floods on the Brisbane River. These events would cost hundreds or thousands of lives and billions of dollars in infrastructure.


No urban sprawl should be permitted on the Hawkesbury-Nepean floodplain. The NSW Government is justifying the dam raising by a massive expansion of dangerous urban development that should never be allowed – it is putting at risk thousands of human lives.

Catchment monitoring and weather forecasting should be used to allow the pre-release of dam water before extreme flash flooding events to reduce the risks downstream.

The NSW Government needs to upgrade flood evacuation routes and infrastructure to maximise the safety of residents, as this is the only measure that will save lives downstream. Simply focusing on big-dams that will flood one of the most protected natural areas in Australia will not solve the problem.

Recent Developments

Following a successful campaign launch at Springwood in late March, the Wild Rivers Campaign successfully lobbied Councillors on Hawkesbury City Council to vote down a motion to support the raising of Warragamba Dam wall.

Wild Rivers Campaigner, Harry Burkitt said, “The Hawkesbury City Council is being asked to support a near billion-dollar dam idea that has no thorough business case, EIS or feasibility study presented on its viability.”

Although, this was just a small victory, as The Carpenters famously sung, we have only just begun! Please join the campaign by following our action plan below.

Action Plan

  • Contact your local MP to tell them you disapprove of the drowning of 4,700 hectares of World Heritage Listed Blue Mountains National Parks
  • Sign the online petition at www.wildrivers.org.au/petition
  • Got some time up your sleeve? Got a skill that you think can help the campaign? Shoot us an email at wildrivers@colongwilderness.org.au

For more information or to support the campaign visit www.wildrivers.org.au

This site uses Akismet to reduce spam. Learn how your comment data is processed.