Tanya Plibersek dam decision a blow to Lake Pedder restoration campaign

Tanya Plibersek has dashed hopes of Tasmania’s famous Lake Pedder beach being restored to its former glory, approving a dam upgrade that locks-in its future flooded beneath 15m of water.

Airplanes taking off from the 3km-long Lake Pedder beach, Tasmania, before it was flooded for a hydro scheme in 1972.

Tanya Plibersek has dashed hopes of Tasmania’s Lake Pedder beach being restored to its former glory, approving a dam upgrade that locks in its future flooded beneath 15m of water.

A long-running campaign has sought the decommissioning of several hydro-electric dams in Tasmania’s southwest, to return the original Lake Pedder, flooded by a hydro scheme 50 years ago, to its original level.

That would see the lake’s unique 3km long and almost 1km wide pink quartzite beach – now beneath 15m of tannin-stained water – restored to its former glory.

On Tuesday, however, it emerged that the federal Environment Minister had approved Hydro Tasmania’s plans to upgrade Edgar dam, without assessing the decommissioning option or requiring a full environmental assessment.

Former Greens leader Christine Milne, convenor of Lake Pedder Restoration Inc, vowed to consider a legal challenge. “It beggars belief that a federal minister charged with protecting the Tasmanian Wilderness World Heritage Area, a place of outstanding universal value, would just tick off on Hydro Tasmania’s plan without conducting a full environmental assessment,” she said.

“We will not take this lying down and will immediately seek her reasons and review what action may be taken.”

A 2017-18 auditor-general report found Edgar and Scott’s Peak dams, built 50 years ago to dam Lake Pedder, were “high risk” and associated with “major risks”.

The dams, whose upgrades will cost more than $70m, were designed when a nearby fault line was thought inactive. It is now known to be active and the original designs are inadequate.

Probability of “dam failure causing high adverse consequences” was between 1 in 1000 and 1 in 10,000. While still a “very low probability”, such a failure could flood the Huon River and Huonville area, population almost 3000.

Ms Plibersek referred requests for comment to her department, which said it had “rigorously assessed” the potential impacts of Hydro’s dam upgrade on the wilderness and threatened species.

“The department found that there will be no significant impacts to matters of national environmental significance if the proposed action is undertaken in accordance with Hydro Tasmania’s extensive avoidance, mitigation and management measures,” a spokeswoman said.

Hydro Tas infrastructure chief Jesse Clark said work would start on the upgrade later in 2024.

“It’s great to get to this point after several years of design, planning, approvals and community consultation,” Mr Clark said.

State Energy Minister Nick Duigan welcomed the decision, saying it would allow Hydro Tas to “continue to maintain this important asset”.

Ms Milne said Ms Plibersek’s decision would “ramp up” rather than end the restoration campaign. “Lake Pedder will be restored,” she told The Australian.

“It is inevitable; just a question of when. All (the upgrade decision) means is that we will see Tasmania waste millions in the meantime propping up the past.

“But they can’t say they didn’t know.

“Don’t forget they had bulldozed a big area at the Franklin (for a dam in the early 1980s) and bulldozed the site at Wesley Vale (for a pulp mill in the late 1989s) and then withdrew.”

Ms Milne says the lake contributes only 57 megawatts, but Hydro Tas says it provides 40 per cent of the water for Gordon Power Station, which can generate 432MW.

The flooding of Pedder in 1972 provoked one of the nation’s first major environmental struggles and gave birth to the world’s first green party.