22-05-2025
Report identifies 'significant structural concerns' at Tasmanian Pioneer Dam, recommends decommissioning
A dam in north-east Tasmania has "significant structural concerns" and should be decommissioned, a report has found.
Neighbouring the small township of Pioneer, the Pioneer Dam is believed to have been built nearly a century ago by the Endurance Tin Mining Company, with "limited records of its construction".
A report released in April, commissioned by the Department of Natural Resources and Environment, found the structural condition of the disused dam was "critically compromised".
It said recent severe weather events had caused trees to fall and create holes in the dam wall, and "unauthorised modifications" including the removal of culvert pipes had further compromised the dam's structural integrity.
Furthermore, it said the top of the dam wall had been used as "unauthorised access to an adjacent campground".
The report recommended the water levels be lowered immediately, and the dam decommissioned, given "indicators of imminent instability".
"The most risk averse and responsible course of action is to implement an immediate reservoir drawdown, followed by a staged decommissioning plan, unless a clear operational need justifies comprehensive rehabilitation works," Max Moller, of Hobart-based Flussig Engineers, stated in the report.
The Parks and Wildlife Service (PWS) said in the short term, it had decided to lower the water level once it receives engineering advice — expected in early July — advising it how to do so.
PWS closed the dam and nearby Pioneer Lake, which is popular for camping and fishing, following a site visit by the engineering company in December.
Alana Keygan lives in Pioneer with her family.
"I used to go kayaking on the lake on a daily basis, take the kids down there. It's just a really beautiful spot to be," she said.
"It's completely silent, you can hear the birds chirping and you're just surrounded by so much nature and beauty."
But she hasn't been since it was closed to the public, and is concerned about a potential dam breach.
The Dorset council is facilitating a community meeting between PWS and residents on Monday to discuss the situation.
Dorset Mayor Rhys Beattie said Flussig Engineers would deliver a briefing on their findings.
"Parks and Wildlife are taking the required steps to assure safety," she said.
Ms Keygan will be attending and advocating for an emergency plan in the event of a breach, and the installation of floodwater warning signs for the roads.
"And what systems are in place for the community to get the word out quickly to each other?" she said.
It's something another Pioneer local, Jenny Bellinger, would also like to see.
"I'm quite concerned on the safety aspect," she said.
"The kids in the town swim in the river because they couldn't go to the lake this year.
"Are kids going to notice that the water is rising quickly? I don't know.
"We need probably a siren there to let everyone know if the dam wall does break."
As part of the report, the engineers undertook modelling to see what would happen if the dam wall breached.
The modelling assumed the weather on the day of the breach was fair, with no rain.
While it predicted no residential or commercial buildings would be inundated, the floodwaters would likely cut off critical access routes and isolate communities.
Ms Bellinger wants more modelling done to see what would happen during rainy conditions.
"I think it needs to be updated to what would happen in a one-in-20-year event or a one-in-50-year event," she said.
The report said further assessments may be required to consider potential loss of life, given Pioneer Lake's use as a recreational camping and fishing site.
