Located in Tasmania's remote southwest within the Tasmanian Wilderness World Heritage Area (TWWHA), the project involved complex engineering and environmental management to strengthen the dam's seismic resilience. 

The upgrade significantly reduces the already low risk associated with a major earthquake on the nearby Lake Edgar Fault, further enhancing the safety and reliability of Hydro Tasmania's renewable energy infrastructure. 

The project was carried out in partnership with Hydro Tasmania’s consulting arm Entura, with Tasmanian civil construction company Hall Earthmoving as head contractor for the upgrade works. 

Hydro Tasmania CEO Rachel Watson said the successful completion of the project was a major achievement for Tasmania and the team involved. 

"Completing the Edgar Dam upgrade four months ahead of schedule is an outstanding result and reflects the skill, commitment and collaboration of Hall Earthmoving and the project team," Ms Watson said. 

"This upgrade ensures Edgar Dam is even more resilient in the extremely unlikely event of a major earthquake." 

The major works included construction of a filter buttress along the downstream face of the dam, supported by a new crest wall and sealing works on the upstream side. 

The project completes more than a decade of planning, investigation, design and delivery work. Ms Watson said the project had delivered significant benefits for Tasmania's economy. 

"We're particularly proud that more than 95 per cent of the project budget was spent in Tasmania through local contractors, suppliers and specialist expertise," she said. 

"Projects like this support local jobs, skills and businesses while delivering long-term benefits for Tasmania's renewable energy future." 

Hydro Tasmania adopted stringent environmental controls to protect the sensitive Tasmanian Wilderness World Heritage Area values that surrounds the work site. 

The project was referred under the Federal Government’s Environmental Protection and Biodiversity Conservation Act to ensure proposed mitigation measures would minimise environmental impacts. 

Measures included vehicle and machinery washdown facilities, limiting driving at certain times to protect threatened species, and monitoring and management of water quality. 

"Working in such a sensitive environment required careful planning and a strong commitment to protecting the World Heritage Area's natural values," Ms Watson said. 

"Our team and contractors have demonstrated that major infrastructure projects can be delivered responsibly while maintaining strong environmental standards." 

With major construction now complete, the focus will shift to project demobilisation and Edgar Dam Campground reinstatement and rehabilitation.