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Entura supports swift, successful completion of Edgar Dam upgrade

7 August, 2026

Entura is proud to have contributed specialist expertise to support Hydro Tasmania’s major $35.5m upgrade at Edgar Dam, which has been completed four months ahead of schedule.

The milestone marks the conclusion of more than a decade of planning, investigation, design and delivery of the upgrade – and Entura has collaborated with Hydro Tasmania throughout the journey.

Edgar Dam was built in 1972 as a 17 m-high zoned earthfill dam with a 430 m-long crest and partial concrete capping. It is part of the Gordon–Pedder hydropower scheme, which includes the largest water storage in Australia and provides up to 13% of Tasmania’s power.

Due to updated understanding of the nearby Lake Edgar Fault, previously thought to be inactive, Hydro Tasmania planned to upgrade the dam to strengthen its seismic resilience. The upgrade, for which Entura developed the concept and detailed design, 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 upgrade brings the dam in line with modern engineering standards.

As Edgar Dam is located in Tasmania’s south-west within the Tasmanian Wilderness World Heritage Area (TWWHA), the upgrade project involved significant engineering complexity and rigorous environmental management. This included the need to investigate complex geological conditions, dewater ponded water at the downstream toe, maintain road access on the downstream causeway, limit the disturbance footprint and traffic movements, and work in a very remote location subject to inclement weather conditions.

Entura has supported the project over many years, commencing with the Dam Safety Review in 2010, option studies and geotechnical investigations, and developing the concept design and detailed design of engineering solutions.

More recently, our environment and planning specialists supported the upgrade project with ecological studies and preparation of documentation for planning and environmental approval processes.

Entura provided ongoing support during the construction phase of the project, including design support, engineering inspections, additional geotechnical investigations and geological mapping to confirm that the construction works meet the design intent.

“As part of Hydro Tasmania, Entura is deeply committed to the resilience and safety of Tasmania’s power and water infrastructure and we’re always proud to collaborate with our Hydro Tasmania colleagues and contractors to achieve great project outcomes.” said Wayne Tucker, Entura’s General Manager.

“During the construction phase of the Edgar Dam upgrade, our teams were extremely responsive, providing geotechnical investigation and technical advice whenever needed, so that the contractor could maintain momentum and progress the work efficiently.”

The dam upgrade involved many Tasmanian contractors and subcontractors, led by Hall Earthmoving as the principal contractor.