Rowallan Dam is a 43-metre high earth and rock-fill dam on the Mersey River in Tasmania’s north, and was commissioned in 1968. Its condition and performance were reviewed in 2011 as part of a planned program of risk assessment across our entire asset base.

This review found the dam’s performance was consistent with expectations for a dam of its design, construction and age. However, improved understanding of the dam’s risks meant Hydro Tasmania is now able to reduce risks that were unforeseen in 1968.

The $3.9M Hazell Bros contract is for works to upgrade the existing concrete spillway. Hazell Bros will construct new concrete walls inside the existing spillway walls, while retaining the existing walls in position. The new walls will be anchored into the bedrock beneath the dam using a series of post-tensioned steel anchors on both sides of the spillway. Work on the first stage of the upgrade started in November and will be completed by May 2013.

The second stage of the project will improve the flood capacity of the dam and is scheduled to take place during the 2014/2015 summer.

Hydro Tasmania’s Chief Technical and Operations Officer, Evangelista Albertini, said that the planned work would ensure the dam continued to perform well into the future.

“Hydro Tasmania manages a large asset base including 204 dams and hundreds of kilometres of man-made waterways to direct water to storages and power stations. These assets have been built over nearly a century of hydropower development.

“As the assets age we continue to monitor them for efficiency and safety and we invest to ensure they remain fit for purpose and provide ongoing service for the foreseeable future.”

Albertini said the work on Rowallan Dam will cost $13.4M over three years, and the project is part of Hydro Tasmania’s rolling 10-year asset management plan.

“Planned maintenance and upgrades help to retain our world-class standards. Our major project schedule ensures the electricity supply is reliable and maximises power generation, ensuring Hydro Tasmania remains Australia’s leading producer of renewable energy.”