Corin Dam wall upgrade

In late August, Icon Water contracted Abergeldie to repair and upgrade works to the Corin Dam spillway and its interface with the clay core of the dam wall. The works will make an important contribution to the water supply security to Canberra and the surrounding region. The $1 million dollar contract with Abergeldie ($2.9 million project in total for construction) kicked off in mid-October and completed in May 2016.

Corin Dam, constructed in 1968, is a clay core, rock-fill embankment on the Cotter River, in the Namadgi National Park, about 60 km south west of Canberra. It is one of three water supply storage dams on the Cotter River and is upstream of the Bendora and Cotter Dams. It releases water into the Cotter River to supplement storage in Bendora Dam on an as required basis.

The works included: demolition and reconstruction of a portion of the road access bridge across the spillway, modifications to the bridge abutment with a revised profile up to crest level; demolition of the existing reinforced concrete wave walls and reconstruction to a new profile; removal and reconstruction of a section of the embankment crest with zoned placement of revised filter and core cross-sections; and re-establishment of the road across the dam crest, including a pedestrian path and vehicle barriers.

The dam level, which sat at 50% full, was monitored closely as the works proceed. Upstream flow monitoring was also put in place to warn of potential rapid inflows. These precautions are essential as modifications to the dam wall core will require a short-term lowering of the height of the embankment, temporarily reducing the dam’s capacity.

Icon Water provided regular updates to the community in regards to the progress of the works and when Corin Dam, Corin Road and Stockyard Spur Walking Track. Icon Water endeavoured to minimise any inconvenience to our community, and to work with our stakeholders to ensure a safe and successful project.

 Video by Abergeldie Complex Infrastructure.