Icon Water has contracted Abergeldie for 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 project kicked off in mid-October and is due for completion early in February 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 include; 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 currently sits at just under 50% full, will be monitored closely as the works proceed. Upstream flow monitoring will also be put in place to warm 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.
Abergeldie is a civil engineering contractor with over 25 years’ experience providing services in the utilities, energy and infrastructure sectors: the complex infrastructure needed to build better communities.