WA – Logue Brook Spillway Reconstruction
Author: Bob Wark. The Water Corporation has awarded a contract for the reconstruction of the Logue Brook Spillway. The project commenced in November 2014 and is expected to be completed by July 2015. Logue Brook dam is a 49 m high earthfill dam that supplies water to the Harvey Irrigation District. Completed in 1963, the reservoir formed by the dam was originally designed to store 24 GL. However concerns about the relatively low spillway capacity led to the storage capacity being reduced to 21.7 GL in 2010.
The project involves upgrading the existing side channel spillway from its existing nominal capacity of 25 m3/sec to the 1:1 000 000 AEP flood capacity of 160 m3/sec. The scope of work involves demolition of the existing spillway, excavation for the approach channel, crest structure, chute and stilling basin, placement of 2000 m3 of concrete and reconstruction of the bridge over the spillway.
The reservoir is used extensively for irrigation during the summer holiday period. The storage will remain open for these activities and will continue be managed for irrigation purposes as well. Current storage levels are well down as the storage is at about 50% storage capacity.
Later phases of the remedial works projects will deal with issues of piping through the saddle dam and ultimate upgrading of the spillway capacity.
The current project is currently demolishing the existing spillway.