Remedial works are underway at Balingup Dam and Kirup Dam in the beautiful South-West of WA. Both dams are similar in their original designs with 9 m high earthfill embankments with sweeping trapezoidal channel spillways. The sweeping alignments for both spillways have proven somewhat problematic, with modelling indicating that the chutes would be unable to contain flows that their crests may pass. In addition, the integrity of the concrete was not meeting contemporary standards. Hence, with these deficiencies, new spillways were required.
Water Corporation undertook the design for the works and is now delivering them under a single contract owing to the similarities in the projects and the close proximity of the sites. Works are being undertaken by Entracon.
Working on these sites has delivered significant challenges with alignments constrained to similar ones to their predecessors. The sweeping alignments have been removed by realigning crest embankment areas (Balingup) and adding a side entry chute (Kirup).
Works on-site are currently on track to be complete prior to the Winter of 2020.
Author: Daniel Minson, Senior Engineer – Water Corporation