WA – Logue Brook Dam – Spillway Upgrade Project July 2015
The Water Corporation’s contract for the reconstruction of the Logue Brook Spillway is proceeding as planned. The project commenced in November 2014 and is expected to be completed by the end of July 2015. Logue Brook dam is a 49 m high earthfill dam about 130 km south east of Perth that supplies water to the Harvey Irrigation District. Completed in 1963, the reservoir formed by the dam stores 21.7 GL.
The project involves upgrading the existing side channel spillway from its existing nominal capacity of 25 m3/sec to a 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 amounting to almost 100 000 m3, placement of 2000 m3 of concrete, reconstruction of the bridge over the spillway and reinstatement of the road access across the crest of the dam.
Progress was delayed for more than a week due to severe bushfires in the region. While the fires did not directly threaten the site, there were no firefighting resources available to fight a fire if one broke out near the site.
The site June 2015
By early June the project had reached the stage where the final sections of the chute floor were being poured and preparations were in hand to place the access bridge. The curved approach walls were also being constructed.
Site July 2015
By early July the bridge was in place and fill placing was proceeding in spite of the winter weather. The contractor had stockpiled and protected sufficient fill at the correct moisture content to enable the fill to be placed during dry spells. Protecting the placed fill with plastic sheeting minimised the damage during wet weather. The current planning is that the remainder of the work will be completed by the second week in August, although final sealing of the road may have to be delayed until later in the year.
Final sections of spillway chutewalls being placed, July 2015