Contract Description

The Work consists of the construction of 12,000 feet of various sized tunnels through bedrock ranging from 16 to 32 foot diameter, all by drill and blast methods. Following excavation, the tunnels are finished with a cast-in-place concrete liner. The excavation also includes a powerhouse cavern measuring 148 feet high by 442 feet long by 74 feet wide, as well as 1400 vertical feet of 30 foot diameter shafts. The shafts are also finished with a cast-in-place concrete liner. A total of 450,000 cubic yards of rock is excavated by drill and blast methods, with the waste rock subsequently hauled and placed in the adjacent lake to construct a submerged weir. Temporary rock support consisted of shotcrete and/or rockbolts on an as-needed basis.