Power

Location

Squamish, British Columbia

Owner

Northern Utilities Incorporated

Contractor

Peter Kiewit Sons Co.

Value

$48 million

Northern Utilities selected Peter Kiewit Sons Co., a subsidiary of Kiewit Corporation, to construct this $48 million, design-build, 50-megawatt, run-of-the-river hydroelectric project. The site was a major design and construction challenge due to environmental concerns in the river and surrounding areas. Dam elements included a 21- by 14- by 11-metre-deep powerhouse, penstock and intake facilities, including a rubber weir, radial gate structure, intake structure and sedimentation sluiceway.

Heavy civil and tunneling crews worked simultaneously to complete the facility in less than 30 months. Sitework required 39,000 cu. metres of overburden excavation, 35,500 cu. metres of rock excavation and 8,900 cu. meters of concrete for the powerhouse and intake facilities. The project used a tunnel boring machine to construct a 2,600-metre-long, 4.1-metre-dia. lower tunnel. Additionally, crews built a 427-metre-long, 3.66-metre-dia. D-shaped upper tunnel and a 152-metre-long, 3.35-metre-dia. "raise bore" vertical shaft to connect the upper and lower tunnels.

Major equipment included two 720-RPM, 25-megawatt vertical Francis turbines; twin vertical, synchronous, 30-MVA, 13.8 KV generators; two 30/45 MVA, 13.8/65 KV transformers and static excitation equipment; two 12-cu.-metre/sec. by-pass valves; a 69 KV transmission line; and a 70-tonne powerhouse crane.