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Client: Columbia Basin Trust & Columbia Power Corp.
Location: Castlegar, British Columbia
Completion Date: 2002
Capacity: 170 MW
Capital Cost: $140 Million US; Powerplant overall cost $180 Million US
Project Highlights:
The Hugh Keenleyside Dam is located on the Columbia River, near Castlegar, British Columbia. The dam was completed in 1969, under the terms of the Columbia Treaty between Canada and the
U.S. to provide storage for flood control and increase downstream generation. Neither generating facilities nor provisions for their future installation were incorporated into the dam. Klohn Crippen
Consultants Ltd. carried out site investigations, design and resident engineering for the project from 1961 to completion in 1969. The existing facilities include:
- A concrete gravity dam with a total crest length of 360m and a maximum height of 58m;
- A 450m long zoned earthfill dam with a maximum height of 52m founded on alluvial deposits over 150m deep;
- A 670m long upstream impervious blanket;
- A 15.2m wide navigation lock with a length of 88m and a lift of 23m;
- Four spillway bays controlled by 15.2m wide x 16.8m high vertical lift gates; and
- Two sets of four low level outlets controlled by 6.1m wide x 7.3m high vertical lift gates.
A pre-feasibility study for the addition of a powerplant to the dam was completed by BC Hydro in 1981. Preliminary design of a three-unit powerplant to be located at the end of the existing
concrete structures was completed in 1985. Between 1989 and 1992, Klohn Crippen, in joint venture, completed the final design for a 220 MW three unit powerplant located at the end of the
dam. However, the project was not carried through to construction at that time since it was not economic.
In 1995, the Columbia Power Corporation in joint venture with the Columbia Basin Trust applied for a license to build the powerplant. In late 1996
the Klohn Crippen joint venture was asked to reevaluate the project to determine if the cost and environmental effects of the project could
be reduced. As a result, the project arrangement was revised and the number of units reduced to two. This reduced the construction schedule from seven to four years
and reduced the energy cost more than 25%.
The revised powerplant arrangement consists of a 1500m long approach channel to bypass the existing dam and convey flow to a new
powerhouse built in an outcrop of massive bedrock 400m downstream of the dam. A concrete faced rockfill dam forms the right hand side of the channel downstream of the
existing dam. A short tailrace conveys the water back to the river. This arrangement utilizes the full head at the site and does not alter the existing structures or their performance, which is
a fundamental requirement of dam safety.
In early 1997, Klohn Crippen became the managers of the environmental assessment for the revised project, delivering the comprehensive
report on schedule in late 1997. The project obtained environmental approval in the spring of 1998. Concurrently, Klohn Crippen provided support to the Owner for obtaining a water license. The
Owner elected to implement the project through a design-build contract. Klohn Crippen, as the Owner’s Consultant, assisted in the selection of three pre-qualified design-build teams to bid the
Project. The proposal competition started at the end of 1997 and proposals were submitted in July 1998. Klohn Crippen assisted the Owner with the evaluation of the proposals and the finalization of
the design-build contract with the successful proponent. Klohn Crippen was responsible for reviewing the design and monitoring the work of the contract from commencement at the beginning of 1999 until completion at the end of 2002. The first unit generated power seven months
early and the project was completed ahead of schedule and on budget.
Services:
- Preliminary design
- Licensing
- Proposal evaluations
- Construction monitoring
- Environmental assessment assistance
- Design-build proposal documents
- Contract finalization
- Contract administration
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