Kieways May June 2000 cover story
Each week, nearly 400 visitors make their way to Castlegar, British Columbia, to observe the construction progress at one of North America’s largest design-build hydroelectric projects, the Keenleyside Powerplant.

“This year, we have two summer students working here seven days a week as tour guides at the lookout site,” Greg Dixon, Kiewit project manager, said, “This has been a very popular attraction this summer.”

What tourists are seeing is a magnificent power plant nestled within the most hydro-electrically developed river system in the world, the Columbia River Basin. The Columbia River flows 1,200 mi. from the base of the Canadian Rockies in southeastern British Columbia to the Pacific Ocean in Oregon. It is the third longest North American waterway to reach the Pacific Ocean. The river and its 10 major tributaries are home to more than 400 dams, tapping the majority of Columbia’s generating capacity . . . more than 21 million kilowatts.

Background
The new Keenleyside Powerplant, which is located 11 km. (7 mi.) northwest of Castlegar, has significant ties to its forefather, the Hugh Keenleyside Dam located 415 m. (1,400 ft.) upstream.

The original Hugh Keenleyside Dam, completed in 1969, was one of three large dams constructed in Canada on the Columbia River during the 1960s and 1970s under the terms of the Columbia River Treaty. These dams offered significant benefits to the United States, both for flood control and for power generation optimization.
However, when the original dam was constructed, it was built without a power plant
and contained no provisions for power generation. With advancements in turbine technology and the economics of the design-build process, the Keenleyside Powerplant is becoming a reality for its owners, Columbia Power Corporation and Columbia Basin Trust.

Design-Build After deciding the design-build method would be the most cost-effective and quickest way to construct the new power plant, Columbia Power Corporation solicited proposals. “We chose Kiewit to construct Keenleyside primarily because of their bid and their partners. Kiewit did a better job of putting a team together to work on this project and illustrated the willingness to share and bear risks with those partners,” Lorne Sivertson, president of Columbia Power Corporation, said. “It’s a significant undertaking, but Kiewit has the experience and the knowledge to put together accurate costs and sound concepts, both of which the design-build method requires,” Dixon said.

But it wasn’t just Kiewit’s understanding of the risk that opened the door. The company's innovative design-build approach and creativity were also key factors. “This project would not have happened if we would have built it using the conventional method,” Sivertson said. Frank Margitan, Western Canada District area manager and sponsor of the Keenleyside Powerplant project, agrees. “There is no doubt in our mind that this project would not have come to fruition without the use of design-build,” Margitan said, “Our contracting group and designers have provided the best ideas and their approach has led to the viability of the project.” For the Keenleyside Powerplant project, Kiewit is serving as the general contractor; General Electric Canada Inc. of Lachine, Quebec, the turbine and generator supplier, and Harza Engineering Company of Chicago, Illinois, the project’s designer, are both serving as subcontractors. Together, the project team has extensive experience in constructing, manufacturing and designing large-scale power plants.

A Bird’s Eye View
The project consists of twin 85 MW Kaplan turbine generators, a 427-m. (1,400-ft.) concrete faced rock filled dam and a 1,280-m. (4,200-ft.) concrete lined approach channel that will divert water from the upstream reservoir of the Keenleyside Dam to the new power plant located 400 m. (1,300 ft.) downstream. In addition, Kiewit will realign the roads within the site that connect Keenleyside with the nearby Robson-Broadwater Highway. “This is one of the largest jobs that Kiewit has constructed in Canada without a joint venture partner,” Dixon said.

Work began in March 1999, and includes 4.5 million cu. m. (6 million cu. yd.) of excavation, including 3.9 million cu. m. (5.1 million cu. yd.) of overburden and 689,000 cu. m. (900,000 cu. yd.) of rock excavation. The job also includes 95,000 cu. m. (124,000 cu. yd.) of concrete for the power house and the approach channel; 8,500 tonnes (9,400 tons) of steel and rebar, and all the mechanical and electrical equipment associated with the 85 MW units.

Thirty, 12-in.-dia. deep wells are also being installed along the reservoir and across the approach channel mouth, which will allow the remainder of the channel construction below high water level to be completed in the dry.

The powerhouse itself is a 60 m. by 60 m. by 60 m. (200 ft. by 200 ft. by 200 ft.) deep excavation in solid rock. The 38.1-m. (125 ft.) excavation is separated from the Columbia River only by an 18-m. (60-ft.) wide rock plug. The plugs, which are located at the upstream end of the approach channel and the downstream tailrace, isolate the excavations from the reservoir and river during construction and will be removed upon completion of the powerhouse. Dixon said it’s been a challenge to dig a hole over 60 m. (200 ft.) down in solid rock.

"We envisioned a lot more problems, but we’ve been fortunate that we haven’t
had water seepage due to the precautions we have taken,” Dixon said.

Formwork Fabrication
One of the project’s most difficult steps was the formwork fabrication of the two draft tube elbows. The elbows redirect the water from a 10.5-m. (34-ft.) diameter opening, through a 90- degree radius, exiting through a 24.5-m. wide by 6-m. high (80-ft. wide by 20-ft. high) rectangular cross section. Fabrication of the draft tubes required three months to complete.

“The draft tube elbows are 12.2-m. (40-ft.) tall. Their unique shape will significantly improve the performance of the turbines,” Dixon said.
To complete the powerhouse concrete, various types of formwork were required. In addition to the draft tube forms, the carpenter shop completed over 1,000 sq. m. (10,700 sq. ft.) of cantilever forms; 2,500 sq. m. (27,000 sq. ft.) of flat forms; 345 sq. m. (3,700 sq. ft.) of curved forms for the scroll case; 177 sq. m. (1,900 sq. ft.) of curved formwork panels for the intake piers and 3,500 sq. m. (37,500 sq. ft.) of wood block-outs.

“The carpenters in this valley are the best tradesmen I’ve worked with. The quality of work here is extremely high,” Dixon said.

The formwork erection and stripping operations started in September 1999. Crews have been working three shifts since then to ensure that enough formwork is in place to keep the afternoon shift and night shift concrete pour crews busy. By the end of the summer, 75% of the first stage formwork will have been completed with only the upper intake structure remaining.

Concrete Operations
Two distinctly different methods have been used to place concrete. For mass concrete pours in the foundation of the powerhouse, a conveyor system was designed that would maximize productivity and reduce crane requirements. The conveyor system allowed the placement of the largest pours to be completed in a single shift. For smaller concrete pours, the tower crane and bucket have been used.

Mechanical
Mechanical operations have been working in conjunction with the concrete placement operations in order to install all the embedded items required for the electrical and mechanical equipment. The installation of the Unit One turbine began with the initial setup and welding of the lower pit liner and circular passage liner. The project goal is to complete the installation and commissioning of Unit One by November 2001, followed by Unit Two three months later. This is an average of 10 months ahead of the owners’ turnover date.

Powerhouse in Motion
Because technology has rapidly advanced over the years, the new Keenleyside Powerplant will employ two 85 MW hydraulic turbines, including three large intake and draft tube gates per unit. The turbines will spin relatively slowly, using high amounts of water with low amounts of pressure to produce energy.

“The old dam stored water, but no energy was produced,” Dixon said, “Once the new 18-story power plant is operating, the old dam will become a relatively dormant structure.” Bypassing the existing earth-filled dam, the 1.6-km. (one mi.) long approach channel diverts water toward the new powerhouse. To create power, the channel water enters the turbine scroll cases through six large intake gates. Water then passes through moveable wicket gates and down onto the variable pitch blades of the Kaplan runner. The runner shaft rotates, which in turn rotates the generator shaft and the generator rotor. The rotor, spinning inside the copper windings of the stator, creates a magnetic field which generates electricity. The water then exits through the tailrace.

Benefits to Surrounding Area
Besides providing an environmentally friendly source of generating electricity both for Canada and the United States, this new power plant provides many other added benefits.

“What has been an added plus is that 85% of the local people employed at Keenleyside live within 100 km. (62 mi.). Businesses in this area are also reaping the benefits as well,” Wally Penner, director of community and regional affairs for Columbia Power Corporation, said, “At first, we wondered if we had the labor force, but the workers here have experience in powerhouse construction because they’ve built hydroelectric power plants before.”

As an added bonus, 50% of the power plant’s profits will roll back into the valley’s Columbia Basin Trust, allowing the government to “give back to its constituents” within the area and support regional objectives mandated in the Columbia Basin Trust Act.

Safety
Margitan said that Kiewit’s Keenleyside safety record has been exceptional.

Approximately 550,000 hours have been worked to date, and of that amount, 75% of the work has been self-performed by Kiewit. An overall rate of 0.6 incidents per 200,000 work hours has been experienced by the Kiewit project team.

Project team addresses environmental concerns
Located in a pristine area of the continent, the Keenleyside Powerplant finds its home in one of the most environmentally sensitive parts of Canada. “Times are changing and to obtain the permits to build a project like this, you need a dedicated team that is very conscious of environmental concerns. It’s part of the job, just like safety,” Frank Margitan, Western Canada District area manager and sponsor of the Keenleyside project, said.

“Kiewit is adhering to the environmental requirements, which are very delicate issues,” Lorne Sivertson, president of Columbia Power Corporation, said.
“The Federal Government Fisheries Act states that there be no net loss of fish or fish habitat after construction. We’re required to mitigate or compensate fish loss, so we’ve built the necessary enhancements into this project,” Wally Penner, director of community and regional affairs for Columbia Power Corporation, said.

Enhancements are reflected in the design of the powerhouse’s tailrace. “We’ve oriented the tailrace so that the integrity of the existing eddies are maintained. The eddies create an environment that is good for fish, so we’ve replicated this existing habitat,” Penner said. Reclaiming borrow locations from the previous construction of the Keenleyside Dam during the 1960s is another example of the construction team’s environmental efforts.

“As we complete areas, we immediately re-seed them. As the project proceeds, the regeneration and revegetation of the land continues,” Penner said. Because of the area’s environmental sensitivity, Penner said that extra attention is being given to re-vegetating areas with native grasses and shrubs. A total of 30 hectares (75 acres) will be hydro seeded with local grasses and 60,000 trees and shrubs will be planted to provide a scenic view of the reservoir. “We’re constructing a wetland area, which will be a great habitat for frogs, turtles, ducks and other water fowl,” Penner said, “An access trail for deer and elk has also been maintained.”

One of the benefits of the project’s enhanced design is the dramatic reduction of
dissolved gases into the water environment. These gases cause “bubble trauma” in fish, and are a serious water quality issue within the Columbia River system. In addition, Penner said that water temperature can have a great impact on fish habitats. Therefore, water temperatures are being closely monitored between the reservoir and downstream so that any changes can be observed and mitigated when the new power plant is in operation.

“To maintain a consistent water temperature, we’ve made the canal as deep as the reservoir in order to draw water of varying temperatures and depths,” Penner said.

“It’s a well-thought-out, well-planned design and all measures have been put in place to build an environmentally friendly project that will avoid adverse effects,” Penner concluded.

this page last updated 2/4/07 CUBC home page