The firm that designed and provided construction oversight for central Oregon’s Pelton Round Butte Selective Water Withdrawal Project was honored late last week with a “Grand Award” from the American Council of Engineering Companies.
The award was accepted by Portland General Electric and project engineer CH2M HILL during ACEC’s 2011 Engineering Excellence Awards Gala on Friday at the Grand Hyatt in Washington, D.C. The Pelton Round Butte Hydroelectric Project is co-owned by PGE and the Confederated Tribes of the Warm Springs Reservation of Oregon.
Located near Madras, Ore., on the Deschutes River, the original Round Butte dam, built in the early 1960s, affected water flow and temperature so greatly that native salmon and other fish could not find their way out of the reservoir – Lake Billy Chinook -- and natural migration ceased.
In 2004, in an agreement with the Confederated Tribes of Warm Springs of Oregon, PGE hired CH2M HILL to complete a fish collection and bypass system at the three-dam, Pelton Round Butte Hydroelectric Project. The system is part of an ongoing effort to restore the anadromous fish runs to their natural habitat.
After thorough and complex evaluations, CH2M HILL designed and helped construct the Pelton Round Butte Selective Water Withdrawal Project, which, completed in 2009, is the only known floating surface fish collection facility coupled with power generation in the world. As a result of the selective water withdrawal project, the Pelton Round Butte Hydroelectric project has been certified by the Low Impact Hydropower Institute as a source of green power.
The project was designed to modify the surface current directions to improve guidance of the migrating fish into the fish collection structure, provide a fish sorting and handling system, exclude all fish from passing through the turbines, and ensure the water passing through the turbines complies with the state and tribal water quality standards in order to restore water quality to improve the fish habitat.
For the first time in 40 years, chinook, sockeye and steelhead salmon are able to complete their life cycles as the juvenile fish are passed downstream to the Deschutes River basin and then are able to return as adults to spawn naturally upstream of Round Butte Dam. More than 100,000 juvenile fish were captured and transferred downstream in 2010, its first full year of operation.
The design of the 270-foot-tall steel and concrete structure was significantly influenced by the complex construction challenges and site staging limitations, and 3D modeling was integral in developing the engineering data and material quantities.
The largest construction challenge was when it came to assembling, lowering and attaching the equivalent of a six-story building to the face of the existing power intake that was submerged 270 feet in water. With virtually no room on the crest of the dam, a pontoon barge with central moon pool was used for assembly, and the structure was designed so that remotely operated submerged vehicles could perform nearly all of the underwater work.
Other challenges included the underwater excavation of nearly 200 cubic yards of solid rock without blasting, drilling 11 30-inch-diameter rock sockets each about 30 feet deep, the installation of 1,100 feet of 24-inch-diameter steel pipe piles and the placement of nearly 200 cubic yards of high-strength underwater grout. All work activities were completed with minimal impact to daily power generation.
ACEC’s annual Engineering Excellence Awards competition recognizes engineering firms for projects that demonstrate a high degree of innovation, achievement, and value, and are chosen by a distinguished panel of judges possessing a vast array of industry expertise. Hundreds of projects from around the world are submitted and only 24 are selected as top award winners -- 16 Honor Awards and eight Grand Awards; one Grand Award winner is selected for the Grand Conceptor Award.
The Awards Gala is an elegant black-tie event attended by hundreds of industry leaders, members of Congress, federal agency officials and the media.
Headquartered near Denver, Colo., employee-owned CH2M HILL is a global leader in consulting, design, design-build, operations and program management for government, civil, industrial and energy clients.