KAHLOTUS, Washington -- On Thursday, June 27, Lower Monumental Lock and Dam is celebrating the 50th anniversary of its construction with a commemoration event beginning at 9 a.m. with an open house from 9 a.m. to 10:00 a.m. and a ceremony from 10:15 a.m. to 11:00 a.m. The public is invited to the day’s festivities marking U.S. Army Corps of Engineers efforts to build the dam, navigation lock, powerhouse, fish ladders and recreation areas. The keynote speaker will be Lt. Col. Christian N. Dietz, Walla Walla District Commander.
This congressionally authorized project includes Lower Monumental Dam, powerhouse, navigation lock, two fish ladders, a juvenile fish facility (JFF), and appurtenant facilities providing for navigation, hydroelectric generation, recreation, and irrigation. The dam is located at the head of Herbert G. West Lake, the reservoir created by Lower Monumental Dam. It is 3,791 feet long, with an effective height of about 100 feet. The dam is a concrete gravity-type dam, with earthfill abutment embankments. Construction of the project began in June 1961, and it became operational in 1969. The entire project is considered complete. Construction of the additional generating units started in 1975, and was completed in 1981. The powerhouse has six 135,000-kilowatt units. Power generated during fiscal year 2017 was more than was 2.67 billion kilowatt hours.
There are two fish ladders for migrating adult salmon and steelhead to use. Modifications to improve adult Pacific Lamprey passage include installation of passage structures and metal plating to assist lamprey upstream. In 2007, a spillway weir was installed to improve conditions for juvenile fish passage at the dam. During 2017, more than 3.2 juvenile salmon and steelhead were collected by the Juvenile Fish Collection and Bypass System. About 1.1 million fish were bypassed back into the river, and about 2.1 million were transported for release below Bonneville Lock and Dam.
Lower Monumental is a single-lift lock, 86 feet wide by 666 feet long, with a 100-foot vertical lift. About 2,182,829 tons of commodities passed through the navigation lock during 2017. The cargo primarily consisted of grains, petroleum products, fertilizer and wood products.
About 50 Walla Walla District employees work at the Lower Monumental Project. They serve as electricians, lock operators, mechanics, welders, riggers, painters, utility workers, heavy equipment operators, biologists, park rangers, environmental resource specialists, administrative support staff, maintenance workers and engineers. Together, they manage the safe and continuous operation of the project.
Parking will be on the North Shore, off Devils Canyon Road. Please bring a valid government ID.
To learn more about the Corps of Engineers and its mission in the Walla Walla District, see the District website at www.nww.usace.army.mil.
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