Columbia Basin Project, Grand Coulee Siphon Breaker Building, Grand Coulee, Grant County, WA

Significance: The Siphon-Breaker Building played a small but critical role in the process of delivering water from the Columbia River to the irrigation system. Its main function was to manage the flow at the top of the pump discharge line, where water ran into the stilling pool at the head of the Feeder Canal. When a pump stopped, the flow would reverse and the water would be siphoned back to the Pumping Plant unless there was a mechanism to prevent this action.
Survey number: HAER WA-139-D
Building/structure dates: 1948-1950 Initial Construction
Building/structure dates: 1972-1973 Subsequent Work
Building/structure dates: 1975 Subsequent Work
Building/structure dates: 1980-1982 Subsequent Work