Middle Fork Nooksack River Fish Passage
The Middle Fork Nooksack River Fish Passage Project was the result of 20 years of studies and planning by the City of Bellingham, Washington, and tribal, state, and private partners. This project aimed to bring fish back to the upper reaches of the Middle Fork Nooksack River in Whatcom County, Washington and restore the river more closely to its natural state. The 24-foot dam was built in 1961 to help supply drinking water to the city. Unfortunately it was built without a fish ladder or other passage to allow migrating fish to access vital habitat behind the dam. Chinook salmon, steelhead trout, and bull trout rely on this habitat for spawning and rearing. These fish are a vital food source to endangered southern resident killer whales. Removing this dam could potentially increase Chinook salmon populations in the region by over 30 percent, and in turn save the killer whales.
During the excavation for the pipelines, intake, and fish screen structures, we encountered boulders the size of cars. These boulders were anticipated to have unconfined compressive strengths of 36,000 pounds per square inch (psi) or greater which make it difficult to manually rock hammer.
Multiple blasts were conducted to reduce the boulders so they could be removed. The concrete dam, built in the early 1960s, was also removed by blasting. We drilled and blasted the dam in two 15-foot lifts. This was due to limited access with our equipment because of the height and width of the dam. Seismographs were placed on the existing concrete structures to monitor vibration levels. Blasting mats protected the existing structure which is a portion of the water channel for the city that flows separate from the rest.
Project construction was completed in 2022. The restored river channel now flows through the site of the dam removal. Ongoing monitoring efforts will continue until 2030 to confirm this reach remains passable for fish.
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We currently operate throughout the Western United States. We perform all applications of drilling and blasting including large-scale commercial quarries, heavy construction, road and highway construction, residential and commercial development, and utility and trenchline work.