Tacoma Power upgrades the Barrier Dam

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Our Generation and Natural Resources teams worked hard to complete phase one of an upgrade to the Barrier Dam spillway last year. The utility partnered with multiple agencies and regulators, a consultant, and a contractor, on this multi-year, multi-faceted project. The 12-foot-tall dam is part of our Cowlitz River Project; it diverts returning adult salmon to our fish separating facility. Water washing over the dam lands on a flat concrete slab, bringing lots of tumbling rocks with it. The rocks took their toll on the slab over the last 50 years. Our teams are fixing the damage and changing the spillway design so that rocks won’t be an issue in the future. The teams accomplished the Herculean feat of installing a cofferdam – a temporary dam that enables them to reach the spillway to do the upgrades safely. They worked together 12 hours a day, seven days a week, to put the temporary dam in place, including performing an impressive fish salvage effort after dewatering the cofferdam. The work does not affect public access to the site’s popular boat launch. The teams have the next phase of the upgrade planned for the summer of 2022.

{ Our dedicated staff successfully saved fish after dewatering the cofferdam. u The new spillway begins to take shape.