Judy Reservoir Dam B, located in Sedro Wooley, Washington, is a critical water supply infrastructure managed by a public utility. Built in 1946 by URS Grenier Woodward-Clyde, this earth dam stands at a hydraulic height of 80 feet, with a structural height of the same measure. The dam has a storage capacity of 5100 acre-feet, primarily serving water supply purposes for the region.

With a surface area of 140 acres and a drainage area of 1.5 square miles, Judy Reservoir Dam B plays a crucial role in regulating the flow of the Tr-Skagit River. The dam has a high hazard potential but is currently in a satisfactory condition, as confirmed by the last inspection in January 2019. The dam is under the regulatory oversight of the Washington Dept of Ecology, ensuring that it meets all necessary safety and environmental standards to continue providing reliable water resources to the community.