Replacing the old Crookston dam with rock rapids remedied a significant ecological and life safety hazard on the Red Lake River. And now the project was recognized with an Honor Award at the American Consulting Engineers Council–Minnesota’s 39th Annual Engineering Excellence Awards banquet, held January 27, 2006. Widseth Smith Nolting worked closely with the City of Crookston on this noteworthy project.

The former Ottertail Power dam west of downtown Crookston posed a threat on several fronts—to people, wildlife, and the environment. The dam was built in the early 1900s and rebuilt in 1942. Its vertical abutment produced an undertow that posed severe safety and stability hazards as well as ecological disruption. Eighteen deaths had occurred at the site since 1949, and erosion was an increasing threat to nearby homes and Riverview Healthcare.

Ten boulder weirs were constructed to replace the old dam. Each of the curved weirs is higher toward the sides to keep the river’s flow in the center of the channel. Plunge pools between weirs dissipate energy and serve as resting places for migrating fish. The upstream water surface has been maintained at the same elevation that existed with the former dam. Constructed rapids have been completed on the Red River of the North in Grand Forks and Fargo and on the Red Lake River in East Grand Forks.

The needs of the community as well as the region were complex, and the dam removal and rock rapids construction project not only met each challenge but also provided canoeists, kayakers, and anglers with a natural, attractive, and inviting recreational area.

ACEC–Minnesota’s annual competition recognizes engineering achievements that exhibit the highest degree of merit and ingenuity. Entries were judged on the basis of originality and innovation; future value to the engineering profession; social, economic, and sustainable design considerations; complexity; and meeting the client’s needs.

WSN is a multi-disciplined firm of over 140 employees providing engineering, architectural, land surveying, and environmental services. Its offices are located in Alexandria, Baxter/Brainerd, Bemidji, and Crookston, Minnesota; and Grand Forks, North Dakota.