Breaching of a small irrigation dam in Oregon: A case study
irrigation, dam removal, fish passage, habitat, degradation, water quality, dams, migration, salmon, steelhead, stream habitat, diversion, upstream
Journal or Book Title
North American Journal of Fisheries Management
Dam removal or breaching (partial removal) is an increasingly common remedy for fishpassage, habitat degradation, water quality, and other problems caused by dams in the UnitedStates. The Jackson Street Dam, built in 1960 on Bear Creek in Medford, Oregon, resulted in abarrier to migration of Pacific salmon (Oncorhynchus spp.) and steelhead (O. mykiss), loss ofstream habitat, eutrophication, and an algae-choked impoundment in downtown Medford. The 11-ft-high concrete and wooden structure was owned and operated by the Rouge River ValleyIrrigation District as one of its primary diversions. The dam was breached in 1998, culminating a13-year, US dollar sign1.2 million effort led by the Rouge Valley Council of Governments and theMedford Urban Renewal Agency in collaboration with the irrigation district, other governmentagencies, and local citizens. Breaching reduced the dam to a series of three concrete stepsdropping 1 ft each, thereby providing fish passage and restoring a free-flowing stream within theformer impoundment. Before the dam was breached, a replacement diversion was built upstreamof the dam site to provide water to the irrigation district. The new 3-ft-high diversion is equippedwith effective fish passage facilities and is removed from October to April when irrigation is notneeded. Major factors affecting the project were the large number of stakeholders with conflictingmissions, underestimation of the project's cost and time frame, tests of the new diversion beforebreaching of the old dam, perseverance of key project supporters, and lack of opposition to theproject. Lessons learned from the project include the importance of stakeholder collaboration,selection of a volunteer lead agency or organization, consideration of the project owner's needs,education of the public about the project, accurate budget development, and setting realisticexpectations. A set of 10 recommendations is provided for the planning and implementation ofsimilar efforts, based on the lessons learned from this and other successful dam removal orbreaching projects.