Restoration of the Mississippi River Gorge: Issues and research needs

The Mississippi River Gorge has long been of central importance ecologically and economically to the Twin Cities, Minnesota region. It was unique for its high-gradient, boulder-cobble bed along the Mississippi that was valuable for fish and mussel habitat prior to alteration by locks and dams. Gorge restoration is increasingly discussed, as the river corridor is used more for recreation, commercial, and residential purposes rather than industrial uses. This study was intended to provide a synthesis of existing restoration work in the Gorge, an initial feasibility assessment of restoration actions, and to recommend next steps for restoration and research. We reviewed existing restoration activities and assessed the feasibility of restoring components of the ecosystem for ecological, historical, recreational and economic reasons, using the TELOS framework as an analytical tool. Some components of the Gorge ecosystem can be reestablished without removing the Ford Dam, which submerges part of the Gorge, including islands and historic and cultural features. However, some goals require dam removal, particularly fish and aquatic mussel passage. Future restoration is also limited by reservoir sedimentation. Some steps could be undertaken immediately to increase awareness of the Gorge's historical and ecological value and to collect further information required for restoration activities. More information is needed on the nature of sediment deposits, contaminants, and existing streambed materials before doing intensive ecological restoration. As the Ford Dam ages and maintenance costs increase while demand for parkland increases, the benefits of removal will increase.