The Lock and Dam 22 Fish Passage Improvement Project would restore a migration pathway for fish at Lock and Dam 22 by constructing a fish passage structure known as a fishway on the spillway. If completed, this project would increase access to upstream habitats and improve the size and distribution of native migratory fish populations. The project was developed as part of the Navigation and Ecosystem Sustainability Program and would be the first of this kind on the Upper Mississippi River.
The two main goals of this project are to restore a connection for fish migration on the Upper Mississippi River and to learn from the project so that knowledge gained can be applied to other fish passage projects.
Lock and Dam 22 is located near Saverton, Missouri, on the Mississippi River, roughly 10 miles south of Hannibal, at river mile 301.2. The proposed fish passage structure would be constructed on the spillway portion of the dam, on the side furthest from the Illinois shore, and would extend downstream into the tailwater area.
THE TENTATIVELY SELECTED PLAN
Over the course of the last year, a team of environmental specialists evaluated various project options (called alternatives) to identify how each would perform. This process led to the selection of a Tentatively Selected Plan, also known as a TSP.
The TSP for this Project includes four features:
- A Rock Ramp, known as the fishway, will have a rock bottom and series of aligned boulders with gaps and spaces suitable for water and fish to move in-between.
- A bridge that extends from the storage yard over the fishway and tie into the spillway to enable people and vehicles to move over and around the fishway.
- Water control structures, or stoplogs, will be integrated into the bridge to control the flow of water into the fishway for research and allow for maintenance.
- And finally, a fixed debris boom immediately upstream of the fishway will protect it from large woody debris and ice; and serve as a safe platform for monitoring and fish management activities.