Mississippi River Fish Passage Improvement

Lock and Dam 22 on the Upper Mississippi River is a vital part of the inland navigation system. The surrounding river also serves as an important habitat for native fish. Located near Saverton, Missouri, the waterway structure limits access to the mainstem and tributary habitats many native species rely on for spawning, feeding and seasonal migration. To restore that connection, the USACE Rock Island District launched the Lock and Dam 22 Fish Passage Improvement Project, the first fish passage project funded for construction under the Navigation and Ecosystem Sustainability Program on the Mississippi River.

Stanley Consultants provided final design for the passage improvements, leading a multidisciplinary team of hydraulic, structural, geotechnical, civil, biological, architectural, electrical and mechanical engineers. The project centers on a rock ramp fishway constructed along the spillway. Designed to emulate natural river conditions, the fishway uses rock, boulders, elevation changes and varied flow paths to help fish navigate upstream while maintaining the operational requirements of the active lock structure.

Supporting improvements included a reinforced concrete intake structure, an eight-span bridge system, water control features, steel bulkheads and an upstream ice and debris boom. The design also accounted for flood loading, debris impacts, scour protection, constructability, site access and long-term maintenance in a dynamic river environment.

Beyond restoring ecosystem connectivity, the project was designed to support long-term research and future restoration efforts throughout the Upper Mississippi River system. Stanley incorporated permanent infrastructure for passive integrated transponder tag arrays, split beam hydroacoustics, ARIS imaging sonar, acoustic doppler current profilers and cabled hydrophone telemetry, allowing researchers to monitor fish movement, hydraulic conditions and fish population data over time.

The team also designed the equipment center and research deck, a 750-square-foot structure elevated above the 500-year flood elevation to support remote monitoring, field observations and operations. To improve stakeholder coordination throughout design, Stanley developed a 3D-printed model that helped communicate how the fishway, bridges, lock, dam, debris protection and monitoring systems would function together once constructed.

The completed design reconnects critical habitat for more than 30 native fish species while providing a platform for long-term research and adaptive management. By combining ecosystem restoration, hydraulic engineering and advanced monitoring technology, the project demonstrates how navigation infrastructure and environmental restoration can work together. Data gathered through the monitoring systems will help guide future fish passage improvements throughout the Mississippi River system.