SRF, as part of a design-build team for the United States Army Corps of Engineers (USACE), performed hydraulic analysis and design computation for revetment design along 1.5 miles of dam embankment. The embankment is part of the Lock and Dam #3 facility on the Mississippi River that holds back Marsh Lake and Gantenbein Lake. The revetment design followed EM1110-2- 1601 procedures and included riprap revetment, geosynthetics protection, integrated root wads for habitat, and articulated concrete mat design at spillways associated with each lake.
The Marsh Lake design also incorporated an outlet structure comprised of aluminum stop logs housed within a precast concrete structure and outlet through a 36-inch reinforced concrete pipe. The structure is designed to regulate the Marsh Lake water level. HEC-14 methodology was followed to design an energy dissipater at the culvert outlet.
Access and construction sequencing were critical to a successful project. Coordination with the contractor allowed for efficient and effective designs that were able to better accommodate the unpredictable nature of this large riverine system.
The project design adhered to Wisconsin DNR, Minnesota DNR, USACE and Minnesota PCA rules and permits. Construction limits were strongly dictated by extreme environmental conditions, environmentally sensitive areas, and the need to maintain the flow of commerce.