Locks and dams constructed on the Upper Mississippi River (UMR) ensure a navigable channel for nautical transportation and river commerce, but fragment aquatic habitat and disrupt fish and mussel populations. While fish passage devices are essential to reestablish longitudinal connectivity and restore ecosystem function, their effectiveness on the UMR is poorly understood. This study evaluated the performance of four fish passage alternatives at Melvin Price Locks and Dam (Mel Price) near Alton, Illinois, one of 29 lock and dam structures on the UMR, using a two-dimensional depth-averaged hydrodynamic model. The model simulates hydraulic characteristics including water depth and flow velocity. Fishway design criteria were established based on fish swimming performance (velocity thresholds) and body size (depth requirements) to ensure passage for multiple species with a range of swimming abilities. Four fishway alternatives were tested: three stepped pool alternatives and a nature-like constant sloped rectangular channel with elevated roughness. The stepped pool alternatives feature a series of pools separated by weirs. Flow over the weirs is influenced by blocks placed along their crests. The three stepped pool alternatives are: a rectangular channel with equally spaced blocks along the weir crests, a trapezoidal channel with equally spaced blocks along the weir crests, and a rectangular channel with variable block spacing along the weir crests.
Matthew Raymond Kliegl (Sun,) studied this question.