Creating wet acres in the Missouri River for fish populations

Abstract

From the early 19th century to the present, engineering of the Missouri has transformed the river from a complex multi-channel system with highly variable width and depth into a much more uniform, single-thread channel that is narrower, deeper, shorter, and characterized by much more uniform flow. This transformation process has caused the reduction of the overall length of the Missouri by 10% and decreased the channel surface area by as much as 80% in some reaches. The overarching goal of this research is to evaluate the hydraulic performance of different structures found in the Missouri River for creating new shallow water habitat (SWH). Such structures include dikes found in their original form, notched dikes and chevron dikes. A channel surface area qualifies as a SWH when the flow depth is less than 5ft and the depth-averaged velocity is less than 2.5 ft/s. The hydraulic performance of the aforementioned structures will be evaluated via detailed field monitoring studies for a range of flow conditions and for different locations within the stream. In addition, a 2-D hydrodynamic model will be used to describe the flow patterns around the hydraulics structures. The code will provide for different flow conditions the flow depth and velocity variation introduced by the structures. This paper presents the first phase of this ongoing research by comparing the numerical simulations with the field measurements.