Sediment Control at Water Intakes along Sand-Bed Rivers

Abstract

Results from five physical hydraulic model studies of riverside water intakes situated along the Missouri River reach between Sioux City, Iowa, and St. Louis, Missouri, are presented. Movable-bed, undistorted Froude-scale models are used to determine the effectiveness of structural modifications in the vicinity of the intake to limit the influx of bed-load sediments. Solutions developed in each case include a series of submerged flow-turning vanes located on the riverward side of the intake. A sediment-barrier wall between the vanes and intake increases the streamwise velocity component, enhancing the effectiveness of flow-turning vanes in maintaining a deep scour trench. Effective solutions determined using physical hydraulic models are verified at the prototype scale, as demonstrated by years of trouble-free operation at locations where the recommended sediment-control measures have been installed. Results presented in this paper provide design guidelines for bed-load sediment control at riverside water-intake structures on sand-bed rivers.