Abstract: The Yazoo Backwater Area, located in west Central Mississippi, has historically experienced major flood events caused by high floodwaters from the Mississippi River and interior rainfall accumulation. To manage this, the US Army Corps of Engineers, Vicksburg District (MVK) proposed the construction of a 12-pump, 14,000-cfs-capacity pump station. The pump intake performance of the proposed pump station was evaluated using a scaled physical hydraulic model. The 1:17.62-scale model incorporated the hydraulically relevant components of the design including the inlet channel, all 12 intake bays with formed suction intakes and pump columns, abutments, and surrounding topography.
Various pump-operating conditions and intake water-surface elevations were evaluated for acceptable pump performance. Approach-flow conditions were generally symmetrical with minor contraction at the intake divider walls. The outer pump bays produced a less uniform flow distribution. Surface vortices were found to be unacceptable for several pump-operating conditions at the minimum-intake water elevation (EL) and pump-on water-surface elevation. Tests indicated that vortex suppressor beams would be required in the pump bays to reduce the severity and frequency of surface vortices. With the beams installed, the pump intakes provided satisfactory hydraulic performance for the approach-flow conditions.