Pump‐Station Intake‐Shoaling Control with Submerged Vanes

The circulating water‐pump intake at Iowa Power's Council Bluffs Power Station Unit 3, located along the left concave bank of the Missouri River near Council Bluffs, Iowa, has suffered from chronic fine‐sand shoaling problems both within the intake bays and just outside the intake structure. In order to maintain the pump‐intake bays sediment‐free, an innovative scheme of promoting a deep scour trench in front of the intake is developed using a 1:36‐scale movable‐bed model. On the basis of the model testing results, an array of submerged vanes, comprising two rows of 13, 9‐ft (2.7‐m) wide sheet‐pile vanes, were installed in the prototype in August 1985.The prototype performance of these vanes has been found to be excellent during the past 3.5 yr, and no dredging has been required. The positive riverbed‐scouring approach developed in this study may be a viable solution to resolve persistent sediment‐deposition problems at numerous riverside water intakes.