Author(s): Jesus Gracia-Sanchez; Victor Franco
Linked Author(s):
Keywords: Solid discharge; Sediment flushing; Bottom outlet; Reservoir sedimentation; Retrogressive erosion
Abstract: The convenience of using a bottom outlet to flush sediment from a hydroelectric plant project is evaluated. The project pretends to use one tunnel of the river diversion as a bottom outlet. Despite the use of induced retrogressive erosion on the river bed, the bottom outlet’s efficiency is low and implies a great waste of water. Sediment removal is strongly restricted by the reservoir’s shape and the low discharge load available for flushing. A physical model shows important sediment problems in the tunnel. In contrast, prototype computations showed no sediment deposits or obstruction in the sluice gates. Analysis of these opposite results is one of the main purposes of this study. A numerical model is used to simulate the retrogressive erosion on the channel bed in the reservoir. The calibration of the numerical model used data from a physical model of the bottom outlet structure.
Year: 2004