Sediment Control at Lateral Diversions: Limits and Enhancements to Vane Use

Abstract

This paper presents the findings of laboratory flume experiments conducted to determine the limits to which submerged vanes can be used in preventing excessive bed-sediment ingestion into lateral diversions of flow from alluvial channels. The experiments show that a scheme of submerged vanes placed at the diversion entrance admits only a negligible rate of bed-sediment entry into the diversion when the ratio of unit discharge in the diversion to unit discharge in the main channel, qr, is less than about 0.2. Beyond this value, the effectiveness of the vanes diminishes. The sediment-control performance of the vanes can be enhanced in several ways. One enhancement is the use of a skimming wall in conjunction with the vanes. The wall and the vanes are effective for values of qr up to about 0.3. Another enhancement is to widen the diversion entrance such that, at the entrance, qr does not exceed about 0.3. Further potential enhancements (modified vane shape, uniformity of flow distribution into the diversion,...