Evaluation of Sediment Diversion Design Attributes and Their Impact on the Capture Efficiency

Abstract

AbstractMany riverine systems have been disconnected from their receiving basins by flood-protection levees and other engineered systems. Reconnecting these alluvial rivers with their receiving basins is a viable option to nourish and sustain existing coastal wetland systems as well as to build new land. This sediment nourishment can be accomplished through direct dredging and placement or through sediment diversions. Efficient design of sediment diversions is important to maximize the land building potential. This study’s objective is to quantitatively identify key design attributes of sediment diversions, influencing their ability to capture sediment. The outfall channel alignment angle (ϕ), intake invert elevation, and diversion size are hypothesized as key parameters. The analysis is limited to sediment grain sizes larger than 63 μm and has been performed using a validated three-dimensional numerical model. A time integrated sediment-water ratio was used as an indicator to reflect efficiency of sedime...