Designing or Evaluating a Spillway? Know the Controllers of the Control Section!

ABSRACT ONLY - Inadequate spillway capacity is one of the most common deficiencies at dams and embankment dam overtoping and breaching is responsible for more than a third of recent dam failures in the United States. While designing a spillway, an understanding of the conditions at the spillway control section and their impacts to conveyance and overall hydraulic behavior is required to provide an efficient, sustainable solution.
Conditions at the control section such as crest shape, structural features, approach conditions, obstructions, and tailwater submergence can impact a spillway's hydraulic performance. Oftentimes well-defined relationships for these various spillway crest conditions on spillway performance are not available, and therefore, their impacts are difficult to evaluate.
This presentation will provide a perspective on spillway control section conditions that are sometimes overlooked, but can adversely impact spillway performance. Actual spillway case studies will be used as examples. Recommendations for confirming spillway performance using CFD modeling will be discussed.