Override discharge under bridge
For some cases such as (1) bends; (2) large overtopping flows over approach roadways; or combinations of (1) and (2), the flow distribution under the bridge becomes complex and HEC-RAS may not be able to properly model these conditions. Under these conditions, user can override the discharge under the bridge to account for such complex flow patterns. Several examples of such problems and suggested solutions are presented in the ABSCOUR Users Manual, Chapter 11, Appendix A. This approach is generally recommended for sensitivity analyses rather than for final scour evaluations.