Lateral Weir and Split Flow Optimization with the Hydrologic Engineering Center's River Analysis System (HEC-RAS)

The Hydrologic Engineering Center (HEC) has added Lateral Weir and Split Flow Optimization capabilities to our river hydraulics software, HEC-RAS. The new capabilities are part of the steady flow computations and work in subcritical, supercritical and mixed flow regimes. The lateral weir optimization allows for general weir profiles that span multiple cross sections and computes the flow based on a sloping water surface from cross section to cross section. Lateral weirs can include multiple gates with gate openings specified by profile. The split flow algorithm enables the steady flow program to balance flows between streams to solve a looped or diverging network. This paper presents the capabilities that have been added to HEC-RAS for Lateral Weir and Split Flow Optimization. The input specifications and computation procedures are described.