New One-Dimensional Sediment Features in HEC-RAS 5.0 and 5.1

The current version (5.0) of the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) and the imminent version (5.1) include an array of new sediment transport capabilities. Previous HEC-RAS versions were limited to quasi-unsteady flow and vertical bed change. HEC-RAS 5.0 and later versions eliminate each of these limitations, including unsteady flow capabilities, lateral cross section change with the USDA-ARS bank stability and toe erosion model (BSTEM), and several other features that expand the model’s applicability. Coupling sediment transport with the HEC-RAS unsteady flow capabilities also leverages unsteady capabilities for sediment analysis, including mixed flow regimes, lateral and inline structures, and operational rules. Additionally, recent versions of HEC-RAS include new bed change algorithms, cohesive transport approaches, armoring methods, and an array of new output options. This paper will highlight the new one-dimensional (1D) sediment capabilities in recent versions of HEC-RAS.