Semi‐automated hydraulic model wrapper to support stakeholder evaluation: A floodplain reconnection study using 2D hydrologic engineering center's river analysis system

Abstract Floodplain reconnection projects are largely nature‐based solutions that have great potential to restore channel stability, attenuate stormwater, improve flood resilience, and improve water quality. The suite of possible restoration options for a given study area must consider the multiple uses and functions of river corridors, along with the potential impacts and benefits to adjacent infrastructure. Therefore, decision‐support frameworks designed to help stakeholders compare floodplain reconnection scenarios to best meet site‐specific design objectives are needed. A River Scenario Evaluation Tool (RiverSET) was designed in Python as a wrapper around a two‐dimensional hydraulic model (2D Hydrologic Engineering Center's River Analysis System, 2D HEC‐RAS) to guide an alternative analysis of various floodplain reconnection techniques. RiverSET runs each reconnection scenario in sequence and extracts the values needed to evaluate scenarios at user‐defined regions of interest. The results of these evaluation parameters (depth, duration, stream power, percent time inundated, and velocity) are compiled and displayed for review and synthesis. RiverSET's utility is demonstrated here through a case study on the Black Creek in Vermont, United States, involving five floodplain reconnection scenarios and a variety of stakeholders.