Flood Potential Portal: A web tool for understanding flood variability and predicting peak discharges

The Flood Potential Portal (https://floodpotential.erams.com/) has been developed for the contiguous United States, as a practitioner‐focused tool that uses observational data (streamgages) to enhance understanding of how floods vary in space and time, and assist users in making more informed peak discharge predictions for infrastructure design and floodplain management. This capability is presented through several modules. The Mapping module provides tools to explore variability using multiple indices, and provides detailed information, figures, and algorithms describing and comparing flooding characteristics. The Cross‐Section Analysis module allows users to cut regional‐scale sections to interpret the role of topography in driving flood variability. The Watershed Analysis module provides multiple methods for quantifying expected peak discharge magnitudes and flood frequency relationships at user‐selected locations, including the integration of observed trends in flood magnitudes due to climate change and other sources of nonstationarity into decision making. The Streamgage Analysis module performs streamgage flood‐frequency analyses. These modules are based in part on the flood potential method, through the use of 207 zones of similar flood response defined using more than 8200 streamgages with watershed areas <10,000 km2. Regression models that define each zone had high explained variance (average R2 = 0.93). An example is provided to illustrate use of the Flood Potential Portal for the design of a hypothetical bridge replacement.