Reza Jamshidi (Northeastern University, United States); Yuyang Li (Northeastern University, United States); Jenna Brooks (Northeastern University, United States); Kelsey Pieper (Northeastern University, United States); Nate Jones (University of Alabama, United States); Wilson Mize (North Carolina Dept. of Health and Human Services, United States)

A significant fraction of the global population is reliant on unregulated private wells for drinking water, which lack routine monitoring of water quality. However, many of these users are at risk of well water contamination due to surface water flooding. Our research advances well water surveillance after disasters by enhancing identification of well users at-risk of flood-related contamination using NASA Surface Water and Ocean Topography (SWOT) satellite observations. Our study is focused on North Carolina in collaboration with the State’s Department of Health and Human Services. In this presentation, we present updates on our near real-time flood inundation mapping system. First, SWOT derived water surface elevations are assessed at USGS gauge locations throughout the state. Next, given that SWOT is not intended to capture peak flood conditions within our surveillance systems, observations for a range of river discharges are used to calibrate and validate our mapping system. To assess the value of integrating SWOT data into our systems, calibrated model results are compared to output from previously calibrated HEC-RAS hydraulics models (elevations and extents) and water extents derived from Sentinel-1. To illustrate the capabilities of our surveillance system, results for a recent flood event (Hurricane Helene, September 2024) are presented.