Stakeholder Driven Sensor Deployments to Characterize Chronic Coastal Flooding in Key West Florida

A changing climate and growing coastal populations exacerbate the outcomes of environmental hazards. Large‐scale flooding and acute disasters have been extensively studied through historic and current data. Chronic coastal flooding is less well understood and poses a substantial threat to future coastal populations. This paper presents a novel technique to record chronic coastal flooding using inexpensive accelerometers. This technique was tested in Key West, FL, USA using storm drains to deploy HOBO pendant G data loggers. The accuracy and feasibility of the method was tested through four deployments performed by a team of local stakeholders and researchers between July 2019–November 2021 resulting in 22 sensors successfully recording data, with 15 of these sensors recording flooding. Sensors captured an average of 13.58 inundation events, an average of 12.07% of the deployment time. Measured flooding events coincided with local National Oceanic and Atmospheric Administration (NOAA) water level measurements of high tides. Multiple efforts to predict coastal flooding were compared. Sensors recorded flooding even when NOAA water levels did not exceed the elevation or flooding thresholds set by the National Weather Service (NWS), indicating that NOAA water levels alone were not sufficient in predicting flooding. Access to an effective and inexpensive sensor, such as the one tested here, for measuring flood events can increase opportunities to measure chronic flood hazards and assess local vulnerabilities with stakeholder participation. The ease of use and successful recording of loggers can give communities an increased capacity to make data‐informed decisions surrounding sea level rise adaptation. Plain Language Summary Floods occurring outside of storm events are increasing in number due to low‐lying coastal communities' exposure to rising sea levels. The extent and impacts of localized and recurrent flooding events are under‐studied compared to extreme storm events. Damaging floods can occur during a high tide or a rain event, and with these chronic floods increasing in frequency, the cumulative impacts caused by sequential events need to be better understood. Therefore, this paper presents a deployment method and results of low‐cost sensors that can capture flood occurrences and durations in targeted areas using storm drains as a deployment location. A team of researchers and local government employees successfully deployed these sensors between July 201