311 - High-resolution Hydrodynamic Observations to Inform Decision-making in Interdependent Coastal Stormwater System

Interdependent coastal infrastructure systems are vulnerable to the increasing risk of sea level rise, storm surge, and extreme precipitation. The resilience of stormwater systems plays a critical role in avoiding cascading impacts on other critical systems. The built stormwater infrastructure systems operate against the dynamic combined effects of tidal waves and extreme precipitation. As such high-quality observations to monitor the rainfall-runoff responses and tidal wave effects on backwater flow are critical to – understanding how the designed system functions in uncertain scenarios, improving hydrodynamics models used for flood assessment and forecasting, and supporting informed decision-making for climate adaptation. We present the value of high-resolution hydrodynamic observation at Tyndall Air Force Base (AFB) near Panama City, Florida by setting up an experimental data collection system using bi-directional stormwater flow sensors, which measures watershed runoff and backwater flow from the East Bay. We also collected and analyzed high-resolution precipitation data from locally installed rain gauges, and NOAA’s tidal stations’ water levels to correlate high tides with backwater flow. We utilize these observations to build and routinely calibrate the hydrodynamic Stormwater Management Model (SWMM) for Tyndall AFB, and present how the high-resolution observation helps to increase understanding of the physical hydrological and hydraulic processes at coastal regions, refine the predictive capability of floodwater level and volume with less bias and errors, and supports adaptation and resilience planning.