39-6 An Integrated Flood Modeling Approach for FEMA Floodplain Mapping in Complex Karst Watersheds

Session: Understanding Karst Hydrology and Karst Aquifers Using Innovative Tracers and Other Technologies

Presenting Author:

Authors:

Abstract:

Threats from stormwater flooding in Kentucky are ongoing and, in the past five years alone, billions of dollars of damage, along with dozens of lives, have been lost due to unpredictable and poorly mapped floodplains and a lack of flood extent and monitoring data. These hazards are exacerbated in karst regions, where landforms like caves, sinkholes, and underground rivers serve as threat multipliers for hazardous environmental conditions, which are then compounded by continued population growth and development in urban areas. In Kentucky, nearly 50% of the state is karst and relies upon, and is impacted by, groundwater resources. Recent flooding across the state in 2021, 2022, and again in 2025 caused headlines due to the repeated, widespread, and intensive occurrence of these flood events in the state. Recent studies suggest more than 50% of infrastructure is not protected in karst areas based on FEMA 100-year floodplain maps. Stormwater infrastructure in karst areas is often integrated with the groundwater system, such as in Bowling Green, KY, through the use of sinkholes and injection wells, which can exacerbate flooding and complicate modeling efforts. This study builds upon a successful pilot study to develop a predictive flood mapping and modeling method using ArcGIS GeoAI toolbox for urban karst groundwater systems using a high-resolution precipitation and water level data monitoring network, while integrating that model and the requisite parameters with FEMA-approved modeling software. The outcomes of this work allow for better understanding and predictability of the karst hydrologic response to a 100-year flood events, and those of varying, smaller magnitudes, while serving as an integrated framework for future modeling and community partnerships to address these floodplain mapping and stormwater management issues in other karst areas.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-11080

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.