Charleston Harbor in South Carolina faces increasing compound flooding driven by storm surge, tides, rainfall, and river discharge. This project will deliver decision-ready, validated evidence quantifying how wetlands perform to reduce urban compound flooding impacts in the harbor.
Why We Care
Charleston Harbor is vulnerable to compound flooding, when storm surge, tides, heavy rainfall, and river flows occur together. At the same time, the harbor contains extensive wetlands that may help reduce flooding in nearby developed areas.
Local and regional planners need clear, usable information showing where wetlands provide flood protection and how much difference they make. Stakeholders — including the City of Charleston Office of Resilience, U.S. Army Corps of Engineers (USACE), and South Carolina Sea Grant — have identified ingestible GIS-ready flood layers showing “with vs. without” wetland and nature-based solution scenarios as the highest-value capstone output for immediate use in planning workflows.
What We Are Doing
Building on modeling advances and a validated wetland-resolving hydrodynamic framework developed for Winyah Bay, South Carolina, the project team will operationalize an urban-aware modeling system with riverine boundary forcing to simulate compound flooding for three historical storms and one synthetic extreme event. Paired simulations will quantify the nature-based solutions “protection signal” as spatial differences in total water level, inundation depth, and flood extent. Primary products will include GeoTIFF and feature-class GIS layers, along with infrastructure-relevant summaries highlighting flood mitigation effects in stakeholder-priority areas. Model performance will be validated against tide gauge and stream gauge observations and available inundation evidence, and uncertainty will be documented.
Benefits of Our Work
The project team will advance a coupled river-coastal modeling system within an urban context to deliver decision-ready GIS products that quantify wetland flood protection benefits for stakeholder use. These datasets will be delivered in formats compatible with City of Charleston and USACE planning systems, enabling immediate application in flood resilience planning and wetland protection evaluation.
The project is led by Dr. Shaowu Bao with Coastal Carolina University. The project is part of the Cooperative Institute for Research to Operations in Hydrology (CIROH).