Charleston, South Carolina Flood Zones

Charleston faces a combination of coastal and inland flood risks. Storm surge from hurricanes and tropical storms pushes seawater inland, while heavy rainfall simultaneously overwhelms rivers, bayous, and drainage infrastructure. This dual threat means flooding can come from multiple directions at once. The most common FEMA flood zone designations in Charleston are Zone AE, Zone VE, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $44.2M. The county is rated "Very High" for coastal flood risk by FEMA's National Risk Index. Properties in Charleston's VE zones face additional wave action risk beyond still-water flooding, which typically results in higher insurance premiums and stricter building requirements.

Combined coastal and inland flood exposure in Charleston means properties may face higher premiums than areas with only one flood source. FEMA's Risk Rating 2.0 accounts for multiple flood sources, including coastal surge distance, river proximity, and rainfall-driven flooding. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.

Flood maps in areas with combined coastal and inland risk are among the most complex in the FEMA system. Major storms often trigger FEMA restudies that can significantly shift zone boundaries. Letters of Map Revision (LOMR) after hurricanes may expand SFHA coverage as new storm data is incorporated. Use our free lookup tool to check the current flood zone for any Charleston address.