Flood Zones in Horry County, South Carolina

Horry County's flood risk isn't just a coastal-storm-surge story -- it's a river-backflow story, and it produced a genuine flood record during Hurricane Florence in 2018. This page covers the inland/river mechanism, the county's own resilience planning, and the specific checks a land buyer should run beyond a standard FEMA flood-map lookup. (Beachfront erosion and storm-surge risk specific to the Myrtle Beach market are covered by our sister site, usbeachlife.com.)

This page covers what's specific to Horry County. For the general explanation, see the national guide.

Why Horry County floods differently than a typical inland county

Horry County sits at the lowest, flattest downstream end of two major river systems -- the Pee Dee and the Waccamaw -- plus the Atlantic Intracoastal Waterway, all three of which flooded during Hurricane Florence in 2018. The mechanism matters for anyone evaluating river-adjacent or low-lying land here: flooding on the Waccamaw doesn't only come from local rainfall, it comes substantially from the much larger Pee Dee River backflowing upstream into the Waccamaw and its tributaries once the Pee Dee itself is running high, and Horry's broad, flat topography then drains that floodwater away slowly rather than quickly. That combination is why Horry County flooding tends to crest later and recede slower than a storm's rainfall alone would suggest -- a real pattern documented in this county's flood history, not a generic hurricane-risk statement.

That mechanism produced a genuine record during Hurricane Florence: the Waccamaw River crested nearly four feet above any flood level previously recorded, an outcome contemporaneous reporting described as far higher than most residents ever expected. The high water closed major roads for days, including SC-9 near Longs, SC-905, SC-22, and SC-90, cutting off travel across large parts of the county's interior. For a buyer evaluating land anywhere near the Waccamaw, Pee Dee, or their tributaries, that 2018 record is the practical benchmark to ask about -- not just the FEMA-mapped base flood elevation, but how a specific parcel fared, or would have fared, against a flood that exceeded prior records by that much.

The county's own resilience planning and the Corps' ongoing study

Horry County has responded with real, specific planning rather than treating Florence as a one-off event: the county's Flood Resilience Master Plan (a summary report dated October 2022) lays out the county's own assessment of flood vulnerability and mitigation priorities, and is worth reading directly for any parcel in a flood-prone area rather than relying on secondhand summaries. Separately, and more recently, the U.S. Army Corps of Engineers has an active Waccamaw River flood-risk-management feasibility study underway, with a formal Review Plan document (Revision 02) dated June 2024 -- meaning federal-level flood-mitigation planning specific to this river system is still an open, ongoing process, not a settled matter. A buyer or long-term landowner should track that study's progress, since its eventual recommendations (which could include anything from levee or drainage improvements to updated floodplain mapping) may directly affect a specific property's flood designation or insurance requirements down the line.

For the immediate, practical step: Horry County's own online-services portal provides a FEMA flood-map lookup by parcel, which is the right starting point for confirming a specific tract's current flood-zone designation. But given the county's documented history of a flood that exceeded prior records, and an ongoing federal study that could reshape flood mapping for the Waccamaw corridor specifically, don't treat a current FEMA flood-zone designation as a permanent or complete answer -- ask the county's Emergency Management department about known trouble spots and the county's own Flood Resilience Master Plan findings for the specific area, in addition to the FEMA lookup itself.

Flood Zones and River Flood Risk in Horry County, South Carolina

Why Horry County floods differently than a typical inland county

The county's own resilience planning and the Corps' ongoing study

Ready to talk to someone who knows land?