Your local government can tell you in which flood zone your property is located. For Unincorporated Charleston County, Awendaw, Hollywood, James Island, Lincolnville, McClellanville, Meggett, Ravenel, Rockville, and Seabrook Island please contact floodservices@charlestoncounty.org to obtain a flood zone determination letter. Flood zone determinations for property within incorporated areas of Charleston County should contact the applicable municipality.

Flood Insurance Rate Maps for Charleston County are also available on-line at the Federal Emergency Management Agency (FEMA) map service center.

Your local government can tell you which flood zone your property is located in, whether or not the property is considered Coastal A, whether or not the property is contained within a COBRA zone, historic flood levels for the general area, whether or not the property is in a mapped repetitive loss area, if the property is in a dam failure inundation zone, and anticipated flood depths of a property. Contact floodservices@charlestoncounty.org.

Charleston County has experienced many hurricanes and other severe storms throughout our history, the most recent of which were Hurricanes Hugo in 1989 and Hurricane Floyd in 1999. The greatest threat for flooding in the Charleston County area is from storm surge associated with a hurricane from the Atlantic Ocean.

The LiMWA line is the Limit of Moderate Wave Action. It is depicted on the FEMA flood map viewer as a solid green line. This delineates the "Coastal A Zone." This zone is characterized by wave heights between 1.5 and 3 feet during a base flood event. To benefit Charleston County's Community Rating System score, Coastal A areas are held to the same construction standards as V/VE zones.

If a property within Charleston County is in one of the following flood zones:

Zone A:

No base flood elevations determined.

Zone AE:

Base flood elevations determined.

Zone AH:

Flood depths of 1 to 3 feet (usually areas of ponding); base flood elevations determined.

Zone AO:

Flood depths of 1 to 3 feet (usually sheet flow on sloping terrain); average depths determined. For areas of alluvial fan flooding, velocities also determined.

Zone A99:

To be protected from 100-year flood by Federal flood protection system under construction; no base flood elevations determined.

Zone V:

Coastal flood with velocity hazard (wave action); no base flood elevations determined.

Zone VE:

Coastal flood with velocity hazard (wave action); base flood elevations determined.

Shaded Zone X:

Areas of 500-year flood; areas of 100-year flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 100-year flood.

Zone X:

Areas determined to be outside 500-year flood plain.

Zone D:

Areas in which flood hazards are undetermined, but possible.

Additional information regarding flood zones and flood insurance is available from the National Flood Insurance Program.

Federally subsidized flood insurance is available through the National Flood Insurance Program for most properties located in Charleston County and its inclusive municipalities. Damage caused by flooding is not covered by a standard homeowner's insurance policy. A separate flood insurance policy is required for flood peril coverage.

Flood insurance is available for buildings only, contents only, or both buildings and contents. Insurance agents or the National Flood Insurance Program should be contacted for flood policy information. There is generally a 30-day waiting period for flood insurance policies to become effective. Charleston County currently has a few parcels of land that could potentially be developed located in "Coastal Barrier Resource"protected areas (COBRA zones). Under Federal law, the National Flood Insurance Program may not issue flood insurance policies for structures built in COBRA zones. If flood insurance is available for structures built in COBRA zones, it will be through a private insurer.

FloodSmart provides flood insurance, flood zone maps, floodplain maps and flood information to help protect your home from flooding and elevated water tables.

The Charleston County Flood Damage and Prevention Ordinance mandates that certain procedures be followed for construction-related work within properties designated as flood zones on the Charleston County Flood Insurance Rate Maps. Copies of this ordinance are also available from the Building Inspection Services Department upon request.

The National Flood Insurance Program requires that if the cost of reconstructing, rehabilitating, adding to, or otherwise improving a structure equals or exceeds 50 percent of the building's assessed or appraised value, then the building must meet the same construction requirements as a new building. An improvement of 50 percent or more to a structure is known as a "Substantial Improvement". These requirements also apply to buildings that are substantially damaged; however, the value used in making the substantial improvement determination is the pre-damage value of the structure. In Charleston County and the jurisdictions for which it provides inspection-related services, the values of construction work on building permits taken out on a property during the past five (5) years are included in the determination of a "Substantial Improvement". This regulation is enforced through the construction permitting process. Any questions regarding "Substantial Improvements" may be referred to the Building Inspection Services Department.

Flood Elevation Requirements:
The finished floor of all new and substantially improved residential structures must be elevated to a minimum of two feet above the base flood elevation indicated on the applicable flood insurance rate map. A flood elevation certificate indicating this elevation must be submitted prior to any building inspection except for a foundation inspection. This certificate must be of the latest version available.

Floodproofing Requirements:
Only non-residential structures in all flood zones may be floodproofed to a minimum of two foot above the base flood elevation in lieu of elevating the finished floor to this elevation. A pre-construction (prior to the plans being released for permit) and an as-built (prior to final building inspection) floodproofing certificate must be completed by a South Carolina registered Architect and/or Professional Engineer for all floodproofed buildings. Construction plans for floodproofed buildings must also be sealed by a South Carolina registered Architect and/or Professional Engineer.

Equipment Elevation Requirements:

With the exception of one electrical outlet and one switch on a Ground Fault Interrupter (as required to meet the National Electrical Code), there may be no electrical wiring, plumbing fixtures, mechanical fixtures, other equipment, appliances, or ductwork located within new or substantially improved structures below two foot above the base flood elevation. Replacement HVAC systems in all "A, AE, AH, AO, A99" flood zones must be located either at or above the existing finished floor elevation or the design flood elevation, whichever is lower, unless the property is undergoing a "Substantial Improvement," in which case the HVAC system must be elevated to or above two feet above the base flood elevation.

Construction Materials Requirements:

Per FEMA, only Flood Resistant Materials Technical Bulletin 2 (Class 4 or 5 materials) are permitted to be used below the base flood elevation unless the structure is a floodproofed non-residential structure.

Flood Control Vent Requirements:
Enclosed areas below the base flood elevation (e.g. garages, sheds, crawl spaces, etc.) must be provided with flood control vents located and sized in accordance with FEMA requirements (e.g. a minimum of two (2) openings on different walls, located within a maximum of 12 inches of grade, sized at a minimum of one square inch per one square foot of enclosed area, with vents that allow the free-flow of flood waters at all times. If these specifications are not met, a South Carolina registered Architect or Professional Engineer must certify in writing that the structure is designed to comply with FEMA requirements regarding equilization of hydrostatic and hydrodynamic forces.

Permitted Uses Below Base Flood Elevation:

Permitted uses below the base flood elevation are restricted to those necessary for building access, vehicle parking, and limited storage of yard-related equipment.

Refer to the Charleston County Flood Damage and Prevention Ordinance

Lowest Horizontal Member Elevation:
The lowest horizontal structural member of all new and substantially improved structures must be elevated to a minimum of two feet above the base flood elevation indicated on the applicable flood insurance rate map. A flood elevation certificate indicating this elevation must be submitted prior to any building inspection, except for a foundation inspection. This certificate must be of the latest version available.

Plan and Certificate Requirements:

Wall section and foundation plans for structures in "V or VE" flood zones must be designed and sealed by a South Carolina Registered Professional Engineer and/or Architect. Plans must detail breakaway wall construction, foundation design, and scour depth. If spread footings are used, the bottom of the footing must be a minimum of 12 inches below the anticipated scour depth at the structure location. Pre-construction "V-Zone design" and "V-Zone Breakaway wall" certificates must be submitted with the construction plans for review. As-built "V-Zone design" and "V-Zone Breakaway wall" certificates must be submitted prior to a final building inspection. Obtain copies of these certificates from the Building Inspection Services Department.

Equipment Elevation Requirements:

With the exception of one electrical outlet and one switch on a Ground Fault Interrupter (as required to meet the National Electrical Code), there may be no electrical wiring, plumbing fixtures, mechanical fixtures, other equipment, appliances, or ductwork located within new or substantially improved structures below one foot above the base flood elevation. Replacement HVAC systems in "V and VE" flood zones must be located either at or above the existing finished floor elevation or the base flood elevation, whichever is lower, unless the property is undergoing a "Substantial Improvement," in which case the HVAC system must be elevated to or above two feet above the base flood elevation.

Construction Materials Requirements:

Per FEMA, only Flood Resistant Materials Technical Bulletin 2 (Class 4 or 5 materials) are permitted to be used below the base flood elevation.

Permitted Uses Below the Flood Elevation:

Permitted uses below the base flood elevation are restricted to those necessary for building access, vehicle parking, and limited storage of yard-related equipment.

Walls Below the Base Flood Elevation:

All walls below the base flood elevation must be designed and certified by a South Carolina registered Professional Engineer and/or Architect to break away from a water load less than that which would occur during the base flood.

Fill Restrictions:

No fill is permitted to be used for structural purposes in "V and VE" flood zones. Landscaping fill is only permitted if a South Carolina registered Professional Engineer certifies in writing that the fill will not cause wave run-up or deflection.

Obstructions Prohibited:

No obstructions are permitted below the base flood elevation within a structure. Obstructions not located within a structure (e.g. permanent planters, elevated swimming pools, elevated tennis courts, certain types of fences, etc.) are also not permitted unless a South Carolina registered Professional Engineer certifies in writing that the obstructions will not cause wave run-up or deflection.

For properties located in Unincorporated Charleston County, Awendaw, Hollywood, McClellanville, Meggett, Ravenel, Rockville, and Seabrook Island, the Building Inspection Services Department maintains copies of flood elevation certificates for all new construction and substantially improved structures. If your structure was constructed in one of these jurisdictions since late 1970's, the Building Inspection Services Department may have an elevation certificate on file for your structure. For structures where an elevation certificate is not available on file, a S.C. Registered Land Surveyor will need to survey the elevation of the structure and complete the flood elevation certificate form. Charleston County does not survey structures for the purpose of completing flood elevation certificates.

To obtain an elevation certificate on file for your structure email your request to buildingservices@charlestoncounty.org; including the address of property and/or tax map identification number and your contact information. A permit specialist will contact you regarding the elevation certificate and a researching fee will apply.

The Charleston County Emergency Management Department has information available on safety measures for flooding and other hazard events. The Federal Emergency Management Agency also maintains an electronic library of resources on flood safety. The South Carolina Flood Mitigation Program office also provides information on flood safety. It is important to remember to not drive through flooded areas.

The Charleston County libraries also have multiple publications available in their reference sections on protecting property from flood damages.

Below you will find links to the CRS Protecting Floodplain Resources. These documents are also available at all sixteen Charleston County library branches.

• Above the Flood: Elevating Your Floodprone House, FEMA-347, 2000
• Answers to Questions About the National Flood Insurance Program, F-084, 2011
• Coastal Construction Manual, FEMA-P-55, 2011
• Elevated Residential Structures, FEMA-54, 1984
• Protecting Manufactured Homes from Floods and Other Hazards, FEMA P-85, 2009
• Mitigation of Flood and Erosion Damage to Residential Buildings in Coastal Areas, FEMA-257, 1994
• Protecting Building Utilities from Flood Damage, FEMA P-348, 1999
• Protecting Building Utilities from Flood Damage, FEMA P-348, 1999
• Protecting Floodplain Resources, FEMA-268, 1996
• Reducing Damage from Localized Flooding, FEMA 511, 2005
• National Flood Insurance Program brochures:
  • Your Homeowner Insurance Does Not Cover Floods..., FEMA F-061
  • Preferred Risk Policy - Low-Cost Insurance for Homeowners and Renters, FEMA F-436
  • Preferred Risk Policy - Low-Cost Flood Insurance for Businesses, FEMA F-437
  • Why You Need Flood Insurance, FEMA F-683
  • Flood Insurance Claims Handbook, FEMA-687
  • Build Back Safer and Stronger - What You Need to Know, FEMA F-777
  • Flood Insurance Requirements for Recipients of Federal Disaster Assistance, FEMA F-695
  • Myths and Facts about the National Flood Insurance Program, FEMA F-002

The Federal Emergency Management Agency maintains an electronic library of reference materials on topics such as retrofitting structures for enhanced flood and hurricane resistance and protecting building utilities from flood damages. The Charleston County libraries also have multiple publications available in their reference sections on protecting property from flood damages. Since Charleston County is subject to hurricanes, measures such as protecting glazed openings in your buliding against high wind damages should also be taken for property protection.

Charleston County has passed an ordinance prohibiting the dumping of trash, landscape debris or other materials into stream channels, ponds, basins or ditches that regularly carry or store stormwater in the unincorporated areas of Charleston County. These channels are routinely cleaned and maintained by the Public Works Department. Residents of Unincorporated Charleston County are encouraged to assist in maintaining the drainage channels and ditches by removing or reporting obstructions (i.e. shopping carts, debris, trash, etc.) at (843) 202-7600. Keeping drainage channels free of obstruction reduces flooding potential in the event of heavy rains.

First and foremost, make certain the building is structurally sound and is not going to collapse or cause other physical harm prior to entering a damaged structure. Shut off the electrical and/or gas service to the structure if there is any possibility that the service is damaged. Notify all applicable insurance carriers of the damage immediately to begin the claims process.

If your property is one of many damaged by an event, make sure the address of your property is clearly indicated for inspectors and insurance adjusters.

Take photographs of any damaged areas. Secure the property from any additional damages if possible. Wait for your insurance company to give you clearance to begin cleaning up damaged areas.

The Federal Emergency Management Agency also has information available online regarding the first steps to take after a flood and about repairing your flooded home. Be careful to avoid injury during post-event clean-up and salvage operations. Make sure any contractors you hire to repair your property are licensed or registered for the type of work they are performing and obtain applicable permits prior to starting work on your property.

Licensing and permit information is available from the Building Inspection Services Department.

Charleston County coordinates a regional planning initiative, involving the County and municipalities within Charleston County, in developing and maintaining the Charleston Regional Hazard Mitigation Plan.This plan is updated annually to reflect changes that have occurred during the year. Anyone who would like to provide input into the Charleston Regional Hazard Mitigation Plan may do so by e-mailing the Building Services Department at buildingservices@charlestoncounty.org, or by calling the department at (843) 202-6930. The public is also invited to attend committee meetings regarding plan updates.

If you have any questions contact (843) 202-6930

Flood hazard areas in Charleston County may contain wetland areas which serve natural and beneficial functions such as flood moderation, water quality enhancement, ground water recharge, and habitat for wildlife. Beachfront areas may also contain primary ocean front dunes, which serve as buffers against minor wave height fluctuations and beach erosion. Protecting these areas maintains their important functions. Activities that disturb beachfront and saltwater wetlands should not be undertaken without first obtaining permits from the South Carolina Department of Health and Environmental Control Office of Ocean and Coastal Resource Management. Any disturbance of freshwater wetlands requires a permit from the U.S. Army Corps of Engineers and certification from S.C. DHEC's Office of Ocean and Coastal Resource Management.

The United States Geological Survey (USGS) has placed stream gages in rivers and streams that indicate real-time water elevations at the following locations within Charleston County:

• Cooper River at Highway 17 - 021720709
• Cooper River at Mobay N. Charleston 02172053
• Cooper River at Filbin Creek - 021720677
• Cooper River at Customs House - 021720711
• Turkey Creek at SCDOT Maintenance Yard - 021720646
• Ashley River near N. Charleston - 021720869

For topographic map information please contact the Building Inspection Services department

These stream gage elevations are to be used for approximations only.

Always follow emergency instructions that will be broadcast over local television and radio stations through the Emergency Alert System as weather advisories are released or updated by the National Weather Service. If evacuations are required, it is imperative that you follow instructions. Street patrols and door-to-door notifications may be used if an evacuation is mandatory. Generally, residents are given 48-72 hours notice in advance of a hurricane.

Charleston County also uses a telephone notification system for emergency information. For more information and free registration, please visit http://alert.charlestoncounty.org.

Questions regarding emergency procedures may be directed to the Emergency Management Department.