Your local government can tell you in which flood zone your property is located.  For unincorporated Charleston County, Awendaw, Kiawah Island, Meggett, and Rockville, contact the Charleston County Planning Department to obtain a flood zone determination.  Flood zone determinations are available for property in other municipalities in Charleston County through 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.

Back To Top
 

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. 

Back To Top
 

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 U.S. Hwy. 17 (Grace Memorial Cooper River Bridge) (USGS site number 021720709)

• Cooper River at Filbin Creek in North Charleston (Interstate 526) (USGS site number 021720677)

• South Santee River at the State Pier Near McClellanville (USGS site number 02171905)

• South Santee River Near South Santee (USGS site number 02171850)

• Shem Creek Near Hwy. 17 in Mt. Pleasant (USGS site number 021720713)

• Bulls Creek Near Drayton Hall (USGS site number 021720875)

The USGS also provides topographic map information, which may be used for approximating at what stream water elevations land flooding may occur.  The following are the latitude and longitude references for the stream gages in Charleston County to use in accessing these topographic maps:
 

• Cooper River at U.S. Hwy. 17 (Grace Memorial Cooper River Bridge)  (Latitude 32° 48’ 11”; Longitude 79° 54’ 55”)

• Cooper River at Filbin Creek in North Charleston (Interstate 526) (Latitude 32° 53’ 25”; Longitude 79° 57’ 47”)

• South Santee River at State Pier Near McClellanville (Latitude 33° 09’ 15”; Longitude 79° 21’ 16”)

• South Santee River Near South Santee (Latitude 33° 11’ 02”; Longitude 79° 24’ 22”)

• Shem Creek Near Hwy. 17 in Mt. Pleasant (Latitude 32°48’47”; Longitude 79° 51’ 13.2”)

• Bulls Creek Near Drayton Hall (Latitude 32° 49’ 3.7”; Longitude 80° 2’ 22.3”)

These topographic maps and 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 Charleston County Emergency Preparedness Department. 

Back To Top
 

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

*  “A” Flood Zones may be “A”, “AE”, or “AO” Zones.

** “V” Flood Zones may be “V” or “VE” Zones

Additional information regarding flood zones and flood insurance is available from the

National Flood Insurance Program.

Back To Top
 

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

Act” 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.

Back To Top
 

Back To Top
 

Back To Top
 

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 Services Department.

Back To Top
 

Floodproofing Requirements:
Only non-residential structures in all “A” flood zones may be floodproofed to a minimum of one 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 one foot above the base flood elevation.  Replacement HVAC systems in all “A” 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 one foot above the base flood elevation.

Construction Materials Requirements:
Per FEMA, only Flood Resistant Materials Technical Bulletin 2-93 (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

Back To Top
 

Plan and Certificate Requirements:
Wall section and foundation plans for structures in “V” 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 Charleston County Building 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” 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 one foot above the base flood elevation.

Construction Materials Requirements:
Per FEMA, only Flood Resistant Materials Technical Bulletin 2-93 (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” 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.

Lateral Addition Requirements:

Construction plans for lateral additions to properties located in “V” flood zones must be sealed and provided with certifications by a South Carolina Registered Professional Engineer and/or Architect as indicated above.  Pre-construction and As-built Design and Breakaway Wall Design certificates, as applicable, must be submitted for lateral additions in “V” Zones. If the amount of work done to construct the addition plus any construction-related work permitted within the past five (5) years from when the addition is permitted is less than 50 percent of the market value of the structure to which it is attached, the addition must be at a comparable or higher elevation than the structure to which it is being attached.  If the amount of work done to construct the addition plus any construction-related work permitted within the past five (5) years from when the addition is permitted is 50 percent or more of the market value of the structure, contact the Building Services Department for assistance.

Refer to the Charleston County Flood Damage and Prevention Ordinance for additional information.

Back To Top
 

Back To Top
 

Back To Top
 

Back To Top
 

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 Charleston County 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.

Back To Top
 

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.

Back To Top
 

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 Services Department.

Back To Top
 

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 jrennhack@charlestoncounty.org, or by calling the department at (843) 202-6940.  The public is also invited to attend committee meetings regarding plan updates.   For meeting dates and times, contact the Building Services Department, check the meeting notice section of Charleston area newspapers, or view the bulletin board at the Charleston County Lonnie Hamilton III Public Services Building (4045 Bridge View Drive, North Charleston, SC).

Back To Top