The Flood Hazard

Each hurricane season, June 1st - November 30th, an approaching hurricane poses a potential danger of rising sea levels with wind driven waves and strong currents. The Sea Islands of the southern coast of South Carolina are low-lying, separated from the mainland by salt marshes, estuaries and tidal rivers. This outer coastal plain as far as eighty miles inland is less than one hundred feet above sea level. This fact along with the large range between high and low tides makes the southern coast particularly vulnerable to destructive flooding. Historically an average of one hurricane or tropical storm makes landfall on the South Carolina coast every four to five years. Since 1900, when more accurate records were kept, eight category 2 or larger storms have visited destruction on the Sea Island’s south coast. Although our Hilton Head Island community has not experienced such flooding since Hurricane David in September, 1979, our neighbors in South Carolina have suffered during Hurricane Hugo. More recently Andrew caused damage in Florida and Louisiana. To prepare for the eventuality of a hurricane every citizen should be aware of the Town of Hilton Head Island's Emergency Preparedness Plan, evacuation routes and proper property protection measures.

Flood Warning System

Enter each hurricane season prepared. Have on hand extra supplies, bottled water, non-perishable food, a flashlight and a radio with extra batteries. Keep your car fueled.

When a hurricane watch covers your area, stay tuned to radio or television for all NOAA national weather service advisories. Locally stations WYKZ-FM 98.7 and WLOW 107.9 FMalong with other SC emergency broadcast stations will give up-to-date information. If a hurricane is expected to strike within 24 hours, a warning is issued. Local officials will broadcast an evacuation order so that the Island is clear 12 hours prior to gale force winds. Follow directions given by plantation security, firefighters, sheriff's deputies and SC Highway Patrol troopers to the designated evacuation routes. Remember, leave early.

Flood Safety

If a hurricane warning is issued, citizens could be asked to evacuate. Before leaving, windows and doors should be locked and tapped or boarded up. Towels or rugs should be put around openings to reduce seepage. Light weight or easily damaged items should be moved to the highest location possible, secured and covered with plastic. Be sure to secure outdoor furniture and potted plants. Small appliances should be unplugged and utilities turned off - only if you know how. Dangerous chemicals, insecticides, herbicides or gasoline should be put in water tight containers and in a high spot. If you have pets take food and water with you.  Pack your car with the following: portable radio, flashlight, batteries, blankets, extra clothing, baby products, food, medicines, toilet articles, important papers and valuables. Remember to drive safely using designated evacuation routes. Watch for dangling electrical wires and flooded low spots.

Flood Insurance

The National Flood Insurance Program (NFIP) was created by Congress in 1968 to provide homeowners flood insurance at a reasonable cost. Since homeowners policies do not cover flooding, separate policies are available on almost any enclosed building and its contends including single family homes, condominiums, mobile homes on foundations and commercial buildings. Contents of rental units are also insurable. Depending on your coverage, location (flood hazard zone) and elevation of the structure, rates will vary. On single family homes the maximum coverage is $250,000 on the building, $100,000 on contents. There are separate deductibles on the building and contents. Policies can be written for one year.

Flood insurance is required by law for federally financed loans when buying, building or improving structures. But you must act in advance. There is a thirty day waiting period on new policies. Check with your local insurance agent for specific rates and coverage.

Property Protection Measures

When building a new structure in a flood hazard zone, the surest way to protect property and minimize damage is to build above the base flood elevation and strictly follow all building codes. Older properties, while elevated, may be below the base flood elevation due to changing federal regulations. In this case, the best way to minimize damage is to eliminate any enclosed habitable spaces at ground level, provide watertight closures at windows and doors, remove any non-water resistant materials below base flood elevation, move any mechanical and electrical equipment below base flood elevation to a higher location in the building and structurally reinforce the foundation. In the extreme case, existing structures built on a concrete slab at grade can best be protected by raising the entire structure to base flood elevation and building a new foundation meeting current codes. Flood protection assistance is provided at no charge by the Town of Hilton Head Island. Site visits can be arranged to advise property owners of the most appropriate flood protection methods. The US Army Corps of Engineers will be participating with Town Engineering staff.

Planning in advance is the surest way to protect your property.

Floodplain Regulations

All development and construction activity on Hilton Head Island must be permitted and must conform to the International Building Code and the Town's Municipal Code. Municipal Code sections which govern are the Land Management Ordinance, Title 16, Chapter 7 - Design and Performance Standards and Title 15, Building and Building Codes, Chapter 9 - Flood Damage Controls. The FEMA Flood Hazard Zone map has been adopted as part of the code. It identifies four zones in which a range of flooding and flood damage can occur. A flood disclosure statement is required on all plats and in deeds within V and A zones.

• V Zone - coastal high hazard subject to 100 year flooding and storm surge
• A Zone - 100 year flood plain
• B Zone - 100 to 500 year flood plain
• C Zone - minimal flooding

The following Flood Insurance Map information from the 1977, 1984, and 1986 maps is available at no cost from the town: community number, panel number and suffix, date of FIRM, FIRM zone, base flood elevation.

Residential structures must be constructed so that the lowest floor elevation is no lower than the base flood elevation as specified by the Flood Hazard Zone Map. Non-residential structures, if constructed below the base flood elevation, must be floodproofed and certified by a licensed South Carolina registered architect or engineer. Verification of the actual elevation of the lowest habitable floor of all new or substantially improved structures is required on an Elevation Certificate. All elevation certificates are maintained as public record. Copies may be obtained at no cost from the Town of Hilton Head Island. There are special construction requirements of any enclosed area below base flood elevation in both A and V zones and any fill or change of topography must be permitted. Manufactured homes also have special foundation requirements in A and V zones.

The NFIP requires that existing structures meet the same regulations as new construction if they are substantially improved or repaired after being substantially damaged. Substantial improvement means that the cost of reconstruction, rehabilitation, additions or improvements equals or exceeds 50% of the building’s market value or the market value before it was damaged.

Illegal floodplain development or illegal modification of a structure in a floodplain can often endanger adjoining properties by diverting flood waters or producing damaging debris. The of Town Hilton Head Island Community Development Department can answer inquiries or investigate any reports of illegal floodplain construction.

Natural Resources

As a coastal barrier island it is important that Hilton Head Island preserve and maintain the natural resources which protect the land when storms occur. Dunes and sandy beaches buffer inland areas from high tides and wind driven storm surges. When a dune is breached flood waters spread far inland damaging property. Renourishment projects help to prevent this by replacing the sand that nature has scoured away. The Island’s wetlands and marshes also serve a vital function in protecting the land from flooding. They absorb great quantities of water allowing potentially damaging waters to disperse over many acres. The Town’s Municipal Ordinance protects these natural resources by encouraging their preservation and prohibiting destructive development.

The Island’s drainage system is a network of man-made and natural water carrying channels forming eleven separate watersheds. Just as with the natural resources which protect the Island, the drainage system is of particular importance in times of severe rain storms. Destructive flooding can result from a failure in the storm water runoff system which drains the developed areas of the Island finally discharging stormwater to the surrounding salt waters. Teams of Town staff routinely inspect the water carrying channels twice a year for any problems which might cause local flooding. Their recommendations result in needed maintenance. To reinforce the need to protect our drainage network the Town of Hilton Head Island Municipal Ordinance 17-6-111 prohibits the alteration of the drainage system by the dumping of refuse or debris.

The of Town Hilton Head Island Community Development Department can answer inquiries or investigate any reports of illegal alteration of protected natural areas or drainage channels.

For additional information on Flood Mitigation issues in the Town of Hilton Head Island, the following sources may be of assistance: