Build responsively

Permit requirements


Permits are required for all types of development in the floodplain, not just for the construction of buildings. For instance, if you intend to clear a site, install fill, or regrade an existing site, you must first submit plans and secure a permit from the Town of Mount Pleasant. These permitting requirements are in place to help control activities which may increase the flood hazard on your property or for a neighboring property. Before you build, fill, or otherwise develop in the floodplain, please contact the Building Inspection Division at 849-2029 or the Planning Department at 884-2029. Also, if you see construction, clearing, or filling in the floodplain but no permit sign is posted, please notify the Town at one of the above numbers.

Information concerning special construction requirements in the floodplain, such as freeboard and flood resistant materials, may be obtained by contacting the Building Inspection Division at 843-884-5184. Also, the Town’s Flood Damage Prevention Ordinance is available online.

Substantial Improvement/Substantial Damage Requirements

If your home or business sustains damage or if you are making improvements to the structure and/or the interior of the building, then the Town’s Flood Damage Prevention Ordinance may affect how you rebuild or make improvements if your structure is located in a flood zone. For instance, a building that is “substantially damaged” must be repaired to meet the same construction requirements as a new building, including the elevation requirements. “Substantial damage” is damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50% of the market value of the structure before the damage occurred. It is important to note that substantial damage includes damage of any origin, not just flooding. A house that is damaged 50% or more by a fire or tornado must also be brought into compliance with the current flood regulations.

A “substantial improvement” is any repair, reconstruction, alteration, or improvement to a structure, the cumulative cost of which for a ten-year period equals or exceeds 50% of the fair market value of the structure either before the start of construction of the improvement, or if the structure has been damaged or is being restored, before the damage occurred. As with substantial damage, buildings that are substantially improved must meet the same construction requirements as new buildings. Note that costs are cumulative for ten years. If, for instance, a structure underwent renovation work six years ago that was equal to 30% of its value and then sustains 25% damage in a storm this year, then the 50% threshold for a ten-year period will have been exceeded and the structure will have to be brought into compliance with the current flood regulations.

The substantial improvement/substantial damage regulations can be complex. If you are planning repair or renovation work on a structure in a flood zone, please contact the Building Inspection Division at 884-5184 to determine if your project will be impacted by these regulations. General information on substantial damage/substantial improvement can also be obtained from FEMA’s web site.

Drainage System Maintenance


The Town has a complex storm drainage system composed of open ditches and closed pipe sections. These systems may be owned by the Town, State, the County, or private property owners. The ditch systems and piped systems work together to carry stormwater runoff from homes and roadways to area ponds, creeks, and marshes. It is critical to maintain these systems in a high flow capacity to reduce flood occurrences. To accomplish this, the Town inspects major ditch systems twice a year and cleans systems as needed or reported. Residents should take extra care to prevent debris from entering the ditch and piped systems. Blockages or flooded areas can be reported to the Stormwater Office at 843-856-2157 for investigation and cleaning.