MOUNT PLEASANT — Concerns about flooding have been rising across the Charleston area, and now the town of Mount Pleasant is taking steps to change its flood regulations, including by raising the height required for new buildings.
For years, buildings in the town had to be set a foot above what's known as base flood elevation in order to reduce the risk of flood damage.
Base flood elevations vary by location. Some buildings on high ground may not need to be elevated, while others might need to be a dozen feet above ground level just to reach the base elevation.
The freeboard requirement, as it's called, adds height on top of the base flood elevation. Starting in 2021, Mount Pleasant plans to require 2 feet of freeboard instead of 1 foot.
The Town Council gave the rule initial approval unanimously on Tuesday. Charleston County and cities including Charleston, North Charleston and Summerville, have previously made similar changes.
“This is like a technical correction, not a major policy change," Mayor Will Haynie said before the Town Council vote.
Rob Rogerson, the town's program manager for building inspections, said the higher standard will help with the town's federal flood rating, which can aid in reducing insurance costs.
"Elevation, of course, is a pretty important part of resiliency," he said. "With sea-level rise, even if people are skeptical about what causes it, that's something we've been seeing here."
The increased building height and other more technical changes to local regulations have been encouraged by state and local regulators as new flood maps are adopted.
The extra foot of freeboard isn't a huge difference in terms of new building construction, but the seemingly small change does two other things:
- It means that some older buildings will be considered less flood-resistant than newer ones.
- Older buildings might have to be elevated if they are badly damaged and then repaired, because buildings where renovations or improvements exceed 50 percent value must meet current code requirements.
The rebuilding requirement proved controversial and was an election issue when the city of Charleston prepared to increase its freeboard requirement in 2019.
In March, the city's elected officials struck a compromise, requiring 2 feet of freeboard for new construction, but 1 foot for homes that are substantially damaged. The goal was to avoid requiring an existing home to be elevated if it were badly damaged, by a fire for example, and the repairs exceeded 50 percent of the home's value.
If Mount Pleasant Town Council gives final approval to the 2-foot freeboard rule, it would take effect Jan. 29 along with new federal flood maps for the town.