Charleston Floodplain Management

The City of Charleston is a community participant in the National Flood Insurance Program (NFIP) and Community Rating System (CRS). Our participation in these programs helps to reduce the risk of current and future flooding, resulting in a more resilient community.”

Floodplain Management Banner

Announcements 

  • FEMA 2019 Elevation Certificate is now available. All Elevation Certificates signed and sealed on or after Feb. 21th, 2020 must be completed using the most current version. 

    • This version will expire on November 30th, 2022

  • Flood design elevation increase: Effective July 1st, 2020, all residential & non-residential new construction, and non-residential substantial improvements, in the Special Flood Hazard Area (SFHA) must be designed 2 ft. above Base Flood Elevation (BFE). Residential substantial improvement will remain at 1 ft. above BFE.
  • FEMA has updated the risk rating methodology for the National Flood Insurance Program (NFIP) to include additional risk factors for more equitable pricing.
  • Ordinance to Prohibit Slab-on-Grade Foundations (building diagrams 1A, 1B, 2A, and 3) in the SFHA or 100-year Floodplain will become effective for projects applied on or after January 1, 2024
    • The amendment to the City's Stormwater Ordinance was passed on April 11, 2023 with support from Charleston Trident Association of Realtors, the Coastal Conservation League, Charleston Homebuilders, the Southern Environmental Law Center and the Historic Charleston Foundation, as well as City staff and members of City Council. 
      • Fill is used to elevate large portions of development sites, as such, slab-on-grade foundations can be used for new or redeveloped home residential construction. 
      • Large quantities of fill can alter drainage sites, may lessen rainfall infiltration, accelerate runoff and/or displace water onto neighboring properties and downstream communities. 

floodplain

(Image credit: Lincoln Co. WI, Land Services)

Goals

  • To promote, where practical, the natural functions of the floodplain
  • To reduce loss of life and reduce damage to property from flooding
  • To mitigate damage to structures in the Special Flood Hazard Area (SFHA) from flood events

Objectives

  • Promote, manage, and enforce Federal Emergency Management Agency (FEMA) requirements and recommendations
  • Promote, manage, and enforce National Flood Insurance Program (NFIP) requirements and recommendations
  • Promote, manage, and expand participation in the NFIP’s Community Rating System (CRS)
  • Manage and make available Flood Insurance Rate Map (FIRM) information
  • Manage development within the Special Flood Hazard Area (SFHA)

Natural and Beneficial Floodplain Functions:


The natural functions of floodplains, when preserved or restored to their undeveloped state, provide a range of benefits to both natural and human systems. These benefits fall into the following categories: 

  1.  Water Resources:

    • Provides floodwater storage and conveyance which reduces the severity of floods or storm surge
    • Allows sediment to settle out of stormwater, attenuates excess nutrients, and supports other qualities managed under the community’s National Pollutant Discharge Elimination System (NPDES) permit 
    • Allows groundwater recharge

  2. Biologic Resources:

    • Provides habitat for feeding and reproduction for fish and wildlife species
    • Support high rates of biologic production and diversity

  3. Societal Resources:

    • Riparian and coastal vegetation helps stabilize river banks and beaches against erosion
    • Agricultural and wildlife harvesting, including shellfish harvesting
    • Recreational and aesthetic enjoyment

Spaces which provide natural and beneficial floodplain functions in the Charleston area include salt marsh, intertidal wetlands, coastal barriers (such as dunes and maritime forest), and forested wetlands. Regulating development in these sensitive areas helps to preserve their community benefit. 

Learn more about floodplain functions: Natural and Beneficial Floodplain Functions: Floodplain Management— More than Flood Loss Reduction (ASFPM, 2008)

Resources-  

Be sure to click on the 2022 Flood Information Guide to learn more information about flooding preparation in your neighborhood.