Building Within the Floodplain

The most important step is to build a residence with the lowest living floor elevated above the Base Flood Elevation plus 1 foot (BFE+1).This is a requirement of the Florida Building Code. The lowest living floor of a new home must also be 18 inches above the crown of the road if paved or 24 inches above the crown of the road if unpaved. The crown of road requirements are standards established in the Collier County Floodplain Management Ordinance.

In February 2020, FEMA released FEMA Policy #104-008-03, a policy defining accessory structures and agricultural structures and specifying conditions and limitations that must be imposed when communities allow property owners to build those structures using wet floodproofing techniques instead of complying with the NFIP requirements to elevate or dry floodproof nonresidential structures. The Code of Federal Regulations–44CFR 60.3(c)(3)(i)(ii) enacted in 1976, requires all new construction and substantial improvement of non-residential structures in flood hazards have the lowest floor elevated to or above the base flood elevation, or together with attendant utility and sanitary facilities, be designed so that below the base flood elevation the structure is watertight with walls substantially impermeable to the passage and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

 Though this requirement has been established for many years, communities nationwide participating in the NFIP have not enforced it. It has been a common practice for communities to allow for the construction of nonresidential structures below the base flood elevation incorporating wet floodproofing, rather than complying with the requirements set forth in the Code of Federal Regulations. FEMA Policy #104-008-03 outlines the requirements communities must adhere to when permitting structures incorporating wet floodproofing to the building design. Communities must now require the completion of a variance to allow at-grade wet floodproofed accessory and agricultural structures.

 In May of 2021, The Florida State Floodplain Management Office began assisting communities with amending their local floodplain management ordinances to include these changes. This guidance included model language and a regulatory process framework the community can implement in response to the Policy to allow at-grade wet floodproofed accessory structures. This new criteria does offer benefits to the property owner. Structures to be sited at-grade utilizing wet floodproofing will no longer be required to submit an Elevation Certificate as part of the permitting process.

There are six major types of improvements that can be considered for an existing building that can help reduce or eliminate flood damage risks. They include:

• Elevation
• Relocation
• Wet Floodproofing**
• Dry Floodproofing**
• Levees and Floodwalls
• Demolition and Reconstruction

**Floodproofing techniques are approved for non-residential buildings and have specific requirements for their applicability.

More information on retrofitting can be found on the Information on Retrofitting Your Home document (PDF, 604KB)and in the FEMA Homeowners Guide to Retrofitting.(PDF, 5MB)