Question:
Is it the intent of R322.1.4 (Establishing the design flood elevation) #1 to use the definition of the 100 year storm elevation found in section 3109 FBC which refers the Department of Environmental Protection (DEP) and establishes the elevation for locations seaward of the Coastal Construction Control Line (CCCL)?
Comment:
The question revolves around the use of R322 which is titled Flood-Resistant Construction. Section 322.1 indicates this section applies to properties in the Special Flood Hazard Area (SFHA) and are located in either A or V zones. For the properties located in an "X" zone, or outside of the SFHA would this also apply if the property is located seaward of the CCCL? Further, the DEP model appears to indicate it applies to the "lowest structural horizontal member" only and not all of the construction. As an example, if a property is located seaward of the CCCL, partially in an AE-6, partially in an X for the SFHA zones and the lowest floor is the garage slab located at an elevation of 8, meeting or exceeding the AE6 and freeboard requirements, and the bottom of the lowest horizontal structural element supporting the habitable floors above is located at the DEP requirement of 16, do the requirements for construction in the flood zone still apply? These requirements would be things such as frangible walls, no electrical, mechanical or plumbing installed in the area and all equipment such as condensers, water heaters and so required to be installed above the DEP required elevation.
Existing Interpretations and/or Declaratory Statements Related to this request
Input Received:
Okay - taking a stab at this one.
If the Building Dept is responsible as the Flood Plain Manager and there is no other local ordinance that would circumvent the code reference, then yes.
The Division of Emergency Management, State Floodplain Management Office offers the comments below. We also encourage review of the CCCL Fact Sheet prepare for the Florida Building Commission by Building A Safer Florida (https://www.floridadisaster.org/dem/mitigation/floodplain/ (Community Resources/FBC Resources),
1. Sec. R322 applies to dwellings within the scope of the FBC, Residential that are in the flood hazard area governed by in R322. Table R301.2(1) footnote (g) refers to local floodplain management ordinances for adoption of maps and studies.
2. Regarding the specific question about R322.1.4, before looking at that section and which flood elevation to use, see Sec. R322.1.1, structures seaward of the CCCL. Sec. R221.1 identifies the “predicted forces of a 100-year storm event in accordance with Section 3109 … and “the more restrictive provisions shall govern.”
3. The following is DEM’s understanding of the requirements of Sec. 3109 pertinent to the inquiry:
a. Sec. 3109 applies to all sites seaward of the CCCL, even those locations that are in FEMA Zone X.
b. Sec. 3109 requires use of the higher of the elevation in ASCE 24, local elevation if more freeboard adopted, or the DEP 100-year storm elevation.
c. Sec. 3109 has requirements that apply between the Base Flood Elevation (FEMA) and the DEP 100-year storm elevation. See especially Sec. 3109.3.4 (walls and enclosures).
d. Breakaway walls are required when there is an enclosure below the DEP 100-year storm elevation and above the ASCE 24 elevation (or locally adopted if more freeboard), and uses of those enclosures are limited to those in the definition for “allowable uses.”
e. Breakaway walls, with flood openings, are required if there is an enclosure below the ASCE 24 elevation (or locally adopted if more freeboard), and uses of the enclosure are limited to parking, storage, building access.
f. Sec. 3109.3.2 requires foundations to be piles or columns and “shallow foundations and stemwalls are not permitted.”
g. Sec. 3109.3.5 allows structural slabs that don’t breakaway if designed by an engineer.
Answer:
The Florida Division of Emergency Management, State Floodplain Management Office offers the comments below. We also encourage review of the CCCL Fact Sheet prepared for the Florida Building Commission by Building A Safer Florida (https://www.floridadisaster.org/dem/mitigation/floodplain/ (Community Resources/FBC Resources),
1. Sec. R322 applies to dwellings within the scope of the FBC, Residential structures that are in the flood hazard area governed by in R322. Table R301.2(1) footnote (g) refers to local floodplain management ordinances for adoption of maps and studies.
2. Regarding the specific question about R322.1.4, before looking at that section and which flood elevation to use, see Sec. R322.1.1, structures seaward of the CCCL. Sec. R322.1.4 identifies the “predicted forces of a 100-year storm event in accordance with Section 3109 … and “the more restrictive provisions shall govern.”
3. The following is DEM’s understanding of the requirements of Sec. 3109 pertinent to the inquiry:
a. Sec. 3109 applies to all sites seaward of the CCCL, even those locations that are in FEMA Zone X.
b. Sec. 3109 requires use of the higher of the elevation in ASCE 24, local elevation if more freeboard adopted, or the DEP 100-year storm elevation.
c. Sec. 3109 has requirements that apply between the Base Flood Elevation (FEMA) and the DEP 100-year storm elevation. See especially Sec. 3109.3.4 (walls and enclosures).
d. Breakaway walls are required when there is an enclosure below the DEP 100-year storm elevation and above the ASCE 24 elevation, or locally adopted elevation if higher and/or more freeboard is required, and uses of those enclosures are limited to those in the definition for “allowable uses.”
e. Breakaway walls, with flood openings, are required if there is an enclosure below the ASCE 24 elevation, or local elevation if higher and/or more freeboard is required, and uses of the enclosure are limited to parking, storage, and building access.
f. Sec. 3109.3.2 requires foundations to be piles or columns and “shallow foundations and stemwalls are not permitted.”
g. Sec. 3109.3.5 allows structural slabs that don’t breakaway if designed by an engineer.
Commentary:
None.
Comments on Draft:
looks good
I agree
I like it. I'm emphesizing by using CAPS: There's a sentence that might need adjusting ...the elevation in ASCE 24, local elevation if (HIGHER) freeboard (IS) adopted.
