Preliminary new FEMA flood map information indicates changes for tens of thousands of county parcels

Commissioner Smith asks for board discussion of information, with adjustments especially indicated for Siesta Key and east county property owners

This Aug. 30 photo shows flooding in the intersection of Beach Road and Columbus Boulevard on north Siesta Key, as Hurricane Idalia was passing through the Gulf of Mexico. Image courtesy Sarasota County

Sarasota County Commissioner Mark Smith has won the support of his board colleagues for a formal discussion of a recent county staff report that covers new Federal Emergency Management Agency (FEMA) flood elevations and best practices.

Among the findings in that Aug. 4 report is the fact that preliminary FEMA map changes would add about 27,000 county parcels, with 7,700 buildings, to the Special Flood Hazard Area. Conversely, the report says, about 19,000 parcels with 2,400 structures, would be removed from that area.

The report specifically points out that numerous changes would affect Siesta Key, including the lowering of the Base Flood Elevation by 4 feet in the county’s AE flood zone. The county website says the AE zone includes areas subject to a 1% annual chance of inundation. “Mandatory flood insurance purchase requirements apply,” the website notes.

The report defines “Base Flood” as “a regulatory standard commonly referred to as a ‘100-year’ flood or ‘1% chance’ flood. Base Flood Elevation is the highest elevation of the water surface associated with Base Flood. Freeboard refers to an extra margin of protection that requires the lowest floor of a building to be one (or more) feet above Base Flood Elevation (BFE).”

The board members received the report in response to a policy discussion they held during their Dec. 9, 2022 retreat, the document explains.

Matt Osterhoudt, director of the county’s Planning and Development Services Department, provided the report to the commissioners.

“I’d also like an opportunity to meet with Matt,” Smith said during the Sept. 12 County Commission meeting, so Osterhoudt “can enlighten me on nuances of his memo. There’s some new wrinkles there that I wasn’t aware of,” Smith added.

An architect with decades of experience, Smith lives on Siesta Key.

When Chair Ron Cutsinger sought clarification that Smith was seeking the scheduling of a discussion of the report during an upcoming regular meeting, Smith affirmed that that was his intent.

After checking with the other commissioners, Cutsinger gave County Administrator Jonathan Lewis the direction to proceed with the scheduling.

The Aug. 4 report explains, “FEMA has initiated a physical map revision based on more accurate scientific and technical data available.” It adds, “Preliminary FEMA studies show BFEs [Base Flood Elevations] changing … Areas in the eastern portion of Sarasota County were previously shown outside of a Special Flood Hazard Area (SFHA), or identified as Zone A without an established [Base Flood Elevation], and are now shown in a SFHA with [Base Flood Elevations]. Zones AO, AH, and Coastal A are also new,” the report points out.

The report explains the following in regard to the above zones:

  • “Coastal A: areas subject to moderate wave action based on proximity to the Gulf of Mexico.
  • “Zone AH: areas of shallow flooding where [Base Flood Elevations] are shown on the FIRM [FEMA Flood Insurance Rate Map].”

The document also notes, “A FIRM is an official map of a community created by FEMA [that] shows both the Special Flood Hazard Areas (high-risk areas, defined as land with a one percent chance of flooding in any given year) and the insurance risk premium zones applicable to the community. FIRMs change over time in accordance with changing flood risks (e.g., drainage patterns).”

  • “Zone AO: areas of shallow flooding where Base Flood Depths (feet above ground) are shown on the FIRMs instead of BFEs.”

The county website says Zone AO encompasses areas subject to a 1% chance of shallow flooding — “usually sheet flow on sloping terrain” — where average flood depths are between 1 and 3 feet. The mandatory purchase of flood insurance also applies to those areas.

This graphic provides details about Base Flood Elevation. ‘LiMWA’ stands for limited moderate wave action. Image courtesy of ResearchGate

A document on the county webpages regarding flood maps points out that in Zones A, AE and AH, the “top of the lowest occupiable floor must be at or above the minimum elevation required by the Sarasota County Floodprone areas Ordinance.”

For structures in Zone AO, the “top of the lowest occupiable floor must be 1 foot or higher above the minimum flood depth shown on FIRMs.”

The Aug. 4 staff report also points out, “[S]everal changes are shown throughout Siesta Key with Zone VE (covering the beach and [Intracoastal Waterway areas]) expanding slightly and lowering one foot in [Base Flood Elevation] …. Some parcels near the Point of Rocks formation are now in the new Zone AO designation, where property owners would need to add one to two feet for flood level above existing grade, and one foot of freeboard.”

The report further notes, “Communities such as Sarasota County must adopt floodplain management regulations that reference new or revised studies including maps in general and specifically for participation in the National Flood Insurance Program, at a minimum.” In Sarasota County’s Floodprone regulations, which are included in Chapter 54, Article XVI of the County Code, the report added, 1 foot of freeboard is required, “which is the minimum FEMA/National Flood Insurance Program requirement. This is consistent with the comparable counties reviewed for current standards in place …” Those are Charlotte, Collier, Lee and Manatee.

The report does point out that staff research into practices among comparable counties did not find any other local jurisdictions “that have purposely adjusted their BFEs.”

This graphic is included in a FEMA guide for home construction in coastal areas, published in December 2010.

Changes in FEMA’s flood maps “are provided through the issuance of a Letter of Final Determination (LFD), which sets the effective date of a new FEMA Flood Insurance Rate Map (FIRM),” the report says.

“The latest preliminary revised FIRMS were presented on December 31, 2019,” the document notes. “As of this report, the finalization of the map products has not been completed. FIRMS are effective six months after the [Letter of Final Determination] is issued.”

“From a policy perspective,” the report continues, the commissioners could consider the following options:

  • 1. “Maintain the minimum requirements, ‘as-is.’ Note that this includes updating the Floodprone regulations … [of the County Code] to align with the updated FIRMs,” a process on which staff is working. “Board action will not be needed until staff brings forward draft amendments that are … being prepared and requests the Board to authorize advertisement of a public hearing.
  • 2. “Sarasota County could opt for a higher freeboard requirement; or
  • 3. “Sarasota County could opt to adjust the [Base Flood Elevations].”

If the commissioners chose Option 2 or Option 3, the report continues, and provide the related policy guidance, then “staff would conduct a more detailed analysis to better understand the implications. Staff would also prepare draft amendment language to the Floodprone regulations … for the Board to consider and authorize advertisement of a public hearing.”