WAKULLA COUNTY, FLORIDA AND INCORPORATED AREAS COMMUNITY COMMUNITY Wakulla County NAME NUMBER SOPCHOPPY, CITY OF 120620 ST. MARKS, CITY OF 120316 WAKULLA COUNTY (UNINCORPORATED AREAS) 120315 EFFECTIVE September 26, 2014 Federal Emergency Management Agency FLOOD INSURANCE STUDY NUMBER 12129CV000A NOTICE TO FLOOD INSURANCE STUDY USERS Communities participating in the National Flood Insurance Program have established repositories of flood hazard data for floodplain management and flood insurance purposes. This Flood Insurance Study (FIS) may not contain all data available within the repository. It is advisable to contact the community repository for any additional data. Part or all of this FIS may be revised and republished at any time. In addition, part of this FIS may be revised by the Letter of Map Revision process, which does not involve republication or redistribution of the FIS. It is, therefore, the responsibility of the user to consult with community officials and to check the community repository to obtain the most current FIS components. Initial Countywide FIS Effective Date: September 26, 2014 TABLE OF CONTENTS Page 1.0 INTRODUCTION ...............................................................................................................1 1.1 Purpose of Study ......................................................................................................1 1.2 Authority and Acknowledgments ............................................................................1 1.3 Coordination ............................................................................................................2 2.0 AREA STUDIED.................................................................................................................3 2.1 Scope of Study .........................................................................................................3 2.2 Community Description ...........................................................................................4 2.3 Principal Flood Problems .........................................................................................5 2.4 Flood Protection Measures ......................................................................................7 3.0 ENGINEERING METHODS ..............................................................................................7 3.1 Hydrologic Analyses ................................................................................................8 3.2 Hydraulic Analyses ................................................................................................10 3.3 Coastal Hydrologic Analyses .................................................................................12 3.4 Coastal Hydraulic Analyses ...................................................................................18 3.5 Vertical Datum .......................................................................................................30 4.0 FLOODPLAIN MANAGEMENT APPLICATIONS .......................................................31 4.1 Floodplain Boundaries ...........................................................................................32 4.2 Floodways ..............................................................................................................33 5.0 INSURANCE APPLICATION .........................................................................................39 6.0 FLOOD INSURANCE RATE MAP .................................................................................40 7.0 OTHER STUDIES .............................................................................................................41 8.0 LOCATION OF DATA .....................................................................................................41 9.0 BIBLIOGRAPHY AND REFERENCES ..........................................................................43 i TABLE OF CONTENTS – continued Page FIGURE Figure 1 – Transect Schematic 19 Figure 2 – Transect Location Map 23 Figure 3 – Floodway Schematic 34 TABLES Table 1 – Scope of Revision 3 Table 2 – Summary of Discharges 10 Table 3 – Summary of Stillwater Elevations 16-18 Table 4 – Transect Descriptions 24-26 Table 5 – Transect Data 27-30 Table 6 – Floodway Data 35-38 Table 7 – Community Map History 42 ii TABLE OF CONTENTS – continued EXHIBITS Exhibit 1 – Flood Profiles Buckhorn Creek Panel 01P Lost Creek Panels 02P-03P Sopchoppy River Panels 04P-06P St. Marks River Panel 07P West Branch Buckhorn Creek Panel 08P Exhibit 2 (Published Separately) – Flood Insurance Rate Map Index Flood Insurance Rate Map iii FLOOD INSURANCE STUDY WAKULLA COUNTY, FLORIDA AND INCORPORATED AREAS 1.0 INTRODUCTION 1.1 Purpose of Study This countywide Flood Insurance Study (FIS) investigates the existence and severity of flood hazards in, or revises and updates previous FISs/Flood Insurance Rate Maps (FIRMs) for the geographic area of Wakulla County, Florida, including the City of Sopchoppy, the City of St. Marks, and the unincorporated areas of Wakulla County (hereinafter referred to collectively as Wakulla County). This FIS aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study has developed flood risk data for various areas of the community that will be used to establish actuarial flood insurance rates. This information will also be used by Wakulla County to update existing floodplain regulations as part of the Regular Phase of the National Flood Insurance Program (NFIP), and will also be used by local and regional planners to further promote sound land use and floodplain development. Minimum floodplain management requirements for participation in the NFIP are set forth in the Code of Federal Regulations (CFR) at 44 CFR, 60.3. In some States or communities, floodplain management criteria or regulations may exist that are more restrictive or comprehensive than the minimum Federal requirements. In such cases, the more restrictive criteria take precedence and the State (or other jurisdictional agency) will be able to explain them. 1.2 Authority and Acknowledgments The source of authority for this Flood Insurance Study is the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This FIS was prepared to include all jurisdictions within Wakulla County in a countywide FIS. Information on the authority and acknowledgments for each jurisdiction included in this countywide FIS, as compiled from their previously printed FIS reports, is shown below. Sopchoppy, City of: The hydrologic and hydraulic analyses for the FIS report dated February 15, 1984, were prepared by the U. S. Geological Survey, for the Federal Emergency Management Agency (FEMA). That work was completed in January 1981. St. Marks, City of: The hydrologic and hydraulic analyses for the FIS report dated September 18, 1979, were prepared by the U. S. Geological Survey (USGS), for the Federal 1 Emergency Management Agency (FEMA). That work was completed in February 1978. Wakulla County (Unincorporated Areas): The hydrologic and hydraulic analyses for the FIS report dated June 17, 1986, were prepared by Gee & Jensen EAP Inc., for FEMA under Contract No. H- 4625. That work was completed in January 1981. For the June 17, 1986 Wakulla County FIS, the coastal analyses were revised by Coastal and Offshore Engineering and Research, Inc. (COER). This revision affects the area known as Shell Point, which lies on the coast in the vicinity of Walker Creek. Transect 4 was recomputed using new information supplied by COER. For this countywide FIS, revised coastal analyses for the Gulf of Mexico, including the entire shoreline of Wakulla County, have been prepared for FEMA by the Northwest Florida Water Management District (NWFWMD) under Contract No. EMA-2008-CA-5886. Additionally, the St. Marks River and Wakulla Gardens area was studied using detailed methods and all approximate flood hazards have been re-evaluated. All unrevised detailed studied streams have been redelineated using updated topographic data. This work was completed in 2011. Base map information for this FIRM was developed from high resolution digital orthoimagery provided by the Florida Department of Transportation. This information was produced at a resolution of 1 foot in 2010. The coordinate system used for the production of this FIRM is Florida State Plane North Zone 0903, referenced to the North American Datum of 1983 (NAD83) HARN. Corner coordinates shown on the FIRM are in latitude and longitude referenced to the State Plane projection, NAD 83 HARN. Differences in the datum and spheroid used in the production of FIRMs for adjacent counties may result in slight positional differences in map features at the county boundaries. These differences do not affect the accuracy of information shown on the FIRM. 1.3 Coordination Consultation Coordination Officer’s (CCO) meetings may be held for each jurisdiction in this countywide FIS. An initial CCO meeting is held typically with representatives of FEMA, the community, and the study contractor to explain the nature and purpose of a FIS, and to identify the streams to be studied by detailed methods. A final CCO meeting is held typically with representatives of FEMA, the community, and the study contractor to review the results of the study. 2 The dates of the initial and final CCO meetings held prior to the countywide FIS for Wakulla County and the incorporated communities within its boundaries are in the following tabulation: Community Name Initial CCO Date