Notice to Flood Insurance Study Users
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LINCOLN COUNTY, MAINE (ALL JURISDICTIONS) Lincoln County COMMUNITY NAME COMMUNITY NUMBER COMMUNITY NAME COMMUNITY NUMBER Alna, Town of 230083 Monhegan Plantation 230511 Bar Island 230916 Newcastle, Town of 230218 Boothbay, Town of 230212 Nobleboro, Town of 230219 Boothbay Harbor, Town of 230213 Polins Ledges Island 230929 Bremen, Town of 230214 Ross Island 230922 Bristol, Town of 230215 Somerville, Town of 230512 Damariscotta, Town of 230216 South Bristol, Town of 230220 Dresden, Town of 230084 Southport, Town of 230221 Edgecomb, Town of 230217 Thief Island 230920 Haddock Island 230918 Thrumcap Island 230928 Hibberts Gore, Township of 230712 Waldoboro, Town of 230086 Hungry Island 230917 Webber Dry Ledge Island 230930 Indian Island 230919 Western Egg Rock Island 230926 Jefferson, Town of 230085 Westport, Town of 230222 Jones Garden Island 230925 Whitefield, Town of 230087 Killick Stone Island 230927 Wiscasset, Town of 230223 Louds Island 230915 Wreck Island 230924 Marsh Island 230921 Wreck Island Ledge 230923 PRELIMINARY DATE: February 7, 2014 Federal Emergency Management Agency FLOOD INSURANCE STUDY NUMBER 23015CV001A 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) report may not contain all data available within the Community Map Repository. Please contact the Community Map Repository for any additional data. The Federal Emergency Management Agency (FEMA) may revise and republish part or all of this FIS report at any time. In addition, FEMA may revise part of this FIS report by the Letter of Map Revision process, which does not involve republication or redistribution of the FIS report. Therefore, users should consult with community officials and check the Community Map Repository to obtain the most current FIS report components. Selected Flood Insurance Rate Map (FIRM) panels for this community contain information that was previously shown separately on the corresponding Flood Boundary and Floodway Map (FBFM) panels (e.g., floodways, cross sections). In addition, former flood hazard zone designations have been changed as follows: Old Zone(s) New Zone Al through A30 AE Vl through V30 VE B X (Shaded) C X Initial Countywide FIS Effective Date: TABLE OF CONTENTS 1.0 INTRODUCTION ........................................................................................................ 1 1.1 Purpose of Study ................................................................................................ 1 1.2 Authority and Acknowledgments ...................................................................... 1 1.3 Coordination ...................................................................................................... 4 2.0 AREA STUDIED .......................................................................................................... 5 2.1 Scope of Study ................................................................................................... 5 2.2 Community Description ..................................................................................... 6 2.3 Principal Flood Problems ................................................................................... 9 2.4 Flood Protection Measures .............................................................................. 12 3.0 ENGINEERING METHODS .................................................................................... 13 3.1 Hydrologic Analyses........................................................................................ 13 3.2 Hydraulic Analyses .......................................................................................... 21 3.3 Coastal Hydrologic Analyses ........................................................................... 25 3.4 Coastal Hydraulic Analyses ............................................................................. 26 3.5 Vertical Datum ................................................................................................. 41 4.0 FLOODPLAIN MANAGEMENT APPLICATIONS.............................................. 43 4.1 Floodplain Boundaries ..................................................................................... 43 4.2 Floodways ........................................................................................................ 44 4.3 Base Flood Elevations ..................................................................................... 49 4.4 Velocity Zones ................................................................................................. 49 5.0 INSURANCE APPLICATIONS ................................................................................ 49 6.0 FLOOD INSURANCE RATE MAP ......................................................................... 51 7.0 OTHER STUDIES ...................................................................................................... 54 8.0 LOCATION OF DATA .............................................................................................. 54 9.0 BIBLIOGRAPHY AND REFERENCES ................................................................. 54 i TABLE OF CONTENTS – (Continued) FIGURES Figure 1 – Transect Schematic ................................................................................................... 27 Figure 2 – Transect Location Map ............................................................................................. 36 Figure 3 – Floodway Schematic ................................................................................................ 45 TABLES Table 1 – Initial and Final CCO Meetings ................................................................................... 4 Table 2 – Areas Studied by Detailed Methods ............................................................................ 5 Table 3 – Areas Studied by Approximate Methods ..................................................................... 5 Table 4 – Major Storms in Boothbay Harbor ............................................................................ 10 Table 5 – Summary of Discharges ............................................................................................. 17 Table 6 – Summary of Stillwater Elevations ............................................................................. 18 Table 7 – Manning’s “n” Values ............................................................................................... 24 Table 8 – Transect Descriptions ................................................................................................ 29 Table 9 – Transect Data ............................................................................................................. 37 Table 10 – Vertical Datum Conversion Values ......................................................................... 41 Table 11 – Floodway Data ......................................................................................................... 46 Table 12 – Community Map History ......................................................................................... 52 EXHIBITS Exhibit 1 – Flood Profiles Damariscotta River Panels 01P – 02P Kennebec River Panels 03P Little Medomak Pond Outlet Stream Panels 04P Medomak River Panels 05P – 15P Sheepscot River Panels 16P Exhibit 2 – Flood Insurance Rate Map Index Flood Insurance Rate Map ii FLOOD INSURANCE STUDY LINCOLN COUNTY, MAINE (ALL JURISDICTIONS) 1.0 INTRODUCTION 1.1 Purpose of Study This countywide Flood Insurance Study (FIS) report investigates the existence and severity of flood hazards in the geographic area of Lincoln County, Maine including the Towns of Alna, Boothbay Harbor, Boothbay, Breman, Bristol, Damariscotta, Dresden, Edgecomb, Jefferson, Newcastle, Nobleboro, S. Bristol, Somerville, Southport, Waldoboro, Westport, Whitefield, and Wiscasset; the Township of Hibberts Gore; and Bar Island, Haddock Island, Hungry Island, Indian Island, Jones Garden Island, Killick Stone Island, Louds Island, Marsh Island, Monhegan Plantation, Polins Ledges Island, Ross Island, Thief Island, Thrumcap Island, Webber Dry Ledge Island, Western Egg Rock Island, Wreck Island, Wreck Island Ledge (referred to collectively herein as Lincoln 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 county that will establish actuarial flood insurance rates and to assist the county in its efforts to promote sound floodplain management. Minimum floodplain management requirements for participation in the National Flood Insurance Program (NFIP) are set forth in the Code of Federal Regulations 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. The Digital Flood Insurance Rate Map (DFIRM) and FIS report for this countywide study have been produced in digital format. Flood hazard information was converted to meet the Federal Emergency Management Agency (FEMA) DFIRM database specifications and Geographic Information System (GIS) format requirements. The flood hazard information was created and is provided in a digital format so that it can be incorporated into