Mobile County, Alabama Multi-Hazard Mitigation Plan I
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2015 Mobile County, Alabama Multi-Hazard Mitigation Plan I. Comprehensive Plan A multi-jurisdiction plan City of Bayou La Batre City of Chickasaw City of Citronelle City of Creola Town of Dauphin Island City of Mobile Town of Mt. Vernon City of Prichard City of Saraland City of Satsuma City of Semmes Mobile County Prepared under the direction of the Mobile County Hazard Mitigation Planning Committee With the support of the Mobile County EMA by: Funded in Part through the FEMA Pre-Disaster Mitigation Grant Program April 1, 2016 2015 Mobile County, Alabama, Multi-Hazard Mitigation Plan I. Comprehensive Plan City of Bayou La Batre, City of Chickasaw, City of Citronelle, City of Creola, Town of Dauphin Island, City of Mobile, Town of Mt. Vernon, City of Prichard, City of Saraland, City of Satsuma, City of Semmes, and Mobile County Mobile County EMA Lehe Planning, LLC www.mcema.net www.leheplanning.com 348 N. McGregor Ave. 300 Century Park S, Suite 216 Mobile, AL 36608 Birmingham, AL 35226 251-460-8000 205-978-3633 The preparation and publication of this plan was funded in part by a FEMA grant under the Pre-Disaster Mitigation Grant Program awarded to the Mobile County EMA. Copyright © 2015 by Lehe Planning, LLC. All Rights Reserved. This document contains proprietary materials and methods copyrighted by Lehe Planning, LLC. Permission is granted to the Mobile County Emergency Management Agency (EMA) for its internal use. Use by anyone other than the Mobile County EMA requires the express written permission of Lehe Planning, LLC. You may not copy, modify, publicly display, distribute, reverse engineer, or incorporate into your products or services this document (or any of the information or data structures contained herein) without the express written authorization of Lehe Planning, LLC. April 1, 2016 ii CONTENTS 2015 Mobile County Multi-Hazard Mitigation Plan Contents Executive Summary ..................................................................................................................... ix Chapter 1 Introduction ......................................................................................................... 1-1 1.1 Background .................................................................................................. 1-1 1.2 Authority ....................................................................................................... 1-1 1.3 Funding ........................................................................................................ 1-2 1.4 Eligibility for FEMA Hazard Mitigation Assistance Grants ............................. 1-2 1.5 Initial Plans ................................................................................................... 1-4 1.6 The 2010 Mobile County Multi-Hazard Mitigation Plan Update ..................... 1-4 1.7 The 2015 Mobile County Multi-Hazard Mitigation Plan Update ..................... 1-5 Chapter 2 Prerequisites………………………………………………………………….. ............. 2-1 2.1 Federal Prerequisites ................................................................................... 2-1 2.2 Plan Approval Required for Mitigation Grants Eligibility ................................ 2-1 2.3 Multi-Jurisdictional Participation ................................................................... 2-2 2.4 Multi-Jurisdictional Plan Adoption ................................................................. 2-3 Chapter 3 Community Profiles ............................................................................................ 3-1 3.1 Federal Advisory Guidance for Community Profiles...................................... 3-1 3.2 Summary of Plan Updates ............................................................................ 3-1 3.3 Geographic Setting and History .................................................................... 3-2 3.4 Government ................................................................................................. 3-7 3.5 Physical Features ......................................................................................... 3-7 3.6 Climate ....................................................................................................... 3-10 3.7 Demographics ............................................................................................ 3-10 3.8 Economy .................................................................................................... 3-17 3.9 Utilities ....................................................................................................... 3-23 3.10 Media ......................................................................................................... 3-23 3.11 Transportation ............................................................................................ 3-24 Chapter 4 The Planning Process......................................................................................... 4-1 4.1 Federal Requirements for the Planning Process .......................................... 4-1 4.2 Summary of Plan Updates ............................................................................ 4-2 4.3 Opportunities for Public Comment on the Plan ............................................. 4-3 4.4 Opportunities for Involvement in the Planning Process ................................. 4-5 4.5 Review and Incorporation of Applicable Plans and Documents .................... 4-6 4.6 How the Plan was Prepared ......................................................................... 4-8 4.7 Who was Involved in the Planning Process ................................................ 4-10 4.7.1 The Hazard Mitigation Planning Committee .................................... 4-10 4.7.2 The Guidelines of the Hazard Mitigation Planning Committee......... 4-11 4.7.3 Preparation of the Plan Update ....................................................... 4-12 4.8 How the Public was involved in the Planning Process ................................ 4-12 i CONTENTS 2015 Mobile County Multi-Hazard Mitigation Plan 4.9 The Plan Review and Update Process ....................................................... 4-13 Chapter 5 Risk Assessment ................................................................................................ 5-1 5.1 Federal Requirements for Risk Assessments ............................................... 5-1 5.2 Summary of Plan Updates ............................................................................ 5-2 5.3 Identification of Hazards Affecting Each Jurisdiction ..................................... 5-2 5.3.1 Types of Hazards .............................................................................. 5-2 5.3.2 Sources for Identifying Mobile County Hazards ................................ 5-7 5.4 Hazard Profiles ........................................................................................... 5-11 5.4.1 Hurricanes Profile ........................................................................... 5-11 5.4.2 Floods Profile .................................................................................. 5-23 5.4.3 Severe Storms Profile ..................................................................... 5-27 5.4.4 Tornadoes Profile ........................................................................... 5-29 5.4.5 Wildfires Profile ............................................................................... 5-34 5.4.6 Droughts/Heat Waves Profile .......................................................... 5-41 5.4.7 Winter Storm/Freezes Profile .......................................................... 5-43 5.4.8 Earthquakes Profile ........................................................................ 5-46 5.4.9 Landslides Profile ........................................................................... 5-54 5.4.10 Dam/Levee Failures Profile ............................................................. 5-57 5.4.11 Sinkholes (Land Subsidence) Profile .............................................. 5-61 5.4.12 Tsunamis Profile ............................................................................. 5-65 5.4.13 Man-made/Technological Hazards Profile ...................................... 5-66 5.5 Vulnerability of Structures within Each Jurisdiction ..................................... 5-68 5.5.1 Scope of Structure Inventory ............................................................ 5-68 5.5.2 Inventory Methodology ..................................................................... 5-68 5.5.3 HAZUS-MH Structure Inventory ....................................................... 5-71 5.5.4 Existing and Future Structure Vulnerabilities by Hazard ................... 5-75 5.6 Estimate of Dollar Losses to Vulnerable Structures .................................. 5-125 5.6.1 Scope and Purpose of Loss Estimates ........................................... 5-125 5.6.2 Loss Estimate Methodology ........................................................... 5-125 5.6.3 HAZUS-MH Loss Estimates ........................................................... 5-127 5.6.4 Loss Estimates Based on Historical Records ................................. 5-144 5.6.5 Recommended Risk Assessment Measures .................................. 5-144 5.7 General Description of Land Uses and Development Trends ................... 5-145 5.7.1 Impacts of Development Trends on Vulnerability............................ 5-145 5.7.2 Past Trends .................................................................................... 5-145 5.7.3 Future Trends ...............................................................................