Howard County Natural Hazards Mitigation Plan Table of Contents Section 1 Table of Contents ...................................................................................... 1-1 Section 2 Executive Summary .................................................................................. 2-1 Section 3 Background ............................................................................................... 3-1 3.1 Introduction 3.1.1 Scope of Plan 3.2 Howard County Government Organization 3.3 Background 3.3.1 Geography 3.3.2 Climate 3.3.3 History of Howard County 3.3.4 Population 3.3.5 Land Use 3.3.6 Growth and Development 3.3.7 Transportation 3.3.8 Community Assets 3.4 The Maryland State Hazard Mitigation Plan Section 4 Approval and Adoption ............................................................................ 4-1 4.1 IFR Requirement for Approval and Adoption 4.2 Authority 4.3 Approval and Adoption Process 4.4 Adoption Resolution Section 5 Planning Process ...................................................................................... 5-1 5.1 IFR Requirements for the Planning Process 5.2 What is Hazard Mitigation? 5.3 Natural Hazard Mitigation Plan Update Process 5.4 Planning Process 5.4.1 Organize Resources iii 2012 Howard County Natural Hazards Mitigation Plan 5.4.2 Assess Risks 5.4.3 Develop a Mitigation Plan 5.4.4 Implement Plan and Monitor Progress Section 6 Hazard Identification, Profiling, and Ranking .......................................... 6-1 6.1 IFR Requirement for Hazard Identification and Profiling 6.2 Hazard Identification 6.2.1 Overview of Howard County’s Natural Hazards History 6.2.2 Natural Hazards Related Deaths, Injuries, and Property Damage 6.3 Losses Due to Major Disasters 6.4 Overview of Type and Location of All Natural Hazards 6.4.1 Floods 6.4.2 Severe Winter Storms 6.4.3 Wildfires 6.4.4 Hurricanes & Tropical Cyclones 6.4.5 Tornados & Wind Storms 6.4.6 Lightning 6.4.7 Earthquakes 6.4.8 Drought & Extreme Heat 6.5 Methodology for Identifying Natural Hazards for Additional Analysis Section 7 Vulnerability Assessment and Loss Estimation ..................................... 7-1 7.1 IFR Requirement for Risk Assessments 7.2 Overview and Analysis of Howard County’s Vulnerability to Hazards 7.3 Estimate of Potential Losses 7.3.1 Flood Risk in Howard County 7.3.2 Hurricane and Tropical Storm Wind Risk in Howard County 7.3.3 Winter Storm Risk in Howard County 7.3.4 Tornado Risk in Howard County 7.5 Summary of Risk Assessment iv 2012 Howard County Natural Hazards Mitigation Plan Section 8 Mitigation Strategy .................................................................................... 8-1 8.1 IFR Requirements for Mitigation Strategy 8.2 Mitigation Goals and Objectives 8.3 Previous and Ongoing Mitigation Initiatives 8.4 Continued Compliance with NFIP 8.5 Mitigation Actions Items 8.5.1 Evaluating Mitigation Actions for Cost-Effectiveness 8.6 Prioritized Mitigation Actions Items 8.7 Existing Plans, Policies, Programs, and Resources Section 9 Plan Intergration ........................................................................................ 9-1 9.1 IFR Requirements for Plan Integration 9.2 Introduction 9.2.1 Plan Howard 2030 – General Plan 9.2.2 Zoning Ordinance 9.2.3 Subdivision Regulations 9.2.4 Howard County Building Code 9.2.5 Floodplain Development Regulations 9.2.6 Stormwater Management 9.2.7 Emergency Operations 9.2.8 Columbia Watershed Management Plan 9.2.9 2006 Land Preservation, Recreation, and Parks Plan 9.2.10 Capital Improvement Program Section 10 Plan Monitoring and Maintenance .......................................................... 10-1 10.1 IFR Requirements for NHMP Monitoring and Maintenance 10.2 Distribution 10.3 Implementation 10.4 Monitoring and Progress Reports 10.5 Circumstances that will Initiate NHMP Review and Updates 10.6 Continued Public Involvement v 2012 Howard County Natural Hazards Mitigation Plan Appendices A. General Description of Natural Hazards .................................................................................... A-1 B. Natural Hazards Mitigation Plan Steering Committee Meeting Agendas ................................... B-1 C. Natural Hazards Mitigation Plan Steering Committee Meeting Sign In Sheets ........................ C-1 D. Natural Hazards Mitigation Plan Steering Committee Meeting Minutes ................................... D-1 E. Public Meeting Documents ........................................................................................................ E-1 F. Natural Hazards Mitigation Plan - Website ............................................................................... F-1 G. Engaging Stakeholders ............................................................................................................ G-1 H. 2011 Flood Mitigation Plan - Mitigation Actions ....................................................................... H-1 I. FEMA’s Letter of Approvability ................................................................................................... I-1 J. Adoption Resolution for Howard County .................................................................................... J-1 K. FEMA’s Final Letter of Approval ................................................................................................ K-1 L. Key Terms ................................................................................................................................. L-1 M. Department Acronyms ............................................................................................................. M-1 N. Acronyms .................................................................................................................................. N-1 List of Illustrations Maps Howard County Districts .......................................................................................................................... 3.2-1 Howard County and Surrounding Jurisdictions .................................................................................... 3.3.1-1 Howard County Population Centers ...................................................................................................... 3.3.3-2 Howard County Land Use ..................................................................................................................... 3.3.5-1 Howard County Population Density ...................................................................................................... 3.3.6-1 Howard County Residential Permits 2006-2010 ................................................................................... 3.3.6-3 Howard County - Critical Facilities ........................................................................................................ 3.3.8-2 Howard County Major Watersheds ....................................................................................................... 6.4.1-1 Howard County 100 Year Flood Plain ................................................................................................... 6.4.1-3 Columbia & Ellicott City 100 Year Flood Plain ...................................................................................... 6.4.1-4 Maryland Average Annual Snowfall ...................................................................................................... 6.4.2-1 Historical National Flood Insurance Program Claims in Howard County, Maryland 1977-2010 ............ 7.3.1-3 Table Howard County Climatic Averages ....................................................................................................... 3.3.2-1 Population Estimates for 2000, 2010, and 2020 ................................................................................... 3.3.4-1 2010 Census Data: Demographic and Housing Statistics .................................................................... 3.3.4-2 2005-2009 American Community Survey 5-Year Estimates: Demographic and Housing Statistics .... 3.3.4-3 2005-2009 American Community Survey 5-Year Estimates: Economic Characteristics ...................... 3.3.4-5 Howard County: Residential Permits .................................................................................................... 3.3.6-2 Top Ten Employers in Howard County ................................................................................................. 3.3.6-4 vi 2012 Howard County Natural Hazards Mitigation Plan Howard County - Critical Facilities ........................................................................................................ 3.3.8-1 Major Presidential Disaster Declarations in Howard County (1965 to 2010) ........................................ 6.2.1-1 Emergency Declarations in Howard County (1965 to 2010) ................................................................. 6.2.1-2 Estimated Damages for Federally Declared Disasters in Howard County, Maryland (1965 to 2010) ...... 6.3-1 Definition of High, Medium, and Low Probability of Occurrence .............................................................. 6.4-1 Comparison of Flood Hazard Zones (Effective FIRM vs. Preliminary DFIRM)...................................... 6.4.1-2 Structures Located in the 100-year Floodplain by General Occupancy Type ....................................... 6.4.1-5 Howard County: Flood Events from 1996 to February 2011 Resulting in Property Damage ................ 6.4.1-6 Howard County: Winter Storm Events Resulting in Property Damage, 1995 – February 2010 ............. 6.4.2-2 Fires and Acres Burned in Maryland from 2004-2009