King County Hazard Mitigation Plan Update Volume 1: Planning-Area-Wide Elements REVIEW DRAFT April 2014 King County HAZARD MITIGATION PLAN UPDATE VOLUME 1: PLANNING-AREA-WIDE ELEMENTS REVIEW DRAFT APRIL 2014 Prepared for: King County Office of Emergency Management 3511 NE 2nd Street Renton, WA 98056 Prepared by: Project #103S2548 King County Hazard Mitigation Plan Update; Volume 1—Planning-Area-Wide Elements TABLE OF CONTENTS Executive Summary .............................................................................................................. ES-1 PART 1— THE PLANNING PROCESS Chapter 1. Introduction to the Planning Process.................................................................. 1-1 1.1 Why Prepare This Plan? ....................................................................................................................... 1-1 1.1.1 The Big Picture ................................................................................................................... 1-1 1.1.2 Local Concerns ................................................................................................................... 1-1 1.1.3 Purposes for Planning ......................................................................................................... 1-2 1.2 Who Will Benefit From This Plan? ..................................................................................................... 1-2 1.3 How to Use This Plan .......................................................................................................................... 1-2 Chapter 2. Plan Update—What Has Changed ....................................................................... 2-1 2.1 The Previous Plans ............................................................................................................................... 2-1 2.2 Why Update? ....................................................................................................................................... 2-1 2.3 The Updated Plan—What Is Different? ............................................................................................... 2-2 2.4 Changes in Development ..................................................................................................................... 2-7 2.5 The 5-Year Progress Report ................................................................................................................. 2-8 Chapter 3. Plan Methodology ................................................................................................. 3-1 3.1 Grant Funding ...................................................................................................................................... 3-1 3.2 Formation of the Planning Team ......................................................................................................... 3-1 3.3 Establishment of the Planning Partnership .......................................................................................... 3-1 3.4 Defining the Planning Area.................................................................................................................. 3-3 3.5 The Steering Committee ...................................................................................................................... 3-3 3.6 Coordination with Other Agencies ...................................................................................................... 3-4 3.7 Review of Existing Programs .............................................................................................................. 3-5 3.8 Public Involvement .............................................................................................................................. 3-5 3.8.1 Strategy ............................................................................................................................... 3-6 3.8.2 Public Involvement Results ............................................................................................... 3-11 3.9 Plan Development Chronology/Milestones ....................................................................................... 3-11 Chapter 4. Guiding Principle, Goals and Objectives ............................................................ 4-1 4.1 Guiding Principle ................................................................................................................................. 4-1 4.2 Goals .................................................................................................................................................... 4-1 4.3 Objectives ............................................................................................................................................ 4-1 PART 2— RISK ASSESSMENT Chapter 5. Identified Hazards of Concern and Risk Assessment Methodology ................ 5-1 5.1 Identified Hazards of Concern ............................................................................................................. 5-1 5.2 Methodology ........................................................................................................................................ 5-2 5.3 Risk Assessment Tools ........................................................................................................................ 5-2 5.3.1 Mapping .............................................................................................................................. 5-2 5.3.2 Dam Failure, Earthquake and Flood—HAZUS-MH .......................................................... 5-2 i King County Hazard Mitigation Plan Update; Volume 1—Planning-Area-Wide Elements 5.3.3 Landslide, Tsunami, Severe Weather, Severe Winter Weather, Wildfire and Volcano...... 5-4 5.3.4 Avalanche ............................................................................................................................ 5-4 5.3.5 Limitations .......................................................................................................................... 5-4 Chapter 6. King County Profile ............................................................................................... 6-1 6.1 Jurisdictions and Attractions ................................................................................................................ 6-2 6.2 Historical Overview ............................................................................................................................. 6-2 6.3 Major Past Hazard Events .................................................................................................................... 6-3 6.4 Physical Setting .................................................................................................................................... 6-3 6.4.1 Geology ............................................................................................................................... 6-3 6.4.2 Soils ..................................................................................................................................... 6-5 6.4.3 Seismic Features ................................................................................................................. 6-6 6.4.4 Climate ................................................................................................................................ 6-6 6.5 Land Use ............................................................................................................................................ 6-11 6.6 Critical Facilities and Infrastructure .................................................................................................. 6-11 6.7 Demographics .................................................................................................................................... 6-17 6.7.1 Population Characteristics ................................................................................................. 6-17 6.7.2 Income ............................................................................................................................... 6-17 6.7.3 Age Distribution ................................................................................................................ 6-19 6.7.4 Race, Ethnicity and Language ........................................................................................... 6-20 6.7.5 Disabled Populations ......................................................................................................... 6-21 6.8 Economy ............................................................................................................................................ 6-21 6.8.1 Industry, Businesses and Institutions ................................................................................ 6-21 6.8.2 Employment Trends and Occupations .............................................................................. 6-22 6.9 Future Trends in Development .......................................................................................................... 6-23 6.10 Laws, Ordinances and programs ...................................................................................................... 6-23 6.10.1 Federal ............................................................................................................................... 6-23 6.10.2 State ................................................................................................................................... 6-25 6.10.3 Local Programs ................................................................................................................