2021 Draft The Confederated Tribes of the Chehalis Reservation Hazard Mitigation Plan Bridgeview Consulting, LLC 915 No. Laurel Lane | Tacoma, WA 98406 | 253.301.1330 2021 Draft The Confederated Tribes of the Chehalis Reservation HAZARD MITIGATION PLAN JANUARY 2021 Prepared for: The Confederated Tribes of the Chehalis Reservation 30 Niederman Road Oakville, WA 98568 Prepared by: Bridgeview Consulting, LLC 915 No. Laurel Lane Tacoma, WA 98406 Tel 253.301.1330 The Confederated Tribes of the Chehalis Reservation Hazard Mitigation Plan TABLE OF CONTENTS Acknowledgments ................................................................................................................... ix Executive Summary ................................................................................................................. ix Plan Development Methodology .................................................................................................................. 2 Phase 1—Organize and Review .................................................................................................................... 2 Phase 2—Risk Assessment ........................................................................................................................... 2 Phase 3—Engage the Public ......................................................................................................................... 3 Phase 4—Assemble the Plan ........................................................................................................................ 3 Phase 5—Plan Adoption and Maintenance ................................................................................................... 3 Chapter 1. General Information .............................................................................................1-1 1.1 Purpose and Authority ...................................................................................................................... 1-1 1.1.1 Confederated Tribes of the Chehalis Reservation’s Response to DMA .......................................... 1-1 1.1.2 Progress Report of 2010 Hazard Mitigation Plan ............................................................................ 1-2 1.1.3 Funding Sources ............................................................................................................................... 1-3 1.2 Implementation and Assurances....................................................................................................... 1-4 1.3 Who Will Benefit From This Plan?.................................................................................................. 1-5 1.4 How to Use This Plan ...................................................................................................................... 1-5 1.5 Changes Between the 2010 and 2020 Plan Update .......................................................................... 1-5 Chapter 2. Planning Process .................................................................................................2-1 2.1 Planning Resource Organization ...................................................................................................... 2-1 2.1.1 Funding of the 2021 Hazard Mitigation Plan ................................................................................... 2-1 2.1.2 Defining the Planning Area .............................................................................................................. 2-1 2.1.3 Formation of the Tribal Hazard Mitigation Planning Team............................................................. 2-2 2.1.4 Planning Team Meetings .................................................................................................................. 2-3 2.1.5 Coordination with Other Agencies ................................................................................................... 2-4 2.1.6 Review of Existing Information ....................................................................................................... 2-6 2.1.7 Public Involvement .......................................................................................................................... 2-6 2.1.8 Plan Development Chronology/Milestones ................................................................................... 2-11 Chapter 3. Confederated Tribes of the Chehalis Reservation profile .................................3-1 3.1 History and Government .................................................................................................................. 3-1 3.2 Location and Geography .................................................................................................................. 3-2 3.3 Climate ............................................................................................................................................. 3-3 3.4 Demographics, Development and Regulation .................................................................................. 3-4 3.4.1 Tribal Enrollment ............................................................................................................................. 3-5 3.4.2 Age Distribution ............................................................................................................................... 3-5 3.4.3 Income .............................................................................................................................................. 3-5 3.4.4 Disabled Populations ........................................................................................................................ 3-6 3.4.5 Economy .......................................................................................................................................... 3-6 3.5 Major Past Hazard Events ................................................................................................................ 3-7 3.6 Land Use and Future Development Trends .................................................................................... 3-12 3.6.2 Critical Facilities and Infrastructure ............................................................................................... 3-15 3.6.3 Age and Type of Building Stock .................................................................................................... 3-18 3.6.4 Transportation ................................................................................................................................ 3-19 3.6.5 Bridges ........................................................................................................................................... 3-20 3.6.6 Rail ................................................................................................................................................. 3-20 i The Confederated Tribes of the Chehalis Reservation - Hazard Mitigation Plan 2021 3.6.7 Hazardous Materials ....................................................................................................................... 3-20 Chapter 4. Capability Assessment ........................................................................................4-1 4.1 Existing Regulations ........................................................................................................................ 4-6 4.1.1 Federal .............................................................................................................................................. 4-6 4.1.2 State-Level Planning Initiatives ....................................................................................................... 4-8 4.1.3 General Public Safety Information ................................................................................................... 4-8 Chapter 5. Hazard Identification and Risk Assessment Methodology ...............................5-1 5.1 Overiew ............................................................................................................................................ 5-1 5.2 Hazard Identification and Profiles.................................................................................................... 5-2 5.3 Risk Assessment Process and Tools................................................................................................. 5-5 5.3.1 Calculated Priority Risk Index Scoring Criteria............................................................................... 5-5 5.3.2 Hazus and GIS Applications ............................................................................................................ 5-8 5.3.3 Probability of Occurrence and Return Intervals ............................................................................. 5-10 5.4 Limitations ..................................................................................................................................... 5-11 Chapter 6. Drought.................................................................................................................6-1 6.1 General Background ......................................................................................................................... 6-1 6.2 Hazard Profile .................................................................................................................................. 6-1 6.2.1 Extent and Location ......................................................................................................................... 6-1 6.2.2 Previous Occurrences ......................................................................................................................