2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 1. INTRODUCTION ................................................................................................................................ 8
1.1
1.2
1.3
1.4
1.5
1.6
PLAN GOALS & OBJECTIVES ........................................................................................................................9
PLAN ORGANIZATION .................................................................................................................................9
PLAN PURPOSE ...........................................................................................................................................10
HAZARD MITIGATION ................................................................................................................................. 10
SCOPE .........................................................................................................................................................12
AUTHORITIES ..............................................................................................................................................12
CHAPTER 2. PLANNING PROCESS ......................................................................................................................... 14
2.1
2.2
2.3
2.4
2.5
2.6
PLANNING PROCESS ...................................................................................................................................14
LOCAL HMP PLANNING SCHEDULE, MEETINGS, & MITIGATION WORKSHOPS ...........................................15
PUBLIC AND STAKEHOLDER INVOLVEMENT ...............................................................................................15
COORDINATION WITH OTHER AGENCIES, PARTNERS, AND STAKEHOLDERS ..............................................18
EQUITY CONSIDERATIONS FOR UNDERSERVED COMMUNITIES.................................................................19
EXISTING PLANS, STUDIES, REPORTS AND TECHNICAL INFORMATION REVIEWED FOR THE PLAN .............20
CHAPTER 3. COLVILLE RESERVATION PROFILE ...................................................................................................... 23
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.16
LOCATION ...................................................................................................................................................23
TOPOGRAPHY & VEGETATION .................................................................................................................... 23
NATURAL RESOURCES ................................................................................................................................ 24
CLIMATE .....................................................................................................................................................25
LAND OWNERSHIP, LAND USE, & FUTURE DEVELOPMENT ......................................................................... 25
HISTORY......................................................................................................................................................26
POPULATION & DEMOGRAPHICS ............................................................................................................... 28
HOUSING ....................................................................................................................................................30
ECONOMY ..................................................................................................................................................31
AGRICULTURE .............................................................................................................................................32
TIMBER INDUSTRY ......................................................................................................................................33
EDUCATION ................................................................................................................................................33
VULNERABLE POPULATIONS BELOW POVERTY LEVEL ................................................................................. 34
UTILITIES .....................................................................................................................................................35
COMMUNICATIONS ...................................................................................................................................37
TRANSPORTATION...................................................................................................................................... 40
CHAPTER 4. HAZARD RISK ASSESSMENT .............................................................................................................. 42
4.1
4.2
4.3
4.4
4.5
4.6
4.7
IDENTIFIED HAZARDS .................................................................................................................................42
DISASTER DECLARATIONS...........................................................................................................................44
CLIMATE CHANGE IMPACTS & CONSIDERATIONS ...................................................................................... 44
HAZARD PROFILE ........................................................................................................................................46
RISK ASSESSMENT METHODOLOGY............................................................................................................46
FEMA NRI RISK SCORES ...............................................................................................................................51
OVERALL RISK SCORES ................................................................................................................................54
CHAPTER 5. DROUGHT ......................................................................................................................................... 56
5.1
5.2
5.3
5.4
5.5
5.6
5.7
HAZARD DESCRIPTION ................................................................................................................................56
HAZARD LOCATION ....................................................................................................................................56
HAZARD EXTENT/INTENSITY .......................................................................................................................56
PROBABILITY AND FREQUENCY .................................................................................................................. 58
PAST EVENTS ..............................................................................................................................................59
VULNERABILITY AND IMPACTS ...................................................................................................................60
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT........................................................................................ 64
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 6. EARTHQUAKE ................................................................................................................................... 67
6.1
6.2
6.3
6.4
6.5
6.6
6.7
HAZARD DESCRIPTION ................................................................................................................................67
HAZARD LOCATION ....................................................................................................................................68
HAZARD EXTENT/INTENSITY .......................................................................................................................69
PROBABILITY AND FREQUENCY .................................................................................................................. 71
PAST EVENTS ..............................................................................................................................................73
VULNERABILITY AND IMPACTS ...................................................................................................................75
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT........................................................................................ 77
CHAPTER 7. FLOODING ........................................................................................................................................ 79
7.1
7.2
7.3
7.4
7.5
7.6
7.7
HAZARD DESCRIPTION ................................................................................................................................79
HAZARD LOCATION ....................................................................................................................................82
HAZARD EXTENT/INTENSITY .......................................................................................................................88
PROBABILITY AND FREQUENCY .................................................................................................................. 89
PAST EVENTS ..............................................................................................................................................90
VULNERABILITY AND IMPACTS ...................................................................................................................91
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT........................................................................................ 95
CHAPTER 8. HIGH HAZARD DAMS AND LEVEES .................................................................................................. ..98
8.1
8.2
8.3
8.4
8.5
8.6
8.7
HAZARD DESCRIPTION .............................................................................................................................. .98
HAZARD LOCATION .................................................................................................................................. 100
HAZARD EXTENT/INTENSITY .....................................................................................................................104
PROBABILITY AND FREQUENCY ................................................................................................................106
PAST EVENTS ............................................................................................................................................106
VULNERABILITY AND IMPACTS ................................................................................................................. 106
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................110
CHAPTER 9. LANDSLIDE ...................................................................................................................................... 111
9.1
9.2
9.3
9.4
9.5
9.6
9.7
HAZARD DESCRIPTION .............................................................................................................................. 111
HAZARD LOCATION .................................................................................................................................. 112
HAZARD EXTENT/INTENSITY .....................................................................................................................112
PROBABILITY AND FREQUENCY ................................................................................................................113
PAST EVENTS ............................................................................................................................................113
VULNERABILITY AND IMPACTS ................................................................................................................. 115
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................120
CHAPTER 10. SEVERE SUMMER WEATHER ......................................................................................................... 123
10.1
10.2
10.3
10.4
10.5
10.6
10.7
HAZARD DESCRIPTION .............................................................................................................................. 123
HAZARD LOCATION .................................................................................................................................. 125
HAZARD EXTENT/INTENSITY .....................................................................................................................125
PROBABILITY AND FREQUENCY ................................................................................................................131
PAST EVENTS ............................................................................................................................................133
VULNERABILITY AND IMPACTS ................................................................................................................. 135
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................146
CHAPTER 11. SEVERE WINTER WEATHER ........................................................................................................... 151
11.1
11.2
11.3
11.4
11.5
11.6
HAZARD DESCRIPTION .............................................................................................................................. 151
HAZARD LOCATION .................................................................................................................................. 151
HAZARD EXTENT/INTENSITY .....................................................................................................................151
PROBABILITY AND FREQUENCY ................................................................................................................154
PAST EVENTS ............................................................................................................................................155
VULNERABILITY AND IMPACTS ................................................................................................................. 156
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
11.7
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................162
CHAPTER 12. AVALANCHE .................................................................................................................................. 165
12.1
12.2
12.3
12.4
12.5
12.6
12.7
HAZARD DESCRIPTION .............................................................................................................................. 165
HAZARD LOCATION .................................................................................................................................. 165
HAZARD EXTENT/INTENSITY .....................................................................................................................166
PROBABILITY AND FREQUENCY ................................................................................................................168
PAST EVENTS ............................................................................................................................................168
VULNERABILITY AND IMPACTS ................................................................................................................. 168
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................172
CHAPTER 13. VOLCANIC ERUPTION AND ASH .................................................................................................... 174
13.1
13.2
13.3
13.4
13.5
13.6
13.7
HAZARD DESCRIPTION .............................................................................................................................. 174
HAZARD LOCATION .................................................................................................................................. 174
HAZARD EXTENT/INTENSITY .....................................................................................................................175
PROBABILITY AND FREQUENCY ................................................................................................................177
PAST EVENTS ............................................................................................................................................177
VULNERABILITY AND IMPACTS ................................................................................................................. 178
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................180
CHAPTER 14. WILDFIRE ...................................................................................................................................... 181
14.1
14.2
14.3
14.4
14.5
14.6
14.7
HAZARD DESCRIPTION .............................................................................................................................181
HAZARD LOCATION .................................................................................................................................. 182
HAZARD EXTENT/INTENSITY .....................................................................................................................184
PROBABILITY AND FREQUENCY ................................................................................................................186
PAST EVENTS ............................................................................................................................................187
VULNERABILITY AND IMPACTS ................................................................................................................. 190
FEMA NATIONAL RISK INDEX (NRI) ASSESSMENT......................................................................................192
CHAPTER 15. OTHER HAZARDS OF CONCERN ..................................................................................................... 194
15.1
15.2
15.3
15.4
15.5
15.6
15.7
15.8
15.9
15.10
PUBLIC HEALTH EMERGENCY ...................................................................................................................194
REDUCED AIR QUALITY .............................................................................................................................197
ANIMAL DISEASE ......................................................................................................................................200
PLANT DISEASE .........................................................................................................................................203
WIDESPREAD POWER OUTAGE ................................................................................................................205
HAZARDOUS MATERIAL INCIDENT ........................................................................................................... 209
ACTIVE SHOOTER/ACTIVE ASSAILANT ......................................................................................................213
TERRORISM ..............................................................................................................................................215
CYBER ATTACKS ........................................................................................................................................218
GOVERNMENT AND REGULATORY ISSUES ...........................................................................................220
CHAPTER 16. TRIBAL CAPABILITY ASSESSMENT ................................................................................................. 223
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
PLANNING AND REGULATORY CAPABILITIES ............................................................................................223
CODE ADMINISTRATION ...........................................................................................................................224
FINANCIAL CAPABILITIES ..........................................................................................................................226
LEGAL AND REGULATORY CAPABILITIES ...................................................................................................226
ADMINISTRATIVE AND TECHNICAL CAPABILITIES & SUPPORT .................................................................. 227
NATIONAL FLOOD INSURANCE COMPLIANCE & PARTICIPATION ..............................................................228
WARNING, EDUCATION, AND OUTREACH CAPABILITIES ..........................................................................230
PUBLIC SAFETY & RESPONSE CAPABILITIES ............................................................................................... 230
CHAPTER 17. MITIGATION GOALS & CHANGES IN PRIORITY .............................................................................. 243
17.1
MITIGATION GOALS ..................................................................................................................................243
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
17.2
CHANGES IN PRIORITY .............................................................................................................................. 243
CHAPTER 18. MITIGATION STRATEGIES.............................................................................................................. 244
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
MITIGATION ACTION PLAN .......................................................................................................................247
MITIGATION STRATEGY/ACTION TIMELINE PARAMETERS .......................................................................247
MITIGATION STRATEGY/ACTION BENEFIT PARAMETERS ......................................................................... 247
MITIGATION STRATEGY/ACTION ESTIMATED COST PARAMETERS ...........................................................247
MITIGATION STRATEGY/ACTION PRIORITIZATION PROCESS ....................................................................248
MITIGATION PROJECTS .............................................................................................................................249
NEW MITIGATION PROJECTS .................................................................................................................... 250
CURRENT ONGOING MITIGATION PROJECTS ........................................................................................... 328
CHAPTER 19. PLAN MAINTENANCE .................................................................................................................... 367
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
CONTINUED PUBLIC INVOLVEMENT ......................................................................................................... 367
MONITORING, EVALUATING, & UPDATING THE PLAN ..............................................................................367
THE FIVE-YEAR ACTION PLAN ................................................................................................................... 368
ANNUAL TRIBAL HAZARD MITIGATION PLANNING MEETING...................................................................370
FORMAL REVIEW PROCESS ....................................................................................................................... 370
PLAN EVALUATION ...................................................................................................................................371
REVIEW OF MITIGATION ACTIONS............................................................................................................371
MEETING DOCUMENTATION.................................................................................................................... 371
IMPLEMENTATION THROUGH EXISTING PROGRAMS ...............................................................................371
APPENDIX .......................................................................................................................................................... 373
APPENDIX: GLOSSARY............................................................................................................................................374
APPENDIX: PLAN ADOPTION..................................................................................................................................377
APPENDIX: FEMA PLAN APPROVAL........................................................................................................................ 378
APPENDIX: PLAN PARTICIPATION DOCUMENTATION ........................................................................................... 379
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
PART I: PLANNING PROCESS
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 1. INTRODUCTION
The Colville Confederated Tribes land, the incorporated communities that lie within the
reservation boundaries, and outlying reservation trust lands are vulnerable to natural,
technological, and man-made hazards that have the possibility of causing serious threats to the
health, welfare, and security of its residents. The cost of response to and recovery from potential
disasters, in terms of potential loss of life or property, can be lessened when attention is turned to
mitigating their impacts and effects before they occur or reoccur.
This All-Hazard Mitigation Plan seeks to identify hazards and understand their impact on
vulnerable populations, community lifelines, and infrastructure. With that understanding, the
plan sets forth solutions that, if implemented, have the potential to significantly reduce threat to
life and property. The plan is based on the premise that hazard mitigation works. With increased
attention to managing natural, technological, and man-made hazards, communities can reduce the
threats to citizens and through proper land use and emergency planning can avoid creating new
problems in the future. Many solutions can be implemented at minimal cost and social impact.
This is not an emergency response or management plan. Certainly, the plan can be used to identify
weaknesses and refocus emergency response planning. Enhanced emergency response planning is
an important mitigation strategy. However, the focus of this plan is to support better decisionmaking directed toward avoidance of future risk and the implementation of activities or projects
that will eliminate or reduce the risk for those that may already have exposure to a hazard threat.
The Colville Confederated Tribes All Hazard Mitigation Plan was created with the goal of
substantially and permanently reducing the Reservation’s vulnerability to hazards through sound
public policy. By increasing public awareness of potential harm, documenting resources for
risk reduction and loss prevention, and identifying activities to guide the development of less
vulnerable and more sustainable communities, this plan aims to protect citizens, critical
facilities, infrastructure, property, and the natural environment.
The Colville Reservation is governed by elected Colville Business Council (CBC), under a Tribal
Constitution approved in 1938. There are fourteen members, one of whom is chosen as the
Chairman. Politically, the Reservation is divided into four districts; council members are elected
by district. Inchelium District, Omak District, Keller District and the Nespelem District are the
four districts that make up the Colville Reservation. This designation will be the “planning area”
throughout this plan.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 1. Colville Reservation District Map
1.1
PLAN GOALS & OBJECTIVES
The goals of the All Hazard Mitigation Plan include coordinating with local governments to
develop plans and processes that meet the planning components identified in the FEMA Region X
Crosswalk document. The overall objective is risk reduction from natural hazards in the state of
Washington through implementing and updating the Colville Confederated Tribes mitigation plan.
1.2
•
•
•
•
•
PLAN ORGANIZATION
Part I of the plan provides a general overview of the plan and its planning process and
identifies who was involved in revisions of the plan and the process used to develop this
particular revision.
Part II contains a community profile of the Colville Reservation.
Part III provides a brief definition for each natural and man-made hazard. All
hazards identified as affecting the Reservation are analyzed and summarized in a hazard
profile.
Part IV outlines the Mitigation Strategy and identifies the goals, objectives, and mitigation
projects.
Part V details the plan maintenance process and provides a tentative timeline for updating
the plan in the future.
The Appendix contains contact information for the planning team, meetings, public participation,
and plan adoption and endorsement forms.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
1.3
PLAN PURPOSE
This plan exists to identify natural and man-made hazards and threats to the Colville Confederated
Tribes (CCT), prepare mitigation management strategies to address those threats, develop shortterm and long-term goals and objectives for mitigation planning, and to fulfill federal, state, and
tribal hazard mitigation planning obligations. The intention of this plan is to enhance awareness of
and provide mitigation strategies for elected officials, agencies, and the public and develop
actions which will minimize negative outcomes to Colville Reservation’s community members,
the economy, and the environment due to potential natural and man-made hazards and threats. The
well-being of the Colville Reservation rests on reducing risks to life and property in the event of
an emergency/disaster.
PUBLIC DEFINITION FOR THE COLVILLE CONFEDERATED
TRIBES ALL HAZARD MITIGATION PLAN
For the purposes of this plan, public, as defined by the Colville Confederated Tribes (CCT) for
this specific planning initiative, includes residents, businesses, and organizations directly
associated with the CCT, and specifically those tribal citizens living on tribal land or coming onto
tribal lands to work or visit.
1.4
HAZARD MITIGATION
Hazard mitigation is defined as cost-effective actions that have the effect of reducing, limiting, or
preventing the vulnerability of people, culture, property, and the environment to potentially
damaging, harmful, or costly hazards.
Hazard mitigation measures, which can be used to eliminate or minimize the risk to life, culture,
and property, fall into three categories:
1. Those that keep the hazard away from people, property, and structures.
2. Those that keep people, property, or structures away from the hazard; and
3. Those that reduce the impact of the hazard on victims, e.g., insurance.
Hazard mitigation measures must be practical, cost effective, and culturally, environmentally, and
politically acceptable. Actions taken to limit the vulnerability of society to hazards must not, in
themselves, be costlier than the anticipated damages.
Hazard mitigation planning must be based on vulnerabilities and its primary focus must be on the
point where capital investment and land use decisions are made. The placement of capital
investments, whether for homes, roads, public utilities, pipelines, or public works, determine to a
large extent, the nature and degree of a community’s hazard vulnerability. Once a capital facility
is in place, there is little opportunity to reduce hazard vulnerability through correction of errors in
location or construction. It is for this reason that often the most effective mitigation tools are zoning
and other ordinances that manage development in high vulnerability areas and building codes that
ensure new buildings are constructed to withstand the damaging forces of anticipated hazards.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Because disaster events are generally infrequent, the nature and magnitude of the threat is often
ignored or poorly understood. Thus, the priority to implement mitigation measures is low and
implementation is slowed. Mitigation success can be achieved, however, if accurate information
is portrayed through complete hazard identification and impact studies, followed by effective
mitigation management.
The hazards analyzed in this plan include the following:
Natural Hazards
•
•
•
•
•
•
•
•
Severe Summer Weather
o Extreme Heat
o Lightning
o Hail
o Tornado
o Straight-line Wind
Severe Winter Weather
o Extreme Cold
o Winter Storm/Blizzard/Heavy Snow
Avalanche
Wildfire
Flood
o River or Stream Flood
o Flash Flood
High Hazard Dams and Levees
Drought
Volcanic Eruption and Ash
Geological Hazards
•
•
Earthquake
Landslide
Other Hazards of Concern
Although non-natural hazards are not required by FEMA for inclusion in a hazard mitigation plan,
the Colville Reservation wishes to rank and mitigate against a comprehensive list of hazard events
that could impact the Reservation. Due to both the nature of non-natural hazards and the
discretionary status regarding their inclusion, the following hazards of interest have been
briefly and qualitatively assessed for the sake of public education and informing their inclusion
within the hazard ranking and mitigation process.
Biological Hazards
•
•
•
•
Public Health Emergency
Air Quality
Animal Disease
Plant Disease
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Technological (Man-made) Hazards
•
•
•
•
•
•
Hazardous Material Incident
Terrorism
Active Assailant Incident
Government and Regulatory Issues
Widespread Power Outage
Cyber-Security Incident
Per FEMA’s mandate to address all natural hazards, the following natural hazards were not
included because these hazards do not directly impact the Colville Reservation due to geographic
location:
•
Hurricane
Sea Level Rise
Storm Surge
Tsunami
1.5
SCOPE
•
•
•
The plan provides comprehensive hazard identification, risk assessment, vulnerability and impact
analyses, mitigation actions, and an implementation schedule.
1.6 AUTHORITIES
FEDERAL
Public Law 93-288, as amended, established the basis for federal hazard mitigation activity in
1974. A section of this Act requires—as prerequisite for state receipt of future disaster assistance
outlays—the identification, evaluation, and mitigation of hazards. Since 1974, many additional
programs, regulations, and laws have expanded on the original legislation to establish hazard
mitigation as a priority at all levels of government.
Several additional provisions were also included when PL 93-288 was amended by the Stafford
Act that provide for the availability of significant mitigation measures in the aftermath of a
presidentially declared disaster. Civil Preparedness Guide 1-3, Chapter 6—Hazard Mitigation
Assistance Programs places emphasis on hazard mitigation planning directed toward hazards with
a high impact and threat potential.
The Disaster Mitigation Act of 2000 (DMA 2000) was signed into Law on October 30, 2000, by
President Bill Clinton. Section 322 defines mitigation planning requirements for state, local, and
tribal governments. Under Section 322, if states submit a mitigation plan (a summary of
local/regional mitigation plans) identifying natural hazards, risks, vulnerabilities, and proposed
actions to reduce those risks and vulnerabilities, the state is eligible for an increase in the federal
share of hazard mitigation.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Source: H.R.707 - Disaster Mitigation Act of 2000
https://www.congress.gov/bill/106th-congress/house-bill/707
TRIBAL AUTHORITY
Tribal governments play an essential role in implementing effective mitigation. For the purposes
of this plan, tribal governments include not only communities and reservations but also special
service districts with elected boards.
The Disaster Mitigation Act of 2000 (DMA 2000) (P.L. 106-390) provides an opportunity for
states, tribes, and local governments to take a new and revitalized approach to mitigation planning.
DMA 2000 amended the Robert T. Stafford Disaster Relief and Emergency Assistance Act (the
Act) by repealing the previous Mitigation Planning section (409) and replacing it with a new
Mitigation Planning section (322). This new section emphasizes the need for state, tribal, and local
entities to closely coordinate mitigation planning and implementation efforts. To implement the
DMA 2000 planning requirements, FEMA published an Interim Final Rule in the Federal Register
on February 26, 2002. This rule (44 CFR Part 201) established the mitigation planning
requirements for states, tribes, and local communities.
The Colville Confederated Tribes All Hazard Mitigation Plan has been developed pursuant
to the requirements in the Interim Final Rule for hazard mitigation planning and the guidance in
the State and Local Plan Interim Criteria under DMA 2000, the Tribal Multi-Hazard Planning
Guidance and its associated Tribal Multi-Hazard Plan review crosswalk.
The Colville Business Council has adopted the All Hazard Mitigation Plan. This governing body
has the authority to promote sound public policy regarding natural and man-made hazards on the
reservation.
The resolution adopting the plan includes assurances that the CCT will comply with all applicable
federal statutes and regulations in effect with respect to the periods for which it received grant
funding in compliance with 44 CFR 13.11c. The All Hazard Mitigation Plan will be amended
whenever necessary to reflect changes in tribal or federal laws and statutes as required in 44 CFR
13.11d.
The CCT will be responsible for submitting the adopted Hazard Mitigation Plan and will gain
eligibility for mitigation project grants and post-disaster hazard mitigation grant projects.
The Tribe, as a sovereign government, possesses the following law, regulatory, or policy
assets:
• A Constitution, adopted in 1938
• A Tribal code known as the Law and Order Code
• Duly authorized Resolutions (law) passed by the Governing body to protect Tribal
members and other residents, to protect natural resources, and to protect the cultural legacy
and continued cultural existence of the twelve constituent Tribes that make up the
Confederated Tribes of Colville Reservation.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 2. PLANNING PROCESS
2.1
PLANNING PROCESS
Table 1. Plan Participation
Colville Confederated Tribes Planning Process Table
Jurisdiction
Attended at least
one meeting
Met with
Core
Planning
Team
Yes
Yes
Colville
Confederated Tribes
Completed Risk
Assessment
Submitted at
least One
New
Mitigation
Action
Reviewed
Past
Mitigation
Actions
Yes
Yes
Yes
COLVILLE CONFEDERATED TRIBES (CCT) PLANNING TEAM
The following individuals are either members of the original planning team or are significant
stakeholders in the plan. contributed data, involved in postings for informational meetings, or were
reviewers of the Plan.
Name
Taressa Marchand
Chance Cruger
Steve Brown
Cody Desautel
Doug Marconi Jr.
Joe Peone
Rodney Cawston
Table 2. Colville Tribes Hazard Mitigation Planning Team
Amanda Chiles
Manager
Tiffany Circle
Chief Information Officer
Department/Organization
Emergency Management
EMS
Colville Tribal Police
Administration
Planning
Tribal Fish & Wildlife
Environmental Trust
Tribal Occupational Safety and
Health (TOSHA)
IT Department
Robert Sloma
Archeologist
History & Archeology
Ron Toulou
Supervisor
Public Works /
Tribal Water and Sewage
BIA - Range
Environmental Trust /
Air Quality
Colville Indian Housing
Authority
Geographic Information
Systems
Brandton Harvey
Title
Coordinator
Fire Chief
Police Chief
Executive Director
Grants Writer
Director
Director
Range Conservationist
Kathy Moses
Communication Specialist / PIO
Doug Marconi Sr.
Director
Alexander Besemann
Specialist
Chance Garver
Public Affairs / PIO
Administration
Richard Palmer
Ron Garrow
Linda McLean
Director
Government Liaison
Director/4-H/ANR/FRTEP Educator
Department of Transportation
American Red Cross
WSU Extension Office
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Name
Sam Jenkins
Effie Dean
Ed Forseman
Scott Meredith
Lex Lindquist
Title
Ham Radio Team and CERT Member
Ferry
Superintendent
Engineering Technician
Team Lead
Sergeant
Department/Organization
Ham Radio Team and CERT
Nespelem School District
Okanogan County PUD
Avista
Washington State Patrol
2.2 LOCAL HMP PLANNING SCHEDULE,
MEETINGS, & MITIGATION WORKSHOPS
The mitigation plan update process commenced in August of 2023. Public meetings in all four
districts were conducted as follows:
•
•
•
•
•
Keller District on September 20, 2023 at the Keller Community Center at 6 pm
Inchelium District on October 18, 2023 at the Senior Meal site at 6 pm
Omak District on September 21, 2023 at the 12 Tribes Resort and Casino at 6 pm
Nespelem District on October 4, 2023 at the LCGB at 6 pm
Keller General Membership Meeting on October 7, 2023. An information table was
provided.
During the update in 2023/2024, the heads of tribal departments were contacted and encouraged
to participate. Every effort to include the public was made though emails, school flyers, community
posters, informational tables, personal meetings, phone calls, info sessions, surveys, community
outreach through other community entities, and community meetings.
Colville Reservation Hazard Mitigation Plan Update Planning Meeting
The Core Planning Team held a Hazard Mitigation Plan Update meeting with the Hazard
Mitigation Planning Team on April 8, 2024.
2.3
PUBLIC AND STAKEHOLDER INVOLVEMENT
Broad public participation in the planning process helps ensure that diverse points of view about
the planning area’s needs are considered and addressed. The public must have opportunities to
comment on disaster mitigation plans during the drafting stages and prior to plan approval (44
CFR, Section 201.6(b)(1)). The following section details the public outreach strategy, including a
combination of in-person and virtual methods. For the purposes of this plan, public, as defined by
the CCT, includes residents, businesses, and organizations associated with the CCT, and
specifically those tribal citizens living on tribal land.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
PUBLIC SURVEY
The survey was comprised of 19 questions which were primarily multiple-choice questions. The
questions were clear and direct thereby minimizing the chance errors in the survey results. The
respondents were given the opportunity to provide additional input via some open-ended questions
that required individual evaluation; questions such as concerns about specific hazards and locations
they are aware of.
There was a total of 61 surveys returned by the community. All four of the Districts as well as
Off-Reservation Trust Lands are represented in the survey results.
Table 3. Public Participation and Survey
Survey Participation
Respondent Residency
Count
Inchelium District
Keller District
Nespelem District
Omak District
Off-Reservation
11
14
24
7
5
Public/Stakeholder Results and Hazard Risk Rankings
A critical element in the public survey is the respondents were asked to rank their risk concerns.
Wildland Fire and Severe Weather were the top two concerns. Earthquake and Volcanic Eruption
were ranked as the least concerning to the respondents. The following chart represents the results
of the tribal survey answers collected by the mitigation planning team.
Figure 2. Stakeholder Hazard Risk Rankings
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
The survey was not intended to be a scientific sampling of member and resident knowledge of
hazards relevant to mitigation planning. It will create a base line for which the CCT can start to
implement plans to mitigate deficiencies within the community. This exercise has created a
foundation for a more robust plan and training opportunities for the whole community.
That information included the following about this group’s experiences on the Reservation:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
22 do not have fire insurance (Comments: It’s hard to get fire insurance on the
reservation)
41 do not have flood insurance, 10 do not know
47 do have smoke detectors
40 have experienced wildfires
31 have experienced a power failure lasting more than 24 hours
35 have experienced severe weather
8 have experienced household fires
15 are not at all prepared
Almost everyone gets their information from a government source, personal
experience, or local news.
There are also a good number of people that have taken great strides in making
preparations, such as keeping fire extinguishers, smoke detectors, storing supplies,
and taken classes.
41 are interested in taking preparedness classes
The household sizes range from 1-8 people and many have pets or livestock
10 households do not know if they live in a floodplain
40 people said their address is clear from the street
The reliability of cell phone and internet are divided
In the update of this plan, the CCT included a “Self-Identifying Survey” to increase awareness of
people with health issues, disabilities and special needs, English Language Proficiency (ELP), and
the elderly community. People can self-elect to give their contact information to be put on a
confidential list for emergency services which will be held for one year. This list will give the CCT
a better understanding of the demographics in each disaster zone and provide extra assistance as
needed.
ALL HAZARD MITIGATION PUBLIC REVIEW
After the draft plan was completed, a link to the plan was placed on the CCT official website and
promoted via Facebook. The draft plan remained on the website and Facebook until the FEMAapproved and formally adopted Plan was made available. Upon formal adoption of the Plan, the
public engagement strategy shifted toward continual engagement of the public by soliciting and
offering the public an opportunity and forum to provide input regarding known hazards and risks,
and implementation of identified mitigation strategies.
Throughout the plan development process, public and stakeholder input was incorporated into the
Plan.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Future comments on the All-Hazard Mitigation Plan should be addressed to:
Taressa Marchand,
Emergency Management Coordinator
Colville Confederated Tribes
P.O. Box 150
Nespelem, Washington 99155
Work (509) 634-2134
taressa.marchand.psd@colvilletribes.com
HOW PUBLIC INPUT WAS INCORPORATED INTO THE PLAN
This information helped to validate and confirm the risk assessment findings. Open-ended
responses by the public offered greater insight to the damages experienced while residing on the
Colville Reservation.
These, and related findings, helped the planning team determine meaningful mitigation projects.
For example, based on the survey results, it was evident that many on the reservation have concerns
about wildfire and severe weather. These findings informed the inclusion of new mitigation
strategies.
2.4 COORDINATION WITH OTHER AGENCIES,
PARTNERS, AND STAKEHOLDERS
The planning process was initiated by preparing a stakeholders list of individuals whose input was
needed to help prepare the All Hazard Mitigation Plan. Planning partners on the stakeholders list
received a variety of information during the planning process, including meeting notices,
documents for review, and the draft mitigation plan.
On the tribal level, project stakeholders (other than those on the planning team) included CCT
Council members and personnel from various tribal departments. Most of the tribal stakeholders
participated by providing key data and/or offering comments on the draft plan.
Table 4. Stakeholders
Additional Contributors
Name
Amanda Chiles
Robert Sloma
Doug Marconi Jr.
Tiffany Circle
Kathy Moses
Chance Garver
Nanette Vaughn
Ron Toulou
Chance Cruger
Joe Peone and Kirk Truscot
Rodney Cawston
Brandton Harvey
Title
Manager, TOSHA
Archeologist, History and Archeology
Previous Watershed Program Manager
Chief Information Officer, IT
Communication Specialist, Environmental Trust
Public Affairs, Administration
CCT Website
Supervisor, Public Works / Water and Sewage
Fire Chief, EMS
Director, Tribal Fish and Wildlife
Director, Environmental Trust
Conservationist, BIA Range
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Additional Contributors
Name
Steve Brown
Alexander Besemann
Joseph Halford
William Marchand
Randy August
Title
Police Chief, Tribal Police Department
Specialist, GIS
Manager BIA Forestry
Manager, Planning Department
Previous author of this plan and Emergency Manager
Additionally, many of the hazards described in this mitigation plan also affect counties adjacent to
the Colville Reservation. The draft of this plan was sent to each of these neighboring counties,
and their input was considered and implemented. The adjacent counties are listed below:
Submitted For Comment
County
Okanogan
Ferry
Chelan
County Seat
Okanogan
Republic
Wenatchee
Relationship
Occupied
Occupied
Adjacent Trust Lands
2.5 EQUITY CONSIDERATIONS FOR
UNDERSERVED COMMUNITIES
Some disasters occur on larger scales and are more impacted by built environments and most likely
to continually impact those most at risk because of existing health conditions, lack of resources,
being underserved by past mitigation planning work, facing historical disinvestment in their
communities, or other factors. In this case, people in widely different locations can be the most
harmed by repeating disaster cycles, so mitigation strategies should also work to break cycles of
loss caused by social and economic disparities. Hazard mitigation strategies can reduce existing
risk by, for example, relocating a building out of an area that frequently floods. In each case, an
attempt has been made to lessen the harm of a future flood before the event happens. Strategies
may also seek to make future development less vulnerable to hazards at the time it is built.
Examples would be requiring new structures to be elevated above predicted flood levels or by
building structures to better withstand future hazards. Hazard mitigation plans are designed to
involve the input of stakeholders from different perspectives to ensure plans use the best available
data, are aligned with the needs of the entire community, and are in alignment with other plans,
such as comprehensive plans, capital improvement plans, and climate action plans.
This Hazard Mitigation Plan continues to recognize that all members of the community are not
impacted in the same way by natural disasters. Some community members are at more risk, for
several possible reasons. A mitigation strategy that uses a “one size fits all” approach and does not
recognize different levels of risk will not adequately or efficiently support historically underserved
populations and can make inequalities worse after a disaster.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Equitable mitigation success should be measured by assessing who was most impacted in loss of
life or financial harm by past and future disasters, quantifiable reductions of vulnerability to those
most at risk, and increasing engagement with historically underserved populations and community
organizations to better understand how plans and processes and natural hazard events are affecting
different communities.
The Reservation has responsibility to ensure equitable outcomes in the implementation of this plan
and to ensure that action is taken to reduce vulnerabilities to disasters experienced
disproportionately by marginalized populations.
The Climate & Economic Screening Tool provided by the U.S. Council on Environmental Quality
analyzes the three 2010 census tracts on the Colville Reservation for disadvantaged communities.
Tribal areas are defined as Disadvantaged Communities per the screening tool.
Source: Climate and Economic Justice Screening Tool
https://screeningtool.geoplatform.gov
Additionally, the public survey specifically included questions to determine how the Colville
Tribes could better support functional and access needs populations and under served groups in
the Reservation.
2.6 EXISTING PLANS, STUDIES, REPORTS AND
TECHNICAL INFORMATION REVIEWED FOR
THE PLAN
Chapter 16: Tribal Capability Assessment provides a review of key studies, plans, laws, and
ordinances in effect within the planning area that can affect hazard mitigation actions. All these
documents were reviewed and incorporated into this plan as part of the update process.
Table 5. Existing Plans, Studies, and Reports
Existing Plans, Studies, Reports, and Technical Information
How this document contributed to the
2024 Mitigation Plan Update
Hazards, risk analysis, past mitigation actions
Tribal profile, demographic information,
transportation, key tribal priorities
Housing trends
Residential statistics and population trends
Future construction and identification of deficiencies
Document
2023 mitigation plan draft
2020-2040 Comprehensive Plan
2020 Housing Strategy
Comprehensive Housing Plan 2020-2040
2018-2023 Capital Facilities Plan
Mount Tolman Fire Center Wildland Fire Prevention
Plan
Wildland Fire Management Plan (Mt. Tolman)
Forest Management Plan (BIA)
Range Management Plan (Range) dated 2015, updated
in 2021
Wildfire Hazard Profile
Wildfire Hazard Profile
Wildfire Hazard Profile
Wildfire Hazard Profile
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Existing Plans, Studies, Reports, and Technical Information
How this document contributed to the
2024 Mitigation Plan Update
Community Profile and demographic information
Document
Community Economic Development Strategy (CEDS)
Dam Emergency Action Plans for Owhi and Twin
Rivers Dams
Comprehensive Emergency Management Plan (CEMP)
(EM)
Long Term Transportation Plan (CCDOT)
Natural Resources Climate Change Vulnerability
Assessment
FEMA Tribal Mitigation Planning Handbook
FEMA NRI 2024 Data
Comprehensive Economic Development Strategy
2017-2021
Climate Mapping for Resilience & Adaptation
FEMA Geospatial Resource Center
FEMA Resilience Analysis and Planning Tool (RAPT)
NOAA - Climate at a Glance
High Hazard Dam Profile
Risk Assessment and Tribal Capabilities
Community Profile and Changes in Development
Climate Change projections
Tribal planning guidelines
Itemization of Risks for CCT
Increased risk due to development.
Utility information.
Climate change data
Mapping data
Hazard risk and vulnerability data
Climate data
Underserved populations vulnerable to climate change
and disasters
Climate and Economic Justice Screening Tool
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
PART II: COMMUNITY PROFILE
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 3. COLVILLE
RESERVATION PROFILE
3.1
LOCATION
The Colville Reservation is bound on the south and east by the Columbia River, on the west by the
Okanogan River, and on the north by an arbitrary line drawn at the northern boundary of Township
34 of the public lands survey system. Geographically, most of the Reservation is part of the
Okanogan Highlands; the remainder is part of the Okanogan Valley. The Inchelium and Keller
districts are located within Ferry County; the Nespelem and Omak districts are within Okanogan
County.
The Reservation is bisected by the boundary between Ferry County (on the east) and Okanogan
County (on the west). There are two incorporated towns entirely within the reservation: Elmer City
and Nespelem. There are 4 incorporated cities or towns located partially within the Reservation:
Coulee Dam, Okanogan, and Omak. There are four additional “Census Designated Places” (CDPs)
used for gathering census data: Disautel, Inchelium, Keller, and Malott.
Within the Reservation boundary, in addition to privately-owned fee lands, the Army Corps of
Engineers (ACOE), Bureau of Indian Affairs (BIA), and Bureau of Reclamation (BOR) own land.
a
For the construction of both dams, trust lands were taken by the federal government up to
specified elevation level; in the case of Grand Coulee Dam and Lake Roosevelt, all trust lands up
to the 1310-foot elevation line became BOR land. Some private land parcels that extended both
above and below that elevation line, however, were bought out in their entirety.
Under the terms of the 1990 Lake Roosevelt Management Agreement, the Tribe manages the BOR
lands within the “Reservation zone” defined in that agreement. This includes most BOR-owned
lands within the Reservation boundary upstream from the immediate area of the dam.
“Management” rights, however, do not authorize the Tribes to exercise general law enforcement
authority on those lands except when violations are committed by Tribal members.
Because of the risk of landslide due to slope undermining by the newly impounded waters behind
Chief Joseph Dam—which also happened after the filling of Grand Coulee Dam—the ACOE
appropriated easements across trust lands within the Reservation. Although the ACOE did not
acquire fee simple ownership of those lands, the easements it required limit the uses to which
affected lands can be put into use.
3.2
TOPOGRAPHY & VEGETATION
Elevation levels range from a low of approximately 780 feet in the southwest corner of the
Reservation, to over 6700 feet at the summit of Moses Mountain; the average is above 3,000 feet.
Elevation generally increases from south to north and from west to east. The predominant terrain
features were carved by glacial erosion. The Sanpoil River drains much of the eastern interior of
the Reservation south to the Columbia River. The Nespelem River basin and many additional
creeks drain into the Columbia River, and additional creeks drain into the Okanogan
23
River.
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 3. Topographic Map – Excerpt from the CCT Comprehensive Plan
The populated area along the eastern edge of the Reservation is separated by two mountain ranges
from the Tribal and BIA administration at the Colville Agency. During winter the roads across
those two ranges can sometimes be traversed only with difficulty.
3.3 NATURAL RESOURCES
The Colville Agency Integrated Resource Management Plan (IRMP) states the intent to cut 78
mmbf per year. This can be incorporated with fire management, but also requires reforestation to
avoid negative environmental impacts. Colville Reservation is countering this potential by
establishing a nursery of approximately 1.5 million trees.
A unique resource on Colville Reservation is wild horses. The tribe is required to maintain a
stipulated population and provide the necessary habitat for the protected animals. This is important
for the species, but management of rangeland may conflict with tribal development encroaching
upon it, specifically that of wildfire.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
3.4 CLIMATE
Overall temperatures are steadily becoming warmer during the four seasons. This change impacts
the dryer seasons by increasing the frequency of drought while winter becomes wetter rather than
snow. The wetter winters result in precipitation making its way to the streams rather than being
held in snow and icepacks for release during the warmer growing seasons. This shift changes the
moisture content of the earth during the summer months. National Environmental Modeling and
Analysis Center (NEMAC) has developed historical and future climate models. Source: Top Climate
Concerns: The Climate Explorer: https://crt-climate-explorer.nemac.org
3.5 LAND OWNERSHIP, LAND USE, &
FUTURE DEVELOPMENT
The CCT Comprehensive Plan incorporates detailed components for managed land use and
development. The following information is excerpts from the CCT Comprehensive Plan:
•
•
The reservation is primarily rural.
The reservation consists of 1.4 million acres of land; of this, the areas of greatest population
density are in and around the areas of Nespelem and Omak.
The Colville Reservations land is comprised of both Trust Land and Fee Land. Trust Land is
possessed as part of the Reservation ground. Fee Land ownership has a title held by the individual
owner. The two means of ownership present their own use and regulatory requirements.
Figure 4. Colville Reservation Land Use by Parcel
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 5. Colville Reservation Rural Land Use
3.6
HISTORY
Much of the Reservation boundary, as it exists today, was established in 1872 by an executive
order issued by President Grant. At that time the Reservation covered approximately 2.9 million
acres. Members of twelve different tribal groups were either already present within, or later moved
onto, the Reservation.
In 1892, by act of Congress the Colville Reservation was cut approximately in half; the current
Reservation is the southern portion of the original Reservation. The “North Half” was opened to
homesteading, mining, and to other public lands uses. The Tribe retained hunting, fishing, and
gathering rights on the federal lands within the north half. Some lands in the north half had already
been allotted to individuals and remained in tribal trust status. The Tribe has been purchasing lands
in the North Half when funds and land availability allow and is returning these purchased lands to
trust status. One of the larger pieces of land returned to tribal ownership includes the Chopaka
Crossing, a former railroad border crossing located directly upon the U.S.- Canada border.
Beginning in 1916, the south half of the Reservation was opened to “settlement” under the public
land laws. Lands within the Reservation not already allotted to Tribal members were open to
mining claims and patents, homesteading, and even to cash purchases. Large areas of the
Reservation, particularly in the southwest, passed out of trust status and into private non-member
ownership. The map below shows the approximate extent of trust (blue) versus private
26
and
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
government ownership (yellow). Government ownership on the reservation includes federal lands
owned by the Bureau of Reclamation and the Army Corps of Engineers; state lands managed by
Washington State Parks, as well as highway maintenance sites; and county or other local
government lands, including fairgrounds and lands used for road maintenance.
Figure 6. 2023 Map of Tribal Trust lands in Blue and Non Tribal
Trust in Yellow, courtesy of Tribal GIS Program
The Reservation was withdrawn from entry under the public lands laws in 1934; there were no
more mining, homestead, or cash purchase entries within the Reservation after that year. The last
of the legacy mining claims established during the public lands era on the Reservation lapsed in
1993. However, even after 1934 fee lands, allotted trust lands and tribally owned lands within the
Reservation were taken by the federal government for the construction and operation of Grand
Coulee and Chief Joseph Dams.
As with the north half areas, when land is available and funding permits, the Tribe purchases land
within the Reservation boundary and returns it to trust status. In addition to lands within the
reservation boundary and the North Half, there are other parcels of trust lands located in several
counties. These include such lands as the Mill Bay Casino in Chelan County, a former USFS site
in Okanogan County, and others.
The Tribe has continued to lose access to lands in the North Half due to federal government actions.
For example, during the 25-year period from 1983 to 2008, the Bureau of Land Management
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
transferred 3,868 acres of north half lands within Ferry County out of federal ownership. This
action effectively eliminated Tribal hunting, fishing, and gathering rights on those lands.
3.7
POPULATION & DEMOGRAPHICS
Colville Reservation is primarily rural with small pockets of concentrated population. The
following are the major population areas of the Reservation per the 2020 Decennial Census:
Table 6. Colville Tribes Major Populations Centers
COLVILLE TRIBES – MAJOR POPULATIONS CENTERS
Community
Omak
Okanogan
Nespelem
Elmer City
Coulee Dam
Keller
Inchelium
United States Census Bureau: https://data.census.gov
Population
4,860
2,379
180
239
1,211
-
Status
Incorporated
Incorporated
Incorporated
Incorporated
Incorporated
Unincorporated
Unincorporated
ON-RESERVATION AND OFF-RESERVATION POPULATION
The population of the Colville Reservation is approximately 7,063 per My Tribal Area, a division
of the United States Census Bureau. 2,358 for with 33% of the population being over the age of
55 years old. The median household income is $52,199. The poverty level on the Reservation is
24.4% which is about double the rate in the United States at 12.6%. The current census for 2023
will not be published until 2024.
My Tribal Area: https://www.census.gov/tribal
Many enrolled members reside just outside of the Reservation boundaries in communities such as
Grand Coulee, Wilbur, Okanogan, and Omak. The total enrolled membership does not include a
substantial population of descendants who, although not members, have both a familial and
cultural affiliation to the Tribe and receive some services from both the Tribe and IHS. It also does
not include non-members who are married to members.
There are a substantial number of people visiting the Reservation for recreation every summer.
Within the Reservation there are: resorts at Twin Lakes; people with summer homes;
campgrounds; and boating users and beach campers along the Tribe’s Columbia River shoreline.
The National Park Service figures for Lake Roosevelt indicated that, on average, more than 6,000
people visited the park each day during June through August of 2022.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Table 7. Colville Tribes Population by Age Group
COLVILLE TRIBES - POPULATION BY AGE GROUP
Age Range
Population
Under 5 years
398
5 to 9 years
354
10 to 14 years
363
15 to 19 years
424
20 to 24 years
593
25 to 34 years
1,024
35 to 44 years
610
45 to 54 years
949
55 to 59 years
408
60 to 64 years
383
65 to 74 years
948
75 to 84 years
466
85 years and over
153
Colville Confederated Tribes (CCT) Population by Age Group Source: My Tribal
Area (2023)
https://www.census.gov/tribal
VARIABLE POPULATION
The Tribal experience during the 2015 fires showed there were residents who lost homes that had
not even been mapped under the 911 addressing system. It wasn’t known by the Tribe, or by
Okanogan County, that the homes even existed until after they had burned down, and the residents
displaced.
Further, in any widespread natural or other disaster, members and descendants from adjacent
communities may also need assistance. Although the Tribe is not responsible for disaster relief
services outside the reservation (except when they involve off-Reservation trust lands), as a
practical matter those Tribal members may work within the Reservation. If their homes outside the
Reservation are damaged, they may temporarily reside with relatives within the Reservation whose
homes are intact.
Finally, there are three state highways (SR17, SR21 and SR155) and one U.S. Highway (US 97)
traversing the Reservation. All of them serve as trucking corridors; US 97 in particular is used for
international trade with Canada. Each highway has significant daily traffic across the Reservation.
The Inchelium-Gifford Ferry connects the Reservation with SR25, which runs north-south along
the eastern shoreline of Lake Roosevelt. The Inchelium Highway, which runs north from Inchelium
towards the off-Reservation river crossing at Kettle Falls, is a county road but serves the same
function locally as a state highway.
For these reasons, the census data does not adequately reflect the population that may need to be
served in the event of a natural or other disaster. For planning purposes, the population within the
Reservation on any given day is considered to exceed 10,000 people.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
POPULATION TRENDS
The Colville Confederated Tribes (CCT) Comprehensive Housing Plan 2020-2040 performed a
historical analysis of the local population. The population of the Colville Reservation has been
rising though it is not necessarily at a rapid rate. To see that the population is not receding is
encouraging and illustrates aggressive planning and mitigation efforts are worthwhile for the
community.
Figure 7. CCT Population Growth 1990-2017 and CCT Population Projects 2040
3.8
HOUSING
The Colville Confederated Tribes (CCT) Comprehensive Housing Plan 2020-2040 was developed
to identify current housing issues and potential solutions. The plan, while not developed with
hazard analysis as part of its scope, also reveals issues that complicate resiliency and mitigation
opportunities of the existing structures.
The study indicates there are 3,619 housing units on the Reservation at the time of its drafting.
Major issues with the housing stock are twofold; one its makeup and the other being its age. The
following charts are from the Comprehensive Housing Plan 2020-2040:
Figure 8. CCT Housing Types and CTCR Estimated Year Home Was Built
30
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
HOUSING TYPES
The study indicates 23% of the housing stock is comprised of mobile homes. These fabricated
structures are typically made of inferior wood construction and sheet metal cladding; they are
essentially a an “elevated design” of a travel trailer in regard to disaster resiliency. Two examples
of critical concerns are though codes have mandated tiedown requirements they offer inadequate
shelter during high wind events and for extreme heat/cold concerns cooling/heating is inadequate
in terms of equipment and insulation.
HOUSING AGE
The study shows an overwhelming share of the housing was built prior to the year 2000. This,
coupled with the discussion of housing type, adds to the problematic nature of resiliency and
mitigation. The older housing stock will not have been built to as stringent of codes as what the
International Building Code (IBC) requires today. The study indicates that roughly 400 of the
housing units were built under more stringent code requirements, making them less susceptible to
damage. This leaves approximately 3,200 housing units more vulnerable to damage due to their
construction under older, less rigorous codes. The sheer number of structural, thermal, and
cladding inadequacies in older housing stock leaves them vulnerable to disasters and it is
oftentimes cost prohibitive to mitigate them.
3.9
ECONOMY
GOVERNMENT EMPLOYMENT
Government employment within the reservation, both Tribal and BIA, are critical to the local
economy. The five different school districts within the reservation also constitute a significant
employment source. Both Grand Coulee and Chief Joseph Dams are partially located within the
reservation, and their employees should also be considered as part of the government employment
sector.
At the Tribal membership meeting held in October 2018, it was reported that approximately 1,500
persons work for the Tribal government or its business operations. In October 2023 during the
previous planning session the group reported government employment to be approximately 1,250
people, which is significantly down from 2018. Current U.S. Census data, as provided by the My
Tribal Area portal, illustrates the importance of Government Employment to the estimated 3,145
employed residents.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 9. Employment Classification
3.10 AGRICULTURE
Agriculture, in the form of orchards and forage crops as well as livestock production, is a
significant contributor to the local economy. At one time the Nespelem area was extensively
farmed, but the former irrigation works (including diversion dams and weirs) have been largely
abandoned. Large orchards exist along the Columbia and Okanogan rivers in the southwest portion
of the Reservation; as of 2012, they covered 12,040 acres within the Reservation. These attract
seasonal labor force for harvests and have resulted in the construction of temporary housing for
seasonal workers. State and county authorities allow such temporary housing to be constructed
without requiring sprinkler systems or other fire protection measures (such as hydrants or fire
standpipes).
Based upon current data, it is difficult to tell the scope and extent of private sector employment
within the Reservation. Gebbers Farms is a major employer but has not responded to a request for
information about the scope of their activities on the Reservation. Because they have orchards and
other agricultural interests both on and off the Reservation, sometimes within a few miles of each
other, it may be difficult to separate their data between the two.
In addition to orchards, other documented crop production includes corn (920 acres); other forage
crops (11,296 acres); and wheat (13,367 acres).
There is one privately-operated aquaculture operation: raising farmed salmon within multiple
netted pens in the Columbia River (Rufus Woods Lake).
According to BIA statistics from 2011, between 7,000 and 8,000 cattle are grazed on range units
within the reservation each year. (A cow-calf unit is considered one head of cattle for grazing
purposes, so the actual number of animals is higher.) Sheep were not permitted while on the
Reservation, and 200 horses were. One horse grazed under permit is considered to consume the
same forage as 1.5 cow-calf units. In 2022 there were 2882 cow calf pairs permitted on range and
70 horses permitted on range. In 2023 the numbers were slightly higher with 2,964 cow calf pairs
and bulls and 35 horses.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Every five years, the U.S. Department of Agriculture conducts a “Census of Agriculture.” The
most recent one was conducted in 2023 and the results will be released in 2024. So, for this plan
it relies on the 2017 census. That census showed an inventory of 10,476 cattle and calves, as well
as 392 horses. These numbers don’t always match up with the BIA count due to the way they are
tallied by cow-calf pair rather than by animal.
Since 2011, resource damage from wild and feral horses has become more acute. As of March
2018, the Tribe’s natural resource manager estimated that there were approximately 2,000 of these
horses on the reservation. A roundup in 2015 resulted in the capture of 423 horses, although Tribal
land managers wanted to remove 1,000. In 2020 there were approximately 174 horses removed, in
2021 there were approximately 253 horses removed, and in 2023 there were approximately 110
horses removed to date. Essentially, the number of horses removed each year is approximately the
same number of offspring produced each year. The current estimate of 2,000 horses across the
Reservation translates into the consumption of enough forage to support 3,000 head of cattle.
Both the livestock industry and crop production on the Reservation are susceptible to drought,
wildland fire, and disease. Livestock grazing is heavily impacted by fires. In addition to the loss
of cattle in fires, leased Tribal range lands have to be rested to allow recovery following the fires.
This reduces the grazing land available for three years post fire. Although the fire season for 2022
and 2023 was light relative to other seasons, some of these areas are still recovering.
3.11 TIMBER INDUSTRY
Historically timber production has been a major economic resource within the Reservation, but the
last sawmill operating within the Reservation shut down in 2017 after little more than three years
of operation. Both tribally owned timber mills (the Omak Wood Products Mill and the former
Colville Indian Precision Pine plant, also near Omak) shut down in the wake of the Great Recession
that began in 2008. The Omak mill later reopened but shut its doors again in 2017. There is
significant timber production from within the Reservation, but logs are now transported to outside
mills for processing.
The 2015 fires devastated the timber industry, burning an estimated 22% of the marketable timber
within the Reservation. This amounted to approximately 800 million board feet of timber burned,
about ten years’ worth of full production. Although there was a short-term increase in the amount
of logging, as salvage logging took place to bring damaged but still usable trees to market, that
timber was saleable only at reduced prices.
3.12 EDUCATION
The following information is excerpts from the CCT Comprehensive Plan:
The CCT Comprehensive Plan collected the following educational statistics:
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 10. Colville Educational Attainment
3.13 VULNERABLE POPULATIONS
BELOW POVERTY LEVEL
Figure 11. Populations Below Poverty Level
Source: U.S. Census Bureau, American Community Survey
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
3.14 UTILITIES
ELECTRICITY
Electrical power on the reservation comes from four different providers:
1. Okanogan County Public Utility District (PUD) #1, along the western reservation including
eastward along SR155 from Omak to the Paschal Sherman/Mission area.
2. Nespelem Valley Electric Cooperative, which provides power along the SR155 corridor to
the Paschal Sherman/Mission area as well.
3. Ferry County PUD, primarily in the Sanpoil Valley but also to several small areas on the
reservation where power lines come from the north.
4. Avista Energy, for the eastern reservation including Inchelium and Twin Lakes.
Figure 12. Colville Utilities (Electrical, Copper, and Communication Lines) Map
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
WATER
All public utilities on the Reservation are highly dependent upon uninterrupted electrical power;
none have a backup generator or are pre-wired to accept an emergency generator. Every water
system on the Reservation is dependent upon electrical power to operate wells. When power fails,
the water system fails when water pumped into storage tanks is used up. Estimates of the time
before water tanks empty, under normal demand, range from one day (Nespelem) to three days
(Keller). Outside the areas covered by these systems, residents rely on electrically-powered well
pumps for individual residential water supplies.
In the case of water systems, it is not just electrical power failure that could have significant
adverse effects. During the 2015 fires the fire hydrants for the Town of Nespelem failed due to
age-related water main damage. Tribal firefighters in 2015 were faced with the task of defending
a town, without working fire hydrants, in the face of forecasted 40 MPH winds driving the North
Star Fire toward town. The maintenance cycle for the hydrants is every April and October for the
following 7 groups by Public Works.
•
•
•
•
•
•
•
Twin Lakes HUD
Keller Community
Seatons Grove
Nespelem Agency Campus
Omak HUD Moccasin Flats, Lone Pine, and Eagle Nest
Rocky River Road HUD
Malott HUD
Inchelium’s water and sewer is managed by an independent water district.
Water is provided by the following systems:
1. Colville Indian Housing Authority (CIHA) owned and operated systems for the Nespelem
Agency area, Mt. Tolman Fire Center, Keller community, and HUD housing
communities
2. Municipal systems in Coulee Dam-Elmer City, Okanogan, Omak, and Nespelem
3. Privately-operated water system for homes in the Twin Lakes area
4. Privately-operated local water district for the Inchelium area.
5. Private wells
WASTEWATER TREATMENT
Wastewater treatment is provided by five treatment plants. There are numerous private sewage
disposal structures such as septic tanks, including:
1.
2.
3.
4.
Coulee Dam-Elmer City, operated by the Town of Coulee Dam
Nespelem and Agency campus areas, operated by the Tribe
City of Omak
City of Okanogan
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
5. A privately-operated water and sewage district in the Inchelium area
6. Private disposal
Everywhere else on the Reservation on-site septic systems are in use, including some of the larger
operations (such as the Twin Lakes Resort, the Paschal Sherman Indian School and the Mission
campus).
None of the water or sewage systems on the Reservation have emergency power capability. If
power fails, the systems will shut down until either line power is restored or an emergency
generator is located and installed.
In the case of a sewage system, a power failure can have significant environmental impacts. The
system built in the 1970s for the Nespelem and Agency Campus areas includes five sewage lift
stations; none of them has an emergency generator. If a power outage occurs, the sewage lift
stations in the Nespelem and Agency campus areas cannot pump sewage uphill to the sewage
lagoons for treatment.
A power outage of as little as one hour, during peak daytime use of the system, may cause sewage
to begin backing up. One of the lift stations is automatically set to drain into former sewage ponds.
If a septic pump truck is available, the full-time use of that truck to pump from other lift stations
and transport to the sewage lagoon has been able to keep up with the sewage flow. If no pump
truck is available, it may be necessary to open valves to dump raw sewage into the Nespelem River
drainage to avoid sewage flow into residential areas. This is still an ongoing issue but efforts have
been made with the combined efforts of the Tribal Public Works Division and Spokane District
IHS to procure a generator.
3.15 COMMUNICATIONS
Even where there are buried telephone lines, many people do not have land-line telephones. There
is no longer a network of pay phones within the Reservation, even in places such as the Sanpoil
Valley where they would constitute the only reliable emergency communications infrastructure for
the public. Parts of the telephone network on the Reservation are still installed on above- ground
poles vulnerable to windstorms, winter storms, and wildland fire in the same manner as electrical
lines. Much of the telephone network off-Reservation is also above ground, and failures outside of
the reservation impact the Reservation’s phone network as well. In 2014 during the Carlton
Complex series of wildland fires, the Okanogan County 911 system failed due to widely separated
system damage at two different locations.
Cellular telephone coverage is unreliably inconsistent. Two providers--AT&T and Verizon-- have
towers on the Reservation. Their reliable coverage is limited to the Okanogan Valley along the
river, some of the Nespelem area, and some of the Inchelium area. Everywhere else, including
along the SR 155 corridor, cellular telephone coverage can best be described as sporadic. Text
messages often go through when cellular phone calls do not.
An often-neglected impact of communications failures is the impact upon commerce. During the
2014 and 2015 fires when above-ground communication lines burned, they took with them the
ability to use credit cards and to withdraw cash from automated teller machines. Gas stations and
grocery stores have to be connected via internet or telephone lines in order to verify that credit
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
cards/debit cards are valid. Many affected people were unable to buy either fuel or food with their
credit/debit cards and could not obtain cash from ATMs.
In 2023, there were three more communications towers put up on the reservation with COVID
funds, but it is still not enough. There still remain several areas where communication access is
not possible. These towers are utilized by broadband equipment to the communities of Nespelem,
Elmer City, McGinnis/Buffalo Lake Kartar Valley and Rufus Woods along the Columbia River
Road. They currently support 300+ end users with wireless service using 2.5 GhZ spectrum
throughout the communities of Keller, Inchelium, Nespelem and Omak. The Reservation does
have more towers being constructed throughout the Colville Reservation with a priority for internet
capability to both the home and business. There is a potential depending on the tower size for
wireless vendors and the Colville Tribe to co-locate equipment.
Figure 13. Communication Outage
A credit union just outside the
Reservation in Brewster, WA had
electricity but without
communications. Sign displays
“ATM OUT OF SERVICE”. July
2014, Carlton Complex fires
Much of the Columbia River Road and SR 155 corridors (Coulee Dam and Nespelem to Omak),
the Peter Dan/Manila Creek Road and the Cache Creek Road (Sanpoil Valley to points west), the
entire Sanpoil Valley including much of Keller, and much or even most of the Silver Creek and
Bridge Creek roads (Sanpoil Valley to Inchelium and points east) are without cellular phone
coverage.
Cellular telephone systems, while they may have battery or generator backup, cannot run
indefinitely without line electrical power. The 2015 fires, particularly where the Moses Mountain
communications site was involved, showed that. When power lines to that site were destroyed by
fire, the emergency generators powering the AT&T cell tower and powering the Tribal microwave
backbone needed to be refueled regularly. Refueling small-capacity fuel tanks in an active fire area
can be challenging, as demonstrated by this recent fire. At least once, the refueling team had to
evacuate for their safety and leave a disabled vehicle behind. Had these refueling missions failed,
the only working cell tower for a large area of the Reservation (and for Okanogan County), as well
as, the Tribal government’s internet connection would have been lost.
In many jurisdictions, emergency responders can use their agency radios to communicate in the
absence of telephones. That isn’t always true on the Reservation. Much of the northern Sanpoil
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Valley, for example, is a radio dead zone. During a 2014 petroleum tanker accident in the northern
Sanpoil Valley, fire and police responders had to leave the scene to be able to reach a radio repeater
to send and receive radio messages. This delayed the response and may have increased the extent
of the pollution from spilled fuel.
The problem with radio communications has multiple facets. The switch from wideband to
narrowband required new radios and repeater equipment; at the same time, radiocommunications
nationally have been moving from analog to digital radio. The “reach” of broadcasts from digital
radio equipment (the area in which voice transmissions can be understood) is generally better than
with analog transmissions. However, digital signals reflected from multiple terrain features can
appear to a receiving radio to be corrupted and indecipherable. This appears to be a significant
issue in the mountainous environment of the Colville Reservation.
There are currently thirteen mountaintop radio repeater sites on the Reservation, used by Tribal
government entities, as well as, by the BIA. An analysis of radio signal propagation on the
Reservation determined that when the Tribe does convert to digital public safety radios, it will
need to substantially increase the number of communication sites. Contributing to this problem is
the Reservation’s location near the border with Canada. Part of the Reservation is north of the
Federal Communication Commission’s (FCC) “A Line” within which broadcast power is more
tightly restricted to avoid interference with Canadian users.
Although each of these problems can be solved with the application of enough funding, the switch
to narrowband radio was an unfunded mandate imposed upon the Tribal government. Even now,
more than five years after the FCC’s mandatory deadline, portions of the public safety
infrastructure are still wideband. Significant infrastructure investment is needed to bring the
Reservation into the modern communications era using digital public safety radios. It is already
difficult to purchase replacement radios for use on the still-wideband portions of the Tribe’s public
safety radio network.
Tribal broadband internet access is threatened by the fact that it must connect to off-site
transmission systems of varying quality. For example, one crucial stream crossing off-Reservation
consists of a single bundle of fiber optic cable that, as of summer 2018, was still exposed to the
elements and to casual vandalism. Elsewhere, as with telephone lines, fiber is strung on wooden
power poles that can be damaged by ice storms, windstorms, or wildland fire. Although the Tribe
can—and is—putting its own fiber underground, it still has to connect to off-Reservation systems.
AT&T has a FirstNet program. FirstNet is a nationwide cellphone-based network that gives first
responders priority access to the available cellular bandwidth, so first responder calls will be given
a higher priority than all other callers. AT&T has completed construction of FIRSTNET towers at
Elmer City and Moon Mt., Inchelium. All other sites including Keller Butte, Nespelem, Omak
have FirstNet equipment for use.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
3.16 TRANSPORTATION
RAILROADS
Colville Reservation recognizes railroads are an essential part of commerce, but they present
hazards. There is currently only one railroad operational within Colville Reservation.
Cascade-Columbia Railroad
Table 8. Railroads
Railroads
PUBLIC TRANSIT
Colville Reservation is served by multiple public transit authorities.
Table 9. Transit Authorities
Transit Authority
Colville Tribal Transit
Okanogan County Transportation and Nutrition (OCTN)
Okanogan County Transit Authority (TRANGO)
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
PART III: RISK ASSESSMENT
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 4. HAZARD RISK
ASSESSMENT
Risk assessment is the process of measuring the potential loss of life, personal injury, economic
injury, and property damage resulting from natural hazards. It allows emergency management
personnel to establish early response priorities by identifying potential hazards and vulnerable
assets. The process focuses on the following elements:
•
•
•
Hazard identification—Use all available information to determine what types of disasters
may affect a jurisdiction, how often they can occur, and their potential severity.
Vulnerability identification—Determine the impact of natural hazard events on the people,
property, environment, economy, and lands of the region.
Cost evaluation—Estimate the cost of potential damage or cost that can be avoided by
mitigation.
The risk assessment for this hazard mitigation plan update evaluates the risk of natural hazards
prevalent in the planning area and meets requirements of the DMA (44 CFR, Section 201.6(c)(2)).
4.1
IDENTIFIED HAZARDS
There are countless hazards that pose a threat to human life, health, and well-being, and no attempt
is made here to compile an exhaustive list. Those that are addressed in disaster planning are
generally categorized as “natural” or “technological” (sometimes “manmade”). The FEMA
website contains a thorough discussion and list of hazards in the section entitled “National Risk
Index for Natural Hazards” (FEMA, 2022). Some hazards are a threat to all geographic areas while
others (e.g., flooding) are more limited in their extent. Studies were conducted to determine which
hazards are of concern on Colville Reservation.
Colville Reservation hazards were identified, and their frequency of occurrence evaluated using a
number of resources, including:
•
•
•
•
2018 Colville Reservation Pre-Disaster Hazard Mitigation Plan
Hazard planning documents developed by state, federal, and private agencies.
NOAA weather data from the past 72 years
Data from the United States Geological Survey (USGS)
Hazards that have been identified as significant for Colville Reservation that will be considered in
this plan are listed below.
Natural Hazards
•
Severe Summer Weather
o Extreme Heat
o Lightning
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
•
•
•
•
•
•
•
o Hail
o Tornado
o Straight-line Wind
Severe Winter Weather
o Extreme Cold
o Winter Storm/Blizzard/Heavy Snow
Avalanche
Wildfire
Flood
o River or Stream Flood
o Flash Flood
High Hazard Dams and Levees
Drought
Volcanic Eruption and Ash
Geological Hazards
•
•
Earthquake
Landslide
Other Hazards of Concern
Although non-natural hazards are not required by FEMA for inclusion in a hazard mitigation plan,
Colville Reservation wishes to rank and mitigate against a comprehensive list of hazard events that
could impact the Reservation. Due to both the nature of non-natural hazards and the discretionary
status regarding their inclusion, the following hazards of interest have been briefly and
qualitatively assessed for the sake of public education and informing their inclusion within the
hazard ranking and mitigation process.
Biological Hazards
•
•
•
•
Public Health Emergency
Air Quality
Animal Disease
Plant Disease
Technological (Manmade) Hazards
•
•
•
•
•
•
Hazardous Material Incident
Terrorism
Active Assailant Incident
Government and Regulatory Issues
Widespread Power Outage
Cybersecurity Incident
Per FEMA’s mandate to address all natural hazards, the following natural hazards were not
included because these hazards do not directly impact Colville Reservation due to geographic
location:
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
•
•
•
•
Hurricane
Sea Level Rise
Storm Surge
Tsunami
4.2 DISASTER DECLARATIONS
2020
2021
Table 10. CCT Disaster Declarations
Declaration Type
Declaration Title
Severe Storm
Severe Storm, Straightline Winds, and Flooding
Wildfire
Carlton Complex Fire
Wildfire
North Star Fire
Flood
Flooding
Biological
COVID-19 Pandemic
Wildfire
Cold Springs/Pearl Hill
Fire
Wildfire
Chuweah Creek Fire
Wildfire
Cold Springs Fire
2024
Severe Storm
Year of Declaration
2012
2014
2015
2018
2020
2020
Severe Winter Storms,
Straight-line Winds,
Flooding, Landslides, and
Mudslides
Source: https://www.fema.gov/data-visualization/disaster-declarations-tribal-nations
Disaster Number
4083
4188
4243
4384
4481
5351
4631
4584
4775
4.3 CLIMATE CHANGE
IMPACTS & CONSIDERATIONS
One of the most significant issues relating to climate change is documenting that something has
changed. Anecdotal information, and stories, may be useful to help identify what needs to be
examined, but they are not the same as hard data documenting that a change is underway or has
occurred. The various climate change reports utilized in this plan clearly indicate that climate
change is occurring, but they neither identify nor quantify all of the consequential changes that
occur along with climate change.
For the purposes of this plan, climate change has been addressed for each natural hazard. Impacts
are addressed if data is available.
Although projections can—and have been—made about future temperatures and rainfall changes,
further and continued studies are needed to determine the following impacts that affect the CCT
directly:
•
Changing climate could cause changes in plant succession, in both disturbed areas and in
natural environments.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
•
•
•
•
•
•
•
Culturally significant species of plants, both food and medicinal, could decrease their
range and be less common.
Insect pests may proliferate with higher mortality for trees, changing the mix of forest
species. These could include pine and other tree-killing beetles, spruce budworm,
Douglas fir needle midge, etc.
Plant diseases could spread due to warmer winter temperatures. These could include
blister rusts, root rot, and the spread of parasitic plants such as dwarf mistletoe.
If there is more winter precipitation and runoff, it may increase sedimentation. This could
affect fish spawning, require culvert replacement with large culverts, cause damage to
roads as well as to private improvements, damage buried utility lines, and more.
Drought and dry soils may increase erosion, which will end up in streams and culverts.
Soils may also be lost through dust storms.
Lower water levels in streams and rivers, and higher water temperatures, may increase
fish mortality during spawning runs. They may also increase the mortality of nonmigrating fish.
There may be more wildland fires. There may be additional expense to keep cheat grass
and other noxious weeds from taking over newly damaged and opened lands before trees
and other native species can be replanted.
As a general observation, the Tribe is heavily dependent upon revenue from Tribal forests. Various
climate change reports acknowledge that increasing wildfires, insect outbreaks, and tree diseases
will result in increased “forest mortality” and a long-term change in “forest landscapes” (Snover,
2013, page ES-6). Climate change with Tribal forests may affect not just Tribal government
revenues, but private sector employment in the logging and timber industry as well. The socioeconomic impacts of such a change could be significant.
Unanswered questions, which need answers in order to be able to craft a coherent climate change
adaptation strategy, include:
•
•
•
•
•
•
What will invasive species and noxious weeds do to the fire regime? Will they contribute
to more fires that will limit or destroy the availability of traditional cultural, medicinal, or
food plants?
To what extent will plant succession change with climate change?
Will medicinal or cultural plants remain available, or will hotter and dryer summers
reduce their numbers and range?
Has there been a change in the distribution or availability of traditional food plants, such
as roots and berries?
Will vegetation (biomass) be lost due to dryer and hotter summers?
Will habitat for rare, threatened, and endangered species be disrupted and become no
longer suitable for those species?
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
4.4
HAZARD PROFILE
The risk assessments in the following chapters describe the risks associated with each identified
hazard of concern. The following sections were used to describe each hazard and communicate
each respective level of risk:
•
•
•
•
•
•
•
Hazard Description—Each hazard profile contains a description of the general definition
and causes of the hazard. It may also include background information for understanding
the context of the hazard within Colville Reservation.
Location—The location or region in Colville Reservation where each hazard may occur is
described.
Historical Frequency & Probability of Future Occurrence—This section identifies past
hazard events of note that have occurred in Colville Reservation. It also includes the
likelihood of each hazard occurring again if available.
Extent—The strength or magnitude of each hazard is defined, usually through a form of
measurement, such as a formula, scale, chart, or graph.
Impacts & Loss Estimates—The potential impacts of each hazard on the county are
discussed. This section also outlines the potential economic/monetary loss from a hazard
event, in addition to loss of property, structures, facilities, systems, livestock, and life.
FEMA NRI Score—The hazard-specific FEMA National Risk Index scores for each
natural hazard is included.
Related Hazards—The hazard profiles that fall under a greater hazard category can be
found within this section.
4.5 RISK ASSESSMENT METHODOLOGY
Each hazard included in this plan was assessed and ranked based on a pre-defined hazard risk
methodology consistent with FEMA’s mitigation plan requirements. Information from the hazard
profiles and input from subject matter experts were used to inform the hazard risk assessment
process. The following is a description of the key factors.
PROBABILITY/LIKELIHOOD OF OCCURRENCE
The probability of occurrence of a hazard is indicated by a probability factor based on the
likelihood of annual occurrence:
•
•
•
•
High—Significant hazard event is likely to occur annually (Probability Factor = 3)
Medium—Significant hazard event is likely to occur within 25 years (Probability Factor
= 2)
Low—Significant hazard event is likely to occur within 100 years (Probability Factor = 1)
Unlikely—There is little to no probability of significant occurrence, or the recurrence
interval is greater than every 100 years (Probability Factor = 0)
The assessment of hazard frequency is generally based on past hazard events in the area.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
EXTENT
Extent was assessed in two categories: extent/intensity and catastrophic potential of the hazard.
Numerical impact factors were assigned as follows:
Extent/Intensity—Extent is defined as the range of anticipated intensities of the identified
hazards. Extent is most commonly expressed using various scientific scales, such as the Enhanced
Fujita scale.
•
•
•
•
High—Historical and/or probabilistic models/studies for this hazard indicate the
possibility of a high-intensity incident (Extent Factor = 3)
Medium—Historical and/or probabilistic models/studies for this hazard indicate the
possibility of a medium-intensity incident (Extent Factor = 2)
Low—Historical and/or probabilistic models/studies for this hazard indicate the possibility
of a low-intensity incident (Extent Factor = 1)
Unlikely—Historical and/or probabilistic models/studies for this hazard indicate the
possibility of little to no intensity (Extent Factor = 0)
Catastrophic—The potential that an occurrence of this hazard could be catastrophic.
•
•
•
•
High—High potential that this hazard could be catastrophic (Extent Factor = 3)
Medium—Medium potential that this hazard could be catastrophic (Extent Factor = 2)
Low—Low potential that this hazard could be catastrophic (Extent Factor = 1)
Unlikely—Virtually no potential that this hazard could be catastrophic (Extent Factor = 0)
Each category was assigned a weighting factor to reflect its significance, consistent with those
typically used for measuring the benefits of hazard mitigation actions: a weighting factor of 3 was
assigned for Extent/Intensity and its potential to be Catastrophic.
VULNERABILITY
Vulnerabilities were assessed in three categories: population exposure, property exposure, and
exposure based on changes in development. Numerical impact factors were assigned as follows:
People—Values were assigned based on the percentage of the total population exposed to the
hazard event.
•
High—30% or more of the population is exposed to this hazard (Vulnerability Factor = 3)
•
Medium—15% to 29% of the population is exposed to this hazard (Vulnerability Factor =
2)
Low—14% or less of the population is exposed to this hazard (Vulnerability Factor = 1)
No Vulnerability—None of the population is exposed to this hazard (Vulnerability Factor
= 0)
•
•
Property Exposed—Values were assigned based on the percentage of the total property value
exposed to the hazard event.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
•
•
•
•
High—25% or more of the total assessed property value is exposed to the hazard
(Vulnerability Factor = 3)
Medium—10% to 24% of the total assessed property value is exposed to the hazard
(Vulnerability Factor = 2)
Low—9% or less of the total assessed property value is exposed to the hazard
(Vulnerability Factor = 1)
No Vulnerability—None of the total assessed property value is exposed to the hazard
(Vulnerability Factor = 0)
Changes in Development—Changes in development since the previous plan was approved have
increased or decreased the community’s vulnerability/exposure to this hazard.
•
•
•
•
High—Changes in development have significantly increased the vulnerability/exposure of
the community to this hazard (Vulnerability Factor = 3)
Medium—Changes in development have increased the vulnerability/exposure of the
community to this hazard, but not significantly (Vulnerability Factor = 2)
Low—Changes in development have minimally increased the vulnerability/exposure of
the community to this hazard (Vulnerability Factor = 1)
No Vulnerability—Changes in development have had no effect and/or have decreased the
vulnerability/exposure of the community to this hazard (Vulnerability Factor = 0)
Each category was assigned a weighting factor to reflect its significance, consistent with those
typically used for measuring the benefits of hazard mitigation actions: a weighting factor of 3 was
assigned for People, and a weighting factor of 1 was assigned for Property Exposed and Changes
in Development.
IMPACT
Hazard impacts were assessed in eight categories: population and life/safety, underserved/equity,
property damages, economic, environmental, essential operations, future development, and
climate change. Numerical impact factors were assigned as follows:
Population and Life/Safety: Values were assigned based on (1) best available historical and
probabilistic data for individuals who are vulnerable to the hazard event and (2) the likelihood to
experience adverse impacts in the event of its occurrence.
•
•
•
•
High: Populations exposed to this hazard are likely to experience significant adverse
impacts (Impact Factor = 3)
Medium: Populations exposed to this hazard are likely to experience some adverse
impacts (Impact Factor = 2)
Low: Populations exposed to this hazard are likely to experience minimal adverse impacts
(Impact Factor = 1)
No impact: Populations exposed to this hazard are not likely to experience significant
adverse impacts (Impact Factor = 0)
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Underserved/Equity—Values were (1) assigned based on best available data for underserved
populations vulnerable to the hazard event and (2) are likely to experience
adverse/disproportionate impacts from the hazard incident resulting in greater disparity in equity.
• High—Underserved populations exposed to this hazard are likely to experience significant
adverse/disproportionate impacts (Impact Factor = 3)
• Medium—Underserved populations exposed to this hazard are likely to experience some
adverse/disproportionate impacts (Impact Factor = 2)
• Low—Underserved populations exposed to this hazard are likely to experience minimal
adverse/disproportionate impacts (Impact Factor = 1)
• No impact—Underserved populations exposed to this hazard are not likely to experience
significant adverse/disproportionate impacts (Impact Factor = 0)
Property Damages—Values were assigned based on the expected total property damages incurred
from a hazard incident. It is important to note that values represent estimates of the loss from a
major incident based on historical data or probabilistic models/studies.
• High—More than $5,000,000 in property damages is expected from a single major hazard
event, or damages are expected to occur to 15% or more of the property value within the
jurisdiction (Impact Factor = 3)
• Medium—More than $500,000 but less than $5,000,000 in property damages is expected
from a single major hazard event, or expected damages are expected to more than 5%, but
less than 15% of the property value within the jurisdiction (Impact Factor = 2)
• Low—Less than $500,000 in property damages is expected from a single major hazard
event, or less than 5% of the property value within the jurisdiction (Impact Factor = 1)
• No impact—Little to no property damage is expected from a single major hazard event
(Impact Factor = 0)
Economic—An estimation of the impact, expressed in terms of dollars, on the local economy is
based on a loss of business revenue, crops, worker wages, and local tax revenues or on the impact
on the local gross domestic product (GDP).
• High—Total economic impact is likely to be greater than $10,000,000 (Impact Factor = 3)
• Medium—Total economic impact is likely to be greater than $100,000 but less than or
equal to $10,000,000 (Impact Factor = 2)
• Low—Total economic impact is not likely to be greater than $100,000 (Impact Factor = 1)
• No Impact—Virtually no significant economic impact (Impact Factor = 0)
Environmental Factor: Environmental impact from a major hazard event requiring outside
resources and support; and/or repair, clean-up, restoration, and/or preservation work.
•
•
•
High: Environmental impact from a single major hazard event is likely to be significant,
requiring extensive outside resources and support; and/or repair, clean-up, restoration,
and/or preservation work (Impact Factor = 3)
Medium: Environmental impact from a single major hazard event is likely to be localized,
requiring some outside resources and support; and/or repair, clean-up, restoration, or
preservation work (Impact Factor = 2)
Low: Environmental impact from a single major hazard event is likely to be minimal,
requiring little to no outside resources and support, and/or minimal repair, clean-up,
restoration, or preservation work (Impact Factor = 1)
49
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
•
No impact: No environmental impacts from a single major hazard event is likely (Impact
Factor = 0)
Essential Operations Factor: Impact on the ability of the jurisdiction to meet the essential dayto-day operational demands and needs of the community from a single major hazard event.
•
•
•
•
High: Significant impact on the ability of the jurisdiction to meet the essential day-to-day
operational demands and needs of the community from a single major hazard event (Impact
Factor = 3)
Medium: Some impact on the ability of the jurisdiction to meet the essential day-to-day
operational demands and needs of the community from a single major hazard event (Impact
Factor = 2)
Low: Minimal impact on the ability of the jurisdiction to meet the essential day-to-day
operational demands and needs of the community from a single major hazard event (Impact
Factor = 1)
No Impact: No impact on the ability of the jurisdiction to meet the essential day-to-day
operational demands and needs of the community from a single major hazard event (Impact
Factor = 0)
Future Development—The potential that future development will have on increasing or
decreasing the impact/consequence of this hazard.
•
•
•
•
High—Future development trends will significantly increase the impact/consequence of
this hazard (Impact Factor = 3)
Medium—Future development trends will increase the impact/consequence of this hazard,
but not significantly (Impact Factor = 2)
Low—Future development trends will minimally increase impact/consequence of this
hazard (Impact Factor = 1)
No Impact—Future development trends will not increase the impact/consequence of this
hazard and/or may even decrease the impact/consequence of this hazard (Impact Factor =
0)
Climate Change—The potential that climate change will increase the risk of this hazard (e.g.,
type, location, and range of anticipated intensities of the identified hazard and impacts).
• High—Climate change trends will significantly increase the risk of this hazard and its
impacts (Impact Factor = 3)
• Medium—Climate change trends will increase the risk of this hazard and its impacts, but
not significantly (Impact Factor = 2)
• Low—Climate change trends will minimally increase the risk of this hazard and its impacts
(Impact Factor = 1)
• No Impact—Climate change trends will not increase the risk of this hazard and its impacts
(Impact Factor = 0)
Each category was assigned a weighting factor to reflect its significance, consistent with those
typically used for measuring the benefits of hazard mitigation actions: a weighting factor of 3 was
assigned for Population and Life Safety and Underserved/Equity, and a weighting factor of 2 was
50
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
assigned for Property Damages. In addition, a weighting factor of 1 was assigned for Economic,
Environmental, Essential Operations, Future Development, and Climate Change.
4.6
FEMA NRI RISK SCORES
The National Risk Index (NRI) is a dataset and online tool to help illustrate communities that are
most at risk for 18 natural hazards: Avalanche, Coastal Flooding, Cold Wave, Drought,
Earthquake, Hail, Heat Wave, Hurricane, Ice Storm, Landslide, Lightning, Riverine Flooding,
Strong Wind, Tornado, Tsunami, Volcanic Activity, Wildfire, and Winter Weather. Because not
all hazards are applicable to the Colville Reservation, only those hazards with a defined risk to
the Reservation are included.
The National Risk Index leverages available source data for Expected Annual Loss due to these
18 hazard types, Social Vulnerability, and Community Resilience to develop a baseline relative
risk measurement for each United States county and census tract. These measurements are
calculated using average past conditions, but they cannot be used to predict future outcomes for a
community. The National Risk Index is intended to fill gaps in available data and analyses to better
inform federal, state, local, tribal, and territorial decision makers as they develop risk reduction
strategies.
The Colville Reservation encompasses three distinct census tracts, each with unique geographic
and demographic characteristics:
•
•
•
Census Tract 9400: This tract represents the Ferry County side of the Colville
Reservation.
It is characterized by its rugged terrain and significant forested areas. The region is
known for its natural beauty and is less densely populated, with communities relying
heavily on natural resources and forestry.
Census Tract 9401: Located on the east side of the Colville Reservation within
Okanogan County, this tract includes a mix of residential areas and agricultural lands. It
is more developed compared to Census Tract 9400, with several small towns and
infrastructure supporting agricultural activities.
Census Tract 9402: This tract covers the west side of the Colville Reservation, also
within Okanogan County. Similar to Census Tract 9401, it includes a blend of residential
zones and agricultural fields. However, it also encompasses areas more prone to flooding
due to its proximity to the Okanogan River.
FEMA NATIONAL RISK INDEX SCORE
Table 11. Overall FEMA NRI Score
COLVILLE CONFEDERATED TRIBES
FEMA OVERALL NRI SCORE
Census Tract
FEMA Overall NRI
Score
FEMA Overall NRI Rating
9400
93.2 / 100
Relatively High
9401
83.3 / 100
Relatively Moderate
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
9402
94.2 / 100
Relatively High
Risk Index Scores are calculated using an equation that combines scores for Expected Annual Loss due to natural
hazards, Social Vulnerability and Community Resilience. (Expected Annual Loss X Social Vulnerability /
Community Resilience = Risk Index).
Source: https://hazards.fema.gov/nri/map
SOCIAL VULNERABILITY
Social Vulnerability measures the susceptibility of social groups to the adverse impacts of natural
hazards, including disproportionate death, injury, loss, or disruption of livelihood.
The "Social Vulnerability Score” and “Rating” represent the relative level of a community’s social
vulnerability compared to all other communities at the same level. A community’s Social
Vulnerability Score is also proportional to a community’s risk. A higher Social Vulnerability Score
results in a higher Risk Index Score (FEMA, 2023).
Social vulnerability is one of five components included in the formulation of the “National Risk
Index Score” in addition to community resilience, estimated annual loss (EAL) based on exposure,
annualized frequency, and Historic Loss Ratio (HLR) factors (FEMA, 2023).
Table 12. Overall FEMA NRI Score
COLVILLE CONFEDERATED TRIBES
Census Tract
9400
9401
9402
FEMA NRI SOCIAL VULNERABILITY SCORE
Social
Social Vulnerability Rating
Vulnerability
Score
79.9 / 100
Relatively High
88.9 / 100
97.3 / 100
Very High
Very High
Social Vulnerability is measured using the Social Vulnerability Index (SoVI) published by the
University of South Carolina's Hazards and Vulnerability Research Institute (HVRI).
Source: hazards.fema.gov/nri/social-vulnerability
COMMUNITY RESILIENCE
Community Resilience measures a community’s ability to prepare for anticipated natural hazards,
adapt to changing conditions, and withstand and recover rapidly from disruptions.
Table 13. Community Resilience FEMA NRI Score
COLVILLE CONFEDERATED TRIBES
FEMA NRI COMMUNITY RESILIENCE SCORE
Census Tract
Community Resilience
Score
Community Resilience Rating
9400
2.2 / 100
Very Low
9401
15.5 / 100
Very Low
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
9402
15.5 / 100
Very Low
Community Resilience is measured using the Baseline Resilience Indicators for Communities (HVRI BRIC)
published by the University of South Carolina's Hazards and Vulnerability Research Institute (HVRI).
Source: hazards.fema.gov/nri/community-resilience
EXPECTED ANNUAL LOSS
Expected Annual Loss (EAL) represents the expected economic damage likely to occur yearly due
to hazard events.
Table 14. Expected Annual Loss FEMA NRI Score (All Natural Hazards)
COLVILLE CONFEDERATED TRIBES
FEMA NRI EXPECTED ANNUAL LOSS SCORE
Census Tract
Expected Annual Loss
Score
Expected Annual Loss Rating
9400
89.3 / 100
Relatively High
9401
74.3 / 100
Relatively Moderate
9402
87.9 / 100
Relatively Moderate
Expected Annual Loss scores are calculated using an equation that combines values for exposure, annualized
frequency, and historic loss ratios (Expected Annual Loss = Exposure × Annualized Frequency × Historic Loss
Ratio).
Source: hazards.fema.gov/nri/expected-annual-loss
TRIBAL HAZARD RANKING EXERCISE
Prior to hiring a consultant to update the All Hazard Mitigation Plan, the CCT conducted a hazard
ranking process based on the following criteria: Location/Distribution, Maximum Probable Extent,
Probability of Future Events. These results were considered as part of the final Risk Ranking.
Table 15. Preliminary Tribal Hazard Ranking Exercise
Hazard
Location/
Distribution
(Reservation
Wide)
Maximum
Probable Extent
(Magnitude/
Strength)
Probability of
Future Events
Overall Risk
Significance
Ranking
Communications
Failure
Significant
Severe
Likely
Medium
Climate Change
Significant
Moderate
Likely
Medium
Chief Joseph
Significant
Extreme
Unlikely
Low
Grand Coulee
Significant
Extreme
Unlikely
Low
Owhi Lake
Negligible (<10%)
Low
Possible
Low
Twin Lakes
Negligible (<10%)
Weak
Possible
Low
Upriver Dams
Significant
Moderate to
Extreme
53
Unlikely
Low
Dam Failure:
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Disease, Animal
Extensive
Low
Possible
Low
Drought
Extensive
Moderate
Likely
Medium
Earthquake
Extensive
Extreme
Unlikely
Low
Extreme Heat
Significant
Low
Likely
Low
Flood
Limited (<25%)
Moderate
Likely
Medium
Landslide
Limited (<25%)
Moderate
Likely
Medium
Significant
Moderate
Likely
Medium
Wind
Significant
Severe
Likely
High
Rain
Significant
Severe
Likely
High
Tornado
Negligible
Severe
Unlikely
Low
Utility Failure
(Power Grid and
subsequent)
Significant
Moderate
Likely
Medium
Volcanic Eruption
Significant
Moderate
Unlikely
Low
Wildfire
Extensive
Extreme
Highly Likely
High
Smoke
Significant
Severe
Likely
Medium
Severe Winter
Weather
Severe Storm:
4.7
OVERALL RISK SCORES
The following tables represent the new overall risk scores for the Colville Reservation based on
the described methodology above. Following a data-driven quantitative assessment, the planning
team utilized subject matter knowledge and expertise and further refined the scores. FEMA NRI
Scores and the preliminary Tribal Hazard Ranking were used as appropriate and applicable to
inform the analysis.
Double click the Microsoft Excel icon below to access the full assessment and tool (this is only
accessible when utilizing the Microsoft Word version of the plan).
Table 16. 2024 Hazard Risk Scores for the Colville Reservation
Probability
Consequence
Sum of
Sum of
Sum of
Probability
Weighted
Weighted
Weighted
Hazard Event
Factor
Extent
Vulnerability
Impact
Factors
Factors
Factors
3
15
14
31
Wildfire
High Winds/Severe
3
15
16
15
Winds
Winter Storm and
3
15
16
14
Blizzards
Flood
2
12
8
30
(Riverine/Creek)
Flood (Flash
2
12
11
26
Flooding)
54
60
Total Risk
Total Risk
Score
(Probability x
Consequence)
83
46
66
45
65
50
50
49
49
Consequence
Score
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Drought
Widespread Power
Outage
Public Health
Emergencies:
Pandemic/Epidemic
Extreme Cold
Earthquake
Hazardous Materials
Incidents
Air Quality
Landslides
Cybersecurity
Extreme Heat
Dam/Levee Failure
Terrorism
Animal Disease
Volcanic Eruption and
Ash
Plant Disease
Hail
Active Shooter/Active
Assailant
Lightning
Avalanche
Tornadoes
2
12
12
16
40
41
2
12
10
18
40
41
2
12
10
17
39
41
2
2
9
6
16
16
14
13
39
35
41
37
2
9
6
17
32
34
2
2
2
2
1
1
3
9
9
12
3
18
18
6
10
6
7
10
7
5
3
12
15
8
13
26
26
7
31
30
27
26
51
49
16
33
32
30
29
28
27
27
1
12
15
15
42
24
2
1
9
6
3
16
8
13
20
35
23
21
1
12
8
14
34
20
2
1
1
3
9
6
6
5
5
7
13
14
16
27
25
19
16
15
Table 17. Hazard Risk Scores Legend
Probability Factor
Sum of Weighted
Extent Factors
Sum of Weighted
Vulnerability
Factors
Sum of Weighted
Impact Factors
Consequence Score
1
Low (L)
0–6
Low (L)
0–6
Low (L)
0–12
Low (L)
0–25
Low (L)
0–24
Low (L)
2
Medium (M)
7–12
Medium
(M)
7–12
Medium
(M)
13–26
Medium
(M)
26–50
Medium
(M)
25–59
Medium
(M)
3
High (H)
13–18
High (H)
13–18
High (H)
27–39
High (H)
51–75
High (H)
60–100
High (H)
*The Legend—specifically the assignment of low, medium, and high—provides an additional means to qualitatively assess the probability factor,
sum of weighted factors, and the total risk scores for each hazard.
The Consequence Score represents the sum of the Extent, Vulnerability, and Impact Factors.
The Total Risk Score is a measure of Probability and Consequence.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
CHAPTER 5. DROUGHT
5.1
HAZARD DESCRIPTION
Drought is an expected phase in the climactic cycle of almost any geographical region and is
certainly the case in Washington. Objective and quantitative definitions for drought exist, but most
authorities agree that because of the many factors contributing to it. None are entirely satisfactory
because their onset and relief are slow and indistinct. According to the National Drought Mitigation
Center, drought “originates from a deficiency of precipitation over an extended period of time,
usually a season or more. This deficiency results in a water shortage for some activity, group, or
environmental sector.” What is clear is that a condition perceived as “drought” in a given location
results from a significant decrease in water supply relative to what is “normal” in that area.
DROUGHT TYPES
•
•
•
•
5.2
Meteorological Drought – Defined as below-normal precipitation over a set period. Often,
this type of drought is region-specific based on regional climatology. This drought type is
often what is thought of as ‘drought.’
Agricultural Drought – This type of drought occurs when a reduction in soil moisture
results in unmet demand for crops. This drought type is region-, crop-, and time-specific
and usually occurs after meteorological droughts. Agricultural drought can cause
significant crop losses and economic disruption for agriculture-dependent communities.
Hydrological Drought – This type of drought is driven by a deficiency of surface and
subsurface water resources, often indicated by reduced streamflow, lake or reservoir water
levels, and groundwater table heights. Due to the complex hydrological network that feeds
surface and subsurface water resources, hydrological drought occurs after meteorological
drought.
Socioeconomic Drought – This type of drought occurs when physical water shortages
impact individuals or communities. Socioeconomic drought impacts can vary according to
an individual’s or community’s ability to adapt or mitigate.
HAZARD LOCATION
Drought could occur anywhere on the Colville Tribe Reservation, likely affecting the
entire reservation.
5.3
HAZARD EXTENT/INTENSITY
Figure 14 displays the precipitation conditions for the United States using the Palmer Drought
Severity Index (PDSI), taken from the National Weather Service (NWS). The PDSI quantifies
drought in terms of prolonged and abnormal moisture deficiency or excess. This index indicates
56
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
general conditions and not local variations caused by isolated rain. The PDSI is an important
climatological tool for evaluating the scope, severity, and frequency of prolonged periods of
abnormally dry or wet weather. In addition, it can help delineate disaster areas and indicate the
availability of irrigation water supplies, reservoir levels, range conditions, amount of stock water,
and potential intensity of forest fires (NCAR, 2023).
The PDSI compares moisture deficiency and excess on a numerical scale that usually ranges from
positive five to negative five. Positive values reflect excess moisture supplies, while negative
values indicate moisture demands in excess of supplies.
Figure 14. Palmer Drought Severity Index (PDSI)
Figure 15. U.S. Drought Severity Index by Division
The National Drought Mitigation Center also rates drought nationwide by intensity using a D0
(Abnormally Dry) to D4 (Exceptional Drought) scale, as seen in the map of Washington.
57
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 16. U.S. Drought Monitor – Washington
5.4
PROBABILITY AND FREQUENCY
“Meteorological drought can begin and end rapidly, while hydrological drought takes much longer
to develop and recover. Over the decades, many indices have been developed to measure drought
in these various sectors. For example, the U.S. Drought Monitor depicts drought integrated across
all time scales and differentiates between agricultural and hydrological impacts (NOAA, 2023).”
The NOAA uses the PDSI to measure drought conditions, illustrated in Figure 14. Subsequently,
Figure 17. shows the frequency of drought events in Colville Reservation between the year 2000
and the year 2023.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 17. U.S. Drought Monitor – Colville Reservation (2000-2023)
5.5
PAST EVENTS
Colville Reservation is partially located in Okanogan and Ferry Counties. Ferry County, on the
eastern side of the Reservation, does not have significant drought concerns based on the abovereferenced map. However, Okanogan County, on the western side of the Reservation, is almost
fully within the D0-D4 Zone.
There are combined 17 recorded instances of drought concern recorded by US Drought Monitor
for the two sides of the Reservation since 2005. Colville Reservation has been impacted by three
Excessive Heat Events in the past five years.
1. Okanogan County was impacted in 2021, 2022, and 2023. Cooling Centers were mobilized
within the Colville Reservation. No fatalities were reported on the reservation itself.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Table 18. Extreme Heat Activity
Location
Okanogan
County
Okanogan
County
Okanogan and
Ferry County
St.
Date
WA
6/26/2021
WA
7/25/2022
WA
8/15/2023-8/16/2023
Type
Excessive
Heat
Excessive
Heat
Excessive
Heat
Dth
Inj
PrD
CrD
0
0
0
0
0
0
0
0
0
0
0
0
5.6 VULNERABILITY AND IMPACTS
Water Supply and Quality: One concern regarding drought is regarding a lack of water supply
and a lack of water quality issues. There are a many private wells on the Colville Reservation and
some of these wells are less than 100ft in depth, making them susceptible to drought. A Well Depth
Map below illustrates the areas impacted.
Figure 18. Colville Tribe Well Depth Map
There are a wide range of other drought impacts on the reservation. The following two graphs
illustrate these impacts in more detail.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Figure 19. U.S. Drought Monitor – Ferry Co. Drought Impacts
Figure 20. U.S. Drought Monitor – Okanogan Co. Drought Impacts
Life Safety and Public Health: Droughts affect life safety and public health in several ways.
Health problems can arise from poor water quality, poor food quality, and increased dust in the air.
In addition, droughts make fires more likely, spread more quickly, and make them more
challenging. In addition, poor air quality and a lack of water may reduce residents’ engagement in
recreational activities, reducing overall mental and physical well-being (NDMC, 2023).
Property Damage and Critical Infrastructure: Drought has a negligible impact on buildings.
Possible losses/impacts to critical facilities include the loss of essential functions due to low water
supplies. Severe droughts can negatively affect drinking water supplies. Should a public water
system be involved, the losses could total millions if outside water is shipped. Possible losses to
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
infrastructure include the loss of potable water and water for tribal fire protection. Attempts at
reforestation can also be impeded by abnormally dry conditions.
Timber Industry: Colville Tribe was once heavily reliant on the timber industry. This reliance
has scaled back due to thinning growth, but there are efforts being put into reforestation which is
of environmental and economic benefit. However, the heavy drought risk makes effective sapling
transplanting difficult.
Transportation: Drought can also impact transportation within Colville Reservation. There is a
ferry landing in Keller that is impacted during times of low water. This occurs when the water
level in the reservoir is lowered.
Economy: Although no data demonstrates the economic impact of past drought events on Colville
Reservation, the most significant economic effect of drought is on the agriculture industry.
Environmental: During the 2015 drought, “bluetongue” (a viral disease of deer) killed large
numbers of deer throughout Eastern Washington. News reports stated that 68 whitetail deer
carcasses, killed by bluetongue disease, were collected within the town of Colville in Stevens
County that summer. During another drought year in 1996, 81 deer carcasses were picked up within
the same town. Those deer all died of a similar disease, Epizootic Hemorrhagic Disease (EHD).
Other drought years correlated with EHD outbreaks were 1988 and 2004. Drought is not the only
stressor that can cause an increase in deaths from these two diseases, but it is a significant one.
Because of the importance of hunting to Tribal culture and life, a deer die-off during a drought would
be a significant impact to the Tribe.
Changes in Development and Impact of Future Development: No data exists demonstrating
the impact of drought on future development on the Colville Reservation. Similarly, future
development is not anticipated to increase the probability, magnitude, or vulnerability to this
hazard besides greater exposure of people. However, excessive drought can result in water
shortages and increased competition for limited water resources, which can limit the ability of
developers to expand projects within the Reservation.
Effects of Climate Change on Severity of Impacts: According to University Corporation for
Atmospheric Research (UCAR), climate change is causing more extreme weather events,
including severe drought. UCAR explains that warmer temperatures cause more evaporation,
turning water into vapor in the air and causing drought in some areas of the world. Places prone to
drought are expected to become even drier over the following century (UCAR, 2023).
Climate Change Impact on Drought on the Colville Reservation: Higher temperatures,
increasing variation in precipitation patterns, and changes in lake levels are likely to increase the
vulnerability of communities to extreme events (including flooding, drought, heat waves),
compounding already existing stressors.
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Table 19. 25-Year Climate Projections for Colville Reservation
25-YEAR CLIMATE PROJECTIONS FOR COLVILLE RESERVATION
HIGHER EMISSIONS (RCP8.5)
Colville Reservation is expected to experience a 71% increase in extremely hot days within 25 years.
By 2049, Colville Reservation is expected to have a 2°F increase (from 48°F to 51°F) in average annual
temperatures.
LOWER EMISSIONS (RCP4.5)
Colville Reservation is expected to experience a 52% increase in extremely hot days within 25 years.
By 2049, Colville Reservation is expected to have a 2°F increase (from 48°F to 50°F) in average annual
temperatures.
Source: Neighborhoods at Risk (https://nar.headwaterseconomics.org/5300048550/explore/climate)
Table 20. 25-Year Precipitation Projections for Colville Reservation
25-YEAR PRECIPITATION PROJECTIONS FOR COLVILLE RESERVATION
HIGHER EMISSIONS (RCP8.5)
Colville Reservation is expected to experience a 25% increase in days with heavy precipitation within 25 years.
By 2049, Colville Reservation is expected to experience 0.02 more days of heavy precipitation per year (from
0.08 days to 0.1 days per year).
LOWER EMISSIONS (RCP4.5)
Colville Reservation is expected to experience a 31% increase in days with heavy precipitation within 25 years.
By 2049, Colville Reservation is expected to experience 0.03 more days of heavy precipitation per year (from
0.09 days to 0.11 days per year).
Source: Neighborhoods at Risk (https://nar.headwaterseconomics.org/5300048550/explore/climate)
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2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
Table 21. Future Climate Indicators for Colville Reservation
FUTURE CLIMATE INDICATORS FOR COLVILLE RESERVATION
Indicator
Modeled
History
(19762005)
Min-Max
Early Century
(2015-2044)
Lower
Higher
Emissions
Emissions
Min-Max
Min-Max
Mid Century
(2035-2064)
Lower
Higher
Emissions
Emissions
Min-Max
Min-Max
Precipitation
Average Annual
15”
15”
15”
15”
Total
10-29
10-30
10-30
10-30
Precipitation
Days Per Year
197 days
194 days
194 days
192 days
With
136-220
136-217
135-216
134-214
Precipitation
Days Per Year
168 days
171 days
171 days
173 days
With No
229-145
229-148
230-149
231-151
Precipitation
Maximum
27 days
28 days
29 days
30 days
Number Of
Consecutive Dry
21-43
23-45
23-45
23-46
Days
Temperature Thresholds
Annual days with
0 days
25 days
27 days
31 days
Maximum
temperature >
0-35
2-48
3-50
5-55
90°
Annual days with
0 days
1 day
2 days
3 days
Maximum
temperature >
0-4
0-9
0-10
0-13
100°
Source: (Climate Mapping for Resilience and Adaptation) (2024)
Late Century
(2070-2099)
Lower
Higher
Emissions
Emissions
Min-Max
Min-Max
16”
16”
16”
10-31
10-31
11-31
192 days
192 days
186 days
135-214
134-214
131-207
173 days
173 days
179 days
230-151
231-151
234-158
31 days
31 days
35 days
24-46
24-47
27-50
37 days
39 days
61 days
9-62
9-64
25-87
5 days
5 days
20 days
0-18
0-13
2-38
5.7 FEMA NATIONAL RISK INDEX
(NRI) ASSESSMENT
FEMA NRI ANNUAL EXPOSURE TABLE
Table 22. Colville Reservation Exposure Values
COLVILLE CONFEDERATED TRIBES EXPOSURE
VALUE TABLE FOR DROUGHT EVENTS
9400
Total
Value
$990,918
9401
9402
Census Tract
N/A
Population
Equivalence
N/A
$1,268,000
N/A
$151,991,105
N/A
Building Value
N/A
Agriculture
Value
$990,918
N/A
N/A
$1,268,000
N/A
N/A
$151,991,105
Population
Buildings: Building exposure value is defined as the dollar value of the buildings determined to be exposed to a
hazard according to a hazard type-specific methodology. The maximum possible building exposure of an area
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(Census block, Census tract, or county) is its building value as recorded in Hazus 6.0, which provides 2022
valuations of the 2020 Census.
Population: Population exposure is defined as the estimated number of people determined to be exposed to a
hazard according to a hazard type-specific methodology. The maximum possible population exposure of an area
(Census block, Census tract, or county) is its population as recorded in Hazus 6.0. Population loss is monetized
into a population equivalence value using a VSL approach in which each fatality or ten injuries is treated as
$11.6 million of economic loss (2022 dollars).
Agriculture: Agriculture exposure value is defined as the estimated dollar value of the crops and livestock
determined to be exposed to a hazard according to a hazard type-specific methodology. This is derived from the
USDA 2017 Census of Agriculture county-level value of crop and pastureland with 2018 values for the US
territories. All dollar values are inflation-adjusted to 2022 dollars.
Source: FEMA National Risk Index (2024)
FEMA NRI EXPECTED ANNUAL LOSS ESTIMATES
Table 23. Colville Reservation Expected Annual Loss Table
COLVILLE CONFEDERATED TRIBES
FEMA NRI EXPECTED ANNUAL LOSS - DROUGHT
Population
Population
Equivalence
Building
Value
Agriculture
Value
Total
Value
Expected
Annual
Loss
Score
Expected
Annual
Loss
Rating
11.1
n/a
n/a
n/a
$990,918
$134
77.5
Very Low
10.5
n/a
n/a
n/a
$1,268,000
$161
78.1
Census
Tract
Annualized
Frequency
9400
9401
Very Low
Relatively
9402
9.5
n/a
n/a
n/a
$17,555
$17,555
94.0
Moderate
Annualized Frequency: The natural hazard annualized frequency is defined as the expected frequency or
probability of a hazard occurrence per year. Annualized frequency is derived either from the number of recorded
hazard occurrences each year over a given period or the modeled probability of a hazard occurrence each year.
Population: Population exposure is defined as the estimated number of people determined to be exposed to a
hazard according to a hazard type-specific methodology.
Expected Annual Loss scores are calculated using an equation that combines values for exposure, annualized
frequency, and historic loss ratios (Expected Annual Loss = Exposure × Annualized Frequency × Historic Loss
Ratio). Source: hazards.fema.gov/nri/expected-annual-loss
Source: FEMA National Risk Index (2024)
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FEMA HAZARD-SPECIFIC RISK INDEX TABLE
Table 24. Colville Reservation Hazard Specific Risk Index Table
COLVILLE CONFEDERATED TRIBES
FEMA HAZARD SPECIFIC RATINGS - DROUGHT
Census Tract
Risk Index
Score
Social Vulnerability Rating
Community Resilience Rating
9400
78.5
Relatively High
Very Low
9401
79.4
Very High
Very Low
9402
95.2
Very High
Very Low
Risk Index Scores: are a quantitative rating calculated using data for only a single hazard type. Risk Index
Scores are calculated using data for only a single hazard type, and reflect a community's Expected Annual Loss
value, community risk factors, and the adjustment factor used to calculate the risk value.
Social Vulnerability Ratings: are a qualitative rating that describe the community in comparison to all other
communities at the same level, ranging from “Very Low” to “Very High.” Social Vulnerability is measured using
the Social Vulnerability Index (SVI) published by the Centers for Disease Control and Prevention (CDC).
Community Resilience Ratings: are a qualitative rating that describe the community in comparison to all other
communities at the same level, ranging from “Very Low” to “Very High.” Community Resilience is measured
using the Baseline Resilience Indicators for Communities (HVRI BRIC) published by the University of South
Carolina's Hazards and Vulnerability Research Institute (HVRI).
Source: FEMA National Risk Index (2024)
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CHAPTER 6. EARTHQUAKE
6.1
HAZARD DESCRIPTION
An earthquake is what happens when two blocks of the earth suddenly slip past one another. The
surface where they slip is called the fault or fault plane. The location below the earth’s surface
where the earthquake starts is called the hypocenter, and the location directly above it on the
surface of the earth is called the epicenter (US Geological Survey, 2024). This phenomenon is
illustrated in the figure below.
Figure 21. Earthquake
The earth has four major layers which are the inner core, outer core, mantle, and crust. The crust
and the top of the mantle make up a thin skin on the surface of our planet. But this skin is not all
in one piece – it is made up of many pieces like a puzzle covering the surface of the earth. Not
only that, but these puzzle pieces keep slowly moving around, sliding past one another, and
bumping into each other. These are called puzzle pieces tectonic plates, and the edges of the plates
are called the plate boundaries. The plate boundaries are made up of many faults, and most of the
earthquakes around the world occur on these faults. Since the edges of the plates are rough, they
get stuck while the rest of the plate keeps moving. Finally, when the plate has moved far enough,
the edges unstick on one of the faults and there is an earthquake (US Geological Survey, 2024).
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Figure 22. The Four Major Layers of Earth
Sometimes an earthquake has foreshocks. These are smaller earthquakes that happen in the same
place as the larger earthquake that follows. Scientists can’t tell that an earthquake is a foreshock
until the larger earthquake happens. The largest, main earthquake is called the mainshock.
Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur
afterwards in the same place as the mainshock. Depending on the size of the mainshock,
aftershocks can continue for weeks, months, and even years after the mainshock (US Geological
Survey, 2024).
6.2
HAZARD LOCATION
The below diagram is a simplified
illustration identifying the Cascadia fault
line as the hazard impacting the
Reservation; the hazard, for the most part,
lessens as it moves from the coast inland
toward the eastern border of the state.
The following figure indicates the
Residential seismic zones. The Reservation
is located in the eastern third of the state. The enlarged section of the map includes the general
geographic area of the Reservation. The majority of the Reservation is classified as Category B,
but there are some localized Category D areas along the Okanogan River Valley and north of
Nespelem.
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Figure 23. Washington Seismic Hazard Map
6.3
HAZARD EXTENT/INTENSITY
The severity of an earthquake can be expressed in terms of both intensity and magnitude. However,
the two terms are quite different, and they are often confused. Intensity is based on the observed
effects of ground shaking on people, buildings, and natural features. It varies from place to place
within the disturbed region depending on the location of the observer with respect to the earthquake
epicenter. Magnitude is related to the amount of seismic energy released at the hypocenter of the
earthquake. It is based on the amplitude of the earthquake waves recorded on instruments which
have a common calibration. The magnitude of an earthquake is thus represented by a single,
instrumentally determined value (US Geological Survey, 2024).
Earthquake strength has traditionally been measured using the Richter scale, developed by Charles
Richter in 1935. The Richter scale went through numerous adjustments since its conception and
was eventually replaced by the “Moment Magnitude Scale” for earthquakes larger than 3.5;
however, most still refer to both scales as the Richter scale. The Richter magnitude scale, used as
an indicator of the force of an earthquake, measures the magnitude, intensity, and energy released
by an earthquake with seismographs. Each whole-number increase in magnitude represents a
tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the
magnitude scale corresponds to the release of about 31 times more energy than the amount
associated with the preceding whole number value. It is important to note that the Richter
Magnitude Scale is not used to express damage (US Geological Survey, 2024).
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Table 25. The Richter Scale
Magnitude
< 2.0
2.0 - 2.9
3.0 - 3.9
4.0 - 4.9
5.0 - 5.9
6.0 - 6.9
7.0 - 7.9
8.0 - 8.9
9.0 - 9.9
10 <
THE RICHTER SCALE
Description
Micro earthquakes, not felt.
Minor earthquakes, generally not felt, but are recorded.
Minor earthquakes, often felt, but rarely causes damage.
Light earthquakes, noticeable shaking of indoor items, rattling noises, and significant damage is
unlikely.
Moderate earthquakes, can cause major damage to poorly constructed buildings over small
regions, and possible slight damage to well-designed buildings.
Strong earthquakes, can be destructive in areas up to about 99 miles across in populated regions.
Major earthquakes, can cause serious damage over larger regions.
Great earthquakes, can cause serious damage in regions several hundred miles across.
Great earthquakes, devastating in areas several thousands of miles across.
Massive earthquakes, never recorded, widespread devastation across vast regions.
The effect of an earthquake on the Earth's surface is called the intensity. The intensity scale consists
of a series of certain key responses such as people awakening, movement of furniture, damage to
chimneys, and finally - total destruction. The Modified Mercalli (MM) Intensity Scale is the
common intensity scale used in the United States. This scale is composed of 12 increasing levels
of intensity that range from imperceptible shaking to catastrophic destruction. It does not have a
mathematical basis; instead, it is an arbitrary ranking based on observed effects. The Modified
Mercalli Intensity value assigned to a specific site after an earthquake has a more meaningful
measure of severity to the non-scientist than the magnitude because intensity refers to the effects
actually experienced at that place (US Geological Survey, 2024).
The table below illustrates abbreviated descriptions of the 12 levels of Modified Mercalli Intensity
Scale.
Table 26. Modified Mercalli Intensity Scale
MODIFIED MERCALLI INTENSITY SCALE
Level of
Intensity
Observed Earthquake Effects
I
II
Not felt except by a very few under especially favorable conditions.
Felt only by a few persons at rest, especially on upper floors of buildings.
III
Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people
do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar
to the passing of a truck. Duration estimated.
IV
Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes,
windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking
building. Standing motor cars rocked noticeably.
V
Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects
overturned. Pendulum clocks may stop.
VI
Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster.
Damage slight.
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VII
Damage negligible in buildings of good design and construction; slight to moderate in wellbuilt ordinary structures; considerable damage in poorly built or badly designed structures;
some chimneys broken.
VIII
Damage slight in specially designed structures; considerable damage in ordinary substantial
buildings with partial collapse. Damage is great in poorly built structures. Fall of chimneys,
factory stacks, columns, monuments, walls. Heavy furniture overturned.
IX
Damage considerable in specially designed structures; well-designed frame structures thrown
out of plumb. Damage is great in substantial buildings, with partial collapse. Buildings shifted
off foundations.
X
Some well-built wooden structures destroyed; most masonry and frame structures destroyed
with foundations. Rails bent.
XI
XII
Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent greatly.
Damage total. Lines of sight and level are distorted. Objects thrown into the air.
Earthquakes can trigger other types of ground failures which could contribute to the damage. These
include landslides, dam failures, and liquefaction. In the last situation, shaking can mix
groundwater and soil, liquefying and weakening the ground that supports buildings and severing
utility lines. This is a special problem in floodplains where the water table is relatively high, and
the soils are more susceptible to liquefaction (US Geological Survey, 2024).
6.4
PROBABILITY AND FREQUENCY
Probability: The United States Geological Survey (USGS) determines the probability of
earthquake events through a combination of historical earthquake data, geological and
seismological research, and advanced modeling techniques. This process involves analyzing past
earthquakes to understand patterns of occurrence, fault line activities, and the distribution of
seismic activity across different regions. By studying the behavior of tectonic plates, including
their movement and the stress accumulation along faults, scientists can assess where earthquakes
are more likely to occur. The USGS also utilizes seismic hazard maps that depict the likelihood of
various levels of earthquake shaking in different areas over specific time frames. These maps are
based on models that incorporate the rates at which earthquakes occur in different areas and the
expected ground shaking from those earthquakes.
In addition, the USGS employs probabilistic seismic hazard analysis (PSHA), a method that
quantifies the likelihood of exceeding various levels of earthquake shaking in a given time period,
considering the uncertainties inherent in predicting earthquake behavior. PSHA takes into account
the location, rate, and magnitude of potential earthquakes, as well as how seismic waves will
propagate through the Earth to affect particular locations. The analysis also incorporates the
potential for soil amplification and other local effects that can influence ground shaking intensity.
Frequency: The USGS Earthquake Hazards Program keeps a record of earthquakes throughout
the world in their online Earthquake Catalog. The geographic area considered in this plan for the
Reservation is a 50-mile radius from the approximate center of the Reservation. The following
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table lists all 39 earthquakes recorded for the Colville Reservation area since 1980 with a
magnitude of 2.5 or higher.
Table 27. USGS Earthquake Catalog Data – Geographic Vicinity of Colville Reservation
Date
Location
Magnitude
6/18/1980
4/25/1983
10/10/1984
2/9/1985
7/22/1985
7/24/1985
9/27/1985
12/20/1987
5/2/1988
2/14/1989
3/24/1989
5/9/1989
11/1/1989
3/21/1990
4/1/1990
7/24/1990
3/31/1992
5/19/1998
6/18/1998
11/8/1998
11/12/1998
1/7/1999
1/7/1999
1/31/1999
11/25/2000
4/25/2001
5/1/2002
12/26/2002
3/20/2003
7/27/2006
10/29/2007
8/15/2010
11/18/2011
9/1/2015
10/17/2015
7/9/2017
7/20/2017
11/18/2019
10 km WSW of Tonasket, Washington
12 km SW of Tonasket, Washington
4 km SW of Electric City, Washington
13 km ESE of Mansfield, Washington
14 km ESE of Mansfield, Washington
14 km ESE of Mansfield, Washington
17 km NNW of Banks Lake South, Washington
17 km NNW of Banks Lake South, Washington
17 km NNW of Banks Lake South, Washington
28 km S of Republic, Washington
16 km SSW of Republic, Washington
12 km WSW of Malott, Washington
13 km NNW of Riverside, Washington
Washington
13 km NNW of Hartline, Washington
9 km SW of Tonasket, Washington
12 km NNW of Keller, Washington
10 km WNW of Valley, Washington
8 km NNW of Torboy, Washington
21 km W of Nespelem Community, Washington
22 km WSW of Nespelem Community, Washington
16 km ENE of Bridgeport, Washington
15 km ENE of Bridgeport, Washington
22 km N of Keller, Washington
13 km SSE of Oroville, Washington
25 km WNW of Republic, Washington
5 km NNW of Omak, Washington
28 km W of Curlew, Washington
6 km WNW of Tonasket, Washington
3 km SSW of Electric City, Washington
5 km NW of Tonasket, Washington
2 km N of Bridgeport, Washington
8 km WSW of Riverside, Washington
15 km N of Nespelem Community, Washington
14 km N of Nespelem Community, Washington
9 km NNW of Riverside, Washington
9 km N of Riverside, Washington
19 km NW of Hartline, Washington
M 2.9
M 3.0
M 3.0
M 2.6
M 2.5
M 2.7
M 2.5
M 2.7
M 2.6
M 2.9
M 2.6
M 4.5
M 2.5
M 2.7
M 2.8
M 2.9
M 2.5
M 2.7
M 2.6
M 2.7
M 3.0
M 2.9
M 2.7
M 3.1
M 3.1
M 2.6
M 2.9
M 2.8
M 2.7
M 2.7
M 2.6
M 2.6
M 4.6
M 4.2
M 2.5
M 2.9
M 2.6
M 3.5
72
ShakeMap
IV
III
III
V
IV
III
IV
2024 Colville Confederated Tribes (CCT) All Hazard Mitigation Plan
The figure below illustrates peak ground accelerations having a 2% probability of being exceeded
in 50 years, for a firm rock site. The long-term national seismic hazard map is based on the most
recent USGS models for the conterminous U.S. (2018), Hawaii (1998), and Alaska (2007). These
models are based on seismicity and fault-slip rates and consider the frequency of earthquakes of
various magnitudes (US Geological Survey, 2024).
Figure 24. Long-term National Seismic Hazard Map
6.5
PAST EVENTS
The Washington Department of Natural Resources states there have been fifteen earthquakes in
excess of an M5 since 1870. The included exhibits are distributed by the Washington State
Department of Natural Resources; Tribes within Washington have contributed information
through oral history dating back to approximately 900 AD, which has been corroborated with
separate tribes and resultant tsunamis as far away as Japan (WA DNR, 2024).
One major earthquake affecting the Colville Reservation is thoroughly documented in the
historical record. That is the series of earthquakes and aftershocks that began on December 14,
1872, and lasted into 1874. Known variously as either the North Cascades or Lake Chelan
earthquake, recent research has attempted to better determine the magnitude and the epicenter. The
earthquake was felt from Salem, Oregon, in the south to as far north as central British Columbia.
In the west, people ran out of buildings in Seattle and Victoria when they felt the earthquake. Items
fell off shelves as far away as Colville, in Stevens County (Nisbet, 2015). Closer to the epicenter,
the earthquake damaged a trading post built near the mouth of the Wenatchee River and threw
settlers to the ground. The third aftershock caused a landslide approximately four
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miles north of the mouth of the Entiat River, which completely dammed the Columbia River.
Miners who crossed the Columbia River on the dam were stranded on the wrong side when the
river broke through the landslide (Hackenmiller, 1995). As much as five feet of subsidence
occurred at the mouth
of
the
Wenatchee
River
(Nisbet,
2015). The
Columbia River rose at least fifty feet overnight after the landslide, flooding fields and a trading
post. Significant subsidence and major landslides occurred as far east as Whitestone Rock on the
Columbia River as well as at the mouth of the Spokane River. The only documented fatality
occurred when a Spokane woman, upset by the earthquakes, ran away from her community near
the mouth of the Spokane River and was later found dead (Nisbet, 2015).
A Jesuit missionary, Father Urban Grassi, was on the Colville Reservation shortly after the
earthquake and was a regular visitor. In 1874 he wrote this about the Sanpoil Tribe:
This Tribe more than any other on the Columbia for the past two years has been visited by
God with earthquakes that in some places has sunk the ground, in others has piled it up
greatly, and in others has broken the sides of the mountains. (Nisbet, 2015)
Following the 1873 earthquake, there was famine on the Reservation because people were not able
to gather foods as they normally did (Ackerman, 1996).
Figure 25. Lake Chelan Earthquake
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The 1964 Alaskan earthquake, measured at 9.2 on the Richter scale, was felt in Washington; onthe-ground effects were measured if not felt as far away as Texas and Louisiana (Geiger, 2014).
Tsunami waves that struck Washington’s Pacific coast are well-documented. What is less wellknown is that rock fall apparently caused by the earthquake occurred on State Route 21 along the
Sanpoil River in Ferry County (Fagerlie, 2018).
6.6 VULNERABILITY AND IMPACTS
Life Safety and Public Health: According to FEMA, earthquakes can impact life safety and
public health in different ways. Some of the most common impacts are as follows:
•
•
•
•
•
•
•
•
•
Injuries and Loss of Life: The violent shaking and structural damage caused by earthquakes
can result in injuries and, in severe cases, loss of life. Falling debris, structural collapses,
and ground ruptures can pose immediate risks to individuals in affected areas.
Structural Damage: Earthquakes can cause extensive damage to buildings, homes, and
infrastructure, making them unsafe for occupancy. This can lead to injuries, homelessness,
and the need for temporary shelter.
Displacement: Earthquake-affected individuals may be forced to evacuate their homes due
to damage or the threat of aftershocks. This displacement can lead to overcrowding in
emergency shelters and increased stress for affected individuals and families.
Mental Health Impact: Earthquakes can have long-lasting psychological effects, including
trauma, anxiety, and post-traumatic stress disorder (PTSD), which may require mental
health support and counseling.
Strain on Healthcare Systems: Earthquakes can overwhelm healthcare systems with an
influx of injured individuals in need of medical attention. Hospitals and medical facilities
may face challenges in providing care and resources.
Infrastructure Disruption: Critical infrastructure, including roads, bridges, utilities, and
communication networks, can be damaged, affecting emergency response capabilities and
access to essential services.
Water Supply Contamination: Ground shaking can damage water supply systems, leading
to contamination of drinking water sources. This poses health risks and requires water
treatment and distribution efforts.
Fire Hazards: Earthquakes can cause gas leaks and damage to electrical systems, increasing
the risk of fires. Fire outbreaks can lead to additional injuries, property damage, and air
quality issues.
Aftershocks: Aftershocks following the initial earthquake can further damage weakened
structures, hinder response efforts, and prolong the risks to life safety and public health.
Property Damage and Critical Infrastructure: Generally, wood frame buildings and structures
on solid ground fare best during
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