Chehalis Reservation
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Chehalis Reservation
Natural Hazards
Mitigation Plan 2009
Table of Contents/Introduction
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Table of Contents/Introduction
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Table of Contents/Introduction
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TABLE OF CONTENTS
Authorizing Resolution/Table of Contents
Authorizing Resolution ............................................................................ 2
Table of Contents ................................................................................... 4
Chapter 1: Introduction
Introduction .......................................................................................... 8
Chapter 2: Planning Process
Planning Process .................................................................................... 10
Table 1.1 Jurisdiction Adoption and Approval Dates of the 20032008 Hazard Mitigation Plan for the Thurston Region .......... 10
Table 1.2 2008-2009 Hazard Mitigation Planning Workgroup for
the Confederated Tribes of the Chehalis Reservation .......... 11
Plan Update 2008-2009 .......................................................................... 12
Chehalis Reservation Community Process .................................................. 13
Natural Hazards Preparedness Questionnaire ............................................. 16
Chapter 3: Chehalis Reservation Profile
Tribal Government ................................................................................. 21
Table 2 Chehalis Tribe Employees ......................................... 22
Statistical Profile .................................................................................... 23
Socio –Economic .................................................................................... 23
Tribal Lands .......................................................................................... 24
Historic/Traditions/Culture ...................................................................... 25
Chapter 4: Risk Assessment
Risk Assessment Introduction .................................................................. 27
Table 3.1 Hazard/Risk Rating ............................................... 27
P’ucú/Flood – Identification & Profile ......................................................... 30
Table 3.2 Historical Flood Events Table .................................. 32
Identification and Profile ............................................................... 34
Characteristics of Flooding ............................................................. 34
Flood – Historic Profile .................................................................. 36
Table 3.3 USGS Advanced Hydrologic Prediction Service:
Seattle, Chehalis River near Grand Mound, Flood Categories 37
Table 3.4 USGS Advanced Hydrologic Prediction Service:
Seattle, Chehalis River at Centralia Flood Categories .......... 38
Topography ................................................................................. 40
Soil Types on the Chehalis Reservation............................................ 41
Impacts ...................................................................................... 42
Data/Chehalis Community Awareness ............................................. 44
Yakwa†t&mx/Earthquake - Identification and Profile ................................... 45
Geology ...................................................................................... 47
Earthquake – Historic Profile .......................................................... 49
Table 3.5 FEMA Disaster Assistance Totals July 31, 2001.......... 51
Table of Contents/Introduction
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Future Earthquake Potential........................................................... 52
Impacts ...................................................................................... 52
Chehalis Community Awareness ..................................................... 54
Severe Winter Storm – Identification & Profile ............................................ 55
Severe Storm – Historic Profile....................................................... 57
Future Severe Storm Potential ....................................................... 58
Impacts ...................................................................................... 58
Data/Chehalis Community Awareness ............................................. 59
Volcano – Identification & Profile .............................................................. 60
Volcano – Historic Profile ............................................................... 60
Impacts ...................................................................................... 63
Data/Chehalis Community Awareness ............................................. 63
Wildfire – Identification & Profile .............................................................. 65
Wildfire – Historic Profile ............................................................... 65
Impacts ...................................................................................... 66
Data/Chehalis Community Awareness ............................................. 66
Climate Change ..................................................................................... 67
Assessing Vulnerabilities - Identifying Structures ........................................ 69
Transportation Facilities ................................................................ 70
Table 3.6 Chehalis Reservation IRR Inventory ........................ 73
Table 3.7 Chehalis Reservation Bridge Inventory..................... 84
Estimating Potential Losses............................................................ 90
Table 3.8 Chehalis Tribe 2007-2008 COPE Table ..................... 91
Analyzing Development Trends ...................................................... 101
Land Use Criteria................................................................ 102
Primary Land Use Designations ............................................ 102
Summary of Proposed Development Zones ............................ 104
Summary of Tribal Land Use Goals and Objectives ............................ 106
Assessing Vulnerabilities - Assessing Cultural and Sacred Sites ..................... 107
Plan Incorporation and Coordination ......................................................... 107
Chapter 5: Mitigation Strategy
Identification & Analysis of Tribal Mitigation Actions .................................... 108
Mitigation Plan goals............................................................................... 109
Identification and Prioritization of Mitigation Initiatives ................................ 110
Implementation of 2004 Plan Tribal Mitigation Actions ................................. 111
Tribal Capacity Assessment ..................................................................... Apx A
Tribal Funding Sources ........................................................................... Apx B
Mitigation Strategy ................................................................................. Apx B
Implementation of Tribal Mitigation Actions ............................................... Apx B
Chapter 6: Plan Maintenance Strategy
Adoption by Tribal Governing Body ...................................................................................... 116
Implementation .................................................................................................................... 116
Plan Monitoring & Evaluation ............................................................................................... 116
Plan Maintenance ................................................................................................................. 117
Distribution of Revisions ....................................................................................................... 118
Mitigation Measures and Project Close Outs ....................................................................... 118
Continued Public Involvement .............................................................................................. 119
Table of Contents/Introduction
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APPENDICES
A. Tribal Capability Assessment.......................................................... 120
Table 4.1 Chehalis Tribe Hazard Management Policies .............. 121
Hazard Management Plans and Capabilities ................................................ 124
Evaluation of the Tribe’s Policies Related to Development in Hazard Prone
Areas .............................................................................................. 125
B. Mitigation Strategy- Tribal capacity assessment and tribal funding
sources....................................................................................... 126
C. Mitigation strategy-Identification and analysis of tribal mitigation
actions ....................................................................................... 126
D. Mitigation Measures ...................................................................... 127
Structural Mitigation Measures .................................................. 127
Table 4.2 Structural Mitigation Measures ……………………… 128
Mitigation Responsibilities and Timeframes............................. 129
Non-Structural Mitigation Measures ........................................... 131
Table 4.3 Non-Structural Mitigation Measures ............... 132
Non-Structural Mitigation Responsibilities and Timeframes ....... 132
Mitigation Funding Resources …………………………………………………………………………….134
BIBLIOGRAPHY ……………………………………………………………………………………………… 136
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Chapter 1: INTRODUCTION
The Confederated Tribes of the Chehalis Reservation (Chehalis Tribe or the Tribe)
developed this Natural Hazards Mitigation Plan (NHMP) in accordance with the
requirements of 44 CFR Part 201 and Section 322 of the DMA 2000, Federal
Emergency Management Agency (FEMA). In addition, the Tribe has consulted
technical guidance documents provided by FEMA and other agencies in the
preparation of our NHMP.
This plan is an update. The Chehalis Tribe previously participated in the 2004
Natural Hazards Mitigation Plan, Thurston Region. In this updated plan, the
Chehalis Tribe sets forth specific analysis, identification and mitigation of hazards
for the Chehalis Indian Reservation.
Funding for the development of this plan was provided by the Chehalis Tribe and
the Bureau of Indian Affairs, Indian Reservation Roads, Transportation Planning.
The Chehalis NHMP was created to assist the Chehalis General Council and Business
Committee, Tribal staff and Tribal community members plan for and reduce the
human and economic losses and costs of flooding and other natural hazards and
disasters.
The Chehalis Reservation is located within a large floodplain and subject to minor
flooding events up to five times annually. Flooding sufficient to limit access to the
reservation, covering one or more reservation access roads, occur with a frequency
of about every 2.6 years. Flood events up to and above 15 year frequency cover 75
percent of the reservation lands, with incremental encroachment on roads and
homes.
The development of a tribal NHMP is essentially to guide future efforts to effectively
mitigate flooding and other natural hazards on the Chehalis Indian Reservation and,
in coordination with other jurisdiction as appropriate, to mitigate and respond to
natural hazards generated and adjacent to the Reservation or those that cross
Reservation boundaries.
The Comprehensive Emergency Management Plan (CEMP) is the ONLY governing
document pertaining to governmental operations during Emergencies/Disasters;
effective as of the end of March 2007, with the passing of Confederated Tribes of
the Chehalis Reservation Resolution (CEMP; Appendix B; pg. 40.). All additional
revisions will become effective once the Business Committee reviews and approves
the revisions. This is the primary document for managing emergencies/disasters.
Table of Contents/Introduction
Page 8
For the Glossary of Terms, Comprehensive Emergency Management Plan (CEMP)
See Chehalis CEMP, Appendix A, page 31.
The Natural Hazards Mitigation Plan (NHMP) is a supporting document to the Tribal
Comprehensive Emergency Management Plan (CEMP), will comply with all
standards and guidelines established within, for example:
1.
1.
2.
3.
Authority to Execute
Plan Maintenance
Review of the Base Document
Appendices Change Process
NOTE: The following PDM areas are classified as Appendices to this plan, and will
comply with all criteria outlined with the Tribal CEMP pertaining to Appendices:
A: Tribal Capability Assessment
B: Mitigation Strategy
1-Tribal Capacity
2-Tribal funding
C: Tribal Mitigation Actions
D: Implementation of Tribal Mitigation Actions
Table of Contents/Introduction
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Chehalis Reservation Natural Hazard Mitigation Plan
Chapter 2: PLANNING PROCESS
This section describes how the plan was prepared, who was involved in the process,
and how the public was involved.
The Natural Hazard Mitigation Plan for the Thurston Region (2004) established
multi-jurisdictional hazards for the region, including the Chehalis Indian
Reservation.
When the first plan was written, 44 CFR did not accommodate for Indian Tribe
jurisdiction plans. With the amending of the CFR to include Indian tribal
government plans, 207.1, the Confederated Tribes of the Chehalis Reservation
(Chehalis Tribe or Tribe) declared their intention to develop a specific hazard plan
for the Chehalis Indian Reservation.
In May 2008, the Emergency Management Council of Thurston County sent a letter
to 39 local stake holders to participate in the update of the Natural Hazards
Mitigation Plan for the Thurston Region. A total of 26 jurisdictions actively
participated in the plan update process including 18 of the original plan partners
plus eight new participating jurisdictions.
In Feb 2008, the Chehalis Tribe became aware of the 207.1 amendment to 44 CFR,
allowing for Indian tribal government plans and made the decision to pursue
development of a Reservation specific hazard plan under the individual tribal
jurisdiction. Thurston Regional Planning Council, coordinator of the Thurston
Regional Planning Process, was informed of the Tribe’s decision.
The following table comprises the Hazard Mitigation Planning workgroup for the
2004 Natural Hazard Mitigation Plan.
Table 1.1 Jurisdiction Adoption and Approval Dates of the 2003-2008
Natural Hazard Mitigation Plan for the Thurston Region
Jurisdiction
Adoption
Approval
Thurston County
Town of Bucoda
Town of Lacey
City of Olympia
City of Rainier
City of Tenino
City of Tumwater
City of Yelm
Confederated Tribes Of the Chehalis
Reservation
Fire District 4- Rainier
August 4, 2003
May 24, 2005
September 11, 2003
December 9, 2003
March 2, 2005
July 22, 2003
July 15, 2003
August 13, 2003
July 19, 2003
October 3 2003
August 17, 2005
October 6, 2003
October 6, 2003
April 6, 2005
October 6, 2003
October 6, 2003
October 6, 2003
October 6, 2003
August 12, 2003
October 6, 2003
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Chehalis Reservation Natural Hazard Mitigation Plan
Fire District 9- McLane
Fire District 13- Griffin
Intercity Transit
Providence St. Peter Hospital
School District, North Thurston Public Schools
School District, Olympia
School District, Rainier
School District, Tumwater
School District, Yelm Community Schools
The Evergreen State College
August 14, 2003
August 14, 2003
June 2, 2004
May 6, 2004
January 18, 2005
August 9, 2004
June 12, 2003
November 28, 2004
July 9, 2003
October 6, 2003
October 6, 2003
October 6, 2003
August 25, 2004
February 28, 2005
October 6, 2003
October 6, 2003
October 6, 2003
December 23, 2004
October 6, 2003
Chehalis Tribe representatives for the 2004 workgroup were David Burnett, Tribal
Chairman; Lennea Magnus, Planning Director and Ralph Wyman, Public Safety
Director. This group also served as workgroup participants between 2003 and
2008.
In March 2008, the Tribe recruited additional workgroup members to initiate the
process of updating the plan and developing a Natural Hazards Mitigation Plan
(NHMP) of specific to Confederated Tribes of the Chehalis Indian Reservation.
Table 1.2 2008-2009 Hazard Mitigation Planning Workgroup for the
Confederated Tribes of the Chehalis Reservation
Name
Position
Jurisdiction/Agency
David Burnett
Chairman
Lennea Magnus
Planning Director
Amy Loudermilk
Transportation Planner
Ralph Wyman
Public Safety Director,
Chief of Police,
Emergency Services
Coordinator
Natural Resources
Director
Language Program
Coordinator
Communications,
Newsletter Editor
Tribal Elder
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Mark White
Dan Penn
Fred Shortman
Catherine Barr
Jill Kangus
Anne Sullivan
Mark Stewart
Chapter 2
Emergency Manager
Emergency Manager
WA State Hazard
Mitigation Officer
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Confederated Tribes of
the Chehalis Reservation
Lewis County
Grays Harbor County
WA State
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Chehalis Reservation Natural Hazard Mitigation Plan
Diana Coho
Kelly D. Cox
Sophi Beym
CFM, DHS-FEMA
Mitigation
Hazard Mitigation Officer
VP Planning and
Technology
FEMA
FEMA
Tribal Emergency
Management Systems,
LLC
PLAN UPDATE 2008-2009
The Regional Plan contained a large volume of material that was not specific to the
Reservation culture, community or geography as it was a multi-jurisdictional plan
covering a much larger region. The decision was made to rewrite the plan utilizing
information very specific to the tribal culture and geographical location of the
Chehalis Indian Reservation.
The Committee’s role was to: participate in all aspects of the plan update process,
meets as needed at the workgroup or within their department/agency to review,
update and amend sections of the plan and coordinate comments from their
department/agency, review, edit and/or commend on all elements of the draft and
final plan.
Chapter 1: Introduction was rewritten to clarify governing emergency documents
for the Chehalis Tribe.
Chapter 2: Planning Process was rewritten to update the material to reflect our
current planning process and participants.
Chapter 3: Thurston County Profile contained an overview of the greater
Thurston County Region. Similar information providing an overview of tribal
government, demographic and geography is now found in the Chapter 3 Chehalis
Reservation Profile.
Chapter 4: Risk Assessment consolidates the risk assessment and the hazard
profiles into a single section. The four original hazard profiles included earthquake,
flood, storm, and landslide. The Thurston County update contains flood,
earthquake, severe storm, volcano and wildfire. In its update, Chehalis Tribe also
added wildfire and volcano to its update. Landslide, however, was not included as
the Chehalis Reservation is relatively flat, with no mountainous formations, hills,
buttes or other threat of landslide. Analysis of structures, including transportation
facilities, on the Chehalis Reservation was greatly increased and detailed.
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Chehalis Reservation Natural Hazard Mitigation Plan
Chapter 5: Mitigation Initiatives were substantially modified in the update to
the Chapter 5, titled MITIGATION STRATEGY-IDENTIFICATION AND ANALYSIS OF
TRIBAL MITIGATION ACTIONS. Specific discussion of Thurston County staff
processes, broad statements regarding regional and multi-jurisdictional activities
were eliminated to reflect the mitigation planning and strategies specific to the
Chehalis Indian Reservation. Discussion of abbreviations and formatting of the plan
charts were also eliminated. The number and detail of mitigation strategies specific
to the Chehalis Indian Reservation were greatly increased.
Chapter 6: Monitoring, Implementation and Maintenance was also revised to
reflect the plan’s focus on the Reservation community and to align with tribal
procedures and protocols and were also revised to reflect current federal planning
requirements.
Annexes – The updated plan deleted the sections for multiple jurisdictions outside
the Chehalis Reservation.
Appendices were revised to serve the needs of the plan update.
Chehalis Reservation Community Process
The type and outcome of public meetings are as follows. Lennea Magnus, Planning
Director for the Confederated Tribes of the Chehalis Reservation, hosted two
community open forums. Seven hundred (700) advance notices were mailed out
prior to the forums. The mailing list included all enrolled tribal members and nonIndian reservation households.
During the public meetings participants were also interviewed one-on-one and were
asked to complete a survey (below) identifying the most important natural hazards
facing the community. They were also asked to comment on what the Tribe does
right, when responding to emergency events, and what could be improved upon.
Tribal members and residents had the following opportunities to comment prior to
final approval. On June 4, 2008, two open public meetings were held, focused upon
the primary natural hazard concerns of the community. Twelve Tribal members
and reservation residents attended the first meeting and the second meeting was
attended by (16) sixteen Tribal members and reservation residents. The residents
were interviewed one-on-one focusing upon the most critical hazards facing the
community. The community members commented on the tribal government
response to emergency incidents and were asked for their opinion on emergency
response improvements. In addition, tribal employees were encouraged to
comment and share opinions.
Next, research methods based upon guidelines from C.F.R. 44, 201.7 – Tribal
Mitigation Plan directed the planning methodology. Comprehensive research
conducted online and at the Learning Resource Center at the National Emergency
Training Center in Emmitsburg, MD created the opportunity to gather additional
resources in data, maps and journal articles. Input gathered from the Chehalis
community meetings directed the selections for areas of interest. Each hazard or
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Chehalis Reservation Natural Hazard Mitigation Plan
risk identified during the community meeting determined the mitigation priorities.
The timeline to complete the plan is as follows: The Hazard Mitigation Plan was
initiated in February of 2008 by the Chehalis Business Committee. They, in turn,
directed the Tribal planning department to implement the project with a completion
date of October 2008.
The type and outcome of public meetings are as follows. Lennea Magnus, Planning
Director for the Confederated Tribes of the Chehalis Reservation, hosted two
community open forums. Seven hundred (700) advance notices were mailed out
prior to the forums. The mailing list included all enrolled tribal members and nonIndian reservation households.
During the public meetings participants were interviewed one-on-one and were
asked to identify the most important natural hazards facing the community. They
were also asked to comment on what the Tribe does right, when responding to
emergency events, and what could be improved upon.
Tribal members were involved in the planning process by using the Chehalis Tribal
newsletter as the primary method of communication and were given the
opportunity to review the plan in draft. Tribal residents received copies of the draft
plan before the formal review team. They were encouraged to review the plan, and
submit their comments to a local phone number. All comments by tribal members
were included in the plan.
The planning team initiated the process, developed the goals, objectives and
timeline, assigned the lead agency and completed the introduction. They provided
data to support the reservation profile; geography; and population demographics
including languages, culture, history, household size, household characteristics,
number of housing units, employment, median income, household income, poverty
level, families below poverty, and education. Their contribution also included an
overview of the tribal government structure and a comprehensive list of Tribal Land
Use and Community Development Ordinances and Plans (1997 – 2008). This list
consists of: (8) eight ordinances; (6) phases of the Facilities Master Plan; (1) one
culture/historic report and (6) studies and plans for waste water, ground water
assessment and long range transportation plans. Each person took personal
responsibility to initiate the Natural Hazard Mitigation Plan, review the draft and
actively provide comment(s) for accuracy and attention to detail.
In addition, outreach to other entities was in the form of telephone conversations
requesting a review of the draft. Technical research references Mitigation Plans
from other counties; portions of those plans are included. The local county
Emergency Managers were given notice of the upcoming document, expectations
and due date. Outreach to U.S. Department of Homeland Security (DHS) - Federal
Emergency Management Agency (FEMA) officials included telephone conversations
to Kelly Cox, Hazard Mitigation Officer – Alaska, and email conversations with
Diana Coho, FEMA, Certified Flood Manager (CFM) requesting preliminary review of
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Chehalis Reservation Natural Hazard Mitigation Plan
the NHMP. Stakeholders had the opportunity to review, comment and guide the
development of the plan.
In addition to the public meetings, a community questionnaire was distributed
with a response of 30 completed surveys.
Chapter 2
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Chehalis Reservation Natural Hazard Mitigation Plan
NATURAL HAZARDS PREPARNESS QUESTIONNAIRE RESULTS
Total number of surveys = 30
Numbers highlighted in blue depict number of people answering.
1.
In the past ten years have you or someone in your household experienced a
natural disaster such as earthquake, severe winter storm or wind storm,
flood, wildfire, or other type of natural disaster?
25
Yes
1.1
2.
83%
0
0%
If “Yes”, what type of natural disaster has you or someone in your
household experienced?
Coastal Erosion
Drought
0
1
0%
3%
Dust Storm
Earthquake
0
16
0%
53%
Flood
26
87%
Landslide
Wildfire
4
0
13%
0%
Household
Fire
Tsunami
Volcanic
Eruption
Windstorm
Winter
Storm
Other
9
0
30%
0%
2
21
7%
70%
18
60%
0
0%
How concerned are you personally about each of the following natural
disasters affecting the Chehalis Reservation? (1-very concerned, 5-not
concerned)
#1
3.
No
#2
#3
%
#4
#5
Drought
0
0%
0
0%
3
10%
9
30%
15
50%
Dust Storm
Earthquake
Flood
Wildfire
House Fire
Volcanic
Wind Storm
Winter Storm
Other
0
2
11
0
2
0
1
0
1
0%
7%
37%
0%
7%
0%
3%
0%
3%
0
5
9
4
6
3
11
13
0%
17%
30%
13%
20%
10%
37%
43%
0
12
5
9
8
1
8
9
0%
40%
17%
30%
27%
3%
27%
30%
0
8
2
8
8
8
5
5
0%
27%
7%
27%
27%
27%
17%
17%
30
0
0
8
4
16
3
1
0%
0%
0%
27%
13%
53%
10%
3%
Have you ever received information about how to make your family and
home safer from natural disasters?
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Chehalis Reservation Natural Hazard Mitigation Plan
Yes
3.1
5
0
8
0
1
7&
40%
17%
0%
6‐12 mo
5‐more
6
0
.5
20%
0%
1‐2
yr
4
13%
27%
0%
3%
Govt/Tribal
Red Cross
Other
2
2
1
7%
7%
3%
Insurance
Non‐profit
1
0
3%
0%
Govt/Tribal
Agency
Utility
Red Cross
Not Sure
9 30%
4 13%
5 17%
1 3%
1 3%
19
7
16
2
63%
23%
53%
7%
What is the most effective way for you to receive information about how to
make your home and family safer from natural disasters?
Newspaper
Radio
6.
12
Who would you most trust to provide you with information about how to
make your family and home safer from natural disasters?
News Media
Insurance
University
Non‐Profit
Other
5.
No
From whom did you last receive information about how to make your
family and home safer from natural disasters?
News media
Utility Co
Not sure
4.
43%
If “Yes”, how recently”
Last 6 mo
2‐5 yr
3.2
13
12
7
40%
23%
Television
Other
9
22
30%
73%
To help in communicating information to others about how to better prepare
for a natural disaster, which phrase best describes how to prepare for a
disaster?
Natural Disaster Readiness
10
33%
Emergency Preparedness
9
30%
Disaster Preparedness
Natural Hazards
Risk Readiness
7 23%
1
3%
In the following list, please check those activities that you HAVE
DONE in your
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Chehalis Reservation Natural Hazard Mitigation Plan
8
household, PLAN TO DO in the near future, HAVE NOT DONE, or are
UNABLE
TO DO.
A) Attended meetings or received written information on natural
disaster or emergency preparedness.
B) Talked with members in your household about what to do in case of
a natural disaster or emergency?
C) Developed a “Household/Family Emergency Plan” in order to decide
what everyone would do in the event of a household
emergency?
D) Prepared a “Disaster Supply Kit” (stored extra food, water,
batteries, or other emergency supplies)?
E) In the last year, has anyone in your household train in the first aid
or Cardio-Pulmonary Resuscitation (CPR)?
8A
B
C
D
E
9.
Have
Done %
7
23%
10
33%
4
13%
5
17%
17
57%
Not Done
17
8
14
10
7
%
57%
27%
47%
33%
23%
Unable
To Do
%
0
0
0
0
0
0%
0%
0%
0%
0%
Building a disaster supply kit, receiving first aid training and developing a
household/family emergency plan are inexpensive activities that require a
personal time commitment. How much time (per year) are you willing to
spend on preparing your household for a natural disaster or emergency
event?
0‐1 hr
8‐15 hr
10.
Plan to
do
%
4 36%
10 33%
11 37%
12 40%
4 13%
4
8
13%
27%
2‐3 hr
16+
4
1
13%
3%
4‐7 hr
Other
3
3
10%
10%
What steps, if any, have your or someone in your household take to prepare
for a natural disaster?
Food
Flashlight
Battery Radio
Smoke Det.
First Aid/CPR
Comm. Plan
Other
Chapter 2
12
19
10
21
16
4
2
40%
63%
33%
70%
53%
13%
7%
Water
Batteries
First Aid Kit
Disaster Kit
Fire Escape
Utility Shut Off
14
15
16
4
3
4
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47%
50%
53%
13%
10%
13%
Chehalis Reservation Natural Hazard Mitigation Plan
11.
Does your household have insurance coverage for earthquake events?
6
10
Yes
Don’t Know
12.
16
37%
53%
No
13
43%
17
2
57%
7%
No
8
27%
How much money are you willing to spend to better protect your family and
home from natural disasters?
$5000
15.
11
Would you be willing to spend more money on a home that had features that
made it more disaster resistant?
Yes
N/A
14.
No
Did you consider the possible occurrence of a natural hazard when you
bought/moved into your current home?
Yes
13.
20%
33%
= 1
3%
$100‐499= 2
7%
Other
3%
= 1
$2500‐
4999 = 2
$100‐1 = 3
7%
10%
$1000‐
2499
= 3
Nothing = 2
10%
$500‐999 = 2
7%
7%
Don’t Know
=12
40%
What nonstructural or structural modifications for earthquake have you made
to your home?
Anchor
Latches
Sec. Propane
Other
Sec. Home
Br. Chimney
None
4
4
2
2
8
2
14
16.
Indicate your age.
17.
Indicate your gender.
Chapter 2
13%
13%
7%
7%
27%
7%
47%
Secure Heater
Flex. Conn.
None
6
1
15
20%
3%
50%
Brace Sheathing
Brace Masonry
Other
2
2
2
7%
7%
7%
Median age of 35
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Chehalis Reservation Natural Hazard Mitigation Plan
Male
18.
4
13%
20
67%
Please indicate your level of education.
0
7
6
0
Grade School
HS Grad/GED
College Deg
Other
19.
Female
0%
23%
20%
0%
Some HS
Some College
Post Degree
0
14
2
0%
47%
7%
4
4
13%
13%
How long have you lived on the Chehalis Reservation?
Less than 1
5‐9 years
20 years
0
4
14
0%
13%
47%
1‐5 years
10‐19 years
20.
If you have lived on the Chehalis Reservation for less than 1 year,
in what state did you live before your move to Chehalis.
21.
Do you have access to the Internet or World Wide Web?
Yes
22.
83%
No
4
13%
63%
No (rent)
9
30%
No
Apartment 3‐4
Manf. Home
0
0
6
0%
0%
20%
Do you own your home?
Yes
23.
25
19
Do you live in a single-family home?
17
57%
Yes
Duplex
4
13%
Apartment 5
0
0%
Other
1
3%
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Chehalis Reservation Natural Hazards Mitigation Plan
Chapter 3: CHEHALIS RESERVATION PROFILE
Tribal Government
The Chehalis tribal governing body is the General Council, which is comprised of all
enrolled members 18 years of age and older. The Business Committee, a fivemember body elected by the General Council for two-year terms, oversees tribal
administration and business. The Business Committee is composed of the Tribal
Chairman, Vice Chairman, Secretary, Treasurer, and Fifth Council Member.
The tribe’s administrative functions are overseen by the general manager who reports
directly to and receives policy direction from the Business Committee. The general
manager oversees tribal operations through a departmental structure. The tribe’s
organizational structure and management system promote a separation of policymaking and management functions, and establish clear lines of authority within the
organization.
The Chehalis Tribe provides a wide variety of public services to the community
including Law Enforcement, Corrections, a Tribal court system, Medical/Dental
Services, Head Start/Early Head Start, Elders meals and center, Vocational
Rehabilitation, Education, Planning, Natural Resources, cultural and heritage
programs and mental and behavioral health services including substance abuse
counseling.
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Chehalis Reservation Natural Hazards Mitigation Plan
A variety of federal and state grant and contract awards are administered throughout
the tribal departments. During the most recently completed audit report, ending
December 31, 2008, the Chehalis Tribe expended $30,237,359 on federal services
and programs. Department of Interior (DOI) and Department of Health and Human
Services (DHHS) encompass about 74% of revenues, with state and other federal
grants and contracts contributing 26% of grant/contract revenues. Current grant
awards being implemented include the following: two projects in IHS Special
Diabetes Program for Indians, COPS Tribal Resources Program, ACF Indian Head
Start/Early Head Start, Dept of Justice Indian Alcohol and Substance Abuse grant,
Department of Education Indian Education and BIA Transportation Planning and
Indian Reservation Roads Construction.
The Chehalis Tribe operates several successful entertainment enterprises including
the Great Wolf Lodge Resort, a 400 room hotel, convention center and indoor water
park; the Lucky Eagle Casino, 106,000 sq ft casino and Eagles Landing Hotel, a 70room hotel. The Tribe also owns and operates three convenience stores, two with a
gas station; a cigarette stamping business and two construction companies. The
Lucky Eagle Casino is very successful and has been in operation since 1996. The
Chehalis Tribe opened the Great Wolf Lodge in 2008. The Chehalis Tribe has a total
of 1,498 employees.
Table 2 Chehalis Tribe Employees
Chehalis Tribe Employees
Chehalis Tribal Administration and Services
143
Lucky Eagle Casino
667
Great Wolf Lodge
593
Eagle’s Landing Hotel
24
Chehalis Tribal Enterprises
71
Total tribal employment 2009
1,498
Source: Chehalis Tribe Human Resources Department, Feb. 2009
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Chehalis Reservation Natural Hazards Mitigation Plan
Statistical Profile:
Confederated Tribes of the Chehalis Reservation
Population, 1990 ----------------------------- 491
Population, 2000 ----------------------------- 691
Average Annual Population Growth ----------- 3.5%
Tribal Enrollment 2000------------------------- 629
Tribal Enrollment 2009------------------------- 828
Service Population, 2000 ------------------ 2,143
Service Population, 2006 ------------------ 3,453
Households, 2000 ---------------------------- 194
Average Household Size, 2000 ---------------- 3.56
19 and under ------------------------------303 _______ 44%
20 - 64 ------------------------------------- 347 ________ 50%
65 and over --------------------------------- 41 ________ 6%
Median Age --------------------------------- 25
Race and Ethnic Categories, 2000:
White --------------------------------------- 239
32.2%
Black/African American --------------------- 3
0.4%
American Indian &
Alaska Native ------------------------------ 388
52.2%
Asian ------------------------------------------0 0.0%
Native Hawaiian &
Other Pacific Islander ----------------------- 0
0.0%
Other Race ---------------------------------- 12
1.6%
Two or More Races ------------------------- 49
6.6%
Hispanic* ----------------------------------- 52
7.0%
Housing Units, 2000
Single-Family ------------------------------ 139
Multifamily ---------------------------------- 25
Manufactured Homes ---------------------- 51
Median Household Income
1989 (Census 1009 in 1999 $’s) -----$18,556
1999 (Census 2000) ------------------ $30,000
Explanation: *Person of Hispanic Origin can be of any race
Source: Thurston Regional Planning Council, Profile 2009
Socio-Economic
Figures from the 2000 U.S. Census confirm the Chehalis Reservation population of
691 persons. This is an increase of 41% over the 1990 U.S. Census. In direct
comparison, Grays Harbor County population increased a mere 4.7%, Thurston
County population increased 28.6%, and Washington State American Indian/Alaska
Native populations increased 29%. According to The U.S. Bureau of Indian Affairs,
U.S. Labor Force Report, 2006 there are 728 enrolled members of the Chehalis
Tribe. The same report accounts for a service population of 3,453; a service
population is defined as “enrolled and non-enrolled Native Americans living on and
near the Reservation and non-Native American with familial or economic ties to the
Reservation and receiving services”. Census 2000 data indicate a majority of the
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Chehalis Reservation Natural Hazards Mitigation Plan
population, approximately 44%, under the age of 19, with a median age of 24.5
years. By contrast, Grays Harbor County has a median age of 36.8 and Thurston
County a median age of 36.5.
Tribal Lands
The Chehalis Reservation is located in southwestern Washington State in a river
valley formed by the confluence of the Black River and the Chehalis River. The
Reservation is approximately 5,000 acres in size and consists of agricultural areas,
residential neighborhoods and forested stands. The mountains of Capitol Forest
and the Doty Hills to the north border the valley.
The current and historical paths taken by the Chehalis and Black rivers dominate
the Chehalis Reservation. The current river channels within the Reservation
contain approximately (10) ten miles of the Chehalis River and the principal fish
harvested are Spring Chinook Salmon, Coho Salmon, Fall Chum Salmon,
Fall/Summer Chinook Salmon and Winter Steelhead.
Historically surrounded by thick forests, the Chehalis Reservation currently has
over 2,700 acres of forested stands. There are many stands of White Oak and
Douglas Fir as well as riparian areas consisting of a mixture of Western Red Cedar,
Big Leaf Maple, Cottonwoods and Alder trees. Many of the stands are second
growth populations due to the heavy logging that occurred here within the past 100
years. The regular flooding of the rivers has created fertile soils in the valley. The
rich soils combined with the long growing season provide a productive agriculture
zone. Agriculture became prevalent in the valley and on the Reservation once
European settlers moved to the area in the late 1800s. At the peak of farming
activities on the Reservation, there were approximately 1,100 acres of land used
for raising crops like hay or alfalfa or pasturelands for livestock.
The large quantity of wetlands, riparian areas and water features along with unique
land features such as acres of natural prairie lands, provide habitat for a great
variety of flora and fauna. Some of the major animal species found in the area
include: elk from the Olympic Elk Herd, white-tailed deer, river otter, opossum,
raccoon, bald eagle, great blue heron, kingfisher and approximately (3) three miles
of the Black River, upstream from the mouth of the river. Many wetlands, sloughs
and oxbow ponds are remnants of old river channels. Tribal members utilize the
river in many ways but primarily for harvesting salmon in customary fishing sites.
Unique flora found on the Reservation includes camas, shooting stars, wild
strawberries and white oak.
Since the adoption of the Chehalis Comprehensive Plan, 2004, the Tribe has
pursued a policy of purchasing farmland located primarily on the floodplain for
conservation purposes including
reforestation, wildlife habitat and wetlands
development.
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Chehalis Reservation Natural Hazards Mitigation Plan
Historic/Traditions/Culture
Historically, the indigenous population of the Chehalis originally occupied a specific
geography within the Chehalis watershed. This watershed encompasses a region
from the foothills of the Cascade mountain range to the Pacific Ocean in the
southwest region of the state of Washington. “Chehalis” is a collective name for
several Shalishan Tribes living on the Chehalis River, its affluent, and in Grays
Harbor. The Chehalis people have lived on a reservation since the 1850s; however,
important archaeological, cultural, and historic sites are scattered throughout the
original indigenous geography.
The Chehalis Tribe did not sign a treaty but in 1864, by executive order, land was
set aside for the Chehalis reservation. In 1939, the Confederated Tribes of the
Chehalis reservation was formed and approved by the federal government and its
Constitution was amended in 1973 (Chehalis). “In the old days we gathered sacred
roots and berries. We fished the Chehalis, Black, Cowlitz, Satsop, Wynoochee, Elk,
Johns, Skookumchuck and Newaumkum rivers. Our people fished and hunted from
the mountains, across the prairie, to Grays Harbor and the lower Puget Sound. In
the old days, the baskets carried and stored our foods. We relied upon the
baskets, the rivers, the land, the roots, the berries, the fish, and the animals. Our
lives were tied together by the Creator” (Bellon, Francis and Hicks).
At one time, there were many villiages in the Upper Chehalis region, principal ones
being located in the Upper Chehalis region, principal ones being located at the
mouths of rivers and creeks. Elders of the Tribe have identified major village sites
as they remembered from years previous, including the mouths of Lincoln Creek,
Scatter Creek, Skookumchuck River, Black River, Cedar Creek and at Grand Mound.
A very large settlement once stood at Grand Mound; its name was ‘aqáygt,
meaning “long prarie”. About a mile above the mouth of the Skookumchuck was a
village called ‘tè·’wt’n, meaning “fording place”. Where the Black River enters the
Chehalis near Oakville there was a village called s ‘àc
l’t, or “made lake”.
Continuing down river, there were villages at the mouth of Cedar Creek and below
Porter. Near Malone was ‘nsxà·wm or “carrot place” indicating a place where wild
carrots were plentiful (Bellon, Francis and Hicks).
Within the village lived one or more extended families or “house groups”, each
occupying it’s own large (from 80-100 feet long) house constructed from cedar
planks. The house group included a headman, his wives and relatives, and may
have included some slaves, either captured or traded from other Tribes. Each
family within the longhouse had its own fire, and cattail mats were often hung as
partitions. Around the inside walls of the house was a double row of cedar
platforms used for sleeping and sitting, covered with several thicknesses of mats.
Above the platforms were shelves for storing household goods and provisions.
Smoke left the building through a hole in the roof covered with a hinged board that
could be opened or closed with a pole. Unlike Puget Sound, where the houses had
shed-type roofs, the Chehalis house had a gabled roof and verticle wall boards.
During the summer months when the house was not lived in, the boards were
lowered and fresh air let in (Bellon, Francis and Hicks). Gaining a livlihood from the
resources of the land and waters demanded adjustment to seasonal patterns.
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Chehalis Reservation Natural Hazards Mitigation Plan
The Upper Chehalis like all tribes in the area, followed the natural cycle of the flora
and fauna of their territory and moved about a great deal during the course of the
year to collect certain kinds of foods. Various species of fish were caught at certain
places. Elk hunting took place when travel in the mountains was easiest. Large
quantities of fish, meat, roots and berries were dried or smoked, then stored inside
the longhouse. Women gathered and prepared all the vegetable foods. Camas
bulbs, roots of bracken fern, wild sunflower, wild carrots, acorns, and hazelnuts
formed a part of the Chehalis diet. Berry picking was an important activity during
summer months. Entire families might camp at the berry-picking grounds, the
women and children picking and preparing the fruit while the men went to fish,
hunt and compete in horse races. This was a time that people looked forward to, a
chance to meet friends and relatives and to enjoy games and feasting when the
work was complete (Bellon, Francis and Hicks).
In order to encourage the growth of berries and camas, the Upper Chehalis would
burn the prarie lands every two or three years. In this way they were assured of a
good suppply in those areas. Such resource areas were not used exclusively by
one village but rather shared by serveral villages and even among people of
different tribes. Fishing occupied the men beginning in late spring and ending in
late fall. Four kinds of salmon, (Chinook, pink, silver and dog) as well as steel
head frequented the waters of the Upper Chehalis territory. Small fish like suckers
and trout could be caught year round. Eels migrate up the Chehalis River in late
spring and at Rainbow Falls, caught on the rocks as they attemped to assend. In
June, eels could be found also in Lincoln Creek just before the fishing began in the
Skookumchuck. The resources of nearby salt-water areas supplemented the diet of
the Upper Chehalis; they went up the Black River to Mud Bay to gather clams and
to catch flounder.
The Upper Chehalis used a combination of spears, hooks, nets, traps and weirs to
obtain their year’s supply of salmon. Members of two or more families shared in
the catch. When one group had caught enough for its needs, another group came
and fished the site. Spears and gaff hooks were essential fishing gear throughout
this area. The spear was generally used in shallow water or at traps and weirs, the
hooks in deeper water. The Upper Chehalis used a variety of nets, including seine
nets, tubular nets and dip nets. A strong reliance on fish in the subsistence
economy of the Upper Chehalis is typical of a river people, but they also relied
heavily on deer, elk and smaller game that frequented their terriroty. When an elk
was killed, the hunting party butchered and dried the meat before packing it all the
way to the villiage. The successful hunter gave a feast at which he shared the elk
meat with his friends and relatives. Elk tallow was used like butter on dried fish and
meat, and also rubbed on the face to prevent chapping.
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Chehalis Reservation Natural Hazards Mitigation Plan
Chapter 4: RISK ASSESSMENT
Risk Assessment Introduction
The Confederated Tribes of the Chehalis Reservation (Chehalis Tribe) developed this
plan to meet the requirements of C.F.R.44, 201.7, Tribal Mitigation Plan. More
importantly, the plan was created to reduce future loss of life, land and property
due to natural hazards that affect the Tribe. It is difficult to predict when natural
hazards will affect the Reservation; however, it is accurate to say they will.
The Chehalis Tribe is a small, tightly knit community. The Tribe, Tribal community,
contractors, Tribal employees, and others worked closely together to assess create
this risk assessment.
The largest and most costly disasters to occur in the area of the Reservation have
been floods. The most recent disaster occurred in December of 2007. The
Reservation faces many natural and manmade hazards. Although some are on a
seemingly small scale, they often prove disabling to the Reservation community.
During one of the community meetings, tribal members were invited to list all the
possible hazards that they thought might impact the community. Work group
members were also invited to list all potential hazards that they believed could
possibly occur.
The hazards listed are the result of these brainstorming sessions. Once listed, the
work group ranked the probably of occurrence, vulnerability of the community and
overall risk rating.
Table 3.1 Hazard/Risk Rating
Hazard
Probability of
Occurrence
Flooding
High
Earthquake
High
Severe Storm
High
Volcano
Low
Wildfire
High
Drought
Medium
Landslide
Low
Tsunami
Low
Vulnerability
Overall Risk Rating
High
High
High
High
Low
High
Medium
Low
High
High
High
Medium
Medium
Medium
Medium
Low
Risk Rating: and adjective description (High, Medium, or Low) of the overall threat
posed by a hazard is assessed for the next 25 years. Risk is the subjective estimate
of the combination of a given hazard’s probability of occurrence and the
reservation’s vulnerability to the hazard.
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Chehalis Reservation Natural Hazards Mitigation Plan
•
High: There is a strong potential for a disaster of major proportions
during the next 25 years; or history suggests the occurrence of
multiple disasters of moderate proportions during the next 25 years.
•
Medium: There is a medium or moderate potential for a disaster of
less than major proportions during the next 25 years.
•
Low: there is little potential for a disaster during the next 25 years.
Probability of Occurrence: An adjective description (High, Medium, Low) of the
probability of a hazard impacting the Chehalis Reservation within the next 25 years.
•
High: there is great likelihood that a hazardous event will occur within
the next 25 years.
•
Medium: There is a medium likelihood that a hazardous event will
occur within the next 25 years.
•
Low: There is little likelihood that a hazardous event will occur within
the next 25 years.
Vulnerability: Vulnerability can be expressed as a combination of the severity of a
natural hazard’s effect and its consequential impacts to the community. An
adjective description (High, Medium, Low) of the potential impact a hazard could
have on the Chehalis Reservation. It considers the population, property, commerce,
infrastructure and services as risk relative to the surround region and counties.
•
High: The total population, property, commerce, infrastructure and services
of the reservation that are uniformly exposed to the effects of a hazard of
potentially great magnitude. In a worst case scenario, there could be a
disaster of major to catastrophic proportions.
•
Medium: The total population, property commerce, infrastructure and
services of the reservation that are exposed to the effects of a hazard of
moderate influence; or the total population, property, commerce,
infrastructure and services of the reservation are exposed to the effects of a
hazard of moderate influence, but not all to the same degree; or an
important segment of the total population, property, commerce,
infrastructure and services of the reservation are exposed to the effects of
the hazard. In a worst case scenario, there could be a disaster of moderate
to major, though not catastrophic, proportions.
•
Low: A limited area or segment of the population, property, commerce,
infrastructure and services of the reservation is exposed to the effect of a
hazard. In a worst case scenario, there could be a disaster of minor to
moderate proportions.
The following hazards were identified for further study:
1.
2.
Flood
Earthquake
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Chehalis Reservation Natural Hazards Mitigation Plan
3.
4.
5.
Severe Winter Storm
Volcano
Wildfire
The hazards selected for study were identified as most likely to occur, based on
reservation history and experience and are of the most concern to community
residents. All hazards with a “high” probability of occurrence – Flooding,
Earthquake, Severe Storm and Wildfire were selected for study. Volcano was also
selected as the reservation is within 75 of Mount St. Helens which has erupted
several times in the past 30 years. While the likelihood of eruption is “medium”, the
vulnerability of the reservation is considered “high” as the pyroclastic eruptions of
this volcano are likely to reach the reservation and particularly detrimental and
harmful to mechanical and electrical equipment. Pyroclastic or ash eruption also
carries heightened health risk for persons with certain medical conditions which are
prevalent on the reservation.
RISK ASSESSMENT
Above map of flood affected areas, December 2007 incident.
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Chehalis Reservation Natural Hazards Mitigation Plan
P’ucú (Kinkade)
Flood
The Great Spirit, angry about the wickedness of people and animals, decided to rid the earth of all but
the good animals, one good man, and his family. At the Great Spirit's direction, the man shot an arrow
into a cloud, then another arrow into that arrow, and so on, making a rope of arrows from the cloud to
the ground. The good animals and people climbed up. Bad animals and snakes started to climb up, but
the man broke off the rope. Then the Great Spirit caused many days of rain, flooding up to the snow
line of Takhoma (Mount Rainer). After all the bad people and animals drowned, the Great Spirit
stopped the rain, the waters slowly dropped, and the good people and animals climbed down. To this
day, there are no snakes on Takhoma. [Clark, pp. 31-32] Once a big flood came, people made ropes
of twisted cedar limbs and used them to fasten their canoes to mountains. The flood covered the
Olympic Mountains. Some of the ropes broke, and the canoes drifted to the country of the Flatheads.
That is why the Skokomish and the Flatheads speak the same language. [Clark, p. 44] (Clark 44)
http://blog.americanrivers.org/wordpress/index.php/2007/12/06/lessons‐from‐flooding‐in‐the‐pacific‐
northwest/
Definitions
Cfs = Cubic Feet per Second
NWS = National Weather Service
Flood stage is the elevation of a river’s surface at a gauging station, determined by NWS,
at which overflow of the natural banks of a river begins to cause damage in the local area
by flooding.
Flow is the amount of water flowing in a river past the gauging station, usually stated in
cubic feet per second - sometimes called stream flow or discharge.
Gage height is the elevation of a river’s surface at a gauging station, in reference to an
established elevation point – sometimes called stage. (USGS)
PROBABILITY
Grays Harbor County is the most vulnerable county to floods in Washington State
(Washington State Hazard Mitigation Plan, 2004, Tab 7.1.4 – p. 17) and floods are
the most common natural disaster to occur in the County. The frequency of a
moderate or higher flood event in the County from 1956 to 2004 was every three
years. Recent studies have identified the frequency and peak flows of floods have
increased since 1990. The probability of future flooding, based on long-term trends,
can be assumed to be at least once every three years. The probability could be
higher if present trends continue given there were seven major floods from 1990 to
2003 included in Federal Disaster Declarations.
The cause of flooding in Grays Harbor County is a combination of climate,
topography, and land development. A predominately marine climate with mild wet
winters dictates weather patterns in the County. Flood season usually begins in
early November when heavy rainfall occurs. Pacific frontal systems become
stationary over the region, bringing long periods of rainfall through February and
often extending into March.
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Chehalis Reservation Natural Hazards Mitigation Plan
Annual precipitation is 65” to 75” on the coast, 80” to 90”near the foothills, 125” to
150” on the windward slopes of the Olympic Mountains, and 100” for the Willapa
Hills.
During long periods of rainfall, river and stream channels fill to overflowing. Intense
precipitation combined with mild temperatures will cause snowmelt on the south
slopes of the Olympic Mountains which can also induce or increase flooding.
Extensive floodplains and wetlands contribute to the regional nature of flood events
in the County. River floods happen most often when winter storms bring heavy
rains from the southwest. The heavy precipitation causes the main river or stream
channel’s flood capacity to be exceeded. The effect of this is overflowing rivers and
streams allowing water to flow from the floodway onto the floodplain.
The Chehalis River, a dominant factor in floods in the County, meanders east to
west along a broad, flat river valley terminating in Grays Harbor. The largest
tributaries of the Chehalis are the Satsop and Wynoochee Rivers originating on
mountain slopes north of the river. The Chehalis River Basin is the second largest
river basin in the state of Washington outside the Columbia River Basin. The total
drainage area of the Chehalis River Basin is 2,660 square miles of which
approximately 85% is forest lands. Approximately 257 square miles (164,000
acres), or 9.7% of the basin is agricultural land.
Approximately 75 percent of the Chehalis Reservation is located in the drainage of
the Chehalis River Basin, creating an active floodplain that is subject to minor levels
of flooding annually, with moderate or higher flooding occurring every three years.
In the last three decades, the Chehalis Reservation has experienced several very
large floods, including the 1986, 1990, 1996 and 2007 floods, each of which ranked
as a flood of record at the time of its occurrence.
Flooding within the Chehalis Reservation restricts access to the Reservation for
periods of one or more days, isolating portions of the Reservation, and may cause
failure of individual water and waste water systems. Flooding of Chehalis
Reservation lands requires immediate evacuation of non-residents, invacuation of
residents (that is, keeping people within a building or other location while a
dangerous situation exists outside the building or location), and severely limits
access to basic goods and services. Severe flooding also can contribute to the
formation of swift-moving water in floodways that is capable of significantly
endangering residents and their property. Flooding of this type can affect more
than two-thirds of the Chehalis Reservation. The consequences of floods within the
Chehalis Reservation have been very costly in terms of human life, property and
economic health. Significant damage has occurred to public and private
investments, interrupted public services and schools and closed businesses.
Flooding from 15-year and greater recurrence interval storms is severe, and
endangers roads and many structures within the floodplain. (Chehalis
Comprehensive Flood Hazard management Plan, 2009)
Typically, high water levels occur between November and February. Moderate
flooding occurs when the flow rate exceeds about 26,000 cfs. Since 1972, this has
occurred more than 20 times. Major flooding occurs when the rate exceeds about
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Chehalis Reservation Natural Hazards Mitigation Plan
50,000 cfs. This has happened six times since 1972. In February 1996, the record
flow rate was 75,000 cfs. The Black River is a slow, meandering stream that flows
through Thurston County for approximately 19 miles. Extending from Black Lake,
marshland lines the river and the water table is perennially at or above the ground
surface. Back-flow from the Chehalis River causes the preponderance of flooding
along the Black River and similar recurrence intervals are expected.
The reservation, because of the relative land area and population affected, is
exposed to high vulnerability. The frequency of flooding, the potential for
simultaneous flooding events, involving both the Black and Chehalis rivers, plus the
historical record of recurrent flooding and cumulative costs, all suggest the
assignment of a high-risk rating. (Thurston County IV-26).
Probability, likelihood and frequency of flood incidents in Chehalis Reservation are
high, with moderate to severe intensity. The histories of floods are as follows:
A review of USGS flood gauge data shows that over a 37 year period, 1970-2008,
there have been twelve major flood events on the Chehalis Reservation. Since
1990, seven major flood events have occurred.
Table 3.2 Historical Flood Events Table
Historical Flood
Events
Flood
Gage @
Centralia
December 2007
74.78
KCSF*
74.31
73.5
72.4
71.99
71.65
71.3
71.17
70.2
Flood
Gage @
Grand
Mound
20.23
KCFS*
19.98
19.34
18.18
18.41
18.21
18.12
17.73
February 1996
January 1990
January 2009
November 1986
January 1972
November 1990
December 1975
January 1971
April 1991
17.66
December 1996
70.18
February 1990
69.91
17.46
*KCFS (Thousands of Cubic Feet Per Second) for a particular stage at that river location
A Recent flood event, December 4, 2007, set a new record in peak stream flow in
the upper watershed of the Chehalis River. The stream flow indicates a pattern
resulting from a very intense rainstorm, according to the U.S. Geological Survey.
Peak stream flow was recorded at 51,100cfs before floodwater swamped the
instruments and destroyed equipment at Doty, WA. The previous record peak flow
recorded at Doty was 28,900 cfs during the February 1996 flood. (USGS)
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Chehalis Reservation Natural Hazards Mitigation Plan
(USGS, Chehalis Basin)
Thurston County in its Natural Hazards Mitigation Plan, September 2009, Table 4.3.4,
notes the following probability of Chehalis River flooding as follows:
Flood Severity
Events 1968 to
2009
Annual
Probability
Rate of
Occurrence
(years)
Minor
62
151/2%
.7
Moderate
23
56.1%
1.8
Major
9
22.0%
4.6
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Chehalis Reservation Natural Hazards Mitigation Plan
Identification and Profile
Floods cause loss of life and damage to structures, crops, land, flood control
structures, roads and utilities. Floods also cause erosion and landslides and can
transport debris and toxic products that cause secondary damage. Flood damage in
Washington State exceeds damage by all other natural hazards. There have been
28 Presidential Major Disaster Declarations for floods in Washington State for
flooding since 1970. While not every flood creates enough damage to merit such a
declaration, most are severe enough to warrant intervention by authorities. Since
1980, to repair public facilities, help individuals recover from flood disasters and
pay measure to prevent future flood damage required a $522 million dollar
investment. That is nearly 40% of the $1.37 billion dollar amount spent on disaster
relief and hazard mitigation during this time. The magnitude of most floods in
Washington depend on particular combinations of intensity and duration of rainfall,
pre-existing soil conditions (i.e. was ground wet or frozen before the storm), area
of basin, elevation of rain or snow level and amount of snow pack. Synthetic
changes to a basin can also affect the size of floods. (Pudlo 7.1.4 p1)
A flood is a general or temporary condition of partial or complete inundation of
normally dry land areas from (1) overflow of inland or tidal waters (2) the unusual
and rapid accumulation of runoff or surface waters from any source, or (3) mud
flows or the collapse of shoreline land. (County 77) Several factors determine the
severity of floods, including rainfall intensity (or other water source) and duration.
A large amount of rainfall over a short time span can result in flash flood conditions.
In locations where soil is saturated from a previous wet period or if rain is
concentrated in an area of impermeable surfaces, such as a large parking lot, paved
roadway or other impervious developed area, a small amount of rain can also result
in floods. Topography and ground cover are also contributing factors for floods.
Water run-off is greater in areas with steep slopes and little or no vegetative
ground cover. The frequency of inundation is affected by climate, soil and channel
slope.
Characteristics of Flooding
1.
Stationary frontal systems
2.
Heavy precipitation
3.
Increasing frequency of events
4.
Saturated soils
5.
Erosion
6.
Flooding in association with another hazard event
Types of flooding common in the Chehalis area are:
1.
River or stream building floods,
2.
Flash floods,
3.
Groundwater flooding
River and stream building floods occur because of prolonged heavy rainfall, a
rapidly melting snow pack or a combination of these. According to the Natural
Hazards Mitigation Plan for Thurston County, “historically, Thurston County must
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experience two or three days of rainfall averaging 2-5 inches per day for this type
of flooding to occur”. (T. County IV-21) The Chehalis River has flooded because of
events in their watersheds outside of the reservation. River floods happen most
often when winter storms bring heavy rains from the southwest. Heavy
precipitation events occur when water exceeds the main river or stream channel’s
flood capacity. The effect of this is over flooding rivers and streams allowing water
to flow from the floodway onto the floodplain. In addition, solid saturated with
moisture will weaken and destabilize banks contributing to more flooding and
erosion. The Chehalis River, a dominant factor in floods, meanders east to west
along a broad, flat river valley terminating in Grays Harbor. The largest tributaries
of the Chehalis are the Satsop and Wynoochee Rivers originating on the mountain
slopes north of the river. River and stream building floods are the most common
because of many river and stream and development patterns along them. (T.
County IV-21)
There are three types of river flooding:
1.
Nuisance/Minor flooding: The River exceeds bank-full conditions at one or
more locations, generally flooding fields and forests. Some roads may be
covered but passable. There may be enhanced erosion of some riverbanks.
2.
Moderate flooding: Individual residential structures are threatened and
evacuation recommended for selected properties. Some roads may be
closed. Moderate damage may be experienced.
3.
Major flooding: For neighborhood and community residents living on specific
areas along the river the risk is higher and evacuation recommended. Major
through fares may be closed and major damage is expected
A flash flood is a quick rise and fall of water level. Flash floods generally result
from intense storms dropping large amounts of rain within a short period onto
watersheds that cannot absorb or slow the flood. The natural terrain and
vegetation of the Chehalis reservation help to reduce the potential for flash floods.
As development continues, increasing the distribution and proportion of impervious
surfaces, the threat from flash floods will increase. (T. County IC-22) Ground water
flooding occurs when there is a high water table and persistent heavy rains. An
upper, thin layer of permeable soils overlaying an impermeable layer of hardpan
causes this situation.
As the ground absorbs more and more rainwater, the groundwater table rises and
shows itself as flooding in areas where the land surface is below the water table.
The conditions have historically been most severe in the second and subsequent
years of consecutive wet years. According to the Army Corps of Engineers, the
frequency of a groundwater flooding disaster is every 25 years. (T. County IV-22)
FEMA has mapped most of the known floodplains in the United States. The
Chehalis River extends for only 8.6 miles in Thurston County has an extensive
floodplain, covering over (8) eight square miles. Land use is primarily agriculture,
houses are scattered sparsely over the area. Some flooding occurs nearly every
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year, but damage is usually light. Historically, minor/nuisance flooding occurs
when the flow rate exceeds about 14,000 cfs. Since 1972, the river has exceeded
the flow rate 48 times.
Groundwater has historically been most severe in the second and subsequent years
of consecutive wet years. According to the U.S. Army Corps of Engineers (“Corps”)
post even report on the storm of 1996-97, the frequency of groundwater flooding
disaster is every 25 years. This was the first widespread flooding disaster event
since 1972 and the worst on record until the winter of 1996, which was considered
the “event of record” until December 2007. The 2007 event set a new record in
peak stream flow in the upper watershed of the Chehalis River. The stream flow
indicates a pattern resulting from a very intense rainstorm, according to the U.S.
Geological Survey. Peak stream flow was recorded at 51,100 cfs before floodwaters
swamped the instruments and destroyed equipment at Doty, WA. The previous
record of peak stream flow recorded at Doty was 28,900 cfs during the February
1996 floor. (USGS)
Statistically, the Corps estimates there is approximately a 70% chance that the
1996-97 flooding will be equaled or exceeded at least once during a 30-year
mortgage cycle. According to FEMA records for the March 1997 high groundwater
flood event, only 15 of 237 damage sites (6%) occurred within the mapped 100year floodplain. When added together, the 100- and 500- year floodplains it
increased to 9%. (T. County IV-24)
Flood – Historic Profile
Data gathered from the United States Geological Survey (USGS); NWS; Thurston
County; Grays Harbor and Washington State Mitigation plans created this section of
the NHMP. The data limitations were few. Technical data in the form of real-time
surface water sites are available for download from the USGS website. The
following chart indicates real-time surface-water sites monitored by the USGS.
Identification No: 12027500 is Chehalis River near Grand Mound, WA and
Identification No: 12025100 is Chehalis River at Centralia. USGS river gauging
stations form the backbone of flood-warning systems in the state. Federal agencies
such as the Corps of Engineers and the NWS and others, use the real-time stream
flow data from USGS river gauging stations to monitor the rivers closely to protect
people and property. (Clemen)
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(FEMA, Debris after Washington Flood)
Table 3.3 USGS Advanced Hydrologic Prediction Service: Seattle, Chehalis
River near Grand Mound, Flood Categories (in feet) (USGS)
Major Flood Stage
Moderate Flood Stage
Flood Stage
Action Stage
17
15.5
14
12.2
Historical Crests
20.23 feet
19.98 feet
19.34 feet
18.41 feet
18.39 feet
12/04/2007
02/09/1996
01/10/1990
11/25/1986
12/29/1937
Flood Impacts (Chehalis River near Grand Mound):
At 19.0 feet, the Chehalis River will cause severe near record flooding, with deep
and swift floodwaters inundating the Independence Valley. Flooding will occur all
along the river including headwaters, tributaries and other streams within and near
the Chehalis River Basin.
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At 17.5 feet, the Chehalis River will cause major flooding, inundating roads and
farmlands in Independence Valley. Deep and swift floodwaters will cover SR-12
and Independence and Moon Roads. Flooding will occur all along the river including
headwaters, tributaries, and other streams within and near the Chehalis River
Basin.
At 15.5 feet, the Chehalis River will flood several roads in Independence Valley with
swiftly moving water including SR-12 and James, Independence, Moon and
Anderson Roads. Floodwaters will cut off access to and from Chehalis reservation
and inundate nearby farmlands and some residential structures may be threatened.
At 14.0 feet, the Chehalis River will flood several roads in Independence Valley
including James Road, Independence Road and Moon Road. Floodwaters will also
cover nearby farmlands
At 12.5 feet, the Chehalis River will locally spill out of its banks into nearby fields
and over a few roads. (USGS)
Table 3.4 USGS Advanced Hydrologic Prediction Service: Seattle, Chehalis River at
Centralia Flood Categories (in feet)
Major Flood Stage
72
Moderate Flood Stage
68.5
Flood Stage
65
Action Stage
61
Historical Crests
72.78 feet
74.31 feet
73.5 feet
71.99 feet
71.65 feet
12/04/2007
02/09/1996
01/10/1990
11/25/1986
01/21/1972
Flood Impacts (Chehalis River at Centralia):
At 73.4 feet, the Chehalis River will cause severe near record flooding with deep
swift floodwaters inundating residential and business areas, roads including I-5 and
farms. Flooding will occur all along the river including headwaters, tributaries and
other streams within and near the Chehalis River Basin.
At 72.0 feet, the Chehalis River will cause major flooding inundating residential and
commercial areas, farms and many roads including I-5. Floodwaters will be deep
and swift in some areas. Flooding will occur all along the river including
headwaters, tributaries and other streams within and near the Chehalis River Basin.
At 68.5 feet, the Chehalis River will flood some residential and commercial areas
with water encroaching upon the first floor of some homes and businesses. Swift
floodwaters will cover some roads.
At 65.0 feet, the Chehalis River will cause shallow flooding of farmlands and some
roads.
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At 53 feet, the Chehalis River will spill over its banks into nearby pasturelands
around Chehalis and Centralia.
(FEMA, Road Damage from Washington Floods)
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Topography
Geological formations determine the topology of the Chehalis reservation. The
geological map show older terraces forming “islands” of higher ground surrounded
by alluvial floodplain. The higher terraces are 10 – 20 feet above surrounding lands
and are the only areas of the reservation that do not flood.
The reservation land has an elevation of up to 115 feet above mean sea level on
the highest eastern terrace. The surrounding floodplains average around 95 feet.
The elevations drop on the western end of the reservation corresponding to the fall
in the Chehalis River. The western terrace averages about 88 feet in elevation
while the floodplains near the river, average about 70 feet. With the exception of a
few relatively steep escarpments between the terraces and the floodplain, the land
slopes at a very gradual rate.
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Soil Types on the Chehalis Reservation
The Chehalis Reservation holds six soil classifications:
CLASS I: Very little Class I land occurs in Western Washington. There is one small
section subject to flooding and not currently used for agriculture.
Symbol
Name
Class
Woodland
Ce
Chehalis Loam
0-2% I
2o
CLASS II: Class II is the largest soil class, subject to annual flooding good for
agriculture.
Symbol
Name
Class
Woodland
Suitability
8a
Abiqua Silty Clay Loam
IIw
F4-Ig, F4G
Arta silt loam
IIw
30Hp
Ca
Camas clay loam
IIs
3c
12A
Chehalis silt loam
IIw
OwHp
Cf
Chehalis silty clay loam
IIs
2o
13A
Cloquqato silt loam
IIw
OwHp
CLASS III: Class III are generally found next to Class II soils and are generally
found near the river or lower and are subject to more frequent and deeper flooding.
In some cases, there is winter ponding and they are found narrow, lower, flood
channels that interface with Class II soils.
Symbol Name
Class
Woodland Suitability
22A
Bear Prairie Silt Loam
IIIs
20Hp
Cb
Camas gravelly loam
IIIs
3c
Nb
Newberg sandy loam, 20%
IIIs
3c
59A
Newberg silt loam
IIIw
2o
87A
Rennie silty loam clay loam
IIIw
OwHp
Wc
Wapato silty clay loam
IIIw
OwLp
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CLASS IV: Class IV is caused by frequent and severe flooding, is generally clayey,
or silty, and is poorly drained. There are few narrow bands found.
Symbol
Name
Class
Woodland
77L
Klone gravelly silt loam IVe
2fHp
18A
Nemah gravelly silt loam IVw
OwLp
Ra
Reed clay
IVw
CLASS V: Class V is the second largest types of soils found. Class V soils are
composed of gravelly terrace soils and excessively drained. They are typical prairie
soils become very dry in the summer season.
Symbol
Name
Class
Woodland
Fa
Fitch gravelly
0-3% VIs
4f
sandy loam
Fb
Fitch gravelly sandy loam
3-15% VIs
4f
30A
Sol Duc gravelly loam
Vis
3fHp
8A
Spanaway very gravelly sandy loam Vis
3fMp
Sh
Spanaway gravelly sandy loam
Vis
3f
Class VII & VIII: These soils are essentially gravelly bars or sandy bars along the
river.
Symbol
Name
Class
Woodland
Rw
Riverwash
VIIIw
Ow
Ma
Alluvial Land
VIIIw
OwHp
Impacts
Approximately 75 percent of the Chehalis Reservation is located on an active
floodplain that is subject to significant flooding up to five times annually. Flooding
within the Chehalis Reservation restricts access to the Reservation for periods of
one or more days, isolating portions of the Reservation, and may cause failure of
individual water and waste water systems. Severe flooding also can contribute to
the formation of swift-moving water in floodways that is capable of significantly
endangering residents and their property. Flooding of this type can affect more
than two-thirds of the Chehalis Reservation.
The high frequency of flooding is caused by
the unique geologic and physical
environment of the Chehalis Reservation.
These minor floods occur on the west,
central, and eastern areas of the Chehalis
Reservation, and cover up to half of the
Reservation for periods of one or more
days.
December 2007 Flood. Source: Chehalis Tribe
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Flooding of local roads limits access to and from higher ground atop the two glacial
terraces. These two areas become isolated “islands” during most flooding events.
Flood-related impacts to the Chehalis Reservation typically increase with an
increase in the significance of the flood event. Moderate events jeopardize roads,
bridges, property fences, outbuildings, wells and septic systems, and other
structures (including private residences) constructed before the adoption of the
Chehalis Flood Damage Prevention Ordinance. During such floods, residents of the
central part of the Chehalis Reservation must be evacuated to higher ground.
During past events, flooding has resulted significant damages to private and
commercial properties and the evacuation of people from homes built on low
ground. During such events, it may be difficult or impossible to leave the
reservation for up to seven days. A tragic example of the isolation created by
flooding occurred during the 1996 flood, when the Tribe experienced a fatality
resulting from the inability to access emergency medical care.
Major floods resulting in severe impacts, including evacuation of people from
residences in low-lying areas, and the inundation of major access roads, such as
U.S. Highway 12, has historically occurred every 9 to 11 years. Consecutive years
of major flooding (double floods) occur about every 20 years.
The 1996 flood covered 75 percent of the reservation with measured flood depths
up to 10 feet. All access routes, including Howanut Road, Anderson Road, and
Moon Road were under one to four feet of fast-moving water. U.S. Highway 12,
which provides access to many secondary roads, also was flooded, and Interstate 5
was flooded and closed for several days. To improve emergency access, in 2002
the Tribe rebuilt Anderson Road. They elevated and straightened portions of the
road and fitted it with nineteen (19) culverts to allow passage of most flood waters
beneath the road. A hydraulic model was prepared prior to engineering and design
of the road, assuring that the road construction resulted in no net loss of floodplain
storage
During the 2007 flood, homes in the central area of the reservation were inundated
with up to four feet of water. The water moved swiftly and covered the reservation
to record water depths within 24 hours of notification of flooding. At the east end
of the Chehalis Reservation, water overtopped Anderson Road. Up to two feet of
water overtopped U.S. Highway 12 and flowed into the Black River east of Anderson
Road. Southeast of the Reservation, Independence Road was overtopped near the
bridge and a section of the Chehalis River channel migrated south and eroded a
portion of the abandoned railroad grade. The central portion of the Chehalis
Reservation, at the confluence of the Chehalis and Black rivers, was flooded from
U.S. Highway 12 south to the abandoned railroad grade. Floodwater ponded
upstream of the western glacial terrace and rose high enough to overtop
Blockhouse Road and flow down Harris Creek. Between the glacial terrace and
Oakville, bridges and culverts were overtopped, road pavement was damaged, and
houses were flooded. At the west end of the Reservation, portions of Balch Road
were damaged and the east approach to the Sickman-Ford Bridge was overtopped
and damaged. Elsewhere within the Chehalis Reservation, gravel driveways and
rural roads were scoured clean of gravel.
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Reservation flooding has frequently damaged homes, including flooring, walls,
electrical, plumbing, wells, septic, heating. Flooding destroys vehicles and
mechanical equipment. Residents lose household items including furnishings,
clothing, appliances, food, personal keepsakes and household pets. They become
homeless for weeks or months until their homes are repaired or they can find other
lodging. The Chehalis Reservation has a housing shortage and replacement housing
can be difficult to locate. Cleanup and recovery is stressful and further traumatizes
flood victims. Children miss schools days; parents may lose income during the
disruption.
Reservation enterprises are closed during moderate to major flooding and lose
revenue as customers and workers are unable to access businesses due to road
closures and damaged roads.
Residents living on high ground on the reservation are unable to leave during major
flooding to go to work. Children cannot leave the reservation to attend school.
Access to specialty medical care is completely blocked. Firefighters cannot access
the reservation for medical assistance calls or to fight fires. Homes that are not
flooded are still likely to lack clean domestic water or sewer services due to
overtopping of well heads and damage to pumps.
Data
Data limitations were not found, historic data, National Weather Service, USGS
information on floods in the area nearby the Chehalis Reservation. Telephone
conversations with Ted Buehner, Warning Coordination Meteorologist, National
Weather Service, and Seattle/Tacoma added open invitations to educate the public
on StormWatchers and methods to incorporate the Tribe into “StormReady”
program.
CHEHALIS AWARENESS
Twenty-two (22) of 22 people interviewed, ranked flooding as the number one
hazard on the Reservation.
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Yakwałt&mx
(K ink ade)
Thunderbird and Whale
Thunderbird is a bird of monstrous size and lives in a dark hole under the foot of
t h e O l y m p i c g l a c i a l f i e l d . T h u n d e r b i r d s o a r e d f r o m h e r d ar k h o l e i n t h e m o u n t a i n s ,
far out over the placid waters and there poised herself high up in the air and waited
for Whale to come to the surface of the water. Whale came and as quick as a flash,
the powerful bird darted and seized it Whale in her flinty talons. Then, above the
watery surface she lifted Whale and with great effort soared away toward the land
areas. Passing beyond the oceans with her ponderous load, she was compelled to
alight and rest her wings. Each and every time Whale was allowed to reach solid
land there was a terrible battle; for Whale was powerful and fought for its life with
terrible energy. Again Thunderbird would seize Whale; again Whale would escape.
Again Thunderbird caught Whale. High into the air Thunderbird carried Whale over
the land, dropping it to the land surface. Then, at this place there was another
great battle. Thunderbird finally carried Whale to its nest in the lofty mountains,
and there was the final and terrible contest fought. There was shaking, jumping up
and trembling of the earth beneath, and a rolling up of the great waters...
(Sciences)
Earthquake
Probability
Based upon data collected from the Pacific Northwest Seismic Network, in the last
129 years the average earthquakes had a magnitude of 5.716, a range of 7.1 – 4.9
magnitude with 27 occurrences making it a 20.9% probability in the next 129
years. The King County Hazard Mitigation Plan simply states Moderate
Probability/High Impact (p 5-21). Grays Harbor County Hazard Mitigation Plan
scored earthquake an 11 out of possible 12. (p75) Thurston County gave
earthquake a “high probability of occurrence with high vulnerability” (p IV-6).
However, according to Mazzotti and Adams, the last great earthquake along the
Cascadian Subduction Zone was ~1700 A.D. and future occurrence “shows an
interesting bimodal pattern of recurrence interval with long (more than 700 years)
and short (less than 450 years) intervals” (p1956). That would estimate their
probability dates of occurrence, for a great (M~9) earthquake along the Cascadian
Subduction Zone, at 2150 A.D. to 2150 A.D. (+/-130 years). Nevertheless, our
communities should prepare for a seismic event no matter WHAT the simple and
complicated statistics predict. Because according to Huff, “common errors, both
intentional and unintentional, associated with the interpretation of statistics, and
these errors can lead to biased or inaccurate conclusions.”
Identification and Profile
According to Rogers, “the principal hazards from earthquakes are surface faulting,
ground failure and ground shaking”. (Rogers) Rogers states, “Surface faulting
accompanies many large earthquakes, particularly in the western United States,
and occurs when rock on either side of a fault is displaced at the earth’s surface.
The slip may be vertical, horizontal, or a combination of both. In major
earthquakes, the movement along a fault can be as much as (35) feet and the
length of the surface rupture as great as 250 miles. Even small amounts of slip can
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disrupt power, water supply, and communication lines. In an area where the fault
line and roads cross, vertical slip greater than a few inches can completely disrupt
transportation infrastructure.
In addition, faults that pass under structures are likely to cause severe structural
damage if slippage occurs. (Rogers 113) Ground failure (which includes landslides,
liquefaction and settlement) is induced by earthquake shaking in some geologic
materials having unfavorable physical properties. (Rogers 113) Liquefaction occurs
when ground shaking produces high water pressure under the earth’s surface and
causes sand layer to act as liquid. (Rogers 115) Settlement is simply compaction of
loose soils. This phenomenon can be damaging to roadways, particularly near
bridge abutments, where the roadbed may settle while the bridge remains fixed.
(Rogers 115) Although all of these earthquake-induced phenomenon’s can play an
important part in causing damage, it is possible to experience an earthquake in
which the damage is caused solely by ground shaking. In fact, in most
earthquakes, ground shaking is the greatest hazard, causing the largest percentage
of damage. Ground shaking is caused by earth waves that travel away from the
earthquake source and may cause damage at distances of as much as 50-75 miles.
(Rogers 116) Site conditions are a major element affecting the likely intensity of
ground shaking. Thick soils overlying solid rock intend to increase the level of
ground shaking and prolong the duration of shaking. The degree to which this
effect takes place is dependent on certain physical properties of the soil, especially
its velocity, density, and thickness relative to the underlying rock. (Rogers 117)
Larger and longer ground motions could cause total collapse”. (Rogers 118)
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Geology Map of the Chehalis Valley
LEGEND
Qal ‐ Alluvium, deposits of silt, sand and clay left by flood waters
QV ‐ Vashon drift – the older, higher terraces of outwash sand and gravel from the Vashon glacier
Geology
Geology of the Chehalis River Valley is a thick deposit of glacial sand and gravel
filling the entire area between the Black Hills to the North and the Doty Hills to the
South. Recent geomorphology created rich bottomland in between higher gravelly
terraces. Ground water percolates easily through the permeable gravelly outwash
deposits and the underlying bedrock serves to conserve this water at depths of less
than 100 feet. The porous gravelly outwash deposits allow easy lateral as well as
vertical movement of the water.
Depths of the largest Washington earthquakes are not precisely known because the
calculations of depth require a number of seismograms for each earthquake. Before
1949, the number of earthquakes and their locations and sizes were determined
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Chehalis Reservation Natural Hazards Mitigation Plan
almost entirely using newspaper accounts of reported damage. As a result,
information about early earthquakes is incomplete, the locations, depths and sizes
of these earthquakes is less precise than those earthquakes recorded after 1969 by
the University of Washington multi-station seismograph network (Linda Noson).
Exceptions include the 1949, magnitude 7.1, Olympia earthquake and the 1965,
magnitude 6.5 earthquake as they were large enough to be recorded at many
seismograph stations around the world. An interesting fact about this pair of
earthquakes is the lack of aftershocks. According to Algermissen and Perkins, a
lack of aftershock is considered a characteristic of a deep earthquake. Most of the
early large earthquakes in the Puget Sound region were deep. (Perkins)
The size of an earthquake is indicated by a number called magnitude. Magnitude is
calculated from a measurement of either amplitude or duration of specific types of
recorded seismic waves recorded on seismograms. The Richter scale assigns
numerical estimates of the size of an earthquake. The unit assigned to the
logarithmic relation to recorded ground motion increase in size by a factor of 10.
The force at which an earthquake shakes the ground is measured with the Richter
scale, which rates the earthquake's actual force on a scale from 0 to 9. A 0 level
Richter rating cannot even be felt by a person, while a rating of 8 shakes hard
enough to crumble buildings. The Richter scale is based on a reading from a
seismograph — a device that detects the waves sent out by an earthquake. Each
number on the Richter scale indicates an increase of ten times the force of the
previous number. For example, the Richter scale rating of 2 is ten times the force of
a level 1. A Richter scale level of 3 is ten times more powerful than a level two and
one hundred times more powerful than a level l, etc.
The intensity of an earthquake is indicated by the amount of ground shaking at a
particular site, and determined from reports of human reaction to shaking, damage
done to structures and other effects. The Modified Mercalli Intensity (MMI) scale is
the most commonly used scale to rank earthquakes in the United States.
Modified Mercalli Intensity (MMI) Scale (Wood)
1.
2.
3.
4.
5.
6.
7.
Not felt by a very few under especially favorable circumstances.
Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended
objects may swing.
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. Vibration is
similar to the passing of a truck. Duration estimated.
Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes,
windows, doors disturbed; walls make cracking sounds. Sensations like a heavy truck striking
a building. Standing motor cars rocked noticeably.
Felt by nearly everyone; many awakened. Some dishes and windows broken; unstable objects
overturned. Pendulum clocks may stop.
Felt by all; many frightened. Some heavy furniture moved; a few instances of fallen plaster.
Damage slight.
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. Noticed by persons driving in motor cars.
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8.
9.
10.
11.
12.
Damage slight in specially designed structures; considerable in ordinary substantial buildings
with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks,
columns, monuments, walls. Heavy furniture overturned.
Damage considerable in specially designed structures; well-designed frame structures thrown
out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off
foundations.
Some well-built wooden structures destroyed; most masonry and frame structures thrown out
of plumb. Rails bent.
Few, if any masonry structures remain standing. Bridges destroyed. Rails bent greatly.
Damage total. Lines of sight and level distorted. Objects thrown into the air.
Therefore, earthquake hazard can be defined as the probability of occurrence of a
specified level of ground shaking in a specified period of time. Earthquake risk is
defined as the expected or probable life loss, injury, or building damage, given the
probabilities that specific levels of ground shaking occur. (Rogers 120)
Earthquake – Historic Profile
Historically, strong earthquakes have occurred in the Puget Sound region between
Olympia and the Canadian border, in the Cascade Mountains and along the
Washington-Oregon border. (Linda Noson)
On December 14, 1872, a MMI VI earthquake in the Cascade Mountains was felt
over 390,000 square kilometers, extending as far south as Eugene, Oregon and
north into British Columbia and possibly into Alaska. (Hake)
On January 11, 1909, a MMI VI earthquake in Blaine, Washington, near the
northern border of Washington, was felt over 65,000 square kilometers. (Hake)
On January 23, 1920, a MMI VII earthquake occurred near the Strait of Georgia, in
the northern region of Washington, and was felt as far away as Anacortes and
Bellingham, north to Vancouver Island, British Columbia. (Hake)
On July 15, 1936, a magnitude 5.75 or MMI VII earthquake was centered in the
southeastern region, near Walla Walla, Washington and Milton, Oregon. The total
damage amounted to about $100,000 and was felt over 272,000 square
kilometers, including most of Washington, Oregon and northern Idaho. (Hake)
On April 29, 1945, a MMI VI – VII earthquake was reported causing minor damage,
about 100 miles from Chehalis, in North Bend, Palmer and Stampede Pass. The
earthquake was felt over the 130,000 square kilometers or over the greater portion
of Washington, a small section of western Idaho and in the vicinity near Portland,
Oregon. (Hake)
On February 14, 1946, a MMI VII earthquake caused a few deaths and damage
estimated at $250,000. The damage included cracked plaster and slight chimney
failure with a few cases of building damage in Seattle, less than 100 miles from
Chehalis. The earthquake was felt over 182,000 square kilometers from
southwestern British Columbia to northwestern Oregon. (Hake)
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On June 23, 1946, a 7.3 magnitude earthquake was reported in the Strait of
Georgia, less than 100 miles from Chehalis, causing one death, heavy damage and
tsunamis. Damage reports included flooding of fields and highways, fallen
chimneys, and damage to industrial and residential buildings. The earthquake was
felt at Bellingham, Olympia, Raymond, Tacoma, areas in Canada and an estimated
260,000 square kilometers. (Hake)
On April 13, 1949, a MMI VIII earthquake caused an estimated $25 million dollars
in property damage near Olympia, less than 100 miles from Chehalis. Eight deaths
were caused, nearly all buildings in Olympia were damaged, water and gas mains
were broken, and property damage included toppled chimneys and cracked walls.
Power and communication networks were interrupted, transportation was
suspended for several days, and railway bridges were ordered out of commission.
The earthquake was felt in western Canada, eastward to western Montana and
southward to Cape Blanco, Oregon. The total area affected was 400,000 square
kilometers. (Hake)
On November 5, 1962, a MMI VII earthquake caused minor damage in Vancouver,
Washington, and was located about 100 miles from Chehalis; the earthquake also
affected Portland, Oregon. Numerous chimneys were damaged, several buildings
reported fallen ceiling tiles, cracked plaster and broken windows. The total area
affected was over 52,000 square kilometers of Washington and Oregon. (Hake)
On April 29, 1965, a MMI VII – VIII earthquake caused about $12.5 million in
damage throughout 340,000 square kilometers in northeastern region of
Washington, parts of Oregon, northern Idaho, northwestern Montana and part of
British Columbia. Three persons were killed by falling debris and four elderly women
perished from heart failure attributed to the earthquake. (Hake)
On December 20, 1973, the largest earthquake in eastern Washington was a
shallow 4.4 magnitude incident. The earthquake was located near Othello, located
about 300 miles from Chehalis. (Linda Noson)
On May 16, 1976, a 5.1 magnitude earthquake was located in the Puget Sound
area, located about 100 miles from Chehalis. (Linda Noson)
On September 8, 1976, a 4.5 magnitude earthquake was centered in the southern
Puget Sound basin, about 100 miles from Chehalis. (Linda Noson)
On March 11, 1978, a 4.6 magnitude earthquake was centered near Bremerton,
Washington, located less than 100 miles from Chehalis. The main shock was
followed by 44 aftershocks. (Linda Noson)
Beginning on March 24, 1980 through May 21, 1980, Mount St. Helens, located
about 100 miles from Chehalis, generated 312 earthquakes with an average
magnitude of 4.5. (Network)
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On February 13, 1981, a magnitude 7.3 earthquake was felt over 102,000 square
kilometers and had more than 1,000 aftershocks distributed over the St. Helen’s
Zone. Weaver and Smith estimate that the St. Helen’s Seismic Zone could be
capable of generating a magnitude 7.0 + earthquake. (Linda Noson)
On February 28, 2001, a magnitude 6.8 earthquake struck western Washington at
10:55 am local time. The epicenter was located approximately 11 miles northwest
of the capitol, Olympia, located less than 30 miles from Chehalis, and 36 miles
southwest of Seattle. Two aftershocks of magnitudes higher than 2.5 were
recorded during the first 48 hours after the main shock. (Filiatrault A.) On March 1,
2001, a Presidential declaration (FEMA-1361-DR, Washington) was issued for 22
declared counties and 24 Tribal Nations. (FEMA) On July 31, 2001, FEMA released a
summary of the Disaster Assistance totals from this incident. Washington residents
and businesses received $129.7 million in recovery aid and 41,032 registrations
from this disaster exceed the combined total of all other previous Washington
disasters. Since the March 1, 2001 Presidential declaration, $50.02 million in aid
has been approved for temporary disaster housing assistance and minimal repair
grants. Inspectors have completed 36,808 damage verifications in the declared
counties. The Small Business Administration has approved $76.82 million in low
interest loans to homeowners, renters and businesses of all types. The Individual
and Family Grant program has approved $2.86 million for residents affected by the
earthquake. The Chehalis Tribe government was reimbursed for $30,000 damage
to tribal governmental facilities.
Table 3.5 FEMA Disaster Assistance Totals July 31, 2001
County
Registrations
Grays
Harbor
Lewis
Thurston
Chehalis
Tribe
Totals
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2,075
Approved
Temporary
Housing
Assistance
$3,556,692
SBA
Approved
Disaster
Loans
$2,166,400
1,215
5,386
0
$1,797,346
$5,632,584
0
$2,073,400
$12,916,900
0
8,676
$10,986,622
$17,156,700
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FUTURE EARTHQUAKE POTENTIAL
Cascadia Subduction Zone
The Cascadia Subduction Zone (CSZ) is a very long sloping fault that stretches from
Vancouver Island to Northern California. It separates the Juan de Fuca and North
American plates. CSZ is where the two plates meet. Great Subduction Zone
earthquakes are the largest earthquakes in the world and can exceed 9.0.
Earthquake size is proportional to fault area – the last known great earthquake in
the northwest was in January 1700, just over 300 years ago. Geological evidence
indicates that great earthquakes may have occurred at least (7) seven times in the
last 3,500 years suggesting a return time of about 400 to 600 years.
Impacts
The impact from earthquakes to communities is well-evidenced by the catastrophic
events around the world; San Franciso in the United States; Kobe, Japan; Chengdu,
China and Kashmire, Pakistan. Failed bridges, building and other structures can
tran or bury people causing injury or death. Damage to community infrastructre is
common and distrupts public and private commerce and services. Disruptions are
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widespread and include communication, electrical, heat fuel, auto fuel and domestic
water. Structural fires are a secondary hazard from earthquakes. Individuals may
be displaced due to damaged homes or lack heat, light, water and/or sewer
facilities. Major earthquakes may prevent travel to obtain services or aid.
Subsequent econmic impacts to businesses are likely following an earthquake.
Structures built since 2002 on the Chehalis Reservation are built to modern code,
but structures built prior are likely to be vulnerable to ground shaking. Fire fighters
and law enforcment can quickly become over-extended with response and recover
operations. All fire assistance comes from outside the reservation and may face
barriers due to disruption of transportation facilities or maybe unable to respond to
the reservation community due to priority calls within their primary response area.
Tribal services can expect a high number of requests for assistance to law
enforcement, health and social services. Building and structural inspections will
become priorities for planning and permitting services personnel and disrupt other
operations. Tribal government may also be expected to house and feed tribal
members is their residences are unihabitable due to damage or until residences are
inspected. Disruption to phone and transportation services may leave some
residences stranded or trapped and unable to call or send for assistance making
search and rescue operations necessary.
Data
There were no issues of data limitations and data was obtained though the use of
internet, library, journal, and scientific sources available to the public. An analysis
of Tribal vulnerabilities focuses upon the public meeting input. The Tribal
community members were more concerned with floods in the area and not actively
concerned with earthquake.
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CHEHALIS AWARENESS
From the Household Natural Hazards Preparedness Questionnaire, 83% of the
reservation has experienced a natural disaster; however, only 53% of the
reservation had experienced an earthquake. When asked the level of concern
regarding earthquakes, with choices from (1) extremely concerned; (2) very
concerned; (3) concerned; (4) somewhat concerned to (5) not concerned, a
majority (40%) of the surveyed population chose (3) concerned. Only 7% of the
surveyed population said that they were, “extremely concerned” about earthquake
danger.
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SEVERE WINTER STORM
PROBABILITY
According to Washington State Mitigation Plan, Counties Most Vulnerable to High
Winds, with a recurrence rate of >100% - at least one occurrence per year,
Thurston County is vulnerable to meteorological conditions, with a 175% recurrence
rate; Grays Harbor County is vulnerable to meteorological conditions with a 170%
recurrence rate. (Pudlo)
According to Washington State Mitigation Plan, Counties Most Vulnerable to Winter
Storms, with a recurrence rate of >100% - at least one occurrence per year,
Thurston County is vulnerable to meteorological conditions, with a 50% recurrence
rate; Grays Harbor County is not vulnerable to meteorological conditions with a
40% recurrence rate. (Pudlo)
Hazardous Weather Seasons
1.
Flood season: Western Washington – November through February
2.
Windstorm season: October through March.
3.
Snow season: Western Washington – mid November through mid March.
High winds – The National Weather Service defines high winds as sustained winds
of 40 mph or gusts of 58 mph or greater, not caused by thunderstorms, expected
to last for an hour or more. Areas most vulnerable to high winds are those affected
by a strong pressure difference from deep storms originating over the Pacific
Ocean; an outbreak of very cold, Arctic air originating over Canada; or air pressure
differences. Areas considered most vulnerable to high winds are 1) those most
affected by conditions that lead to high winds, as described above, and 2) those
with a high wind recurrence rate of 100 percent, meaning the area experiences at
least one damaging high wind event every year. (Pudlo)
Winter storm – The National Weather Service defines a winter storm as having
significant snowfall, ice, and/or freezing rain; the quantity of precipitation varies by
elevation. Heavy snowfall is 4 inches or more in a 12-hour period, or 6 inches or
more in a 24-hour period in non-mountainous areas; and 12 inches or more in a
12-hour period or 18 inches or more in a 24-hour period in mountainous areas.
Areas most vulnerable to winter storms are those affected by convergence of dry,
cold air from the interior of the North American continent, and warm, moist air off
the Pacific Ocean. Typically, significant winter storms occur during the transition
between cold and warm periods. Areas considered most vulnerable to winter storm
are 1) those most affected by conditions that lead to such storms, as described
above, and 2) those with a recurrence rate of 50 percent, meaning the area
experiences at least one damaging winter storm event every two years. (Pudlo)
FEMA reports four severe storm disaster declarations in 2006 and 2007 for Grays
Harbor County that caused damage or threats to the reservation population
(Disaster Numbers 1734, 1682, 1671, 1641).
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IDENTIFICATION AND PROFILE
A severe storm is an atmospheric disturbance that results in one or more of the
following phenomena: strong winds and large hail, thunderstorms, tornados, rain,
snow, or other mixed precipitation. Typically, major impacts from a severe storm
are to transportation infrastructure, services and loss of utilities. Most storms move
into Washington from the Pacific Ocean. Considered for this profile are the following
severe storm elements (using National Weather Service definitions):
1.
High winds – Storms with sustained winds of 40 mph or gusts of 58 mph or
greater, not caused by thunderstorms, expected to last for an hour or more.
2.
Winter storm – A storm with significant snowfall, ice, and/or freezing rain;
the quantity of precipitation varies by elevation. Heavy snowfall is 4 inches or more
in a 12-hour period, or six or more inches in a 24-hour period in non-mountainous
areas; and 12 inches or more in a 12-hour period or 18 inches or more in a 24-hour
period in mountainous areas.
Precipitation is recorded 20 to 25 days or more each month and December and
January are the wettest months. Snowfall is light in the lower elevations. During the
wet season, rainfall is usually of light to moderate intensity and continuous over a
period. The strongest winds are generally from the south or southwest and occur
during the fall and winter. In interior valleys, wind velocities reach 40 to 50 mph
each winter, and 75 to 90 mph a few times every 50 years. The highest summer
and lowest winter temperatures generally occur during periods of offshore easterly
winds. During most of the year, the prevailing wind is from the southwest or west.
The frequency of northeasterly winds is greatest in the fall and winter. Wind
velocities ranging from four to 12 mph can be expected 60 to 70 percent of the
time; 13 to 24 mph, 15 to 24 percent of the time; and 25 mph or higher, 1 to 2
percent of the time. The highest wind velocities are from the southwest or west and
are frequently associated with rapidly moving weather systems. Extreme wind
velocities can be expected to reach 50 mph at least once in two years; 60 to 70
mph once in 50 years; and 80 mph once in 100 years. (Pudlo)
According to the National Weather Service, there are three ingredients for a storm
to develop cold air, moisture and lift. Cold air below freezing temperatures is
necessary to make snow or ice. Air blowing over a body of water is an excellent
source of moisture to form clouds and precipitation. To raise the moist air to form
clouds and cause precipitation requires lift. An example of lift is warm air colliding
with cold air and raising over the cold dome. The boundary between the warm and
cold air masses is a front. Severe storms are dangerous and cause deaths in by
traffic accidents on icy roads, death by hypothermia from prolonged exposure to
cold and heart attacks from shoveling snow. (Pudlo 5-7 p3) According to the
Center for Disease Control, carbon monoxide poisoning was a major health
consequence of the severe storm in January of 1993. Because of the use of
alternative sources of energy for indoor cooking and home heating, the risk of
exposure to CO increased. (Control)
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Severe Storm – Historic Profile
January/February 1916 – Seattle's Greatest Snowstorm was one of the top 10
weather events in Washington during the 20th Century, according to the National
Weather Service, Seattle Forecast Office. Seattle’s snowfall in January was 23
inches, and February snowfall was 35 inches, for a two-month total of 58 inches.
Seattle recorded its maximum snowfall ever in a 24-hour period, with 21.5 inches
on February 1. Other parts of western Washington received between two to four
feet of snow. Winds created snowdrifts as high as five feet. The region was crippled,
with transportation essentially halted.
January 13, 1950 – The January 1950 Blizzard was one of the top 10 weather
events in Washington during the 20th Century, according to The National Weather
Service, Seattle Forecast Office. On this date, 21.4 inches of snow fell in Seattle,
the second greatest 24-hour snowfall recorded with 25-40 mph winds. January had
18 days with high temperatures of 32 degrees or lower. The winter of 1949-50 was
the coldest winter on record in Seattle, with an average temperature of 34.4
degrees.
October 12, 1962 – The Columbus Day Wind Storm was the top weather event in
Washington during the 20th Century, according to the National Weather Service,
Seattle Forecast Office. This storm is the greatest windstorm to hit the Northwest
since weather recordkeeping began in the 19th century, and called the mother of all
wind storms” in the 1900s. All windstorms in the Northwest are compared to this
one. The Columbus Day Storm was the strongest widespread non-tropical
windstorm to strike the continental U.S. during the 20th century, affecting an area
from northern California to British Columbia. The storm claimed seven lives in
Washington State; 46 died throughout the impacted region. One million homes lost
power. More than 50,000 homes were damaged. Total property damage in the
region was estimated at $235 million (1962 dollars). The storm blew down 15
billion board feet of timber worth $750 million (1962 dollars); this is more than
three times the timber blown down by the May 1980 eruption of Mount St. Helens,
and enough wood to replace every home in the state. Highest recorded wind speeds
(before power went out at recording stations):
1.
2.
3.
4.
Naselle, Washington Coast – gust to 160 mph.
Bellingham and Vancouver – gusts of 113 mph.
Renton – gust of 100 mph.
Tacoma – gust of 88 mph.
April 5, 1972 – Washington's Deadliest Tornado Outbreak was one of the top 10
weather events in Washington during the 20th Century, according to the National
Weather Service, Seattle Forecast Office. Three tornadoes touched down in
Washington State on this day:
1.
An F3 tornado touched down in Vancouver; it swept through a grocery store,
bowling alley, and grade school near where Vancouver Mall is today. It caused six
deaths, 300 injuries, and $50 million in damage.
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2.
Later that day, another F3 tornado touched down west of Spokane near
Davenport, and an F2 tornado struck rural Stevens County.
3.
Numerous severe thunderstorms with large hail and damaging winds were
reported over other areas of eastern Washington.
An F3 tornado has winds of 158-206 mph, and is capable of severe damage. An F2
tornado has winds of 113-157 mph and is capable of considerable damage. Because
of these tornados, Washington led the nation in tornado deaths in 1972.
November 1990 – Statewide Flooding
Federal Disaster #883 - Stafford Act disaster assistance provided $57 million. It
was classified as one of the top 10 weather events in Washington during the 20th
Century, according to the National Weather Service, Seattle Forecast Office. This
storm caused widespread, major flooding on western Washington Rivers. This storm
caused two deaths. Damage estimated at $250 million.
December 1990 – Severe Storm
Federal Disaster #896 - Stafford Act disaster assistance provided – $5.1 million.
Causing floods, snow, and high winds.
January 20, 1993 – The Inauguration Day Wind Storm
Federal Disaster #981, Stafford Act disaster assistance provided – $24.2 million.
This storm claimed five lives.
December 1996 - January 1997 – Ice, Wind, Flooding, Snow-loading, Landslides
Federal Disaster #1159 - Stafford Act disaster assistance provided – $83 million.
Small Business Administration loans approved – $31.7 million. Saturated ground
combined with snow, freezing rain, rain, rapid warming and high winds within a
five-day period produced flooding and landslides. Twenty-four deaths; $140 million
(est.) in insured losses; 250,000 people lost power.
Impacts
The Chehalis Reservation, like most of western Washington is vulnerable to high
winds because of the climatic conditions and prevalence of 100 ft to 150 ft tall
conifer trees. High winds weaken standing trees and structures weighted with snow
or ice. Two predominating species, Douglas fir, which are planted extensively on
the reservation as a timber crop and western hemlock have shallow later root
systems with top heavy crown. Trees are vulnerable to falling when soils are soaked
from ongoing rainfall. Sustained high winds and gusts cause tress to sway
significantly; repetitive swaying can weaken a tree’s root hold in the saturated soils
and force it to topple. Power lines, vehicles, homes and structures may be
damaged. Transportation routes may be blocked. Falling tree limbs and debris can
injure or cause death to individuals. Downed power lines may cause electrocutions.
Severe winter storms cause wide spread power outages annually in our rural
setting, which may take 2 to 5 days or longer to restore. Downed trees and debris
hinder or prevent emergency response capabilities, forcing the closure of tribal
government services and businesses. Homes without power may suffer from cold
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and hypothermia when winds are combined with snow and low temperatures.
Improperly stored foods can become rancid and unsafe to eat. Some people may
resort to trying to heat their home with outdoor grills, exposing themselves and
their families to carbon monoxide poisoning. Risks of home fires increase as people
try to use candles for light, or start wood fires in unsafe stoves or homes with faulty
chimneys or flues. Medically vulnerable individuals may be at risk of severe health
consequences for oxygen respirators or other equipment.
The rural setting of the Chehalis Reservation can increase these impacts as the
reservation is located at the furthest end of two county public utilities and often
must wait longer for power restoration in the event of a storm. About 50% of the
reservation population is dependent on well water, which must be pumped and
septic systems with also utilize pumps. During power outages, many or most of our
rural residents may be completely lacking drinking water or sewer services. When
combined with flooding, this likelihood increases.
Data
The comprehensive data from the State of Washington Hazard Mitigation Plan is
cited throughout this section. The references included: National Weather service,
Seattle Times, FEMA and National Oceanic and Atmospheric Administration.
CHEHALIS AWARENESS
According to the Hazards Survey, over 40% of participants were “very concerned”
about Severe Storms.
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VOLCANO
IDENTIFICATION AND PROFILE
A volcano is a mountain connected to a reservoir of molten rock below the surface
of the earth. Volcanoes are built up by an accumulation of their own eruptive
products, lava and ash. Though there are no volcanoes within Thurston County,
active volcanoes in the Cascade Range, including Mt. Rainier to the east and Mt. St.
Helens to the south, could affect Thurston County with mud and debris flow (lahar),
flooding due to an upstream lahar, and ashfall.
Mt. Saint Helens in Washington state, USA
Volcano – Historic Profile
Cascade Range volcanoes in the U.S. have erupted more than 200 times during the
past 12,000 years for an average of nearly two eruptions per century. At least five
eruptions have occurred during the past 150 years. The last major eruption of Mt.
Rainier was more than 1,000 years ago.
The most recent eruptions in the Cascade Range are the well-documented 19801986 eruptions of Mount St. Helens which claimed 57 lives and caused nearly a
billion dollars in damage and response costs. The effects were felt throughout the
northwest. Thurston County was affected by extensive ash fall which damaged
internal combustion engines, caused transportation problems due to reduced
visibility, and was a general nuisance. There was also an economic impact resulting
from the closure of I-5. Over the past 200 years, Mount St. Helens has erupted
three times, suggesting a recurrence interval of about 70 years.
Mount St. Helens is located 49 miles south of the Chehalis Indian Reservation.
Additional devastating impacts could result if winds move debris and ash toward
Thurston County. This would disrupt transportation and other essential services,
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and cause buildings to collapse while particulates, toxic gases and acid rains could
affect public health, water supplies, animal, aquatic and other plant life.
Another eruption of Mount St. Helens would likely have an impact similar to that
experienced in 1980.
When Mount St. Helens erupted on May 18, 1980, red hot lava did not spew out of
the volcano and pour down its flanks. This perception of a volcanic eruption is a
common one and is probably due in part to pictures seen on television or in books
of the beautiful lava flows and lava fountains in Hawai'i. The type of eruptions in
Hawai'i are known as hawaiian volcanism and are far less dangerous than the
eruptions produced by Mount St. Helens. It is important to know what type of an
eruption a volcano is most likely to produce so that the types of hazards produced
by such an eruption can be identified. Knowledge of these types of hazards, will
help determine where a person would need to go to be safe during a volcanic
eruption.
Volcanic eruptions can be placed into two general categories: those that are
explosive, such as at Mount St. Helens, and those that are effusive, such as in
Hawai'i. The most active volcano in the world, Kilauea Volcano on the big island of
Hawai'i, is generally a nonexplosive volcano (though there have been occasions
when it erupted explosively). Eruptions from it normally result in gently flowing lava
flows, spatter cones, and lava fountains. Another type of nonexplosive volcanism is
flood basalts. Lava flows from this type of eruption are extruded from fissures and
cover vast areas. These nonexplosive eruptions are the least dangerous type of
volcanic eruption since people rarely get killed by them (Francis, 1993). However,
they are devastating and may have global consequences.
Many eruptions are explosive in nature. They produce fragmental rocks from
erupting lava and surrounding country rock. Some eruptions are highly explosive
and produce fine volcanic ash that rises many kilometers into the atmosphere in
enormous eruption columns. Explosive activity also causes widespread ash fall,
pyroclastic flows, debris avalanches, landslides, pyroclastic surges, and lahars.
PROBABILITY
In 1980 the Mount St. Helens eruption killed 57 people, caused nearly $1 billion in
property damage, buried 230 square miles with landslide debris, deposited ash as
deep as a half-inch 300 miles away, and plugged the Toutle and Cowlitz rivers with
mud. Southwest of King County, this mountain presents a potential volcanic threat
to Puget Sound residents because of the probability that hazardous ashfall will be
released during an eruption. In fact, about an hour after the eruption of Mount St.
Helens in 1980, ash began to fall in Yakima in Eastern Washington (about 150 miles
east of Seattle). The ashfall was so heavy it became so dark that lights were turned
on all day. It took 10 weeks to haul away the ash from Yakima's streets, sidewalks,
and roofs. While this hazard was last most spectacularly witnessed over 25 years
ago, recent stirrings at St. Helens have brought that threat back into regional focus.
(King County Office of Emergency Management).
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The United States Geological Survey (USGS) reports that Mount Rainier has
produced moderate quantities of ash in past eruptions. The eruption of Mount St.
Helens in 1980 did deposit a scan layer of ash in Thurston County, but the fallout
did pose a significant threat to the region. Thurston County winds prevail from the
south and west, therefore ash is more likely to fall on the east side of the Cascades
than the west side. If Mount St. Helens was to erupt, a resultant ash plume would
require an easterly wind to deposit ash on the Chehalis Reservation. The USGS
calculates that the annual provability for a significant ash deposit of one centimeter
or greater in Thurston County is .02 percent for the south eastern third of the
county, where the Chehalis Reservation is located. This hazard has a low
probability.
Volcanic Hazards (based on activity in the last 15,000 years).
Areas in blue or purple show regions at greater or lesser risk of local volcanic
activity, including lava flows, ashfalls, lahars (volcanic mudflows) and debris
avalanches, based on the record of the last 15,000 years, as compiled by
Mullineaux (1976). Areas in pink show regions at risk of receiving 5 cm or more of
ashfall from large or very large explosive eruptions, originating at the volcanic
centers shown in blue. These projected ashfall extents are based on
observed ashfall distributions from an eruption ("large") of Mt. St. Helens that took
place 3,400 years ago, and the eruption of Mt. Mazama ("very large") that formed
Crater Lake, OR, 6,800 years ago. There is a moderate to high vulnerability of risk
from these two volcanoes.
The State of Montana Multi-Hazard Mitigation Plan and Statewide Hazard Assessment October 2004
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Impacts
Volcanic ash, like the 1980 ash produced by the pyroclastic emissions of St. Helens,
Washington, is made up of tiny jagged particles of rock and glass (photo on right;
magnified 200 times).
Hazards of volcanic ash:
• Short-circuits and failure of electronic components, especially high-voltage
circuits and transformers (wet ash conducts electricity).
• Eruption clouds and ashfall commonly interrupt or prevent telephone and
radio communications.
• Volcanic ash can cause internal-combustion engines to stall by clogging air
filters and also damage the moving parts. Engines of jet aircraft have
suddenly failed after flying through clouds of even thinly dispersed ash.
• Roads, highways, and airport runways can be made treacherous or
impassable because ash is slippery and may reduce visibility to near zero.
Cars driving faster than 5 miles per hour on ash-covered roads stir up thick
clouds of ash, reducing visibility and causing accidents.
• Ash also clogs filters used in air-ventilation systems to the point that airflow
often stops completely, causing equipment to overheat.
Like airborne particles from dust storms, forest fires, and air pollution, volcanic ash
poses a health risk, especially to children, the elderly, and people with cardiac or
respiratory conditions, such as asthma, chronic bronchitis, and emphysema.
Source: U.S. Geological Survey Fact Sheet 027-00 Online Version 1.0 (USGS 2003c)
Clean up and recovery would likely be the greatest cost to both the public and
private sector. The 1980 eruption of Mount St. Helens posed a major nuisance for
community in Eastern Western. In Yakima, ash removal took ten weeks and cost
$2.2 million. Source: Tilling, Rover, I. et. Al. 1990. Eruptions of Mount St. Helens: Past, Present
and Future, U.S. Geological Survey Special Interest Publication.
Data
There were no issues of data limitations and data was obtained through internet,
library, journal, and scientific sources available to the public. An analysis of Tribal
vulnerabilities focuses upon the public meeting input and the Natural Hazards
Preparedness Questionnaire. The Tribal community members are not actively
concerned with Volcano hazards.
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Chehalis Reservation Natural Hazards Mitigation Plan
CHEHALIS AWARENESS
From the Household Natural Hazards Preparedness Questionnaire, 83% of the
reservation has experienced a natural disaster; however, only 7% of the
reservation had experienced volcanic hazards. When asked the level of concern
regarding volcanic hazards, 10% of participants were “very concerned”, 3% of
participants were “concerned”, 27% of participants were “somewhat concerned”,
and 53% of participants were “not concerned” about volcanic hazards.
Chapter 4
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Chehalis Reservation Natural Hazards Mitigation Plan
WILDFIRE
IDENTIFICATION AND PROFILE
Any instance of uncontrolled burning in grasslands, brush, or woodlands is classified
as a wildfire, whereas uncontrolled burning within a forested area is a forest fire.
Wildfire/Forest Fire - Historical Profile
Forest and wildfires are most likely to occur during the local dry season, mid-May
through October, and anytime during prolonged dry periods causing drought or
near-drought conditions. The probability of a destructive fire depends on weather,
fuel conditions, topography and human activities such as debris burning, land
clearing, camping, and construction. Greater than four out of five forest and
wildfires are started by people, often due to negligent behavior such as failure to
properly extinguish smoking materials or campfires.
There have been no major forest fires or wildfires in Thurston County. However, the
existence of large tracts of public and private forest, increasing population,
increasing recreational use of forested land, and possible changing climate patterns,
all increase the likelihood of a major fire.
Although nearly half of the County is forest land, three general areas are vulnerable
to a major forest fire. These are Capital Forest in the west, Fort Lewis Military
Reservation in the east, and large commercial tracts in the southeast. In each of
these areas, development is prohibited or restricted.
All areas of the county are vulnerable to a wildfire, especially those areas
surrounded by brush and grass which tend to dry out in the hotter months. The
threat of fire increases in years following those years in which a large amount of
debris is added to the forest floor as seen during the summer of 1997 following the
massive amounts of fuel added during the wind and ice storm of December 1996.
The flood of record in 2007 produced a similar abundance of fuel.
The impact of a major fire would be amplified by collateral effects such as loss of
ground cover which could exacerbate runoff, flooding and landslides, loss of
commercial and aesthetic value of the forest, destruction of wildlife habitat, and
damage to power lines, pipelines and the communications and transportation
infrastructure.
PROBABILITY
Wildland fire hazard is somewhat unique in that it is the most frequent occurring
hazard, with over 70 fires starting per year. Wildland fires are also preventable;
over 95% occur as the result of accidents or poor human judgments. It is the only
hazard that can be actively contained or suppressed in real time.
Numerous wildland fires will occur over the next 25 years. While few occur on the
reservation, past fires have threatened homes including the destruction of one
home on the Chehalis Reservation in the past three years.
Chapter 4
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Chehalis Reservation Natural Hazards Mitigation Plan
Thurston County Natural Hazards Mitigation Plan (September 2009) notes an
expected total of 1775 fires may be predicted to occur over the next 25 years in
Thurston County.
The existence of undeveloped grasslands and heavily forested areas, consistent
with the rural nature of the Chehalis Reservation, coupled with an increasing
population and the uncertain impact of a changing climate combine to suggest a
moderate probability of occurrence. Reservation housing is interspersed throughout
grasslands and forested areas. Furthermore, Chehalis lacks on reservation fire
fighting capacity and must request aid from either Grand Mound (Thurston County)
or Oakville’s volunteer fire department (Grays Harbor), creating a delayed
containment or suppression response. The destruction of large tracts of forest land
would have immediate economic impact to the community through lost jobs and
increased public support while collateral economic and social effects could impact
the County for years. Accordingly, a “high” probability rating is assigned.
Impacts
Wildland fire impact depends upon the size and location of the fire. Heat from winddriven flames can destroy virtually any material in its path. People caught off guard
by a rapidly spreading fire could suffer burn injuries or death. People fishing or
hunting or recreating in remote or inaccessible areas of the reservation are
particularly at risk.
Fire fighting consumes significant local and state resources and poses severe
hazards to firefighting crews.
Potential damages include loss of timber and wildlife habitat; economic losses from
lost timber and commercial enterprises on the reservation; loss of residences,
vehicles and their contents; utilities lines and vehicles are also possible. Loss of
vegetation on the slopes of the Chehalis River could seriously threaten fish habit.
Wildland fire also disrupts transportation facilities, requiring detour routes.
Residents may be unable to access to residences; customers may be unable to
access businesses to due heat, smoke or proximity to the wildland fire.
Data
There were no issues of data limitations and data was obtained through the use of
internet, library, journal, and scientific sources available to the public. An analysis
of Tribal vulnerabilities focuses upon the Natural Hazards Preparedness
Questionnaire. The Tribal community members are not actively concerned with
wildfires.
CHEHALIS AWARENESS
From the Household Natural Hazards Preparedness Questionnaire, 83% of the
reservation has experienced a natural disaster; however, the reservation has never
experienced a wildfire. When asked the level of concern regarding wildfires, 13% of
participants were “very concerned”, 30% of participants were “concerned”, 27% of
Chapter 4
Page 66
Chehalis Reservation Natural Hazards Mitigation Plan
participants were “somewhat concerned”, and 27% of participants were “not
concerned” about wildfire/forest fire hazards.
CLIMATE CHANGE
According to James Lovelock, “Gaia Theory is a view of the Earth that sees it as a
self-regulating system made up from the totality of organisms, the surface rocks,
the ocean and the atmosphere tightly coupled as an evolving system. The theory
sees this system as having a goal – the regulation of the surface conditions so as
always to be as favorable as possible for contemporary life”. (Lovelock 162)
Greenhouse effect defined by Lovelock is as follows. “Most of the sun’s radiant
energy is in the visible and near infra-red. The air, when free of clouds and dust, is
as transparent to this radiation as is the glass of a greenhouse. Surfaces on the
Earth, or within the greenhouse, are warmed by sunlight and some of this warmth
is transferred to the air in contact with the surfaces. The warm air stays in the
greenhouse mainly because the walls and green roof prevent the restless wind from
dissipating it.
The Earth is kept warm in a similar but not identical way, by the absorption of
radiant heat emitted from the warm surface by gases, carbon dioxide, water vapor,
and methane. These gases, although transparent to light, are partially opaque to
the longer wavelengths emitted by a warm surface. In the absence of pollution, the
greenhouse effect is benign and has long kept the surface air warm. Without it, the
Earth would be 32°C colder and probably incompatible with life. (Lovelock 162-3).
Currently, the climate centers around the world have reported the Earth’s physical
condition and see it as seriously ill and soon to pass into a morbid fever that may
last as long as 100,000 years. I have to tell you, as intimate members of the Earth
family, that civilization is in grave danger (Lovelock xiii). Without realizing it, we
have poisoned the earth by our emission of greenhouse gases and weakened it by
taking farmland and housing the land that was once the home of ecosystems that
sustained the environment. We have driven the Earth to a crisis state from which it
may never, on a human time scale, return to the lush and comfortable world we
love and in which we grew up (Lovelock xiii). Global vulnerabilities include loss of
habitat, food source, and large-scale wars over basic resources (food, water, and
land base). Local vulnerabilities include possibilities of additional floods due to
“increase of ocean volume mainly from the melting of land base ice” as Jim Hansen
states in Climate Change. He also notes that rapidly rising sea levels will be the
greatest threat because “these changes alter the distribution of forests and deserts
and the availability of land on which to grow food. When the carbon dioxide
abundance passes 500 ppm, we will enter the zone where temperatures will rise to
a new steady state, perhaps six to eight degrees hotter than now (Lovelock 64-5).
According to Wigley and Meehl, et al, in an article in the March 2005 issue of
Science, “sea levels will rise between 10 and 30 centimeters by 2100” (Lovelock
61). Although these sources show an estimated average change in global change, it
Chapter 4
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Chehalis Reservation Natural Hazards Mitigation Plan
does not show “unpredicted extremes, including flood events and storms of great
severity” (Lovelock 60).
There is no limit on data regarding global climate change – the Lovelock book
references well rounded scientific sources including respected scientific journals,
such as Nature and Science; organizations such as the Intergovernmental Panel on
Climate Change (IPCC) and the International Geosphere Biosphere Program (IGBP)
and many respected scientists. Probability of this event is in process as we watch
Arctic ice caps melt, Greenland is disappearing, record heat in Europe killing over
30,000 people and others. In addition, record event report from the National
Weather Service, Seattle, WA 128 am PDT Tuesday October 28 2008, record high
temperature set at Quillayute, WA Airport, a record high temperature of 69 degrees
was set at Quillayute, WA airport yesterday. This breaks the old record of 68 set in
1968. (Service) According to the NOAA Paleoclimatology website, the following
chart provides an overview of developments to support the critical stage our planet
is in. (NOAA)
Past 10
Years
1991 AD
1992 AD
1993 AD 1994 AD
1995 AD
1996 AD
1997 AD
1998 AD
1999 AD
2000 AD
The 1990s Bangladesh August"Storm Severe
Atlantic
Hurricanes Impact of Hurricane La Niña
Wildfires in the
Cyclone
Hurricane of the
ice storm Hurricane Bertha
1997Mitch
linked to
Western U.S.
kills over
Andrew
Century" in
Season
and Fran 1998
devastates drought
burn over 6
138,000.
hits
hits U.S. southeast second
hit North
ENSO
Central
conditions
million acres.
"Perfect
Florida,
east
US cause busiest
Carolina
warm
America,
in much of Over 6 billion
Storm"
killing 54, coast
an
hurricane resulting in event
killing
U.S. and
Homo sapiens
develops
costing
with 270 estimated season
major
estimated estimated high
on planet.
off Nova
$25
missing. $3 billion since
flooding.
at $25 to 11,000.
precipitation
Scotia.
billion.
Midwest in
1871.
$-33
in Pacific
flooding damages. 830 die in
billion
Northwest.
causes
Midwest
$18
heat
billion
wave.
damage.
How do we mitigate against global climate change? Accept that change is coming
and prepare ourselves for the inevitable.
Chapter 4
Page 68
Chehalis Reservation Natural Hazards Mitigation Plan
RISK ASSESSMENT – ASSESSING VULNERABLITIES
IDENTIFYING STRUCTURES
The Vosper Residential Area is a medium density Planned Development Unit (PUD)
located off Balch Road that will be built out over the next 20 years. There are
currently (16) sixteen residential lots planned as (12) single family residences,
including (5) five Housing and Urban Development’s (HUD) and (4) four were
reserved for the three multi-family units. Vosper is a 15.26 acre Tribal trust parcel.
(Council)
The Oakes Residential Area is a medium density PUD located adjacent to the city of
Oakville. The Oakes has (15) single-family lots, five of which are currently
developed. (Council)
The Chehalis Tribal Housing Authority (CTHA) oversees the three HUD housing
developments on the reservation, Tahown, Makum and Davis. Tahown and Makum
are home-ownership developments and Davis is a rental development. Tahown,
Makum and Davis are built out to their full capacities.
In addition, there are scattered rural home sites throughout the reservation. All
housing in the floodplain is scattered site housing owned by both Indian and nonIndian reservation residents.
The Tribal Complex is a collection of government facilities developed around the
Chehalis Baseball Field. Core Tribal government administrative functions including:
accounting, planning and Tribal government are located in the main Tribal Center
facility. The remaining sets of buildings are the hub for community activities and
services, including: social and mental health services, Chehalis Tribal Clinic, Elders
Center, Indian Head Start and Early Head Start, Youth Center, Public Safety, Health
Clinic, Community Center, Natural Resources, and End of the Trail I convenience
store. (Council)
Lucky Eagle Casino and Eagle’s Landing Hotel is a 69 room hotel across from the
Lucky Eagle Casino and there is a 20-space RV park in the hotel parking lot.
(Council)
Great Wolf Lodge, a 400,000 sf Resort and Conference center includes a 24,000 sf
conference center, indoor water park, and a 399 room resort employing 500
people. (Council)
The Tribe operates a convenience store and two convenience store/gas stations.
End of Trail I is located adjacent to the Tribal Center. End of Trail II is located at
the intersection of SR 12 and Anderson Rd. End of Trail III is located immediately
north of the Great Wolf Lodge structure.
Chehalis Tribal Construction, a dirt work company employing 8-10 people, is
located immediately south of End of Trail II on Anderson Road.
Chapter 4
Page 69
Chehalis Reservation Natural Hazards Mitigation Plan
TRANSPORTATION FACILITIES
Ownership of Roads
The Chehalis Reservation Transportation Plan includes approximately 60 miles of
roads under the jurisdiction of the Confederated Tribes of the Chehalis Reservation,
the Bureau of Indian Affairs (BIA), the State of Washington, Grays Harbor and
Thurston Counties, and private owners.
Chehalis Reservation IRR inventory of roads by ownership (see Table 15 for
details):
•
•
•
•
•
•
BIA Roads:
City of Oakville:
Grays Harbor County Roads:
Thurston County Roads:
Private Roads:
WSDOT:
approximately 2 miles
approximately 2 miles
approximately 13 miles
approximately 18 miles
approximately 2 miles
approximately 25 miles
Functional Classification of Roads
The Chehalis Tribe is utilizing the BIA Functional Classification for roads which
consists of an analysis of transportation facilities taking into account current and
future traffic generators, and their relationship to connecting or adjacent BIA, state,
county, federal, and/or local roads, and other intermodal facilities. The Functional
Classification is used to delineate the difference between the various road and/or
intermodal transportation facility standards eligible for funding under the Indian
Reservation Roads (IRR) program.
Transportation
classifications:
facilities
are
classified
according
to
the
following
functional
Class 1 Roads: Major arterial roads providing an integrated network with
characteristics for serving traffic between large population centers, generally
without stub connections and having average daily traffic volumes of 10,000
vehicles per day or more with more than two lanes of traffic.
Class 2 Roads: Rural minor arterial roads providing an integrated network
having the characteristics for serving traffic between large population
centers, generally without stub connections. Class 2 roads may also link
smaller towns and communities to major resort areas that attract travel over
long distances and generally provide for relatively high overall travel speeds
with minimum interference to through traffic movement. Generally provide
for at least inter-county or inter-state service and are spaced at intervals
consistent with population density. This class of road will have less than
10,000 vehicles per day.
Class 3 Roads: Streets located within communities serving residential areas.
Chapter 4
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Chehalis Reservation Natural Hazards Mitigation Plan
Class 4 Roads: Rural major collector road is collector to rural local roads.
Class 5 Roads: Rural local road that is either a section line and/or stub type
roads, make connections within the grid of the road inventory system. This
class of road may serve areas around villages, into farming areas, to schools,
tourist attractions, or various small enterprises. Also included are roads and
motorized trails for administration of forests, grazing, mining, oil, recreation,
or other use purposes.
Class 6 Roads: City minor arterial streets that are located within
communities, and serve as access to major arterials.
Class 7 Roads: City collector streets that are located within communities and
serve as collectors to the city local streets.
Class 8 Roads: This class encompasses all non-road projects such as paths,
trails, walkways, or other designated types of routes for public use by foot
traffic, bicycles, trail bikes, snowmobiles, all terrain vehicles, or other uses to
provide for the general access of non-vehicular traffic.
Class 9 Roads: This classification encompasses other transportation facilities
such as public parking facilities adjacent to inventory routes and scenic
byways, rest areas, and other scenic pullouts, ferry boat terminals, and
transit terminals.
Chehalis Reservation IRR inventory by Functional Class (see Table 15 for
details):
•
•
•
•
Class 1 Roads
Class 2 Roads
Class 3 Roads
Class 4 Roads
approximately 25 miles
approximately 2 miles
approximately 11 miles
approximately 23 miles
Construction Need for Roads
The Chehalis Tribe is utilizing the BIA Construction Need coding system which is
used in cost to construct calculations. In the BIA Construction Need coding system,
transportation facilities are assigned a Construction Need using the following
guidelines: Ownership or responsibility of the facility, whether it is within or
provides access to the reservation or communities in which the majority of the
residents are Indian, and whether it is vital to the economic development of the
Tribe.
A summary of the Construction Need codes are as follows:
Construction Need 0: Transportation facilities which have been improved to
their acceptable standard, or projects/facilities proposed to receive
construction funds on an IRRTIP.
Chapter 4
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Chehalis Reservation Natural Hazards Mitigation Plan
Construction Need 1: Existing BIA Roads needing improvement.
Construction Need 2: Construction need other than BIA roads needing
improvement.
Construction Need 3: Substandard or other roads for which no improvements
are planned (maintenance only).
Construction Need 4: Roads that do not currently exist and need to be
constructed, proposed roads.
Chehalis Reservation IRR inventory by Construction Need (see Table 3.6 for
details):
•
•
•
•
Construction Need 0:
Construction Need 1:
Construction Need 2:
Construction Need 4:
Chapter 4
approximately 4 miles
approximately 2 miles
approximately 55 miles
approximately .3 miles
Page 72
Chehalis Reservation Natural Hazards Mitigation Plan
Table 3.6
Chehalis Reservation IRR Inventory
Map
Length
(miles)
Surface
Type
Construction
Need
2005
Tribal
Inventory
Pg. 81
& 82
Route
No.
1
section
5
2
section
5
3
section
5
4
section
5
5
section
5
5
section
10
6
section
5
7
section
5
8
section
5
Pg. 81
& 82
8
section
10
Moon Road SW
-from Hwy 12 to
bridge
Thurston County
Thurston
0.3
Paved
4
2
X
8
section
15
Moon Road SW
- bridge #1
Thurston County
Thurston
0.038
Paved
4
2
X
Pg. 67
& 68
Pg. 69
& 70
Pg. 71
& 72
Pg. 73
& 74
Pg. 75
& 76
Pg. 75
& 76
Pg. 77
& 78
Pg. 79
& 80
Pg. 81
& 82
Chapter 4
Route Name
Ownership
County
Location
Functional
Class
Code
1999
Official
Status in
BIA IRR
Inventory
Makum Lane
BIA
Grays Harbor
0.1
Paved
3
1
X
X
Davis Drive
BIA
Grays Harbor
0.1
Paved
3
1
X
X
Petoie Lane
BIA
Grays Harbor
0.1
Paved
3
1
X
X
Parsons Drive
BIA
Grays Harbor
0.1
Paved
3
1
X
X
X
(route no.
5)
Fern Drive
BIA
Grays Harbor
0.1
Paved
3
1
X
Oak Lane
BIA
Grays Harbor
0.1
Paved
3
0
X
Tahown Drive
BIA
Grays Harbor
0.2
Paved
3
1
X
X
Lacamus Lane
Moon Road SW
-from School Land Rd. SW
to Hwy 12
BIA
Grays Harbor
0.1
Paved
3
1
X
X
Thurston County
Thurston
0.2
Paved
4
2
X
Page 73
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
X
(rename route to Rt. 5
section 5)
X
X
X
X (rename route to
route 8 section 10,
change length from
1.1 to 0.3
X
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Pg. 81
& 82
Pg. 81
& 82
Pg. 83
& 84
Pg. 83
& 84
Pg. 83
& 84
Pg. 83
& 84
Pg. 83
& 84
Pg. 83
& 84
Pg. 83
& 84
Pg. 85
& 86
Pg. 85
& 86
Route
No.
8
section
20
8
section
25
9
section
5
9
section
10
9
section
15
9
section
20
9
section
25
9
section
30
9
section
35
10
section
5
10
section
10
Chapter 4
Route Name
Moon Road SW
-from end of bridge
to gravel
Moon Road SW
-from gravel south
to end of road
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
Thurston County
Thurston
0.5
Paved
4
2
X
X
Thurston County
Thurston
0.3
Gravel
4
2
X
X
Thurston County
Thurston
2.4
Paved
4
2
X
X
Thurston County
Thurston
.012
Paved
4
2
X
183 Ave SW – from end
of bridge to US 12
Thurston County
Thurston
1.4
Paved
4
2
X
183rd Ave SW – from
Forstrom St. SW to bridge
Thurston County
Thurston
.60
Paved
4
2
X
X
Thurston County
Thurston
.004
Paved
4
2
X
X
Thurston County
Thurston
.60
Paved
4
2
X
X
Thurston County
Thurston
0.6
Paved
4
2
X
X
X (rename Route 10
section 5, change
length from 1.0 to 0.3,
construction need
change from 2 to 3)
rd
183 Ave SW – from Case
Road SW to bridge
rd
183 Ave SW –bridge #1
X
rd
rd
183 Ave SW – bridge #2
X
rd
183 Ave SW – from end
of bridge to Moon Rd. SW
183rd Ave SW – from
Moon Rd. SW to end of
road
188th Ave SW – from
Anderson Rd. to bridge #1
Thurston County
Thurston
0.3
Paved
4
2
X
188th Ave SW –
Bridge #1
Thurston County
Thurston
0.009
Paved
4
0
X
Page 74
X
(route no.
10)
X
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Route
No.
Pg. 85
& 86
10
section
15
Route Name
188 Ave SW
-from end of bridge
#1 to start of bridge
#2
Pg. 85
& 86
10
section
20
188 Ave SW
-bridge #2
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
th
Pg. 85
& 86
Pg. 85
& 86
Pg. 87
& 88
10
section
25
10
section
30
11
section
5
12
section
5
Pg. 87
& 88
12
section
10
Pg. 89
& 90
13
section
5
Chapter 4
Thurston County
Thurston
0.001
Paved
4
0
X
X
Thurston County
Thurston
0.011
Paved
4
0
X
X
Thurston County
Thurston
0.5
Paved
4
2
X
X
Thurston County
Thurston
0.7
Paved
3
2
X
X
0.3
Earth
3
2
X
th
th
188 Ave SW
-from end of bridge #2 to
Moon Rd.
th
188 Ave SW – from
Forstrom St. SW to Marble
St. SW
River Road
Privately owned
Grays Harbor
X
X
(part of
route no.
5327,
section no.
820)
1
Pearson Road
Pearson Road
Secena Road
BIA
Grays Harbor
County
Privately owned
Grays Harbor
Grays Harbor
Grays Harbor
0.6
0.5
1
Gravel
Gravel
Gravel - Poor
3
3
3
Page 75
X
2
X (part of
route no.
5327,
section no.
820)
2
X (route
no. 5327,
section no.
810)
X
X
(rename Route 12
section 5, change
length from 1.1 to 0.6,
const. need changed
to 3)
X
(rename to Route 12
section 10, and const.
need change to 3)
X
(rename route no. to
Route 13, change
length from .5 to 1,
and ownership
changed from County
to Privately owned)
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Pg. 91
& 92
Route
No.
14
section
5
Pg. 93
& 94
14
section
10
14
section
15
14
section
20
14
section
25
14
section
30
14
section
35
14
section
40
15
section
5
Pg. 95
& 96
16
section
5
Pg. 91
& 92
Pg. 91
& 92
Pg. 91
& 92
Pg. 91
& 92
Pg. 91
& 92
Pg. 91
& 92
Pg. 91
& 92
Chapter 4
Route Name
Anderson Road – from
Hwy 12 to start of
bridge #1
Anderson Road
- bridge #1
Anderson Road –from
end of bridge #1 to
Reservation boundary
Anderson Road – from
Reservation boundary
to start of bridge #2
Anderson Road
- bridge #2
Anderson Road –from
bridge #2 to start of
bridge #3
Anderson Road
- bridge #3
Anderson Road –from
end of bridge #3 to
end of road
Balch Road
Howanut Road
-from Anderson
Road to start of
bridge #1
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
X (route
no. 5327,
section no.
840)
X
(rename route to
Route 14 section 5,
change length from
1.5 to 0.2)
Thurston County
Thurston
0.20
Paved
4
0
X
Thurston County
Thurston
0.02
Paved
4
0
X
X
Thurston County
Thurston
0.10
Paved
4
0
X
X
Thurston County
Thurston
0.20
Paved
4
0
X
X
Thurston County
Thurston
0.006
Paved
4
0
X
X
Thurston County
Thurston
0.2
Paved
4
0
X
X
Thurston County
Thurston
0.016
Paved
4
0
X
X
Thurston County,
Thurston
1
Paved
4
2
X
Grays Harbor
County
Grays Harbor
County
Grays Harbor
Grays Harbor
1.0
0.8
Paved
Paved
3
4
Page 76
2
2
X
X
X (route
5327,
sect. 850)
X (part of
route no.
5327,
section no.
880)
X
X
(rename route no. to
Route 15)
X
(rename route no. to
Route 16 section 5 in
IRR inventory )
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Route
No.
Pg. 95
& 96
16
section
10
Pg. 95
& 96
Pg. 95
& 96
Pg. 95
& 96
Pg. 95
& 96
Pg. 95
& 96
Pg. 95
& 96
16
section
15
16
section
20
16
section
25
16
section
30
16
section
35
16
section
40
Pg. 95
& 96
16
section
45
16
section
50
Pg. 95
& 96
16
section
55
Pg. 95
& 96
Chapter 4
Route Name
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
X (part of
route no.
5327,
section no.
880)
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
X(rename
route to Route 16
section 10 , change
length from 3.2 to 0.8)
Howanut Road
-bridge #1
Howanut Road
-from end of bridge
#1 to start of bridge
#2
Grays Harbor
County
Grays Harbor
0.009
Paved
4
2
X
Grays Harbor
County
Grays Harbor
0.6
Paved
4
2
X
Howanut Road
-bridge #2
Howanut Road
-from end of bridge
#2 to start of bridge
#3
Grays Harbor
County
Grays Harbor
0.031
Paved
4
2
X
X
Grays Harbor
County
Grays Harbor
0.4
Paved
4
2
X
X
Howanut Road
-bridge #3
Howanut Road
-from end of bridge
#3 to start of bridge
#4
Grays Harbor
County
Grays Harbor
0.005
Paved
4
2
X
X
Grays Harbor
County
Grays Harbor
0.2
Paved
4
2
X
X
Howanut Road
-bridge #4
Howanut Road
-from end of bridge
#4 to start of bridge
#5
Grays Harbor
County
Grays Harbor
0.005
Paved
4
2
X
X
Grays Harbor
County
Grays Harbor
0.5
Paved
4
2
X
X
Howanut Road
-bridge #5
Howanut Road
-from end of bridge
#5 to Reservation
boundary
Grays Harbor
County
Grays Harbor
0.039
Paved
4
2
X
X
Grays Harbor
County
Grays Harbor
0.5
Paved
4
2
X
X
Page 77
X
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Pg. 95
& 96
Route
No.
16
section
60
Route Name
Howanut Road – from
Reservation boundary to
Elma Gate Rd.
Ownership
County
Location
Grays Harbor
County
Grays Harbor
Length
(miles)
Surface
Type
Functional
Class
Code
0.2
Paved
4
Construction
Need
2005
Tribal
Inventory
2
X
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
X (route
no. 5327,
section no.
870)
X ( route
no. 5327,
section no.
890)
X ( route
no. 5327,
section no.
830)
X ( route
no. 5327,
section no.
830)
X ( route
no. 5327,
section no.
860)
X
X
(rename route no. to
Route 17 in IRR
inventory)
X
(rename route no. to
Route 18 in IRR
inventory)
X
(rename route no. to
Route 19 in IRR
inventory)
X
(rename route no. to
Route 19 in IRR
inventory)
X(rename route to
Route 20 sec. 5, and
change length from
1.6 to 1.4)
Pg. 97
& 98
17
section
5
Fitzgerald Road
Grays Harbor
County
Grays Harbor
0.6
Gravel
3
2
X
Pg. 99
& 100
18
section
5
Niederman Road
Grays Harbor
County
Grays Harbor
0.9
Paved
3
2
X
Pg. 101
& 102
19
section
5
Cemetery Road – from
Elma Gate Rd. to
Reservation boundary
Grays Harbor
County
Grays Harbor
0.5
Paved
3
2
X
Pg. 101
& 102
19
section
10
Cemetery Road – from
Reservation boundary to
South Bank Road
Grays Harbor
County
Grays Harbor
0.3
Paved
3
2
X
20
section
5
20
section
10
21
section
5
22
section
5
23
section
5
23
section
10
South Bank Road
-from Fairview Street
to start of bridge
Grays Harbor
County
Grays Harbor
1.4
Paved
4
2
X
South Bank Road
-bridge
Grays Harbor
County
Grays Harbor
0.204
Paved
4
2
X
X
Prairie Lane
BIA
Grays Harbor
0.2
Paved
3
0
X
X
Tomahawk Drive
Albany Street - from
School Land Road SW to
Hwy 12
BIA
Grays Harbor
0.2
Gravel
3
1
X
X
Thurston County
Thurston
0.3
Paved
4
2
X
X
Thurston County
Thurston
0.2
Paved
4
2
X
X
Pg. 103
& 104
Pg. 103
& 104
Pg. 105
& 106
Pg. 107
& 108
Pg. 109
& 110
Pg. 109
& 110
Chapter 4
Albany Street – From Hwy
th
12 to 185 St. SW
Page 78
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Pg. 111
& 112
Pg. 111
& 112
Pg. 111
& 112
Pg. 113
& 114
Pg. 113
& 114
Pg. 113
& 114
Pg. 115
& 116
Pg. 115
& 116
Pg. 115
& 116
Pg. 117
& 118
Pg. 117
& 118
Pg. 117
& 118
Route
No.
24
section
5
24
section
10
24
section
15
25
section
5
25
section
10
25
section
15
Route Name
Marble Street - from
Albany Street to bridge
Marble Street - bridge
Marble Street – From end
of bridge to Independence
Road
Independence Road –
from Marble Street SW to
start of bridge
Independence Road –
bridge
Independence Road –
from end of bridge to Tribal
Trust Property
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
Thurston County
Thurston
0.4
Paved
4
2
X
X
Thurston County
Thurston
.004
Paved
4
2
X
X
Thurston County
Thurston
0.4
Paved
4
2
X
X
Thurston County
Thurston
0.8
Paved
4
2
X
X
Thurston County
Thurston
0.082
Paved
4
2
X
X
Thurston County
Thurston
1.8
Paved
4
2
X
X
26
section
5
Old Hwy 99 - from State
Hwy to start of bridge
Thurston County
Thurston
0.4
Paved
2
2
X
X
26
section
10
Old Hwy 99 - bridge
Thurston County
Thurston
0.008
Paved
2
2
X
X
Old Hwy 99 – from bridge
to tribal trust property
Thurston County
Thurston
0.8
Paved
2
2
X
X
Case Road SW - north to
start of bridge
Thurston County
Thurston
0.6
Paved
4
0
X
X
Thurston County
Thurston
0.09
Paved
4
0
X
X
Thurston County
Thurston
1
Paved
4
0
X
X
26
section
15
27
section
5
27
section
10
27
section
15
Chapter 4
Case Road SW - bridge
Case Road SW - from
end of bridge to tribal trust
property
Page 79
Chehalis Reservation Natural Hazards Mitigation Plan
Map
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Pg. 119
& 120
Route
No.
28
section
5
28
section
10
28
section
15
28
section
20
28
section
25
28
section
30
28
section
35
28
section
40
28
section
45
28
section
50
28
section
55
28
section
60
28
section
65
Chapter 4
Route Name
Ownership
County
Location
Length
(miles)
Surface
Type
Functional
Class
Code
Construction
Need
2005
Tribal
Inventory
1999
Official
Status in
BIA IRR
Inventory
2006 Proposed
Additions and
Revisions to BIA
IRR Inventory
State Route 12 - I-5
overcrossing (bridge #1)
WSDOT
Thurston
0.04
Paved
1
2
X
X
State Route 12 – RR
overcrossing (bri
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