# Natural Hazard Mitigation Plan 2019 Revision > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/tribal%3Anez_perce%3A2d7709c0ef17aaf8 ## Record - **Collection:** Tribal code - **Document type:** Tribal code ## Text Nez Perce Tribe Natural Hazard Mitigation Plan 2019 Revision Nez Perce Tribe Emergency Management Box 365 – 109 Lolo St Lapwai ID 83540 (208) 621-3760 Prepared By Northwest Management, Inc. - THIS PAGE INTENTIONALLY LEFT BLANK - Forward Nez Perce Tribal Emergency Management is dedicated to the protection of life, property, economic and environmental resources throughout the Reservation. Seeking to inform and educate citizens, provide training and resource coordination and ultimately reduce the vulnerability of Tribal citizens through comprehensive disaster planning and mitigation. “Hazard mitigation is sustained action to reduce or eliminate the long‐term risk to human life and property from hazards. Natural hazard mitigation planning is a process used by state, tribal, and local governments to engage stakeholders, identify hazards and vulnerabilities, develop a long-term strategy to reduce risk and future losses, and implement the plan, taking advantage of a wide range of resources. A state mitigation plan demonstrates commitment to reduce risks from natural hazards and serves as a guide for decision makers for reducing the effects of natural hazards as resources are committed”1 The Nez Perce Tribe Natural Hazard Mitigation Plan was updated in 2017-19 by the Nez Perce Tribe Hazard Mitigation Steering Committee in cooperation with Northwest Management, Inc. of Moscow, Idaho. This Plan satisfies the requirements for a local natural hazard mitigation plan under 44 CFR Part 201.6, in addition this plan fully integrated the processes of FEMA’s Natural Hazard Mitigation Plan with the Community Wildfire Protection Plan as outlined in the Healthy Forest Restoration Act. 1 Federal Emergency Management Agency. “Local Multi-Hazard Mitigation Planning Guidance.” July 1, 2008 i Table of Contents CHAPTER 1 ............................................................................................................................ 1 Background ....................................................................................................................................1 Goals and Guiding Principles...........................................................................................................2 HMP Mission Statement ......................................................................................................... 2 Federal Emergency Management Agency Philosophy ........................................................... 2 Plan Overview ................................................................................................................................4 Update and Adoption Requirements ...............................................................................................5 CHAPTER 2 ............................................................................................................................ 7 Plan Update Process .......................................................................................................................7 Tribal Involvement .................................................................................................................. 8 Public Involvement ................................................................................................................. 9 Incorporation of Existing Plans ............................................................................................. 10 Plan Maintenance ........................................................................................................................ 11 Evaluating and Updating the Plan ......................................................................................... 11 Obtaining Continued Public Involvement ............................................................................. 12 CHAPTER 3 .......................................................................................................................... 13 History and Description of the Reservation ................................................................................... 13 Government .......................................................................................................................... 16 Demographics ....................................................................................................................... 16 Land Use and Development Trends ...................................................................................... 16 CHAPTER 4 .......................................................................................................................... 18 Risk Assessment Overview ........................................................................................................... 18 Flood Hazard Profile ..................................................................................................................... 20 Hazard Description and History ............................................................................................ 20 Probability of Future Occurrence ......................................................................................... 24 Impacts of Flood Events ........................................................................................................ 27 Value of Resources at Risk .................................................................................................... 31 ii Severe Weather Hazard Profile ..................................................................................................... 33 Drought ................................................................................................................................. 34 Hailstorms ............................................................................................................................. 37 Windstorms ........................................................................................................................... 39 Winter Storms ....................................................................................................................... 41 Landslide Hazard Profile ............................................................................................................... 45 Hazard Description and History ............................................................................................ 45 Probability of Future Occurrence ......................................................................................... 47 Impacts of Landslide Events.................................................................................................. 48 Value of Resources at Risk .................................................................................................... 48 Wildland Fire Profile ..................................................................................................................... 50 Wildland Fire Characteristics ................................................................................................ 50 History and Extent................................................................................................................. 52 Wildland Fire Risk.................................................................................................................. 57 Volcanic Eruption Profile .............................................................................................................. 69 Hazard Description and History ............................................................................................ 69 Probability of Future Occurrence ......................................................................................... 72 Impacts of Volcanic Eruption ................................................................................................ 73 Value of Resources at Risk .................................................................................................... 74 Hazardous Materials .................................................................................................................... 75 Hazard Description and History ............................................................................................ 75 Probability of Future Occurrence ......................................................................................... 76 Impacts of Hazardous Materials Release .............................................................................. 77 Values of Resources at Risk .................................................................................................. 77 Vulnerable Areas and Infrastructure ............................................................................................. 80 Residential Structures ........................................................................................................... 81 Critical Infrastructure ............................................................................................................ 83 Cultural and Sacred Sites ...................................................................................................... 85 iii CHAPTER 5 .......................................................................................................................... 86 Mitigation Strategy ...................................................................................................................... 86 Mitigation Goals .................................................................................................................... 86 Mechanisms to Incorporate Mitigation Strategies ............................................................... 87 Development of Mitigation Action Items ............................................................................. 87 2019 Mitigation Action Items ............................................................................................... 90 Capability Assessment .......................................................................................................... 97 Funding Sources .................................................................................................................... 99 APPENDICES ...................................................................................................................... 102 Appendix 1 – Agendas and Sign-in Sheets ................................................................................... 102 Committee Involvement Documentation ........................................................................... 102 Public Involvement Documentation ................................................................................... 107 Record of Survey Respondents ........................................................................................... 111 Appendix 2 – Future Plan Update Guidelines............................................................................... 112 Appendix 3 – Maps with Legends Included .................................................................................. 115 Reservation Location and Land Ownership ........................................................................ 116 Demographics ..................................................................................................................... 117 Land Use .............................................................................................................................. 118 Location of Residential Structures ...................................................................................... 119 Locations of Critical Facilities .............................................................................................. 120 Hazardous Materials Facilities and Transportation ............................................................ 121 Potential Flood Area ........................................................................................................... 122 Dam Failure and Inundation Zones ..................................................................................... 123 Landslide Risk Areas ............................................................................................................ 124 Wildfire Risk ........................................................................................................................ 125 Wildfire History ................................................................................................................... 126 Locations of Active Volcanos .............................................................................................. 127 Appendix 4 – FEMA HMP Requirements ...................................................................................... 128 iv Acronyms AFG ANA DMA 2000 CFR cfs EHS EPA EPCRA FEMA FIRM FIS FMA GIS HMGP HMP IDWR NFIP NPT NPTEC PDM Reservation SFHA Stafford Act HMP Committee Tribe NMI Assistance to Firefighters Grant Administration for Native Americans Disaster Mitigation Act of 2000 Code of Federal Regulations cubic feet per second Extremely Hazardous Substance U.S. Environmental Protection Agency Emergency Planning and Community Right to Know Act Federal Emergency Management Agency Flood Insurance Rate Map Flood Insurance Study Flood Mitigation Assistance Geographic Information System Hazard Mitigation Grant Program Hazard Mitigation Plan Idaho Department of Water Resources National Flood Insurance Program Nez Perce Tribe Nez Perce Tribal Executive Committee Pre-Disaster Mitigation grant program Nez Perce Reservation Special Flood Hazard Area Robert T. Stafford Disaster Relief and Emergency Assistance Act Hazard Mitigation Planning HMP Committee Nez Perce Tribe Northwest Management Inc. v Chapter 1 Background Natural hazards are inherent properties of the Earth that can influence and impact both living and non-living features of the natural environment. Natural hazards vary in scale and potential impact; localized windstorms are capable of damaging and uprooting individual trees while volcanic eruptions can impact or destroy hundreds of square miles of terrain and cause widespread mortality of plants and animals. Certain types of natural disasters are far more common in some regions of the United States than in others. The Pacific Northwest is associated with wildfire, earthquake, and volcanic hazards; the central plains often experience severe storms that are capable of producing tornados up to one mile wide; while the Atlantic coast is periodically exposed to tropical storms and hurricanes. These different landscapes are resilient in the face of a natural disaster but humans and human development are much less so. Humans have always lived with the consequences of natural disasters which often include displaced residents, loss of property, costly clean up and repairs, and lost time which is often measured in years. In response to increasing populations and expansion of development, communities are identifying steps that can be taken to mitigate the impacts of natural hazards. Mitigation measures are preventative actions that make communities and individuals more resilient to natural hazards and reduce the cost of recovery. The goal of this document is to accurately identify risks to the people and property on the Nez Perce Reservation and provide a plan for mitigation efforts in accordance with the Disaster Mitigation Act of 2000. The Federal Emergency Management Agency (FEMA) provides funding opportunities for mitigation actions and requires a hazard mitigation plan (HMP) that identifies risks and vulnerabilities, proposes mitigation strategies and a planning process that includes multi-jurisdictional participation along with public outreach. Additionally, the HMP Committee desires to create a document that is easy to use, actively referenced and is a key component in making the Nez Perce Reservation more resilient to natural hazards. This Reservation-wide Hazard Mitigation Plan is the result of analyses, professional cooperation and collaboration, assessments of hazard risks and other factors considered with the intent to reduce the potential threat posed by natural hazards to people, structures, infrastructure, and unique ecosystems on the Nez Perce Reservation. The Nez Perce Hazard Mitigation Plan was originally approved by Idaho Office of Emergency Management and FEMA in 2006 and was updated in 2009 and again in 2019. This document serves as an update of the Multi-Hazard Mitigation Plan under the Pre-Disaster Mitigation program and will be in effect until 2022. This 1 document assists with the identification and assessment of various potential hazards and helps maintain the Tribe’s eligibility for grants and other funding. The Multi - Hazard Mitigation Plan is developed in accordance with the requirements of FEMA and the Idaho Office of Emergency Management for a reservation-level pre-disaster mitigation plan. The State of Idaho Hazard Mitigation Plan identifies seven natural hazards affecting the State. In an effort to be consistent, the Steering Committee chose six natural hazard annexes from the state-identified natural hazards that pose the highest risk for the Tribe. The hazardous materials annex from the previous plan will also be carried over to this plan. The hazards annexes that will be updated for this plan include: ✓ Flood ✓ Severe Weather ✓ Landslide o Drought ✓ Volcanic Eruption o Hailstorm ✓ Wildland Fire o Windstorm It should be noted that the planning committee decided to exclude earthquake as a separate hazard in the plan as the Reservation is in a relatively stable seismic zone. Although geologists have discovered several regional faults and acknowledge the potential for earthquakes as a result of volcanic activity, earthquakes are considered a low-level threat to life and property on the Nez Perce Reservation due to the low probability of occurrence; mirroring sentiments of the 2006 and 2009 versions of the HMP. Goals and Guiding Principles HMP Mission Statement To make Tribal residents, communities, and businesses less vulnerable to the effects of natural and man-made hazards through the effective administration of hazard mitigation grant programs, hazard risk assessments, wise and efficient infrastructure construction and placement, and a coordinated approach to mitigation policy through federal, state, regional, and local planning efforts. Our combined prioritization will be the protection of people, structures, infrastructure, and unique ecosystems that contribute to our way of life and the sustainability of the local and regional economy. Federal Emergency Management Agency Philosophy Effective November 1, 2004, a Natural Hazard Mitigation Plan approved by the Federal Emergency Management Agency (FEMA) is required for Hazard Mitigation Grant Program (HMGP) and Pre-Disaster Mitigation Program (PDM) eligibility. The HMGP and PDM programs 2 provide funding, through state emergency management agencies, to support local mitigation planning and projects to reduce potential disaster damages. The new local Natural Hazard Mitigation Plan requirements for HMGP and PDM eligibility is based on the Disaster Mitigation Act of 2000, which amended the Stafford Disaster Relief Act to promote an integrated, cost effective approach to mitigation. Local Natural Hazard Mitigation Plans must meet the minimum requirements of the Stafford Act-Section 322, as outlined in the criteria contained in 44 CFR Part 201. The plan criteria cover the planning process, risk assessment, mitigation strategy, plan maintenance, and adoption requirements. FEMA will only review a Tribal Natural Hazard Mitigation Plan adopted by the tribal governing body §201.7(c)(5). Draft versions of local Natural Hazard Mitigation Plans will not be reviewed by FEMA. FEMA will review the final version of a plan prior to local adoption to determine if the plan meets the criteria, but FEMA will be unable to approve it prior to adoption. A FEMA designed plan will be evaluated on its adherence to a variety of criteria, including: • Adoption by the Tribal Governing Body • Multi-jurisdictional Plan Adoption • Multi-jurisdictional Planning Participation • Documentation of Planning Process • Identifying Hazards • Profiling Hazard Events • Assessing Vulnerability: Identifying Assets • Assessing Vulnerability: Estimating Potential Losses • Assessing Vulnerability: Analyzing Development Trends • Multi-jurisdictional Risk Assessment • Local Hazard Mitigation Goals • Identification and Analysis of Mitigation Measures • Implementation of Mitigation Measures • Multi-jurisdictional Mitigation Strategy • Monitoring, Evaluating, and Updating the Plan • Implementation Through Existing Programs • Continued Public Involvement 3 Plan Overview Plan Update Process (Chapter 2) describes the process by which the plan will be updated and maintained once it is adopted. This includes both committee and community involvement in all stages of the process. The following outlines the planning process as described in §201.7(c)(1): (i) An opportunity for the public to comment on the plan during the drafting stage and prior to plan approval, including a description of how the Tribal government defined “public;” (ii) As appropriate, an opportunity for neighboring communities, tribal and regional agencies involved in hazard mitigation activities, and agencies that have the authority to regulate development, as well as businesses, academia, and other private and nonprofit interests to be involved in the planning process; (iii) Review and incorporation, if appropriate, of existing plans, studies, and reports; and (iv) Be integrated to the extent possible with other ongoing tribal planning efforts as well as other FEMA programs and initiatives. Chapter 2 also describes the HMP Committee’s formal plan maintenance process to ensure that the HMP remains an active and applicable document. The process includes monitoring, evaluating, and updating the HMP, monitoring the mitigation measures and project closeouts, and incorporating public input throughout the HMP’s 5-year lifespan. History and description of the Reservation (Chapter 3) provides a general history and background of the Tribe and historical trends for population, demographic, and economic conditions that have shaped the area. Trends in land use and development are also discussed. For public participation in the planning process the Tribal Government defines “public” as current Tribal members. Risk Assessment Overview (Chapter 4) details the process of identifying hazards and describes the process through which the HMP Committee identified and compiled relevant data on all potential natural hazards that threaten the Reservation and the immediately surrounding area. Information collected includes historical data on natural hazard events that have occurred in and around the Reservation and how these events impacted tribal members and their property. The descriptions of natural hazards that could affect the Reservation are based on historical occurrences and best available data from agencies such as FEMA, the U.S. Geological Survey, the Idaho Geologic Survey, and the National Weather Service. Detailed hazard profiles include 4 information on the frequency, magnitude, location, and impact of each hazard as well as probabilities for future hazard events. In addition, Chapter 4 identifies potentially vulnerable assets such as people, housing units, critical facilities. These data were compiled by assessing the potential impacts from each hazard using U.S. Census data, and the Nez Perce Tribe Land Services Program and Housing Authority, and GIS. The resulting information identifies the full range of hazards that the Reservation could face and potential social impacts, damages, and economic losses. Mitigation Strategy (Chapter 5) first provides an overview of the Tribe’s resources in the following areas for addressing hazard mitigation activities: • Existing ordinances, plans, and codes that affect the physical or built environment • The current and potential financial resources to implement the mitigation strategy Chapter 5 also describes the process in which the HMP Committee: • Verified mitigation goals based upon the findings of the risk assessment and the capability assessment • Reevaluated a comprehensive range of appropriate mitigation actions from the 2009 HMP • Reconfirmed mitigation actions to be included in the 2019 HMP’s Action Plan The appendices include the Adoption Resolution, maps and figures, HMP Committee agendas, and public involvement process. Update and Adoption Requirements Adoption by the governing body demonstrates a community’s commitment to fulfilling the mitigation goals and objectives outlined in the HMP. Adoption legitimizes the HMP and authorizes responsible agencies to execute their responsibilities. Following adoption by the Nez Perce Tribal Council, the plan was reviewed and approved by the Idaho Office of Emergency Management and FEMA. A copy of the resolution, adopted by the NPTEC, assures FEMA that the Tribe will comply with both of the CFR requirements. The resolution is presented in Appendix 2. The following is a brief summary of the plan update requirements for Tribes: • Deadlines and Requirements for Regular Plan Reviews and Updates: In order to apply for a FEMA PDM project grant, Tribal and local governments must have a FEMA-approved mitigation plan. Tribal and local governments must have a FEMA-approved mitigation 5 plan in order to receive HMGP project funding for disasters declared on or after November 1, 2004. States and Tribes must have a FEMA-approved Standard or Enhanced Mitigation Plan in order to receive non-emergency Stafford Act assistance (i.e., Public Assistance Categories C-G, HMGP, and Fire Management Assistance Grants) for disasters declared on or after November 1, 2004. State mitigation plans must be reviewed and reapproved by FEMA every three years. Local Mitigation Plans must be reviewed and reapproved by FEMA every five years. • Plan updates. In addition to the timelines referenced above, the Rule includes the following paragraphs that pertain directly to the update of State, Local, and Tribal plans; o §201.3(b)(5) [FEMA Responsibilities] …Conduct reviews, at least once every three years, of State mitigation activities, plans, and programs to ensure that mitigation commitments are fulfilled…. o §201.7(c)(4) [Indian tribal governments] …A system for reviewing progress on achieving goals as well as activities and projects identified in the mitigation strategy. o §201.7(d)(3) [Tribal] must review and revise their plan to reflect changes in development, progress in local mitigation efforts, and changes in priorities, and resubmit it for approval within 5 years in order to continue to be eligible for nonemergency Stafford Act assistance and FEMA mitigation grant funding, with the exception of the Repetitive Flood Claims program. Plan updates must include a system for reviewing the progress on mitigation activities that were identified within the plan. This will involve a comprehensive review and evaluation of each section of the plan and a discussion of the results of evaluation and monitoring activities detailed in the Plan Maintenance section of the previously approved plan. Updates to the plan may validate the information in the previously approved plan, or may involve a major plan rewrite. In any case, a plan update is NOT an annex to the previously approved plan; it must stand on its own as a complete and current plan. The objective of combining these complementary guidelines is to facilitate an integrated wildland fire risk assessment, identify pre-hazard mitigation activities, and prioritize activities and efforts to achieve the protection of people, structures, the environment, and significant infrastructure on the Nez Perce reservation while facilitating new opportunities for pre-disaster mitigation funding and cooperation. 6 Chapter 2 Documentation of the planning process, including public involvement, is required to meet FEMA’s DMA 2000 (44CFR§201.7(b) and §201.7(c)(1)) for an updated local mitigation plan. This section includes a description of the planning process used to update this plan, including how it was prepared, who was involved in the process, and how involved agencies participated. Plan Update Process The Tribal Multi - Hazard Mitigation Plan was developed through a collaborative process with outreach to many of the organizations within the jurisdictional boundaries of Tribal lands. Nez Perce Tribe Emergency Management invited stakeholders to planning meetings throughout the planning process, including personnel from wildlife management, historical preservation, forestry and fire, emergency management, air quality, and others. The planning effort began by organizing and convening a Tribal Steering Committee that incorporated all departments of the Tribal Government as well as outside agencies and neighboring jurisdictions. The Tribe utilized members of the Tribal Emergency Response Planning Team (TERPT) to develop the Hazard Mitigation Plan Committee and begin the update process. HMP Committee meetings began in July of 2017, with meetings held in October, December, January, and March. The planning process included seven distinct steps which were in some cases sequential (step 1 then step 2) and in some cases intermixed (step 5 completed throughout the process): 1. Organization of Resources – The Tribe and Northwest Management Inc. (NMI) worked together to develop a comprehensive list of potential participants as well as a project timeline and work plan. The HMP Committee served as the basis for identifying stakeholders that could provide valuable insight into risk assessments and mitigation strategies during the update process. 2. Collection of Data – Nez Perce Tribal GIS Department collected all data performed in the risk assessment and ancillary data for background information. 3. Field Observations and Estimations –Nez Perce Tribal GIS Department developed risk models and identified problem areas in order to better understand risks, juxtaposition of structures and infrastructure to risk areas, access, and potential mitigation projects. Many of the analyses used in the 2009 plan were reviewed and updated to incorporate new hazard vulnerabilities or changes in development. Additionally, several new risk models and analyses were included in the 2017-19 update process to better represent actual conditions on the Reservation. 7 4. Mapping – Nez Perce Tribal GIS Department developed mapping products as visual tools to support various analyses. All of the maps and databases were updated as part of the 2019 plan update. 5. Public Involvement – the HMP committee with NMI developed a plan to involve the public from the formation of the committee through public meetings and workshops, public review of draft documents, and acknowledgement of the final updated plan by the signatory representatives. 6. Strategies and Prioritization – NMI and the HMP Committee representatives worked together to review the risk analyses and develop realistic mitigation strategies. As part of the 2019 plan update, a record of completed action items as well as a status report of projects was included in the revised mitigation strategies for each jurisdiction. 7. Drafting of the Report – NMI drafted a final updated report document and worked with members of the planning team to review each section, incorporate public comments, proceed with the state and federal review processes, and adopt the final document. Tribal Involvement Individuals that were a part of the HMP Committee, their roles within the planning team, and the jurisdiction they represent are highlighted in Table 1. The HMP Committee made efforts to include individuals, tribal departments, outside state and federal agencies, neighboring counties, and others that have an interest in hazard management on the Reservation. Table 1) Nez Perce Reservation HMP Steering Committee members. Name Department & Title Role in the Planning Process John Wheaton Emergency Management, EM Planner Project Coordinator Aaron Miles Sr. Natural Resources, Manager EOC Wildland Fire Experience Alexis Walker Human Resources, Risk Management Personnel and Building Safety Anthony Broncheau Finance, Grants Coordinator Finance Review Antonio Smith ERWM, Communications Specialist Public Information Officer Alt. Danae Wilson Information Technology, Director Interoperability Darren Williams Legal, Attorney Provided policy and legal information Dave Arther NMPH, Nurse Update Health Information Dave Johnson Fisheries, Manager Fisheries protection and resources Dean Neufeld Public Health, Emergency Management Training and Public Health Expertise Debbie Henry Former Safety Coordinator Critical Infrastructure Safety Ferris Paisano NPT Executive Committee Law and Order Chair Emergency Management Rep. 8 Name Department & Title Role in the Planning Process Jack Bell ERWM, Director Damage Assessment Jackie McArthur Social Services, Director Vulnerable Populations Jeff Handel Forestry and Fire Management (FFM), FMO Wildland fire expert Julie Simpson Air Quality Program, Coordinator Weather and air quality expertise Kayeloni Scott Communications Director Communications Expertise Keith Baird Tribal Historic Preservation Cultural Analysis Ken Clark Water Resources, Director Waterways expertise Kerey Barnowe-Meyer Wildlife Biologist Integrated Resources Planning Kim Cannon Land Services, Director Tribal Lands Expertise Kip Kemak FFM, Fire Prevention Specialist Wildland fire expert Laurie Ames GIS Department, Coordinator Mapping & risk analysis Laurie Ann Cloud Housing, Manager Housing Assistance Mark Reaney Jr. NMPH, Facilities Manager Health Facilities Expertise Marty Antone NPT Chief of Police Law Enforcement Neil Thagard Wildlife, Director Wildlife Expertise Rebecca Miles Nez Perce Tribe, Executive Director Coordinates Logistics Rob Feeley Idaho Office of Emergency Management, AFO State Resources Expertise Ryan Bender Public Health, Specialist Coordinated trainings and plans Stefanie Krantz Water Resources, Climate Change Coordinator Provide information on the influence of climate change to hazards. Tim Droegmiller FFM, Acting Fuels Specialist Provide information on the current fuels conditions across the Reservation. Mark Corrao Northwest Management Inc. Project Lead for NMI Tera King Northwest Management Inc. Project Support for NMI Eric Nelson Northwest Management Inc. Project Support for NMI John Degroot Public Involvement Public involvement in this plan was made a priority from the inception of the project. There were a number of ways that public involvement was sought and facilitated. In some cases, this led to members of the public providing information and seeking an active role in protecting their own homes and businesses, while in other cases it led to the public becoming more aware of the process without becoming directly involved in the planning. 9 Nez Perce Tribe Emergency Management and NMI worked together to develop a brochure to help educate and inform the public on the process the HMP Committee was involved in and what that meant for Tribal members. Two public meetings were used to facilitate information sharing to the public on the various risk analyses and mitigation action items. During these meetings, discussions were led and forms were provided to help gather feedback about the plan components and emergency management issues in general. The workshops were held in the following locations: • Public Workshop #1 was an evening meeting hosted at the Wa-A’Yas Community Center in Kamiah.Public • Workshop #2 was a full day event held at the Clearwater Casino near Lapwai. Following the approval by the HMP committee and NPTEC of the draft document, a period of public comment was provided to further incorporate input on the process and results of the updated Hazard Mitigation Plan. Incorporation of Existing Plans During the planning process, and in particular when preparing the hazard analysis and vulnerability analysis, the HMP Committee consulted various hazard and mitigation-related plans and studies, including the following: 1. Nez Perce Tribe Hazard Mitigation Plan (2009): Review of the previous HMP provided a base for reviewing and updating community profiles, hazards, risks, and mitigation action progress. 2. Nez Perce Reservation Emergency Operations Plan: The Nez Perce Reservation Emergency Operations Plan outlines the policies and concepts that guide response at the local level in response to, and recovery from natural and man-caused disasters. The Emergency Operations Plan describes an array of tribal responses and efforts to save lives, limit human suffering, and protect public health, safety, and property, including wildlife, natural resources, the environment, and local economy from the damaging effects of natural and man-caused disaster emergencies. 3. Idaho County, Idaho Multi-Hazard Mitigation Plan (2015): The Idaho County HMP was referenced for updating hazard profiles and potential mitigation efforts that may overlap with Tribal mitigation strategies. Other counties that fall within the Reservation were in the process of updating their Hazard Mitigation Plans and were therefore not reviewed. 10 After the adoption of the HMP, the Steering Committee will ensure that elements of the HMP are incorporated into other existing planning mechanisms. The processes for incorporating the HMP into various planning documents will occur as (1) other plans are updated and (2) new plans are developed. Accordingly, the Steering Committee will ensure that: • As the Emergency Operations Plan is updated, mitigation action 2.D (emergency evacuation programs) is addressed. • As the Hazard Analysis Priorities is updated, mitigation action 3.B (dam inundation maps) is addressed. • New GIS hazard and asset information from the HMP is integrated into the Tribe’s GIS program. Plan Maintenance Evaluating and Updating the Plan The HMP update was prepared as a collaborative effort among Tribal members on the Steering Committee. The Tribe will continue to use the Steering Committee to monitor, evaluate, and update the HMP. The Emergency Management Coordinator (Steering Committee leader) will serve as the primary point of contact and will coordinate all local efforts to monitor, evaluate, and revise the HMP. Over the past three years, the HMP has not been reviewed. In order to ensure that the HMP will be reviewed on an annual basis, a more streamlined plan maintenance approach will be followed. Every July, the Steering Committee leader will email the Steering Committee and ask each member to review the plan and submit any updates or changes that may need to be made to the plan based on changes to the Hazard Profile, Tribal assets, or the Action Plan. The Steering Committee leader will collect all correspondence and determine if changes need to be made to the plan immediately or should be made prior to the plan update in 2014. During the third year of adoption, the Steering Committee will undertake the following activities to evaluate the plan and ensure that the HMP is readopted in a timely manner: • Review all annual email correspondence regarding plan maintenance. • Thoroughly analyze and update the Risk Assessment. • Prepare a new Action Plan with prioritized actions, responsible parties, and resources. • Prepare a new draft HMP and submit it to the Tribal General Council for adoption. • Submit an updated HMP to the FEMA for approval. 11 Obtaining Continued Public Involvement The Steering Committee is dedicated to involving the public directly in the continual reshaping and updating of the HMP. A copy of the plan will be available at the Tribe’s Main Office. The Steering Committee will also identify opportunities to raise community awareness about the HMP and the hazards that affect the Tribe. This effort could include attendance and provision of materials at Tribal emergency preparedness and response special events. 12 Chapter 3 This section describes the history, location, and geography of the Tribe and the Reservation as well as its government, demographic information, and current land use and development trends. History and Description of the Reservation The Nez Perce Indians, who call themselves NiMiiPuu, have resided in what is now north-central Idaho, southeastern Washington, and northeastern Oregon for thousands of years. Until the mid-1800s, the tribe’s aboriginal territory included over 13 million acres. The territory centered on the middle Snake and Clearwater Rivers and the northern Salmon River. In 1855 the Nez Perce Indians signed a treaty with the U.S. Government reserving 7.5 million acres of land for the Nez Perce Reservation. However, the discovery of gold by the early 1860s prompted the U.S. Government to reduce the Reservation by almost 90 percent, to its current size of 770,000 acres2 (Figure 1). Figure 1) Historical and current day boundaries of the Nez Perce Reservation. By 1877, with continued pressure to sell off the Nez Perce lands, the U.S. Government tried to persuade a band of Nez Perce Indians to leave Oregon and move to the Reservation. While the tribal chiefs began to make preparations to comply, a handful of young warriors attacked some white ranchers in revenge for the rancher killing a warrior’s father, thus beginning the 3-month Nez Perce War. 2 "Gold and the Nez Perce." Native American Netroots, 19 Apr. 2011, nativeamericannetroots.net/diary/929. Accessed 14 Sept. 2018 13 Figure 2) Map of towns and communities on the Nez Perce Reservation and Native American population by County per the 2010 Census. The Nez Perce first fled to Montana and then to Idaho before heading north toward Canada. On September 30, about 40 miles from the Canadian border, a bitter battle ensued and 5 days later, Chief Joseph surrendered with over 400 other tribal members. During the surrender, the U.S. Government promised to return the Nez Perce Indians to the Reservation, but instead, they were sent to Oklahoma. Most of the Nez Perce War survivors returned to the Northwest in 14 1885. Ten years later, the Dawes Severalty Act opened the Reservation to non-Indians. As a result, by 1975, less than 80,000 acres of “checkerboard” land remained under Nez Perce and individual tribal member ownership. Since 1980, a land acquisition program has resulted in an increase of Nez Perce ownership to approximately 100,000 acres, with an additional 40,000 acres held by individual tribal members. Figure 3) Different land use areas on the Nez Perce Reservation. 15 The 1,195.10 square miles of land and 9.22 square miles of water in the current Nez Perce Reservation are located in Nez Perce, Lewis, Latah, Clearwater, and Idaho counties. Communities and towns within the Nez Perce Reservation include Myrtle, Lenore, Ahsahka, Orofino, Spalding, Lapwai, Gifford, Sweetwater, Culdesac, Greer, Reubens, Winchester, Craigmont, Nezperce, Kamiah, Ferdinand, Greencreek, Kooskia, Stites, Peck, Cottonwood Creek, Jacques Spur, Slickpoo Mission, Mohler, and Clear Creek. Figure 2 shows the locations of towns and communities and population by county. Cottonwood, Waha, and Westlake are located off of the reservation but they are close to the boundary. Government The Tribe is governed by the Nez Perce Constitution and By-laws established in 1948 and revised in 1961. The constitution established the Nez Perce Tribal Executive Committee (NPTEC) and a council of all adult tribal members, known as the Tribal General Council. The Executive Committee, consisting of nine members, has the authority to represent the Tribe in negotiations, promote and protect the health, education, and general welfare of Tribal members, administer unrestricted Tribal funds, and set rules governing Executive Committee nominations and elections. Demographics Historically, the Tribe had a population around 6,000, which fell to roughly 1,800 by the 1900s. The decrease in population was due to epidemics from and conflicts with white settlers. Today, the Tribe’s population is 4,082. This includes 1,372 children (up to 19 years old) and 543 elders (55 years and older). With focuses on natural resources, the Tribe’s economic base has traditionally centered around fisheries and forestry. With the construction of the It’se-Ye-Ye and the Clearwater River Casinos the Tribe has diversified its economic base significantly. Land Use and Development Trends The Nez Perce Tribe Land Enterprise Subcommittee is responsible for the generation of revenue through land leasing for the benefit of the Nez Perce Tribe as well as the acquisition of land both on and near the Nez Perce Reservation. Over the past 23 years the Tribe has acquired over 62,300 acres of land on and off the Nez Perce Reservation for economic development, timber management, and wildlife management (Figure 3). In 2004-2006, as part of the Nez Perce Snake River Basin Agreement on water rights, approximately 11,297 acres of scattered tracts of public domain (i.e. Trust lands) were identified for transfer to the Nez Perce Tribe. The total acreage of land administered by the Land Enterprise is 110,000 acres with 55,000 acres in Tribal Trust 16 (i.e. no Individual Trust in this total) and 12,000 acres of fee land on the reservation and 39,000 acres of fee land off the reservation. Figure 4 shows land by ownership on the reservation. Figure 4) Land ownership on the Nez Perce Reservation. 17 Chapter 4 Risk Assessment Overview The requirement of 44 CFR 201.7(c)(2) for conducting a risk assessment is listed below. Understanding the risk to the Tribe requires the identification of each natural hazard that occurs within the jurisdictional boundaries of the Reservation. Profiling each hazard’s spatial extent, frequency, likelihood of future occurrence, and duration will help emergency management better understand the potential impacts associated with natural hazards. Recognizing the Tribe’s level of exposure to a hazard provides a measure of risk and vulnerability from a given hazard to specific locations within the Reservation (Figure 5). (c)(2) A risk assessment that provides the factual basis for activities proposed in the strategy to reduce losses from identified hazards. Tribal risk assessments must provide sufficient information to enable the Indian tribal government to identify and prioritize appropriate mitigation actions to reduce losses from identified hazards. The risk assessment shall include: i. A description of the type, location, and extent of all-natural hazards that can affect the tribal planning area. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. ii. A description of the Indian tribal government vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the tribe. The plan should describe vulnerability in terms of: A. The types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard areas; B. An estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(ii)(A) of this section and a description of the methodology used to prepare the estimate; C. A general description of land uses and development trends within the tribal planning area so that mitigation options can be considered in future land use decisions; and D. Cultural and sacred sites that are significant, even if they cannot be valued in monetary terms. 18 Figure 5) Components of risk per the USGS-Oregon Partnership for Disaster Resilience Research Collaboration, 2006. 19 Flood Hazard Profile Hazard Description and History Floods can be divided into two major categories on the Reservation: river and flash flood. River flooding is associated with a river’s watershed, which is the natural drainage basin that conveys water runoff from rain and snowmelt. River flooding occurs when the flow of runoff is greater than the carrying capacities of the natural drainage systems. Rain water and snowmelt runoff that is not absorbed by soil or vegetation seeks surface drainage paths following natural topography lines. These lines merge to form a hierarchical system of rills, creeks, streams, and rivers. Generally, floods can be slow or fast rising depending on the size of the river or stream. Flash floods are much more dangerous and flow much faster than river floods. Flash floods are caused by the introduction of a large amount of water into a limited geographic extent (e.g. extreme precipitation events in watersheds less than 50 square miles). They also tend to peak quickly (e.g. eight hours or less) and more commonly occur in hilly or otherwise confined terrain. Flash floods occur in both urban and rural settings, principally along smaller rivers and drainage ways that do not typically carry large amounts of water. This type of flood poses more significant safety risks than river floods because of the rapid onset, the high-water velocity, the potential for channel scour, and the debris load.3 River Floods The most commonly reported flood magnitude measure is the “base flood.” This is the magnitude of a flood having a one-percent chance of being equaled or exceeded in any given year. Although unlikely, “base floods” can occur in any year, even successive ones. This magnitude is also referred to as the “100-year Flood” or “Regulatory Flood”. Floods are usually described in terms of their statistical frequency. A "100-year flood" or "100-year floodplain" describes an event or an area subject to a 1% probability of a certain size flood occurring in any given year. This concept does not mean such a flood will occur only once in one hundred years. Whether or not it occurs in a given year has no bearing on the fact that there is still a 1% chance of a similar occurrence in the following year. Since floodplains can be mapped, the boundary of the 100-year flood is commonly used in floodplain mitigation programs to identify areas where the risk of flooding is significant. Any other statistical frequency of a flood event may be chosen depending on the degree of risk that is selected for evaluation, e.g., 5-year, 20-year, 50-year, 500-year floodplain. 3 Statewide Regional Evacuation Study Program. Central Florida Region Technical Data Report. Volume 1-7, Chapter II – Regional Hazards Analysis. Available online at http://www.cfrpc.org/EVACUATION%20MASTER%20DVD%20%20PDF%20VERSION/VOLUME%201/Chapter%202/CFRPC%20Chapter%20II%20-%20Hazards%20Analysis.pdf. 20 The areas adjacent to the channel that normally carry water are referred to as the floodplain. In practical terms, the floodplain is the area that is inundated by flood waters. In regulatory terms, the floodplain is the area that is under the control of floodplain regulations and programs (such as the National Flood Insurance Program which publishes the FIRM maps). The floodplain is often defined as: “That land that has been or may be covered by floodwaters, or is surrounded by floodwater and inaccessible, during the occurrence of the regulatory flood.” 4 The nature and extent of a flood event is the result of the hydrologic response of the landscape. Factors that affect this hydrologic response include soil texture and permeability, land cover and vegetation, land use and land management practices. Precipitation and snow melt, known collectively as runoff, follow one of three paths, or a combination of these paths, from the point of origin to a stream or depression: overland flow, shallow subsurface flow, or deep subsurface (“ground water”) flow. Each of these paths delivers water in differing quantities and rates. The character of the landscape will influence the relative allocation of the runoff and will, accordingly, affect the hydrologic response. Unlike precipitation and ice formation, steps can be taken to mitigate flooding through manipulation or maintenance of the floodplain. Insufficient natural water storage capacity and changes to the landscape can be offset through water storage and conveyance systems that run the gamut from highly engineered structures to constructed wetlands. Careful planning of land use can build on the natural strengths of the hydrologic response. Re-vegetation of burned slopes diverts overland flow (fast and flood producing) to subsurface flow (slower and flood moderating). The failure to recognize or acknowledge the extent of the natural hydrologic forces in an area has led to development and occupation of areas that can clearly be expected to flood on a regular basis. Despite this, communities are often surprised when the stream leaves its channel to occupy its floodplain. A past reliance on structural means to control floodwaters and “reclaim” portions of the floodplain has also contributed to inappropriate development and continued flood-related damages. Winter weather conditions are the main driving force in determining where and when floods will occur. The type of precipitation that a winter storm produces is dependent on the vertical temperature profile of the atmosphere over a given area.5 Unusually heavy snow packs and/or unusual spring temperature regimes (e.g. rapid warming) may result in the generation of runoff volumes significantly greater than can be conveyed by the confines of the stream and river 4 FEMA. Federal Emergency Management Agency. National Flood Insurance Program. Washington D.C. Available online at www.fema.gov. 5 “Snowstorms”. Rampo College. Resource Section for Meteorology. Available online at http://mset.rst2.edu/portfolios/k/khanna_n/meteorology/snowstorms.htm. October 2006. 21 channels. Such floods are often the ones that lead to widespread damage and disasters. Floods caused by rapid spring snow melt tend to last for a period of several days to several weeks, longer than the floods caused by other meteorological events. On small drainages, the most severe floods are usually a result of rainfall on frozen ground; however, moderate quantities of warm rainfall on a snow pack, especially for one or more days, can also result in rapid runoff and flooding in streams and small rivers. Although meteorological conditions favorable for short-duration warm rainfall are common, conditions for long-duration warm rainfall are relatively rare. Occasionally, however, the polar front becomes situated along a line from Hawaii through Oregon, and warm, moist, unstable air moves into the region. The major source of flood waters on the Reservation is normal spring snow melt. As spring melt is a “natural” condition; the stream channel is defined by the features established during the average spring high flow (bank-full width). Small flow peaks exceeding this level and the stream’s occupation of the floodplain are common events. The magnitude of most floods on the Reservation depends on the particular combinations of intensity and duration of rainfall, pre-existing soil conditions, area of a basin, elevation of the rain or snow level, and the amount of snow pack. Man-made changes to a basin also can affect the size of floods. Although floods can happen at any time during the year, there are typical seasonal patterns for flooding based on a variety of natural processes that cause floods: • Heavy rainfall on wet or frozen ground, before a snow pack has accumulated, typically cause fall and early winter floods • Rainfall combined with melting of the low elevation snow pack typically cause winter and early spring floods • Late spring floods result primarily from melting of the snow pack Flash Flooding There are three types of flash flooding: • Extreme precipitation and runoff events • Inadequate urban drainage systems that become overwhelmed by runoff • Dam failures Events that may lead to flash flooding include significant rainfall and/or snowmelt on frozen ground in the winter and early spring months, high intensity thunderstorms (usually during the summer months), and rainfall onto burned areas where high heat has caused the soil to become hydrophobic or water repellent which dramatically increases runoff and flash flood potential. 22 Flash floods from thunderstorms do not occur as frequently as those from general rain and snowmelt conditions, but are far more severe. The onset of these flash floods varies from slow to very quick and is dependent on the intensity and duration of the precipitation and the soil types, vegetation, topography, and slope of the basin. When intensive rainfall occurs immediately above developed areas, the flooding may occur in a matter of minutes. Sandy soils and sparse vegetation, especially recently burned areas, are conducive to flash flooding. Mountainous areas are especially susceptible to the damaging effects of flash floods, as steep topography may stall thunderstorms in a limited area and may also funnel runoff into narrow canyons, intensifying flow. A flash flood can, however, occur on any terrain when extreme amounts of precipitation accumulate more rapidly than infiltration on any terrain. Flash floods are most common in Washington during the spring and summer months due to thunderstorm activity. Floods that result from rainfall on frozen ground in the winter, or rainfall associated with a warm, regional frontal system that rapidly melts snow at low and intermediate altitudes (rainon-snow) can be the most severe. Both of these situations quickly introduce large quantities of water into the stream channel system, easily overloading its capacity. Occasionally, floating ice or debris can accumulate at a natural or man-made obstruction and restrict the flow of water. Ice and debris jams can result in two types of flooding: • Water held back by the ice jam or debris dam can cause flooding upstream, inundating a large area and often depositing ice or other debris which remains after the waters have receded. This inundation may occur well outside of the normal floodplain. • High velocity flooding can occur downstream when the jam breaks. These flood waters can have additional destructive potential due to the ice and debris load that they may carry.6 Flooding from ice or debris jams is a relatively common phenomenon in central Idaho and can be a significant contributor to flood-related damages. Small jams frequently occur in many of the streams throughout the Nez Perce Reservation, particularly at bridge abutments and culverts. Dam failures also pose a potential flood hazard. A dam failure is the structural collapse of a dam that releases the water stored in the reservoir behind the dam. A dam failure is usually the result of the age of the structure, inadequate spillway capacity, or structural damage caused by an earthquake or flood. The sudden release of water has the potential to cause human 6 Barnhill, Dave, et al. “Flash Floods – How do they occur?”. Waterlines. Division of Water, Indiana Department of Natural Resources. Spring-Summer 1999. Indianapolis, Indiana. 23 casualties, economic loss, and environmental damage. This type of disaster is dangerous because it can occur rapidly, providing little warning and evacuation time for people living downstream. The flows resulting from dam failure generally are much larger than the capacity of downstream channels and can, therefore, lead to extensive flooding. Flood damage occurs as a result of the momentum of the flood caused by the sediment-laden water, flooding over the channel banks, and impact of debris carried by the flow. Probability of Future Occurrence The probability of flood events occurring on Tribal lands is high. Low magnitude flood events can be expected several times each year. Larger magnitude and high impact flood events have occurred, but are not likely in any given year. These types of flood events have the highest probability of occurrence in the winter or early spring and often have a greater impact on the cities of Laiwai, Kamiah, Kooskia, Stites and other communities/infrastructure located near natural floodplains. Minor flash flood events are expected annually most likely as a result of summer thunderstorms or rain-on-snow events. The South Fork of the Clearwater River runs along the southeastern edge of the Reservation through Stites and Kooskia before joining with the main stem of the Clearwater River. The Clearwater River then runs along the eastern edge of the reservation through Kamiah, Greer, and Orofino. Turning west, the Clearwater River then runs near the northern boundary of the Reservation and passes through Ahsahka, Lenore, and various other small communities and outlying residences. The Middle Fork and South Fork of the Clearwater River have a much higher probability of causing flood damage to area residents and communities. Although the USGS data is limited for the South Fork, it is clear that the 1964 flood was well outside the normal range of peak flows for the river. The 1996 and 1997 floods also show up as being above average peak flows; Table 2 summarizes major flood events on the Reservation. Due to the density of development as well as the lack of structurally sound levees, the communities of Kooskia, and Stites as well as several individual residences along the South Fork of the Clearwater have a high risk to flood events. Lawyer Creek also poses a flooding threat to nearby communities. In May of 2018 Lawyer Creek flooded Lawyer Canyon which resulted in the closure of State Highway 162 between Nezperce and Greencreek. Figure 6 shows areas of the reservation that have been identified as flood hazard areas. 24 Figure 6) Identified flood hazard areas on the Nez Perce Reservation. Many dikes and levees have been constructed along both the Middle and South Forks of the Clearwater River in the Kooskia vicinity. A levee on the west bank of the South Fork extends from the mouth upstream to a point across the river from Third Avenue in Kooskia. The levee on the east bank begins approximately 1,000 feet downstream of B Street and extends upstream to approximately 350 feet above First Avenue. The levee begins again at the 25 upstream end of the sewage lagoons, near Kooskia Airport, and extends upstream to approximately 5,000 feet past the southern city limits. South of the city, there are levees in various places along both sides of the South Fork Clearwater River. In February of 1948, the U.S. Army Corps of Engineers (USACE) performed clearing and snagging work along the South Fork levee for 2,000 feet in anticipation of the spring runoff that year. In 1949, the USACE made emergency repairs to 3,000 feet of the same levee above River Mile 1.0. These repairs were required due to the flood of 1948 (Figure 7). Figure 7) The 1948 flood in Kooskia, ID. Table 2) History of FEMA-declared floods on the reservation and in surrounding areas. Year Disaster Location Description 1964 Flood Idaho, Clearwater, Lewis, and Nez Perce Counties Heavy rains and flooding 1974 Flood Clearwater County Severe storms, snowmelt, and flooding 1996 Severe Storm Idaho, Clearwater, Lewis, and Nez Perce Counties Severe storms and flooding 1997 Severe Storm Idaho, Clearwater, and Nez Perce Counties Severe storms, flooding, mud and landslides 2005 Flood Nez Perce County and Reservation Heavy rains and flooding 2010 Severe Storm Idaho and Lewis Counties Severe storms and flooding 2011 Flood Nez Perce Reservation Idaho, Clearwater, and Nez Perce Counties Flooding, landslides, and mudslides 2017 Flood Idaho and Clearwater Counties Severe storms, flooding, landslides, and mudslides After the 1964 flood, local crews constructed a dike along the south side of the Middle Fork. This dike extends from the intersection of Dike Street in Kooskia and U.S. Highway 12, downstream 2,000 feet to a point upstream of the sewage lagoons. The dike along the Middle Fork has been tested twice with large flows in 1972 and 1974. Although flows in these years 26 were not as large as the 1964 flood, they were close, coming within 2,000 cfs. Table 2 displays FEMA declarations of disaster for flood events on the reservation and in surrounding counties. The city of Kooskia has a very high risk of flooding from both the Middle and South Forks of the Clearwater River. The levees currently built along the river banks will likely protect the city from most flood events; however, most of these levees were built over 50 years ago, need maintenance, and may not hold during a large event. There are three major dams are located in the vicinity of the Nez Perce Reservation: Dworshak Dam, Winchester Dam, and Soldiers Meadow Dam. None of these structures has failed or been subject to significant damage. However, a threat of potential dam failure occurred for Winchester Dam following a severe flood/winter storm event in February 1996. Impacts of Flood Events Due to several swift bodies of water on the Reservation, the probability of a flood-related fatality is moderate. Flash flood events in particular, or accidents, could result in a death or injury. First responders or other persons could be pinned under debris and drowned or receive trauma from debris being carried along the waterway. Once flood waters recede, mold can grow in wet material causing a public health hazard. Flood waters may contain sewage and hazardous chemicals that could be left on people’s property following a flood event. Furthermore, water and food may be contaminated and heat and electricity may be inoperable for a period of time. Although the probability of these types of impacts occurring at a moderate to large scale is very low, all of these factors could contribute to a decline in current and long-term health of Tribal residents. The continuity of operations for the Tribe is rarely compromised due to a flood event. The delivery of some services may be hindered by localized flooding in certain areas; however, due to the availability of alternative routes, this is not a significant concern. Damage to facilities, equipment, or files could impact certain organizations or public services depending on the extent of damage and duration of the event. Flood events on the Reservation are most likely to affect private property by damaging homes, businesses, barns, equipment, livestock, and vehicles. Both water and contaminants can damage or permanently ruin equipment. Flood waters can also erode land. This is particularly an issue when lands supporting roads, power lines, pipelines, sewage control facilities, levees, bridges, and other infrastructure are damaged by erosion. Some environmental impacts that may be realized by localized flooding could include erosion of stream banks, loss of riparian plant life, or contamination by chemicals or sewage. Flooding in some areas may have some environmental benefits such as establishing meanders that slow the stream flow, replenishing wetland areas, and replenishing the soil with nutrients from sediment. 27 Flooding on the Reservation is likely to have a significant or long-term effect on the local economy. Depending on the magnitude of the event, individual residents and businesses may be adversely impacted, but the economic viability of the community will not be affected. Severe damage to transportation infrastructure may have a short-term impact on certain communities due to the presence of state and U.S. highway routes, but alternative routes are available. Changes in the timing and intensity of precipitation is an expected result of a changing climate, the Idaho State Hazard Mitigation Plan (SHMP) states that areas within the United States that are prone to flooding will increase by up to 45% by 21007. In addition, by 2050 snowmelt is projected to occur three or four weeks earlier than the 20 th century average. The Clearwater Sub-basin is expected to shift from a snow-dominant basin to a rain-snow and rain dominant basin by mid-century, and heavy downpours are projected to increase by 13% (Hamlet et. Al 2013, U.S. Global Change Research Program8). Heavy downpours in rain-snow mix and rain dominant basins could increase flood risk, and stormwater management challenges. In addition, the dry season, and the fire season, is expected to be longer and more intense in the Pacific Northwest, leading to a greater probability of erosion, mud-slides, and landslides during precipitation events that could exacerbate the severity of floods (U.S. Global Change Research Program, 2014, National Climate Assessment). Development in or near floodplains increases the likelihood of flood damage. New developments near a floodplain add structures and people in flood areas thereby increasing, not the extent of the flood itself, but the impacts or damages that may be caused. New construction can also alter surface water flows by diverting water to new courses or increasing the amount of water that runs off impervious pavement and roof surfaces. This second effect diverts waters to places previously unaffected by flood issues. Unlike the weather and the landscape, this flood-contributing factor can be controlled. Development and occupation of the floodplain places individuals and property at risk. Such use can also increase the probability and severity of flood events (and consequent damage) downstream by reducing the water storage capacity of the floodplain, or by pushing the water further from the channel or in larger quantities downstream.9 7 FEMA U.S. (2013). The Impact of Climate Change and Population Growth on the NFIP through 2100. 8 Alan F. Hamlet , Marketa McGuire Elsner , Guillaume S. Mauger , Se-Yeun Lee , Ingrid Tohver & Robert A. Norheim (2013) An Overview of the Columbia Basin Climate Change Scenarios Project: Approach, Methods, and Summary of Key Results, Atmosphere-Ocean, 51:4, 392-415, DOI: 10.1080/07055900.2013.819555 9 Planning and Flood Risk. Planning Policy Statement 15. The Planning Service, Department of Environment. June 2006. Available online at http://www.planningni.gov.uk/index/policy/policy_publications/planning_statements/pps15-flood-risk.pdf. 28 Dam Failure Three major dams are located in the vicinity of the Nez Perce Reservation: Dworshak Dam, Winchester Dam, and Soldiers Meadow Dam (Figure 8). None of these structures has failed or been subject to significant damage. However, a threat of potential dam failure occurred for Winchester Dam following a severe flood/winter storm event in February 1996. Three of the dams are regulated by the Idaho Department of Water Resources (IDWR). Dams regulated by the IDWR include concrete and earthen structures that are 10 feet higher or store more than 50-acre feet of water. The largest dam located within the Reservation is Dworshak Dam. Dworshak Dam, which is fed by the North Fork Clearwater River, is located in Clearwater County, 5 miles north of Orofino. As the biggest concrete dam in the State, it is over 633 feet high and has a storage capacity of 3,453,000 acre-feet. The second, smaller dam, Soldiers Meadow Dam, is located 6 miles southeast of Waha in Nez Perce County. This earthen dam, which is fed by Webb Creek, is 50 feet high and has a water storage capacity of 2,370 acre-feet. The smallest dam located near Winchester in Lewis County is Winchester Dam. Winchester Dam, which is also an earthen dam, is 36 feet high and can hold more than 850 acre-feet of water. The IDWR classifies potential losses and damages anticipated to downstream areas during a dam failure. Dworshak Dam, Soldiers Meadow Dam, and Winchester Dam are all classified as high risk. Dams rated in this classification can potentially inundate downstream areas with floodwater levels with depths of more than 2 feet and/or a velocity of 2 feet or more per second. Failure of Dworshak Dam would likely be contained without causing failure of McNary Dam, near Umatilla, Oregon. However, dam failure would cause property damage to rail lines along the Clearwater and Snake rivers; Highways 12 and 730; and the Nez Perce Tribal Fish Hatchery on the Clearwater River and numerous other structures in the flood plain. Flooding would occur at Orofino within 45 minutes, with a peak flood time of 3 hours and 45 minutes and a peak water level of 80 feet. Flooding would also affect the Nez Perce National Historical Park within 2 hours, with a peak time of 5 hours and 30 minutes and a peak water level of 55 feet. Floodwater arrival at the confluence of the Snake and Clearwater rivers in Lewiston would be 3 hours and 15 minutes, with a peak water level of 52 feet at 6 hours and 30 minutes. In addition, floodwaters would affect the communities of Mrytle, Lenore, Spalding, and Ahsahka. Floodwaters would not directly impact the city of Lapwai. Failure of Soldiers Meadow Dam would have a significant impact on the city of Lapwai and the Tribal Headquarters. In a sudden failure, floodwaters would reach the city of Lapwai within an hour and affect the entire valley floor at Sweetwater, Lapwai, and Spalding. The depth and duration of the flood is also dependant upon conditions. 29 Figure 8) Dam location and areas likely to be inundated in the event of a dam failure on the Nez Perce Reservation. 30 In a sudden failure, floodwaters from Winchester Dam could reach the city of Lapwai fairly soon. Floodwaters would impact Culdesac, Sweetwater, Lapwai, and Spalding. The depth and duration of the flood is dependant upon conditions and are not absolutely certain. It has been determined that a series of culverts leading this stream through Highway 95 would slow the progress of floodwaters significantly and buffer the impact of dam failure. All three dams are inspected annually by the IDWR to ensure that they are in good operating condition. An imminent dam failure for any of the three dams is not expected due to structural damage caused by earthquakes or flooding. In addition, all three dams are considered to be at low-risk to terrorists’ attacks. Value of Resources at Risk Nearly all of Kooskia on both sides of the South Fork of the Clearwater River and a significant portion of the city along the south side of the Middle Fork, particularly on the eastern edge, have a high risk of flooding. This includes large sections of residential areas as well as much of the Main Street business district. City Hall, the fire department, the airport, the wastewater treatment facility, and three municipal well heads are included in this floodplain. Just south of the city limits, the floodplain also includes the Clearwater Forest Industries mill and a portion of the parcel containing Clearwater Valley High School. Furthermore, a section of State Route 13 through downtown Kooskia and a section U.S. Highway 12 on the north side of the Middle Fork are within the floodplain and could potentially be damaged or closed. The State Route 13 bridge crossing on the Middle Fork and a smaller access bridge about ½ mile upstream are also in the floodplain; however, both of these bridges were built to withstand a major flood event. At the time of the development of this plan, an analysis of the value of structures at risk was not performed due to data limitations. However, Table 3 displays the type and number of structures found in different flood and inundation zones identified on the reservation (hazard zone acronyms are defined below the table). Reservation-wide, more than 1,700 structures are located in tributary flood zones and in the event that the Clearwater River Dam failed, more than 1,700 structures would be at risk. Refer to the maps in this section and the Vulnerable Areas and Infrastructure section for total values at risk on the Nez Perce Reservation. 31 Table 3) Type and number of structures located in both tributary flood zones (all areas within 500ft of tributaries) and Clearwater River dam inundation zones as identified on the Nez Perce Reservation. A count of outbuildings could not be made but the quantity was estimated to be several hundred. Structure Type Homes/Residential Commercial and Commercial-type Other School Buildings Churches Schools Historical Structures Children’s Home Hospital Health Clinic Senior Citizen Facility Prison Outbuildings Total Count of Structures in Designated Hazard Zones F.Z.’s C.R. Dam L.C. Dam WC/SWC 1,302 1,462 738 64 385 297 85 4 16 15 21 5 3 2 6 1 1 3 1 1 1 1 1 1 Hundreds Hundreds Hundreds Several 1,713* 1,779* 856* 68* F.Z.’s –Flood Zones (all areas within 500 feet of tributaries) C.R. Dam –Clearwater River Dam Inundation Zone L.C. Dam –Lapwai Creek Dam Inundation Zone WC/SWC –Webb/Sweetwater Creek Inundation Zone *Value includes countable structures only (outbuildings were not included). 32 Severe Weather Hazard Profile Severe weather is a serious hazard that can and does affect the Nez Perce Reservation on a regular basis. Severe weather affects the entire state of Idaho with varying degrees, due to the complex landscape and the influence from the Pacific Ocean. Although Idaho’s severe weather is minimal in comparison with the rest of the nation, severe weather poses a significant hazard to the state and local communities. Storm-related Presidential Disaster declarations were made for Idaho in 1964, 1972, 1974, 1996, 1997, 2005, 2006, and 2010; Most of these storms resulted in flood damages. Severe weather within the Reservation consists of droughts, hailstorms, and windstorms; Figure 9 is a map of past major storm occurrences in Idaho. The pattern of average annual temperatures for the Reservation indicates the effects of altitude on temperature. The highest annual averages are found in the lower elevations of the Clearwater and downstream to Lewiston. The range between the mean temperature of the coldest and warmest months of the year varies from less than 40F, to well over 50 F at stations in the higher elevation. In summer, periods of extreme heat extending beyond a week are quite rare; the same can be said of periods of extremely low temperatures in winter. In both cases the normal progress of weather systems across the Reservation usually results in a change at rather frequent intervals. Extreme temperatures, when coupled with low precipitation for extended periods of time, can lead to a drought. Figure 9) Past Occurrence of severe storms across Idaho (Idaho Hazard Mitigation Plan, 2013). Thunderstorms are a common occurrence across the Reservation and with them comes the potential for a variety of other severe weather phenomenon. Due to their relative frequency and minimal severity, severe thunderstorms are not well documented across the Reservation. 33 Typically, their impacts are fairly limited and do not significantly affect the communities. The secondary effects of thunderstorms can be widespread and include hail, high winds, and lightning events. Past weather patterns show that severe weather conditions are likely to happen in any part of the Nez Perce Reservation in any given year. The topographical features of the area contribute greatly to the various weather patterns that occur. All areas within this region are vulnerable to severe local storms. Drought Drought is an expected phase in the climactic cycle of almost any geographical region. Objective, quantitative definitions for drought exist but most authorities agree that, because of the many factors contributing to it and because its onset and relief are slow and indistinct, none are entirely satisfactory. According to the National Drought Mitigation Center, drought originates from a deficiency of precipitation over an extended period of time, usually a season or more. This deficiency results in a water Figure 10) Types of drought (National Drought Mitigation Center). shortage for some activity, group, or environmental sector. What is clear is that a condition perceived as “drought” in a given location is the result of a significant decrease in water supply relative to what is “normal” in that area.10 It should be noted that water supply is not only controlled by precipitation (amount, frequency, and intensity), but also by other factors including evaporation (which is increased by higher than normal heat and winds), transpiration, and human use (Figure 10). Drought in Idaho is generally associated with a sustained period of low winter snowfall. This results from a 10 National Oceanic & Atmospheric Administration. 2010. U.S. Drought Monitor. Drought Information Center. U.S. Department of Agriculture. Available online at http://www.drought.noaa.gov/index.html. 34 temporary, yet significant, change in the large-scale weather patterns in the western U.S. The limited snow packs result in reduced stream flows and ground water recharge. Idaho’s system of reservoirs and natural storage can buffer the effects of minor events over a few years, but a series of dry winters (or an especially pronounced single low snowfall event) will result in a shortage of available water. Extended periods of above-average temperatures during the spring and summer can increase the impacts of low snow packs. Flash droughts are another type of drought that are associated with climate change, and are produced from increased temperatures and/or reduced precipitation resulting in rapidly decreasing soil moisture. In every drought, agriculture is adversely impacted, especially in non-irrigated areas such as the dry land farms and rangelands in and throughout the Nez Perce Reservation. Droughts impact individuals (farm owners, tenants, and farm laborers), the agricultural industry, and other agriculture-related sectors. The severity of drought is measured by the Palmer Index in a range of 4 (extremely wet) to -4 (extremely dry). The Palmer Index incorporates temperature, precipitation, evaporation and transpiration, runoff and soil moisture when designating the degree of drought.11 Probability of Future Occurrence The Idaho Department of Water Resources reports that meteorological drought conditions (a period of low precipitation) existed in the State approximately 30% of the time during the period 1931-1982. Principal drought in Idaho, indicated by stream flow records, occurred during 1929-41, 1944-45, 1959-61, 1977, and 1987-92.12 According to the State of Idaho, a drought from 1987-1992 resulted in the worst water shortage in 10 years. Additionally, below-capacity reservoirs resulted in reduced irrigation capacity, plowed-under crops, high water temperatures, and starvation of wildlife due to the lack of perennial grass growth. The Nez Perce Reservation, along with much of Idaho, experienced another seven year drought from 1999 to 2005. While 2006 and 2008 were not drought years, 2007 had severe drought most of the year with extreme drought from August to October. The historical records demonstrate a cyclical pattern that shows drought is likely to occur on the Reservation about every 10 years and last from 1 to 7 years with varying degrees of severity (Figure 11). The effects of droughts will be compounded by the influences of a climate change; altered weather and precipitation patterns, and increased average annual temperatures could lead to prolonged periods of drought. 11 “Drought Monitoring”. National Weather Service Climate Prediction Center. NOAA. February 2011. Available online at http://www.cpc.ncep.noaa.gov/products/monitoring_and_data/drought.shtml. 12 Idaho Department of Water Resources. 2010. Idaho Drought Emergency Declarations. Available online at http://www.idwr.idaho.gov/News/drought/drought.htm. 35 Figure 11) Palmer Drought Severity Index for the Nez Perce Reservation in 2017. Impacts of Drought Events Drought affects water levels for use by industry, agriculture, and individual consumers. Water shortages affect firefighting capabilities through reduced flow and pressure. Drought also affects power production. Much of Idaho’s power is produced by hydro-electric dams. When water levels drop, electric companies cannot produce enough power to meet demand and are forced to buy electricity from other sources. Oftentimes, drought is accompanied by extreme heat. When temperatures reach 90 degrees and above, people are vulnerable to sunstroke, heat cramps, and heat exhaustion. Pets and livestock are also vulnerable to heat-related injuries. Crops can be vulnerable as well. In the past, droughts within the Reservation resulted in significantly lessened crop yields. Drought increases the danger of wildland fires. Fires in rangeland areas are particularly dangerous due to typically high rates of spread and the scattered nature of structures and infrastructure. Compounding the effects of droughts are the impacts from a changing climate. Following the assessment of the Idaho State Hazard Mitigation Plan that recognized the potential to experience more frequent and severe droughts to communities in Idaho, the Tribe recognizes the need to protect water and food resources. 36 Value of Resources at Risk Although the financial impacts of drought can be substantial and extended, accurately quantifying these impacts is problematic. Drought typically does not cause direct losses to structures or infrastructure, although the forest and rangelands throughout the Reservation are at increased risk to wildfires as a result of drought conditions. Reservation lands have experienced numerous large wildland fires in the past two decades resulting in thousands of acres of forest and rangeland burned and numerous structures and livelihoods lost. The resulting smoke and road closures often affect local citizens as well have impacts on the economy. Due to the nature of the hazard, it is difficult to quantify potential loses as a result of drought. However, the tangible losses are most clearly seen in the agriculture and livestock ranching sectors of the Reservation’s economy. Dry land agriculture can be negatively impacted by drought conditions due to reduced yields and limited crop diversification. Livestock ranchers may be forced to recalculate range carrying capacities, change field rotations, and provide supplemental feed for livestock. Reduced hydroelectric power production can also result from decreased water levels in the area reservoirs. Hailstorms Hail can occur in any strong thunderstorm, which means hail is a threat throughout the Reservation. Hail is precipitation that is formed when updrafts in thunderstorms carry raindrops upward into extremely cold areas of the atmosphere. Formation of larger hail stones can fall at speeds faster than 100 miles per hour. Often the hail that occurs does not grow to a size larger than one-half inch in diameter and the areas affected are usually small. Quite often hail comes during early spring storms, when it is mostly of the small, soft variety with a limited damaging effect. Probability of Future Occurrence In July of 1995 several severe thunderstorms moved through the state of Idaho. One thunderstorm in Northern Idaho produced hail .75 inch to 1.50 inches in diameter and high winds that downed power lines and trees in Nez Perce, Lewis, Latah, Shoshone, and Idaho Counties. One-inch hail fell near Cottonwood and 1.50 inches hail fell near Grangeville. This storm damaged the wheat and barley crops at a 100 percent loss in the Cottonwood area. Just south of Cottonwood, trees were uprooted and the roof of an apartment building was torn off causing extensive property damage. This area also suffered a power outage. Winds at Fenn and Cottonwood shattered windows and hail dented automobiles. Large hailstones, 2-3 inches in diameter, were observed throughout some areas of the Pacific Northwest in early spring of 37 1997. Thunderstorms in spring of 2006 and 2007 produced hailstones that were reported at 1.75” in diameter near Culdesac and Lenore. These types of damaging hailstorms are typically infrequent and localized to a fairly small area. Based on previous occurrences, the likelihood of a hailstorm event within the Reservation occurring is every 5 years. The more common hailstorms that often accompany thunderstorms generally occur several times each year, but cause limited to no damage. Impacts of Hailstorms The effects are generally transportation accidents and loss of utilities. When transportation accidents occur, motorists are stranded and schools and businesses close. The effects vary with the intensity of the storm, the level of preparation by local jurisdictions and residents, and the equipment and staff available to perform tasks to lessen the effects of severe local storms. There is no way to prevent severe storms. The weather forces and topography of Nez Perce Reservation will always dictate when and where severe storms will occur. The potential impacts of a severe hail storms include crop damage, downed power lines, downed or damaged trees, broken windows, roof damage, and vehicle damage. Hail storms can, in extreme cases, cause death by exposure. The most common direct impact from ice storms to people is traffic accidents. Over 85% of ice storm deaths nationwide are caused by traffic accidents. Hail storms also have the potential to cause losses among livestock. The highest potential damage from hail storms is the economic loss from crop damage. Even small hail can cause significant damage to young and tender plants. Value of Resources at Risk Although the financial impacts of hail can be substantial and extended, accurately quantifying these impacts is problematic. Hail typically causes direct losses to structures and other personal property as well as to the extensive agricultural development. Potential losses to agriculture can be disastrous. They can also occur locally; thus, individual farmers can have significant losses, but the event may not drastically affect the economy of the Reservation. Furthermore, crop damage from hail will also be different depending on the time of year and the type of crop. Most farmers carry insurance on their crops to help mitigate the potential financial loss resulting from a localized hail storm. Federal and state aid is available with declared hail disasters resulting in significant loss to local farmers as well as the regional economy. Homeowners rarely incur severe damage to structures (roofs); however, hail damage to vehicles is not uncommon. The damage to vehicles is difficult to estimate because the number of vehicles impacted by a specific ice storm is unknown. Additionally, most hail damage records are kept by various insurance agencies. 38 Windstorms The National Weather Service defines high winds as sustained winds of 40 mph or gusts of 58 mph or greater, expected to last for an hour or more.13 Windstorms are frequent across all of the Reservation and they have been known to cause substantial damage (Table 4). Under most conditions, the area’s highest winds come from the northwest. However, during the summer months lightning and thunderstorms often come from the south to southwest. Due to the abundance of agricultural development on the Reservation, crop damage due to high winds can have disastrous effects on the local economy. In the case of extremely high winds, some buildings may be damaged or destroyed, and tractor-trailers overturned. Wind damages will generally be categorized into three groups: 1) structure damage to roofs, 2) structure damage from falling trees, and 3) damage from wind-blown dust on sensitive receptors. Structural injury from damaged roofs is not uncommon. Airborne particulate matter increases during high wind events, especially under drier conditions, which can lead to reduced visibility and increased transportation related accidents. When wind blowing dust events occur, sensitive receptors including the elderly, children, and those with asthma are at increased risk of breathing complications. Table 4) Records of wind gust at the Lewiston Airport, historical maximum recorded wind gust for each month by year recorded. Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Historic Max Year 44 43 43 49 47 47 43 36 41 46 40 38 28 33 43 38 59 31 28 43 56 37 52 55 52 40 37 39 45 41 51 48 52 36 52 32 41 41 39 36 51 43 45 47 37 31 26 52 39 36 41 51 47 37 47 46 33 37 38 44 52 33 46 44 39 39 36 40 49 35 33 40 48 41 43 47 41 39 43 37 39 52 49 52 47 85 32 60 33 39 28 35 41 38 41 39 44 40 37 56 37 24 53 43 46 49 39 36 51 43 44 36 41 48 48 44 37 63 52 36 38 35 41 32 48 40 59 38 47 48 47 48 60 59 55 54 52 52 63 85 47 58 63 59 2000 2008 2004 2002 2006 2001 1998 2011 2000 2001 2010 2008 Microbursts are columns of cold sinking air within a thunderstorm and is typically less than 2.5 miles across and can reach speeds of up to 100 mph. Microburst progress through a series of stages; contact stage is when the descending air makes contact with the surface and the 13 http://www.nhc.noaa.gov/aboutgloss.shtml#h. Accessed October, 2012. 39 highest windspeeds are observed, outburst stage occurs as the air moves outward from the point of contact, and cushion stage is the final stage where winds along the surface begin to slow due to increased friction. Wind speeds from microbursts can cause significant damage and are potentially life threating. A tornado is formed by the turbulent mixing of layers of air with contrasting temperature, moisture, density, and wind flow. This mixing accounts for most of the tornadoes occurring in April and May, when cold, dry air from the north or northwest meets warm, moister air moving up from the south. If this scenario was to occur and a major tornado was to strike a populated area within the Reservation, damage could be widespread. Businesses could be forced to close for an extended period, and routine services such as telephone or power could be disrupted. The National Weather Service defines a tornado as a violently rotating column of air that contacts the ground; tornados usually develop from severe thunderstorms.14 Areas most vulnerable to tornados are those subject to severe thunderstorms or those with a recurrence rate of 5 percent or greater, meaning the Reservation experiences one damaging severe thunderstorm event at least once every 20 years (Table 5). Table 5) List of tornadoes that have touched down in and around the Nez Perce Reservation. ID Date Time Dead Inj. F-Scale Beg. Coord End Coord. County 150 11-Apr-79 14:00 0 0 0 45.92, -116.13 0.00, 0 Idaho 1099 7-Oct-10 17:20 0 0 0 46.13, -116.42 46.13, -116.42 Idaho 1100 7-Oct-10 17:41 0 0 0 46.19, -116.36 46.19, -116.37 Lewis 124 8-May-62 16:00 0 0 2 46.40, -116.80 46.40, -116.60 Nez Perce 280 20-Jun-69 16:35 0 0 1 46.50, -116.80 0.00, 0 Nez Perce 707 31-May-97 15:10 0 0 0 46.42, -116.97 46.42, -116.97 Nez Perce Probability of Future Occurrence On May 31, 1997, six tornadoes touched down in Washington and Idaho in one day. In nearby Lewiston, an F0 tornado along with 70 mph+ winds was observed. In 1999, an intensified thunderstorm produced wind gusts over 50 mph on the Nez Perce Reservation. In December 2006 winter storms produced windstorms of 76 kts (F1 is 73 kts) in Lewis County and several 14 http://www.noaawatch.gov/themes/severe.php. Accessed October, 2012 40 occurrences over 50 kts were reported across the reservation. In May 2008 a funnel cloud was spotted near Grangeville. Throughout the Nez Perce Reservation, the strongest windstorms are generally associated with rapidly moving weather systems that occur between October and March. Generally these south and southwesterly winds can remain at 20–30 mph for several hours and reach peak speeds of more than 50 mph. In the summertime, windstorms are often associated with thunderstorm activity. Based on previous occurrences, the likelihood of a significant windstorm (wind speeds of in excess of 50 mph) occurring on the Reservation is every 4 years. Impacts of Windstorms The impacts of an extreme wind event to the community are usually minimal; however, the area affected by extreme wind events can be widespread making response difficult. Utilities and transportation are usually impacted by extreme wind events, either by poor road conditions to downed trees that block roadways and disrupt power distribution. Damage to structures, largely the loss of roofing materials, does occur on a more localized scale and is influenced by building materials and age of structure. Depending on the season of the event, severe winds may result in a loss of agricultural crops. Value of Resources at Risk It is difficult to estimate potential losses to the Reservation due to windstorms and tornadoes. Construction has been implemented in the presence of high wind events, and therefore, the community has a higher level of preparedness to high wind events than many other areas experiencing lower average wind speeds. Refer to the Vulnerable Areas and Infrastructure for more information about total values at risk on the reservation. Winter Storms Summer water supplies are dependent on winter storms brining snow packs to the mountains that surround the Reservation. While winter snow is a necessary component of life on the Reservation it also brings with it many potential disasters. Winter weather can impact transportation, disrupt utility services, cutoff remote residents from services, and reduce emergency services effectiveness. Winter storms are a part of life on the Reservation. Storms vary in degree and intensity and can occur at any time but are especially probable between September and April. These storms could be localized or could affect the entire state. They can last a matter of minutes or over many days. Typically, winter storms are measured by the amounts of snow accumulated during any given storm. Additionally, these storms could be measured by the accompanied wind or temperatures associated with each storm. 41 In any discussion about winter storms, terminology and the general characteristics of the causes and impacts of winter storms need to be defined. Natural winter storm events are grouped into the following categories: • Showers – Snow falling at varying intensities for brief periods of time. Some accumulation is possible. • Squalls – Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant. Snow squalls are best known in the Great Lakes Region. • Blowing Snow – Wind-driven snow that reduces visibility and causes significant drifting. Blowing snow may be snow that is falling and/or loose snow on the ground picked up by the wind. • Blizzard – A winter storm with winds over 35 mph and temperatures of 20 degrees F., Accompanied by blowing snow that reduces visibility to near zero. • Sleet – Rain drops that freeze into ice pellets before reaching the ground. Sleet usually bounces when hitting a surface and does not stick to objects. However, it can accumulate like snow and cause a hazard to motorists. • Freezing Rain – Rain that falls onto a surface with a temperature below freezing. This causes it to freeze to surfaces, such as trees, cars, and roads, forming a coat or glaze of ice. Even small accumulations of ice can cause a significant hazard. • Severe Winter Storm - defined as one that drops four or more inches of snow during a twelve-hour period, or six or more inches during a twenty-four-hour period. • Ice storm - occurs when cold rain freezes immediately on contact with the ground, structures, and vegetation. Snow plowing on the Reservation occurs from a variety of departments and agencies. The state highways are maintained by the State of Idaho. Plowing of county roads is done by the local highway districts and county road departments. Cities and towns are maintained by their respective road maintenance program and BIA/Tribal roads are maintained by the Tribal Road Maintenance Program. Roads that are not public access, such as roads on private property, are the responsibility of the landowner. Probability of Future Occurrence Historical accounts of past severe winter weather demonstrate the likelihood of future occurrence. The following is a non-comprehensive list of events that occurred within or around the Reservation. 42 Severe Storms, Flooding, Landslides, and Mudslides – FEMA-4313-DR (2017) Much of northern Idaho was declared a major disaster due to severe storms that caused flooding, landslides, and mudslides beginning on March 6 and running through March 28 of 2017. Damage was primarily to roadways and bridges. An estimated cost was $9,625,389 and covered 8 counties in northern Idaho. Severe Winter Storms – FEMA-2452-DR (2016) Counties just north of the reservation in Idaho experienced severe winter storms from December 16-27, 2015. Governor Butch Otter requested a disaster declaration for the three counties effected (Benewah, Bonner, and Kootenai). The storm resulted in damage to public utilities with an estimated cost of $5,290,887. Severe Storms, Flooding, Landslides, and Mudslides – FEMA-1987-DR (2011) March 31 to April 11, 2011 brought flooding that resulted in landslides and mudslides leading to damaged roadways and bridges. The estimated cost to the public was $4,602,005, with a per capita cost for the Tribe at $75.72. Disaster declaration by President Obama allowed for a cost share of emergency work and repair of damaged infrastructure. Heavy Rains and Flooding – FEMA-186-DR (1964) Nicknamed the Christmas Flood of 1964, claiming 47 lives and roughly $4 billion in damage (today’s cost). Areas affected by the storm included ~200,000 square miles in Idaho, Washington, Oregon, and California. Intense rainfall, producing as much as 15 inches in 24 hours in some locations, coupled with frozen ground and melting snow produced increased runoff in streams that were already running high due to snow melt15. Winter storms occur annually with varying degrees of intensity, but are mostly likely to be damaging in the higher elevation communities of Winchester, Craigmont, Greencreek, Nezperce, and Reubens where colder temperatures and limited windbreaks exacerbate the effects of snow accumulation. More extreme winter weather with long term cold temperatures, high winds, and/or snow accumulation occurs about every 3-5 years affecting some or all of the Reservation at one time. Impacts of Winter Storms Winter storms damage roofs by heavy snow accumulations with extent of the damage depending on the moisture content of the snow and the structural characteristics of the buildings. Blowing snow can cause vehicle and other types of accidents and can contribute to 15 The Christmas Flood of 1964. (2014). USGS. Retrieved from: https://www.usgs.gov/news/christmas-flood-1964 43 livestock losses from exposure. Ice can cause damage to powerlines, trees, and some structures and is likely to cause vehicle accidents or at least make driving conditions hazardous. Power outages often occur during winter storms lasting from several hours to days. This has a two-fold impact on residents as not only is power cut to homes and businesses, but primary heating is lost for many residents. Gas furnaces and wood stoves supplement electrical heating, but with wood heating the senior population is at a disadvantage. Frozen water pipes are the most common damage to residential and business structures. Older homes tend to be at a higher risk to frozen water pipes than newer ones. More rural parts of the Reservation are sometimes better prepared to deal with power outages for a few days due to the frequent occurrence of such events; however, prolonged failure, especially during cold winter temperatures can have disastrous effects. All communities should be prepared to deal with power failures. Community shelters equipped with alternative power sources will help local residents stay warm and prepare food. A community-based system for monitoring and assisting elderly or disabled residents should also be developed. All households should maintain survival kits that include warm blankets, flashlights, extra batteries, nonperishable food items, and clean drinking water. Emergency response to severe winter storms includes site visits by police or fire department personnel, opening of shelters, or assistance with shopping, medical attention, and communications. Value of Resources at Risk The economic losses caused by severe winter storms may frequently be greater than structural damages. Employees may not be able to travel to work for several days and businesses may not open. Damages are seen in the form of structural repair and loss of economic activity. Refer to the Vulnerable Areas and Infrastructure for more information about total values at risk on the reservation. 44 Landslide Hazard Profile Hazard Description and History Landslide is a general term for a wide variety of down slope movements of earthen materials that result in the perceptible downward and outward movement of soil, rock, and vegetation under the influence of gravity. The materials may move by falling, toppling, sliding, spreading, or flowing. Some landslides are rapid, occurring in seconds, whereas others may take hours, weeks, or even longer to develop. Although landslides usually occur on steep slopes, they also can occur in areas of low relief.16 Landslides range from shallow debris flows to deep-seated slumps. They destroy homes, businesses and public buildings, undermine bridges, derail railroad cars, interrupt transportation infrastructure, damage utilities, and take lives. Sinkholes affect roads and utilities. Losses often go unrecorded because insurance claims are not filed, no report is made to emergency management, there is no media coverage, or the transportation damages are recorded as regular maintenance. Landslides can occur naturally or be triggered by human-related activities. Naturally-occurring landslides can occur on any terrain, given the right condition of soil, moisture content, and the slope’s angle. They are caused from an inherent weakness or instability in the rock or soil combined with one or more triggering events, such as heavy rain, rapid snow melt, flooding, earthquakes, vibrations, and other natural causes. Other natural triggers include the removal of lateral support through the erosive power of streams, glaciers, waves, and longshore and tidal currents; through weathering, wetting, drying, and freeze-thaw cycles in surficial materials; or through land subsidence or faulting that creates new slopes. Long-term climate change can influence landslide occurrences through increased precipitation, ground saturation, and a rise in groundwater level, which reduces the strength and increases the weight of the soil. Landslides can also be induced, accelerated or retarded by human actions. Human-related causes of landslides can include grading, slope cutting and filling, quarrying, removal of retaining walls, lowering of reservoirs, vibrations from explosions, machinery, road and air traffic, and excessive development. Normally stable slopes can fail if disturbed by development activities. Often, a slope can also become unstable by earthmoving, landscaping, or vegetation clearing activities. Changing drainage patterns, groundwater level, or slope and surface water through agricultural or landscape irrigation, roof downspouts, septic-tank effluent, or broken water or sewer lines can also generate landslides. Due to the geophysical or human factors that 16 “Landslides”. SAARC Disaster Management Center. New Delhi. Available online at http://saarcsdmc.nic.in/pdf/landslide.pdf. Accessed March 2011. 45 can induce a landslide event, they can occur in developed areas, undeveloped areas, or any areas where the terrain was altered for roads, houses, utilities, buildings, and even for lawns.17 Stream and riverbank erosion, road building, or other excavation can remove the toe or lateral slope and exacerbate landslides. Seismic or volcanic activity often triggers landslides as well. Urban and rural living with excavations, roads, drainage ways, landscape watering, logging, and agricultural irrigation may also disturb the solidity of landforms. In general, any land use changes that affect drainage patterns or that increase erosion or change ground-water levels can augment the potential for landslide activity. The frequency of landslides, particularly cut and fill slopes along roads, is due to the geology, vegetation, climate, soils, and other human factors. There are, on occasion, severe landslide events that occur in Idaho. There have been eight declared disasters since 1990.18 Since 1976, major events have had a significant impact on transportation, communities, and natural resources in 1982, 1986 (x2), 1991, 1996-97, 1997, 1998 (x2), 2000, and 2017 (Table 6). Table 6) Landslide disaster declarations from 1982-2011 for Idaho counties. Year 1982 1986 1986 1991 19961997 Month July February March April NovemberJanuary Federal 1997 X 2000 2010 2011 MarchJune May & October June April April-May 2017 May X 1998 X X Counties Affected Boise Boise Boise, Elmore, Lewis, Nez Perce, Owyhee Bonner Adams, Benewah, Boise, Bonner, Boundary, Clearwater, Elmore, Gem, Idaho, Kootenia, Latah, Nez Perce, Owyhee, Payette, Shoshone, Valley, Washington Benewah, Bonner, Boundary, Kootenia, Shoshone Year 1982 1986 1986 1991 19961997 May: Lemhi, Nez Perce, Washington; Oct: Boundary 1998 Kootenai Bonner, Idaho, Shoshone Bonner, Boundary, Clearwater, Idaho, Nez Perce, Shoshone and Nez Perce Tribe Boundary, Bonner, Kootenia, Benewah, Shoshone, Latah, Clearwater, Idaho, Valley 2000 2010 2011 17 Tetra Tech. DMA 2000 Hazard Mitigation Plan. Onondaga County, New York. April 2010. 18 Idaho Bureau of Homeland Security. April 2011. Available online at www.bhs.idaho.gov. 1997 2017 46 Figure 12) Landscapes prone to landslides (slopes greater than 55%) on the Nez Perce Reservation. Probability of Future Occurrence As a frequent natural process, it is likely that landslides across the Reservation will continue to occur, and with altered weather patterns that are expected from climate change we could see an increase from historical frequency of major events. Additionally, there may be compounding 47 effects from increased wildfire activities due to a changing climate and an increase in the number and extent of landslides. Many factors will contribute to increased landslide events including the removal of vegetation causing soils to become more susceptible to erosion, water resistance of post-fire soils, and loss of root structures. All of these factors are commonly associated with second order fire effects, but with prolonged fire seasons and larger wildland fires as is predicted with our changing climate landslides, mudslides and debris flows will likely increase as well. Impacts of Landslide Events Landslides are a recurrent threat to waterways and highways and a danger to homes, schools, businesses, and other facilities. The unimpeded movement over roads—whether for commerce, public utilities, school, emergencies, police, recreation, or tourism—is essential to the normal functioning of the Reservation. The disruption and dislocation of these or any other routes caused by landslides can quickly jeopardize travel and vital services. Although small slumps on cut and fill slopes along roads and highways are relatively common, nearly all of the more significant landslide risks on the Reservation are associated with the steeper, mountainous slopes. Population centers and individual homes in the Clearwater River corridors (Stites, Kooskia, Kamiah, Greer, Ahsahka, Orofino, Spalding) and Lapwai Creek (Lapwai, Culdesac) have the highest risk of experiencing slides. However, most of the damage from slides on the Reservation will likely occur along roadways. Major landslides in communities that are situated along river corridors could cause property damage, injury, and death and may adversely affect a variety of resources. For example, water supplies, fisheries, sewage disposal systems, forests, dams, and roadways can be affected for years after a slide event. The negative economic impacts of landslides include the cost to repair structures, loss of property value, disruption of transportation routes, medical costs in the event of injury, and indirect costs such as lost timber and fisheries. U.S. Highways 95 and 12 have experienced numerous slides of varying severity that have blocked one or both lanes for several days. Slides in the river and stream drainages may also block the channel causing water to back up and spill over into areas not previously at risk to flooding. Numerous communities and homes could be at risk if this type of event were to occur. In many cases, a slide blocking the water channel would also cut off emergency access routes as many roads on the Reservations parallel the streams and rivers. Value of Resources at Risk Slides in the identified Clearwater Impact Zone are more likely to be larger and more damaging as weaknesses in the underlying rock formations give way. Although infrequent, this type of 48 slide has the potential to not only block, but destroy road corridors, dam waterways, and demolish structures. A number of structures lie within the Impact Zone as well as sections of U.S. Highway 12 and State Route 13. U.S. Highway 95 only has a short section of landslide prone slopes in the canyon south of Culdesac, and many of the other highly prone areas within the Reservation are on secondary roadways. At the time of the development of this plan, an analysis of the value of structures at risk was not performed. However, Table 7 shows the type and number of structures found in designated landslide areas across the reservation. In total, there are only about 20 homes/residential structures and several outbuildings that are in landslide risk areas. Refer to the maps in this section and the Vulnerable Areas and Infrastructure for total values at risk on the Nez Perce Reservation. The cost of cleanup and repairs resulting from slumps along roadways is difficult to estimate due to the variable circumstances with each incident including the size of the slide and proximity to a road maintenance shop. Other factors that could affect the cost of the damage may include culverts, streams, and removal of debris. Table 7) Structures at risk to landslides on the Nez Perce Reservation. Structure Type Homes/Residential Structures Outbuildings Total Count 20 Several 20* *Value includes countable structures only (outbuildings were not included). 49 Wildland Fire Profile Wildland Fire Characteristics In general, wildland fire behavior describes how fire reacts to available fuels, local topography, and current weather conditions. The relationships between these three components are dynamic; changing one condition can often exacerbate the affects that the other conditions have on fire behavior. As such, fire behavior is often modeled as a triangle with fuels, topography, and weather serving as the three sides (Figure 13). Understanding the relationships between the fire behavior components has important implications for not only managing an active wildfire but also mitigating wildfire risk. Since fuel is the only component that can be managed directly, management decisions regarding fuel types and fuel loading across the landscape need to be made based on characteristics that are inherent of the region -climate and topography. Strategic fuel breaks, conservation and restoration of native species, and prescribed burns are examples of 13) Fire Behavior Triangle management activities that can reduce wildfire risk and Figure (www.weatherstem.com) simplify the process of assessing potential wildfire behavior. A brief description of each of the fire environment elements follows in order to illustrate their effect on fire behavior. Weather Fire behavior is largely influenced by weather conditions. Wind, moisture levels, temperature, and relative humidity are all factors that determine the rates and which fuels dry and vegetation cures. The ignition potential of fuels is also determined by these factors; weather patterns and trends can be analyzed to determine how likely or easily a certain fuel type will ignite and if a fire will be sustained. Once started, the behavior of a wildfire is further determined by atmospheric stability and local and regional weather. As temperature, wind speed, wind direction, precipitation, storm systems, and prevailing winds all influence fire behavior, weather is the most difficult component of the fire triangle to predict and interpret. As observed in the Yarnell Hill fire in Arizona that killed 19 firefighters, a storm cell can cause a flaming front to change direction abruptly, 90 degrees in the case of the Yarnell Hill fire, and rapidly accelerate up to speeds of 10 to 15 mph. 50 Topography Fires burning in similar fuel types will burn differently under varying topographic conditions. Topography alters heat transfer and localized weather conditions, which in turn influences vegetative growth and resulting fuels. Changes in slope and aspect can have significant influences on how fires burn. In General, north slopes tend to be cooler, wetter, more productive sites. This typically results in heavy fuel accumulations, high fuel moistures, lower rates of curing for fuels, and lower rates of spread. In contrast, south and west slopes tend to receive more direct sun and therefore have the highest temperatures, lowest soil and fuel moistures, and lightest fuels. The combination of light fuels and dry sites leads to fires that typically display the highest rates of spread. These slopes also tend to be on the windward side of mountains which means they tend to be “available to burn” for a greater portion of the year. Slope also plays a significant role in the rate of spread of a fire as fuels upslope from the flaming front are subjected to preheating which means that they readily combust as the fire draws closer. The preheating process is exacerbated as slope increases which results in greater rates of spread and increased flame lengths. Therefore, steep slopes with a south –southwest aspect generally promote intense fire behavior due to dry fuels and the likelihood of predominant, westerly winds. Fuels In the context of wildfire, fuels describe any organic material, dead or alive, found in the fire environment. Grasses, brush, branches, logs, logging slash, forest-floor litter, conifer needles, and buildings are all examples of fuel types. The physical properties and characteristics of fuels govern how fires burn. Fuel loading, size and shape, moisture content, and continuity and arrangement all have an effect on fire behavior. In general, the smaller and finer the fuels, the faster the potential rate of fire spread. Small fuels such as grass, needle litter and other fuels less than a quarter inch in diameter are most responsible for fire spread. Fine fuels, those with high surface to volume ratios, are considered the primary carriers of surface fire. As fuel size increases, the rate of spread tends to decrease due to a decrease in the surface to volume ratio. Fires in large fuels generally burn at a slower rate but release much more energy and burn with much greater intensity. This increased energy release, or intensity, makes these fires more difficult to control. Fuels are classified by diameter as that has important implications for fuel moisture retention. The smaller the diameter, the more quickly the moisture content of a given fuel type changes while l [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/tribal%3Anez_perce%3A2d7709c0ef17aaf8. Public record. Not legal advice.