Table 11 – Wind Storms in Umatilla Countyand Near UIR

  Date            Type     Location        Comments   Information Source

C. – Possible Impacts from Wind Storms

Severe wind storms can break shingles and sometimes damage roof beams.  Where trees are present, severe wind storms can cause trees to blow down or tree limbs to break and fall on power lines or roofs of homes or businesses.   Power outages can occur as a result of major wind storms.  Major wind storms can blow mobile homes off their foundations if not anchored properly.  They can also damage doors and windows in buildings.  Advertising signs may suffer damage or be blown down.  Shrubbery and trees can receive significant damage.  Major wind storms can also damage public facilities and create disaster-related debris. Windstorm clean-up is another impact from wind storms.   Hours of costly overtime pay for public agencies and private entities involved in clean-up are often incurred.

 D. – The Extent and Probable Intensity of Wind Storms within the UIR

Generally, wind storms affect the entire UIR.  Wind speed and duration of high winds vary.  In the last ten years, the city of Pendleton has experienced wind storms each year where steady wind speeds have ranged between 40 to 55 miles per hour with wind gust ranging between 47 and 66 miles per hour.   Summer wind storms that accompany thunderstorms are short duration, but very intense. 

Two scales for judging wind intensity and determining potential damage from winds are the Saffir-Simpson Hurricane Scale and the Fujita Scale used for measuring tornadoes. The Saffir-Simpson Hurricane Scale, which follows, identifies five categories based on wind speed and predicts potential damage.

Category One
Wind speed: 74-95 mph (119-153 km/h)
 Damage: Damage primarily to unanchored mobile homes, shrubbery, and trees along with some coastal road flooding and minor pier damage

Category Two
Wind speed: 96-110 mph (154-177 km/h)
Damage: Roofing, door and window damage to buildings; Considerable damage to shrubbery and trees, mobile homes, poorly constructed signs, and piers

Category Three
Wind speed: 111-130 mph (178-209 km/h)
Damage: Structural damage to small residences and utility buildings; foliage blown off trees and large trees blown down; mobile homes destroyed
 

Category Four
Wind speed: 131-155 mph (210-249 km/h)
Damage: Extensive damage to doors, windows and lower floors of shoreline houses; total roof failures on small residences; shrubs, trees, and all signs blown down; mobile homes completely destroyed
 

Category Five
Wind speed: Greater than 155 mph (249 km/h)
Damage: Complete roof failure on many buildings and some complete building failures with small utility buildings blown over or away; severe and extensive window and door damage; mobile homes completely destroyed

The Fujita Scale, which is depicted in the table below, establishes categories for tornadoes based on wind speed.  It also identifies potential damage.

Based on the history of wind storms in Umatilla County, the intensity of most wind storms is F0 on the Fujita Scale and does not reach category one on the Saffir-Simpson Scale.  On occasion, a few wind storms reach Category Two on the Saffir-Simpson Scale and F1 on the Fujita Scale.  In this plan, these wind storms are considered major wind storms. Based on the history of wind storms listed in subsection 3.2.B., only three storms in the last forty years would be considered major wind storms. This is less than one major wind storm every 10 years.

E. – The Probability of Wind Storms Affecting the UIR in the Future

Blowing wind is a common occurrence in Umatilla County and on the UIR.  However, most wind storms cause no or very minimal damage.  Major damage-causing wind storms are much less frequent.  Therefore, the probability that the UIR will experience a major or damage-causing wind storm is medium.

F. – The Vulnerability of the UIR to Wind Storms

The UIR is not particularly vulnerable to wind storms.  Damage from past major wind storms has been negligible.  Therefore, the UIR has a low vulnerability to wind storms. This assessment is consistent with the Oregon State Hazard Mitigation Plan which does not identify Umatilla County as a county most vulnerable to wind storms.[i]  The risks from wind storms were assessed with a combined overall

 Section 3.6 – Dust Storms

A. – Definition, Causes and Characteristics of Dust Storms

Dust storms are a hazard generally known to occur in the Mid-Columbia River region, which includes Umatilla County .  Within Umatilla County , dust storms occur primarily in western Umatilla County between the Umatilla County line and city of Pendleton . 

The following description of the causes and characteristics of dust storms was obtained from the State of Oregon Hazard Mitigation Plan :[ii]

A dust storm is a strong, violent wind that carries fine particles such as silt, sand, clay, and other materials, often for long distances. The fine particles swirl around in the air during the storm. A dust storm can spread over hundreds of miles and rise over 10,000 feet. They have wind speeds of at least 25 miles per hour.

Dust storms usually arrive with little warning and advance in the form of a big wall of dust and debris. The dust is blinding, making driving safely a challenge. A dust storm may last only a few minutes at any given location, but often leave serious car accidents in their wake, occasionally massive pileups. The arid regions of Central and Eastern Oregon can experience sudden dust storms on windy days. These are produced by the interaction of strong winds, fine-grained surface material, and landscapes with little vegetation. The winds involved can be as small as "dust devils" or as large as fast moving regional air masses.

Approximately half of the dust in today's atmosphere may result from changes to the environment caused by human activity, including agriculture, overgrazing, and the cutting of forests. Data from dust traps near urban areas like Las Vegas show that the spread of housing and other human construction across the desert directly causes increases in dust storms by destabilizing the surface and vegetation.

Intensive tillage of soils in agricultural uses is also a significant condition releasing soil to make it easily transportable by high winds. Depending on the crop and region involved, tillage may be occurring in the spring and/or in the autumn. Research in north-central Oregon and south-central Washington indicates that region's dust problem isn't simply a matter of soil being redistributed from one field to another by the wind. Fine particulate becomes suspended in the air and may travel thousands of miles. Scientists indicate that the region is truly losing soil.

B - History of Dust Storm Disasters in Umatilla County

Table  12 - Dust Storms in Umatilla County

    Date            Type        Location       Comments   Information Source

C. - Possible Impacts from Dust Storms

The impacts from dust storms are the lack of visibility which causes major problems to those driving, particularly while on I-84 where normal driving speeds are over 60 miles per hour.  Also, dust will find its way into homes, barns, other buildings and vehicles which may require extra time spent on cleaning.

Over the past 30 years in Oregon , more than ten people have been killed and more than 60 people injured some very seriously, due to automobile accidents caused by dust storms, often exacerbated by excessive speed.

Of course, air quality is negatively impacted as high concentrations of particulate matter occur during dust storms.  Also, loss of topsoil occurs during dust storms.

D. – The Extent and Probable Intensity of Dust Storms near the UIR

Historically, the area near the Umatilla-Morrow County line to the city of Pendleton is the area most affected by dust storms.  Dust storm warning signs are posted on I-84 near milepost 165 and just to the west of the city of Pendleton .  This sign warns drivers that dust storms may occur within this 40-mile corridor. 

 Because of the UIR’s location further east of Pendleton at the foothills of the Blue Mountain , the reservation does not experience as intense dust storms as those experienced west of Pendleton.  However, dust storms still occur and present a threat to the reservation.  

 E. – The Probability of Dust Storms Affecting the UIR in the Future

There is not a detailed record of the effects of dust storms on the Umatilla Indian Reservation.  There is a history of dust storms causing deaths, injuries damage to lands located in western Umatilla County . Dust storms have occurred and impacted citizens living on the reservation.   Although, the impacts from dust storms may not be as severe as the impacts that harm western Umatilla County , the probability that a future dust storm that affects the reservation is medium.  

F. – The Vulnerability of the UIR to Dust Storms

The Vulnerability of the UIR to dust storms is medium.

Section 3.7 - Drought

A. – Definition, Causes and Characteristics of Drought[iii]

Drought is a period of prolonged dryness resulting from a lack of precipitation or diversion of available water supplies.  They appear to be cyclic and they can have a profound effect on the state’s economy, particularly the hydro-power and agricultural sectors. The environmental consequences are also far-reaching. They include insect infestations in Oregon forests and the lack of water to support endangered fish species.

B - History of Drought in Umatilla County

Table 13 – Dust Storms in Umatilla County

  Date       Type       Location          Comments          Information Source

In 2006, the Umatilla County Hazard Mitigation Plan provides the following statement about droughts affecting Umatilla County :

In a recent letter to Governor Ted Kulongoski, the Oregon Office of Rural Policy sited 44 states of emergency declarations for drought and low water conditions in 23 of Oregon ’s 35 counties over the last five years.  Umatilla County submitted emergency declarations due to low water conditions and drought in 2002 and 2005. 

In addition to the surface water drought, the western part of Umatilla County has had approximately 104,000 acre-feet of groundwater rights curtailed due to groundwater declines.  These groundwater declines have directly impacted fisheries, the aquatic environment, economic development and long-term rural and urban economic security[iv].  

C. - Possible Impacts from Drought

When a drought occurs it affects everyone living and working on the reservation and tribal interests beyond the reservation boundaries.  Droughts cause surface water as well as groundwater declines.  Surface and groundwater declines can directly impact fisheries, the aquatic environment, economic development and long-term rural and urban economic security.   Drought does not affect buildings or infrastructure.  People and livestock suffer most from droughts.  In a drought, community water supplies can be affected sometimes forcing water conservation measures.  

Droughts can affect the Tribes’ interests in other ways.  When a drought occurs, the desire to find other water sources increases.   Droughts can force the execution of water rights which implements irrigation restrictions.  This in turn can ruin agricultural crops.  Accompanying this action can be pressure to change existing water allocations for fisheries, agriculture and other uses increases.

D. – The Extent and Probable Intensity of Drought within the UIR

By definition, droughts are prolonged periods of dryness.  Based on the history of droughts in eastern Oregon , the probable intensity or extent of future droughts in this region will likely be a minimum of 18 months but more likely a three or more year event.

E. – The Probability of Drought Affecting the UIR in the Future

Oregon ’s drought history reveals many short-term and a few long-term events. The average recurrence interval for severe droughts in Oregon is somewhere between 8 and 12 years[v].

The probability that another drought will occur that affects the UIR is high[vi] .

F. – The Vulnerability of the UIR to Droughts

The UIR has a high vulnerability to droughts.

Section 3.8 - Fog

A – Definition, Causes and Characteristics of Fog

Essentially, fog is just a cloud at ground level.  It is made from condensed water droplets.

The National Weather Service defines fog as water droplets suspended in the air at the Earth's surface.

Fog occurs when the air is cooled to the point (the dew point) where it can no longer hold all of the water vapor it contains[vii].  Fog is often hazardous when visibility is reduced to ¼ mile or less. Thick fog or even freezing fog tends to occur in the Blue Mountains during the late fall and winter months. 

Fog that presents the greatest risk occurs as very thick fog hovering over I-84 through the Blue Mountains .

B - History of Fog Disasters in Umatilla County

Table 14 – Fog as a Hazardous Event in Umatilla County

      Date        Type        Location       Comments     Information Source

C. - Possible Impacts from Fog on the UIR

The impacts from thick fog are similar to those of dust storms in that the greatest danger occurs to automobile and truck traffic traveling at higher speeds.  Within the boundaries of the UIR, fog becomes particularly hazardous for freeway travelers using I-84.  In some cases, fog freezes making driving conditions much worse. Fog also has been a hazard on roads within the reservation.  Fog occurs when there is an inversion.  This condition traps pollutants making air quality on the reservation along the river very poor.  This can cause an increase in respiratory problems, particularly for those living on the reservation with respiratory problems..

D. – The Extent and Probable Intensity of Fog within the UIR

Heavy fog, where visibility is equal to or less than ¼ of a mile occurs in Pendleton, Oregon on average about 30 days a year.  The table[viii] below indicates that heavy fog is most likely to occur during the months of November through February. Because the UIR borders the city of Pendleton , it is presumed the table below applies also to the reservation.

Table 15 – The Mean Number of Days with Heavy Fog

E. – The Probability of Fog Affecting the UIR in the Future

The probability of fog occurring during late fall and winter is very high.  Fog primarily affects traffic using the I-84 as it passes through the reservation. Despite the fact that fog is a relatively common occurrence during certain times of the year, fog does not actually affect the UIR very much.  The greatest hazard fog presents is to freeway travelers using I-84 where it passes through the reservation.

F. – The Vulnerability of the UIR to Fog

The vulnerability of the UIR to fog that actually presents a hazard to the reservation is high. The fact that fog does present a greater threat to I-84 travelers passing through the reservation is a concern because the Tribe’s emergency service providers are often first at the scene of an accident.  Freezing fog presents an annual threat during winter months.  Although the Federal Highway Administration and the Oregon Department of Transportation are responsible for managing the risks presented by fog on I-84, Emigrant Hill, the greatest obstacle to safe travel, is located on the reservation. The CTUIR is willing to assist in minimizing the risks associated with the hazards presented by fog. 

Section 3.9 – Earthquakes

A. – Definition, Causes and Characteristics of Earthquakes

Earthquakes are sudden releases of energy that usually occur along existing fractures in the Earth’s surface, called a fault or fault line. The US Geological Survey defines earthquakes as “a sudden slip on a fault, and the resulting ground shaking and radiated seismic energy caused by the slip, or by volcanic or magmatic activity, or other sudden stress changes in the earth.”  Earthquakes occur somewhere on Earth everyday (see http://www.iris.edu/seismon ).  The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause shaking.   Most earthquakes are small and virtually unnoticeable.  Major earthquake can be catastrophic. The two pictures below show the Earth’s tectonic plates and a closer look at the Cascadia Subduction Zone located just off the Oregon coast.

       Earth’s Tectonic Plates           Cascadia Subduction Zone

Two ways of measuring earthquakes that are commonly used are the Richter Scale and the Modified Mercalli Intensity Scale. The Richter Magnitude Scale and the Modified Mercalli Intensity Scale are provided below:

    Richter Magnitude Scale    
    

Less than 3.5
      Generally not felt, but recorded.

3.5-5.4
      Often felt, but rarely causes damage.

Under 6.0
       At most slight damage to well-designed buildings.  Can cause major damage to poorly
                 
    

           
constructed buildings over small regions.

6.1-6.9
      Can be destructive in areas up
    to about 100 kilometers across where people live.

7.0-7.9
         Major earthquake. Can cause
    serious damage over larger areas.

8 or greater
      Great earthquake. Can cause serious damage in areas
    several hundred kilometers across.

Modified Mercalli Intensity Scale

I.   People do not feel any Earth movement.

II.   A few people might notice movement if they are at rest and/or on the upper floors of tall buildings.

III.    Many people indoors feel movement. Hanging objects swing back and forth. People outdoors might   not 

     realize that an earthquake is occurring.

IV.    Most people indoors feel movement. Hanging objects swing. Dishes, windows, and doors rattle. The

     earthquake feels like a heavy truck hitting the walls. A few people outdoors may feel movement. Parked cars

     rock.

V.   Almost everyone feels movement. Sleeping people are awakened. Doors swing open or close. Dishes are

     broken. Pictures on the wall move. Small objects move or are turned over. Trees might shake. Liquids might 

     spill out of open containers.

VI.    Everyone feels movement. People have trouble walking. Objects fall from shelves. Pictures fall off walls.

     Furniture moves. Plaster in walls might crack. Trees and bushes shake. Damage is slight in poorly built

     buildings. No structural damage.

VII .  People have difficulty standing. Drivers feel their cars shaking. Some furniture breaks. Loose bricks fall

     from buildings. Damage is slight to moderate in well-built buildings; considerable in poorly built buildings.

VIII. Drivers have trouble steering. Houses that are not bolted down might shift on their foundations. Tall

     structures such as towers and chimneys might twist and fall. Well-built buildings suffer slight damage.

     Poorly built structures suffer severe damage. Tree branches break. Hillsides might crack if the ground is wet.

     Water levels in wells might change.

IX.    Well-built buildings suffer considerable damage. Houses that are not bolted down move off their

     foundations. Some underground pipes are broken. The ground cracks. Reservoirs suffer serious damage.

X.   Most buildings and their foundations are destroyed. Some bridges are destroyed. Dams are seriously

     damaged. Large landslides occur. Water is thrown on the banks of canals, rivers, lakes. The ground cracks in

     large areas. Railroad tracks are bent slightly.

XI.    Most buildings collapse. Some bridges are destroyed. Large cracks appear in the ground. Underground

     pipelines are destroyed. Railroad tracks are badly bent.

XII.  Almost everything is destroyed. Objects are thrown into the air. The ground moves in waves or ripples.

     Large amounts of rock may move.

Earthquakes often occur along fault lines.  Faults are fractures in the Earth’s crust along which the blocks of crust on either side have moved relative to one another parallel to the fracture.  There are several known fault lines in Umatilla County and on the UIR as depicted in the USGS picture below:

B - History of Earthquakes in Umatilla County

Multiple small and some relatively moderate earthquakes have occurred in Umatilla County .  However, the intensity of many previous earthquakes was not recorded because instruments able to record earth movement were not available for eastern Oregon until the last ten to 15 years. Earthquakes have been happening in this area throughout history but have not been recorded.  DOGAMI believes that the information about earthquakes in eastern Oregon is underestimated[ix].

Table 16 identifies the three earthquakes that were intense enough to be registered as moderate earthquakes on the Richter Magnitude Scale and the Modified Mercalli Intensity Scale. 

Table 16 – Large Recorded Earthquakes in Umatilla County

The earthquake that occurred closest to the UIR happened at 11:08 PM PST on July 15, 1936, near the State line between Milton-Freewater , Oregon , and Walla Walla, Washington . The magnitude 5.75 shock affected an area of about 272,000 square kilometers in the two States and adjacent Idaho . Ground cracking was observed about 6.5 kilometers west of Milton-Freewater, and there were marked changes in the flow of well water (VII).   Also, chimneys were damaged, plaster was broken, and walls cracked. Similar damage was reported in Umapine. Total damage amounted to $100,000. There were numerous aftershocks up to November 17; more than 20 moderate shocks occurred during the night, and stronger ones were felt (V) on July 18 and August 4 and 27[x].

C. - Possible Impacts from Earthquakes

The main concern about earthquakes occurring on the reservation is the possible injuries to the elderly and disabled from falling objects including toppled shelving and articles falling from shelves.  Another impact could be damage to some of the older buildings and modular buildings on the UIR.  Older buildings that could suffer damage include St. Andrews Mission and the old BIA Office building.

Possible impacts from a relatively severe earthquake could result in: (1) breakage to sewer and water lines; (2) cracks in tribal and municipals wells allowing contamination to infiltrate into wells located on the reservation; (3) breaks to natural gas and oil pipelines; and (4) cracks or destruction to older buildings depending on the construction material and whether the building was designed to withstand earthquakes.

The Wild Horse Casino and Resort, Tamastslikt Cultural Institute, the new Public Safety Building (2007), and Cayuse Business Park (2007) were constructed recently to meet the International Building Code.  It is not expected that these buildings would suffer significant damage from a moderate earthquake and hopefully, would withstand the shaking that would result from liquefaction.  Liquefaction is caused when “earthquake waves cause water pressures to increase in the sediment and the sand grains to lose contact with each other, leading the sediment to lose strength and behave like a liquid. The soil can loose its ability to support structures, flow down even very gentle slopes, and erupt to the ground surface to form sand boils. Many of these phenomena are accompanied by settlement of the ground surface — usually in uneven patterns that damage buildings, roads and pipelines.”[xi]

Most of the buildings in Mission and near I-84 are located on land that is identified by DOGAMI’s Preliminary Liquefaction Susceptibility Map as having a “moderate” potential for liquefaction as depicted in yellow on the map below.  This area also has a high potential for “ground shake amplification (See liquefaction susceptibility and ground shake amplification maps in Appendix C – Earthquake folder).

D. – The Extent and Probable Intensity of Earthquakes within the UIR

It is likely that the entire UIR will experience future earthquakes that could be of moderate to high intensity.  This prognosis is based on information regarding past earthquakes with epicenters located near or on the reservation (as depicted in the diagram below) and also on information supplied by DOGAMI that indicates that all of Oregon has been scientifically established by the USGS to have a moderate to high seismic hazard probability.   The Department of Geology and Mineral Industries (DOGAMI) indicates that the seismic network that records earthquakes in Eastern Oregon has only been available in the last 5-10 years. Therefore, the intensity of many previous earthquakes is not available.

E. – The Probability of Earthquakes Affecting the UIR in the Future

Based on the information from DOGAMI for eastern Oregon and the history of earthquakes that have occurred and been recorded in this area, there is a moderate to high probability that the UIR will experience an earthquake in the future that will affect the people and some buildings located on the UIR. 

F. – The Vulnerability of the UIR to Earthquakes

Predicting when an earthquake will strike and its intensity is not feasible.   The best that can be done is analyzing past earthquakes and estimating the chance of future similar earthquakes based on the intervals between those earthquakes of the past.  Because information regarding past earthquakes affecting eastern Oregon is limited and that all of Oregon has been scientifically established by the USGS to have a moderate to high seismic hazard probability, the TERC has concluded that the UIR has a moderate vulnerability to earthquakes.

Section 3.10 – Volcanic Events

A. – Definition, Causes and Characteristics of  Volcanic Events

Volcanoes are a result of the complex interaction of tectonic plates along the Cascadia Subduction

Zone is the process that results in the seafloor plate subducting, or sinking, underneath the North American plate on which we live. As the subducted plate descends, it heats up and begins to melt. This provides the reservoir of heat and molten rock needed to create the magma chambers that lie kilometers deep underneath the Cascades[xii].

B - History of Volcanic Events in the Northwest

There have not been any volcanic eruptions in Umatilla County .  The closest, most recent volcanic eruption was Mount St. Helens in the state of Washington .  A brief history of the closest volcanic activity is discussed in Table 19 below[xiii].

Table  19 – History of Volcanic Events

C. - Possible Impacts from Volcanic Events on the UIR

The impacts from future volcanic events on Umatilla County [xiv] and the UIR would be relatively minor.  The biggest impact from a Cascade Mountain volcanic event would likely be from terpha or volcanic ash that would be carried by the prevailing western winds from an erupting volcano.  If just a small amount of ash (0.5 to 1.0 centimeters) is deposited on the reservation, several negative impacts are possible.  Particles of volcanic ash are so small that people and animals may need protection to ensure that breathing does not become impaired.  Volcanic ash can short-circuit power lines and can also damage painted surfaces due to its abrasive nature.

Perhaps the biggest problem associated with volcanic ash is that it can harm combustible engines and slow or completely stop transportation.  This could negatively impact all businesses on the reservation. On roads and streets, ashfall can create serious traffic problems as well as road damage. Vehicles moving over even a thin coating of ash can cause great clouds of ash to swell. This results in grave visibility problems for other drivers, calling for speed restrictions, and often forcing road closures. It also adds to the potential for health problems for residents of the area. Extremely wet ash creates very slippery and hazardous road conditions. Ash filling roadside ditches and culverts can prevent proper drainage and cause shoulder erosion and road damage.[xv]

D. – The Extent and Probable Intensity of Volcanic Events

Because the reservation is over 100 miles from the nearest Cascade Mountain volcano, the extent and intensity of a volcanic event from the UIR perspective would involve the amount of ash that might be deposited on reservation property.  The farther away from the volcano, the smaller the amount of ash will fall on the reservation.  During the eruption of Mount St. Helen, the reservation received just a dusting volcanic ash.  The probable extent of ash from a volcanic event will be less than the 0.5 to 1.0 centimeters that will negatively impact the reservation.

E. – The Probability of Volcanic Events Affecting the UIR in the Future

The picture below indicates that the UIR has between a 1 percent and a 0.02 percent of being impacted by a Cascade Mountain Range volcano in the future.  The probability distribution reflects the frequency of explosive eruptions at each major Cascade volcano, the variability in thickness of tephra that could be deposited at various downwind distances, and the variability in wind direction. Therefore, the probability that a volcanic event will impact the reservation is very low.

F. – The Vulnerability of the UIR to Volcanic Events

The vulnerability of the UIR to volcanic events is very low.   Therefore, no further analysis or mitigation actions addressing this hazard will be provided.

Section 3.11 – Landslides

A. – Definitions, Causes and Characteristics of Landslides

Umatilla County ’s Hazard Mitigation Plan provides a good description of landslides and their potential for impacts on lands in Umatilla County .  The Umatilla County Hazard Mitigation Plan’s description is as follows:

Landslide or subsidence is the down-slope movement of rock, soil or other debris, or the opening of sinkholes. These hazards are often associated with other events, such as floods or earthquakes. Because of the moderate-to-high relief characteristics of the county’s river beds, along with hill and mountainous terrain in rural areas, the chance of landslides occurring is high but is not deemed to present a serious threat to people or property.

The characteristics of a landslide are depicted in the following diagram from the US Geological Survey[xvi]:

B - History of Landslides Disasters in Umatilla County and UIR

The Umatilla County Hazard Mitigation plan provides the following statement regarding landslides within the county:

Little documentation exists regarding landslide history in Umatilla County .  Due to the fact that most landslide prone areas in Umatilla County are located in areas with little or no development, many of the small and moderate slides have not been documented.  Little or no damage resulting from landslides has occurred in Umatilla County .  The map below depicts where most landslides occur in Oregon .  Very few landslides occur in Umatilla County .  Those that do, occur in primarily in remote portions of the reservation.

C. - Possible Impacts from Landslides

Landslides on the reservation could damage roads, block traffic, damage timber, streams and fisheries.  Because the location of development on the reservation is primarily in valleys some distance from higher elevations (where the greatest potential for most landslides exist), the impacts from landslides on the UIR are generally negligible. 

D. – The Extent and Probable Intensity of Landslides within the UIR

There is no record of landslides occurring within the UIR.  Therefore, there is no way to know the extent or intensity of any landslides that have occurred on the UIR.

E. – The Probability of Landslides Affecting the UIR in the Future

Because landslides that do occur on the reservation occur in remote areas away from any populated areas, the probability that landslides will affect the UIR is very low.

F. – The Vulnerability of the UIR to Landslides

The vulnerability of the UIR to landslides is very low. Therefore, no further analysis or mitigation actions addressing this hazard will be provided.

Section 3.12 – Extreme Heat

A. – Definition, Causes and Characteristics of Extreme Heat [xvii]

Generally, temperatures that hover 10 degrees or more above the average high temperature for the region and last for several weeks are defined as extreme heat. Humid or muggy conditions, which add to the discomfort of high temperatures, occur when a "dome" of high atmospheric pressure traps hazy, damp air near the ground. Excessively dry and hot conditions can provoke dust storms and low visibility. Droughts occur when a long period passes without substantial rainfall. A heat wave combined with a drought is a very dangerous situation[xviii].  At certain levels, the human body cannot maintain proper internal temperatures and may experience heat stroke.   Extreme summer heat occurs primarily east of the Rocky Mountains . Oregon does not experience the very dangerous extreme heat waves like those that occur east of the Rocky Mountains . 

Oregon 's hottest weather occurs when strong high pressure over Oregon brings descending, warming air and clear skies. Winds from the east or south are customary during such periods. Sometimes heat waves in Oregon are very short-lived; in other cases, hot weather can persist for many days. Eastern Oregon experiences much greater temperature variations than western Oregon , and higher temperatures are likely to last longer and be more intense than those west of the Cascades.  Much of the marine air that keeps western Oregon cooler in the summer is blocked by the Cascades and prevented from reaching the eastside, and any air which does cross the Cascades is greatly modified, becoming warmer and drier. As a result, air temperatures typically decrease with increasing elevation, highest air temperatures generally occur at low elevations. Most of eastern Oregon is above 4,000 feet, so high temperatures are considerably lower than in the low elevation deserts of the southwestern U.S. (such as the infamous Death Valley which is actually below sea level). In some places, however, deep river valleys in eastern Oregon have much lower elevations, producing Oregon 's hottest summer temperatures. Pendleton, Ontario and Hermiston are examples of places which frequently experience hot temperatures in summer.

B - History of Extreme Heat Disasters in Umatilla County

Many of the highest single-day temperatures were recorded at Umatilla, on the Columbia River , not far from Pendleton. Before the Umatilla station closed in 1965, it had reported temperatures of 117°, 115° (three times), and 114° (four times)[xix].   However, the fact that high temperatures occur in eastern Oregon , Umatilla County and the UIR does not mean such conditions turn into disasters for two reasons:   first, these conditions occur without the high humidity that normally occurs during heat waves in the Midwest , southern and east coast.  Second, prolonged extreme heat is not a common occurrence.  Most heat waves in Oregon are short lived. 

C. - Possible Impacts from Extreme Heat

Extreme heat conditions don’t normally occur in the Oregon .  High temperatures do occur normally during the summer or early fall.  If a stagnant high predominates to the north or east of Pendleton during the spring, the hot, dry conditions may prove detrimental to crops during late May and June, and cause fire danger in the forest and grassland areas during late summer and early fall.

In the Midwest , south and eastern United States , extreme heat can affect people in a number of ways.  If an extreme heat wave persists, death can occur if proper precautions are not taken.  Extreme heat can kill by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

Heat exhaustion which affects people by dizziness, fatigue, headache, nausea and lightheadedness can occur.  Dehydration is common particularly where extreme heat and high humidity combine. However, the UIR has not experienced these type of “extreme heat” conditions.

Impacts from Extreme Heat on the Special Needs Population within UIR

Because the UIR does not experience the dangerous extreme heat conditions that occur in other parts of the country, there are no impacts to the special needs population on the reservation from extreme heat events.

D. – The Extent and Probable Intensity of Extreme Heat within the UIR

Table 20 below provides information regarding the intensity of high temperatures experienced in Pendleton, Oregon .  Several temperature over 100 degrees were reported.  No information regarding the length of these high temperatures was provided.  The National Weather Service did not list any temperature extremes as an identified disaster.

Table  - 20

E. – The Probability of Extreme Heat Affecting the UIR in the Future

Because very high temperatures and high humidity do not occur together in eastern Oregon , the probability that an extreme heat condition will occur is very low.  Typically, extreme high temperatures that occur during the summer months last only a few days.  The high humidity that combines with high temperatures to cause heat waves in the south, Midwest and eastern United States do not occur in the Pacific Northwest .

F. – The Vulnerability of the UIR to Extreme Heat

The vulnerability of the UIR to experience extreme heat is very low. Therefore, no further analysis or mitigation actions addressing this hazard will be provided.

Section 3.13 – Epidemiological Disasters

A. – Definitions, Causes and Characteristics of Epidemiological Disasters

An epidemiological event becomes a disaster when a disease or virus, that easily infects the general population, causes serious illness, death and overwhelms medical facilities.  The next most likely epidemiological disaster could be a pandemic, which is a global disease outbreak.

For example, an influenza pandemic occurs when a new influenza virus emerges for which there is little or no immunity in the human population.  When this virus emerges, it begins to cause serious illness and then spreads easily from person-to-person worldwide.

B - History of Epidemiological Disasters

There have been numerous epidemiological disasters since man has been keeping records.   Many of these epidemics involved diseases such as influenza, the plague, cholera, typhoid fever, small pox, malaria, and yellow fever.  Current epidemics involve AIDS and SARS class="MsoEndnoteReference">[xx].  Some other infectious diseases that have caused great concern are measles, mumps, rubella, pertussis, diphtheria, varicella, hepatitis, polio and tuberculosis[xxi].

According to PandemicFlu.gov, there were three influenza pandemics in the past century, the Great Pandemic of 1918-1919 (Spanish Flu), an influenza pandemic in 1957-1958 (Asian Flu), and an influenza pandemic in 1968-1969 (Hong Kong Flu).  How these pandemics affected Umatilla County and the UIR is not well documented.

The following statement about the Great Pandemic of 1918 was prepared for delivery by the Honorable Mike Leavitt Secretary of Health and Human Services on March 30, 2006 at the Oregon State Pandemic Flu Summit 2006[xxii]:

The Great Pandemic of 1918 also touched Oregon .   No one is certain when it first did so, for by the time the first reports were made in mid-October, the pandemic had already erupted all over the state—from Pendleton (in the northeast corner) to Portland , and from Baker (near Pendleton) to Eugene .  The city of Medford (located in south-central Oregon) became the first to impose a ban on all public gatherings, when E.B. Pickel, the Health Officer, and C.E. "Pop" Gates, the mayor, issued an edict closing "all places of amusements, theaters, moving picture shows,... churches, lodges, schools, and all public meetings of every description where people congregate—same to be in effect until said epidemic has subsided." When the situation became worse, the city required all residences where someone had been afflicted with the flu to post a blue sign with the words, "Contagious, Influenza" prominently displayed. Later in the pandemic wave, the Medford City Council issued an order requiring all persons in the city conducting business, riding, or walking the streets, to wear masks. There weren't enough masks at first, so all types of masks "from women's veils to handkerchiefs" were used.  Local Red Cross volunteers made masks for Medford , and they provided vital services in other communities as well. For instance, in Klamath Falls (located west of Medford ), Red Cross volunteers not only made masks, they also made pneumonia jackets (of warm flannel), and other needed articles. The need for such supplies was so severe that the Red Cross kept its doors open seven days a week simply to keep up. One public health nurse reported dire circumstances from the countryside. She declared, "there is no food, no bedding, and absolutely no conception of the first principles of hygiene, sanitation, or nursing care." There were some stories of success. For instance, a four-year-old from Portland reportedly recovered from the flu after her mother dosed her with onion syrup and buried her from head-to-toe in glistening raw onions—for three full days. When it comes to pandemics, there is no rational basis to believe that the early years of the 21st century will be different than the past. If a pandemic strikes, it will come to Oregon .

As the preceding statement indicates, once a pandemic spreads to Oregon , it will likely find its way to practically all corners of the state. 

The history regarding the effects of past pandemics (57-58 and 68-69) on those living on the reservation is unknown.   However, the tribe is far more dependent on the traveling public than it was in the 1950s and 1960’s.  Because of the current economic dependence on visitors, influenza or other epidemiological outbreak are more likely to impact the tribe than in the past.

C. - Possible Impacts from an Epidemiological Disaster on the UIR

During a severe pandemic, such as the one that occurred in 1918, there would be large surges in the numbers of people requiring or seeking medical or hospital treatment, temporarily overwhelming health services. High rates of worker absenteeism could also interrupt other essential services, such as law enforcement, transportation, and communications. Because populations will be fully susceptible to a pandemic virus, rates of illness could peak fairly rapidly within a given community. This means that local social and economic disruptions may be temporary. They may, however, be amplified in today’s closely interrelated and interdependent systems of trade and commerce.[xxiii]

An epidemiological disaster would have significant impacts on the CTUIR economy.   If an epidemic occurs, travel will be substantially reduced which would affect all sectors of the tribal economy.   The transportation network will be disrupted.   With a disruption in truck and rail traffic, communities will likely see a reduction in fuel, food, medicines, and other services that depend on transportation.  This would cause prices to rise for many goods and services on the reservation as shortages in needed items would occur.

A pandemic would substantially reduce the number of visitors and travelers that visit the reservation.  It would also place undue pressure on the medical services provided by the Yellow Hawk Clinic.  If a pandemic were as disastrous as the pandemic of 1918, places of public gathering could be closed which would harm the tribal economy.

Impacts from Epidemiological Disasters on the Special Needs Population within UIR

Generally, new epidemics are likely to be harsher on the special needs population as they are either already in poor health or tend to be less inclined to seek medical assistance because they do not have the financial resources to protect themselves from the dangers presented by the disease.

The impacts of a bird flu pandemic on various age groups are not well known. However, people whose immune systems are already challenged will likely suffer the most if an outbreak occurs[xxiv].

A secondary impact from a pandemic is the changing focus of the health care providers.   During an epidemic, health care providers must focus on minimizing and ending the epidemic.  With many patients affected by the “pandemic” disease, patients with other illnesses may be less likely to obtain the type of care they received before the epidemic began.  Also, with the transportation sector crippled, the cost to receive food, medicine, and other needs will likely rise.

D. – The Extent and Probable Intensity of an Epidemiological   

  Disaster at the UIR

If an epidemiological disaster occurs, it potentially could spread throughout the entire reservation and could be hazardous to the 25 to 35 % of the total population based on the percent infected from past pandemics.

E. – The Probability of an Epidemiological Disaster Affecting the

  UIR in the Future

The spread of a highly pathogenic avian H5N1 virus across eastern Asia and into Europe and Africa represents a significant threat, with health professionals concerned about a potential human pandemic. This virus has passed from infected poultry to humans and other mammals, and has had devastating impacts on poultry farming in several nations.[xxv]   Based on the ability of past epidemiological disasters to spread, the probability of a future disaster affecting the UIR is very high.

F. – The Vulnerability of the UIR to Epidemiological Disasters

Stopping the spread of future pandemics from negatively impacting the UIR will be difficult.  The commercial endeavors of the Tribe are dependent of visitors from outside the reservation.   Because of the incubation period for most diseases allows visitors to travel several days before an illness becomes debilitating, it is likely that casino visitors and truck drivers visiting the reservation could spread a disease before it is detected. Therefore, the vulnerability of the UIR to epidemiological disasters is very high.

Section 3.14 – Man-Made Hazards

August 7, 1959 , a truck exploded in Roseburg ,

Oregon – 14 dead, 125 injured, buildings in an

eight-block radius were destroyed; buildings within a

30-block radius were severely damaged. [xxvi]

There are four man-made hazards that are addressed in this plan:

Hazardous Material Spills

Chemical Stockpile Emergency Preparedness Program (CSEPP)

Dam Failure

Gas Pipeline Failure

A. – Definition, Causes and Characteristics of a Hazardous Material Incident on the UIR

Although not common, man-caused accidents involving hazardous materials have the potential to turn into disasters. Because hazardous materials possess at least one of four characteristics, which are ignitibility, corrosivity, reactivity, or toxicity, they can cause death or serious injury if improperly or accidentally released into the environment.  A hazardous material can be in the form of a solid, liquid or gas and, if not properly contained, can cause long-lasting health effects, damage to buildings and homes, and possibly long-term contamination leaving the immediate environment toxic.  Although infrequent, hazard material accidents are most commonly associated with transportation accidents occurring on highways, rail, waterways or pipelines.  However, manufacturing and agricultural industries use hazardous materials every day and can also be a source for man-caused accidents.

A number of hazardous materials are transported by rail, highway and pipeline through the Umatilla Indian Reservation, and hazardous material accidents can be difficult to contain.  So much depends on conditions outside of an emergency-responders control.  If a chemical spill occurs, the level of danger and type of emergency response depends on the chemical involved.  If a poisonous gas is involved, weather conditions, wind direction and speed and whether it is day or night are all variables that will affect the type of response.

The following information[xxvii] provides some additional definitions and describes the characteristics of chemical spills:

The principal modes of human exposure to hazardous materials include:

a)   Inhalation of gaseous or particulate materials via the respiratory (breathing) process,

b)   Ingestion of hazardous materials via contaminated food or water,

c)   Direct contact with skin or eyes.

Exposure to hazardous materials can result in a wide range of negative health effects on humans and animals.  Hazardous materials are generally classified by their health effects.   The most common types of hazardous materials are summarized below.

Flammable materials are substances where fire is the primary threat, although explosions and chemical effects listed below may also occur.  Common examples include gasoline, diesel fuel, and propane.

Explosives are materials where explosion is the primary threat, although fires and chemical effects listed below may also occur.  Common examples include dynamite and other explosives used in construction or demolition.

Irritants are substances that cause inflammation or chemical burns of the eyes, nose, throat, lungs, skin or other tissues of the body in which they come in contact.  Examples of irritants are strong acids such as sulfuric or nitric acid.

Asphyxiants are substances that interfere with breathing.  Simple asphyxiants cause injury or death by displacing the oxygen necessary for life.  Nitrogen is a good example.   Nitrogen is a normally harmless gas that constitutes about 78% of the atmosphere.  However, nitrogen releases in a confined space may result in asphyxiation by displacing oxygen.  Chemical asphyxiants are substances that prevent the body from using oxygen or otherwise interfere with the breathing process.  Common examples are carbon monoxide and cyanides.

Anesthetics and Narcotics are substances which act on the body by depressing the central nervous system.  Symptoms include drowsiness, weakness, fatigue, and in coordination, which may lead to unconsciousness, paralysis of the respiratory system and death.  Examples include numerous hydrocarbon and organic compounds.

Hazardous material located on the reservation are at the following locations:

• Umatilla Electric Coop Substation at Mission

• The Williams Natural Gas Company has three pipelines of 30 inches, 22 inches and 6 inches that cross the reservation

• Cascade Natural Gas has distribution lines of ½ inch to 4 inches that serve the reservation

• Chevron has two liquid petroleum pipelines of 6 and 8 inches that cross the reservation.

• Chevron Oil Storage facility is currently not in use but has environmental issues.

• Arrowhead Travel Plaza has storage facilities for gasoline, diesel and LPG.

B - History of a Hazardous Material Incident on the UIR

A Williams’s natural gas pipeline break and accompanying fire occurred on the morning of January 2, 1999 about four miles east of the community of Mission . The fire lasted about 3 hours.  No one was injured and no property was damaged (Source: CUJ Newspaper, page 1, Jan. 1999).

Hazardous materials are transported every day by rail, truck, river and pipeline.   Also, hazardous chemicals are in storage at area businesses. Thousands of hazardous materials shipments pass through the UIR on the Interstate and on rail lines that pass through the reservation.  The companies that transport and store these chemicals do a very good job with careful handling. Most hazardous material spills are very small and do not require emergency precautions, such as evacuation or shelter in-home protection; but on occasion accidents happen.  The following table identifies train accidents on public road crossings on the reservation.   Only two accidents at the Davis Lane rail crossing involved the transport of hazardous material.  No spills were reported.

Table 21 – Incidents at Public Rail Crossings