Requirement Section 201.6(c)(2): [The plan shall include] a risk assessment that provides the factual basis for activities proposed in the strategy to reduce losses from identified hazards. Local risk assessments must provide sufficient information to enable the jurisdiction to identify and prioritize appropriate mitigation actions to reduce losses from identified hazards.
Risk to natural hazards is a combination of hazard, vulnerability, and capability. The risk assessment process identifies and profiles relevant hazards and assesses the exposure of lives, property, and infrastructure to these hazards. The goal of the risk assessment is to estimate the potential loss in Mesa County, including loss of life, personal injury, property damage, and economic loss, from a hazard event. The risk assessment process allows communities in Mesa County to better understand their potential risk to natural hazards and provides a framework for developing and prioritizing mitigation actions to reduce risk from future hazard events.
The risk assessment for Mesa County and its jurisdictions followed the methodology described in the FEMA publication Local Mitigation Planning Handbook (2013), which includes a four-step process:
(a) 
Identify hazards;
(b) 
Profile hazard events;
(c) 
Inventory assets;
(d) 
Estimate losses.
This article is divided into three parts: hazard identification, hazard profiles, and vulnerability assessments.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Requirement Section 201.6(c)(2)(i): [The risk assessment shall include a] description of the type … of all natural hazards that can affect the jurisdiction.
The Mesa County Hazard Mitigation Planning Committee (HMPC) reviewed data and discussed the impacts of each of the hazards required by FEMA for consideration, which are listed below, to determine the hazards that threaten Mesa County and its jurisdictions:
Avalanche
Expansive Soils
Landslide
Windstorm
Coastal Erosion
Extreme Heat
Severe Winter Storm
Coastal Storm
Flood
Tornado
Dam/Levee Failure
Hailstorm
Tsunami
Drought
Hurricane
Volcano
Earthquake
Land Subsidence
Wildfire
Data on past impacts and future probability of these hazards was collected from the following sources:
State of Colorado Natural Hazard Mitigation Plan (2018)
Mesa County Hazard Mitigation Plan (2015)
Spatial Hazard Event and Loss Database (SHELDUS), a component of the University of South Carolina Hazards Research Lab
National Oceanic and Atmospheric Administration’s (NOAA) National Climatic Data Center
Disaster declaration history from FEMA, the Public Entity Risk Institute, and the U.S. Department of Agriculture (USDA) Farm Service Agency
The HMPC eliminated some hazards from further analysis because they do not occur in Mesa County or their impacts were not considered significant in relation to other hazards. Table 5 lists these hazards and the reasoning for their removal from consideration.
Table 5: Removed Hazards
Hazard
Explanation for Removal from Plan
Coastal Erosion
Mesa County is not near coastal area.
Coastal Storm
Mesa County is not near coastal area.
Hailstorm
Hailstorms occur, but large-sized damaging hail is rare. Past damage has been negligible.
Hurricane
Mesa County is not near coastal area.
Tsunami
Mesa County is not near coastal area.
Volcano
Dotsero, near Glenwood Canyon, is the only volcano of concern in Colorado. It has not erupted in 4,000 years.
The HMPC identified 13 natural hazards that could affect Mesa County and other jurisdictions. These hazards are profiled in further detail throughout this plan. Although not required by the Disaster Mitigation Act of 2000, the HMPC decided to address one manmade hazard – hazardous materials release. The risk from this hazard is related primarily to the transportation of hazardous materials through the County or from a release generated at any one of the number of facilities that produces or stores chemicals on site.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Mesa County has received the following disaster declarations:
Year
Type of Declaration
Hazard
1984
Presidential
Flooding
1995
State
Flooding
2002
Presidential
Wildfires
2002
USDA Disaster
Drought
2006
USDA Disaster
Drought
2012
State
Wildfire
2012
USDA Disaster
Drought
2012
USDA Disaster
Crop
2013
USDA Disaster
Crop
2014
USDA Disaster
Drought
2014
USDA Disaster
Crop
2014
Local/State
Landslide
2015
USDA Disaster
Drought
2015
USDA Disaster
Severe Freeze
2017
USDA Disaster
Severe Freeze
2018
USDA Disaster
Drought
2019
USDA Disaster
Drought
2020
Local/State/Federal
Pandemic
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Requirement Section 201.6(c)(2)(i): [The risk assessment shall include a] description of the … location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events.
Requirement Section 201.6(c)(2)(ii): [The risk assessment shall include a] description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. The description shall include an overall summary of each hazard and its impact on the community.
The hazards identified in this section are profiled individually and a summary of the probability of future occurrence and potential magnitude is provided. Each hazard was also given an overall rating of High – Medium – Low based on the score it received by using the following formula:
Total Score = Occurrences x Impacts (Occurrences x [Geographic Location + Magnitude/Severity])
Detailed profiles for each of the identified hazards include the following information:
(a) 
Hazard Description.
This section consists of a general description of the hazard and the general impacts it may have on a community.
(b) 
Geographic Location.
This section describes the geographic extent or location of the hazard in the planning area and identifies the affected area as isolated, small, medium, or large.
(1) 
Large (8) – Greater than 50 percent of the County affected.
(2) 
Medium (6) – 25 to 50 percent of the County affected.
(3) 
Small (4) – 10 to 25 percent of the County affected.
(4) 
Isolated (2) – Less than 10 percent of the County affected.
(c) 
Occurrence.
This section includes information on historic incidents, including impacts and costs, if known. A historic incident worksheet (worksheet #1) was used to capture the incident information from participating jurisdictions.
(d) 
Future Occurrence.
The frequency of past events is used to gauge the likelihood of future occurrences. Based on historical data, the probability of future occurrence is categorized as follows and given a corresponding score:
(1) 
Highly Likely: (8). Near 100 percent chance of occurrence next year or happens every year.
(2) 
Likely: (6). Ten to 100 percent chance of occurrence in next year or has a recurrence interval of 10 years or less.
(3) 
Occasional: (4). One to 10 percent chance of occurrence in the next year or has a recurrence interval of 11 to 100 years.
(4) 
Unlikely: (2). Less than one percent chance of occurrence in next 100 years or has a recurrence interval of greater than every 100 years.
The probability, or chance of occurrence, was calculated where possible based on existing data.
(e) 
Magnitude/Severity.
This section summarizes the magnitude/severity or extent of hazard event in terms of deaths, injuries, property damage, and interruption of essential facilities and services. Magnitude and severity is classified in the following manner and given a corresponding score:
(1) 
Catastrophic (8). Multiple deaths; property destroyed and severely damaged; and/or interruption of essential facilities and service for more than 72 hours.
(2) 
Critical (6). Isolated deaths and/or multiple injuries and illnesses; major or long-term property damage that threatens structural stability; and/or interruption of essential facilities and services for 24 to 72 hours.
(3) 
Limited (4). Minor injuries and illnesses; minimal property damage that does not threaten structural stability; and/or interruption of essential facilities and services for less than 24 hours.
(4) 
Negligible (2). No or few injuries or illnesses; minor quality of life loss; little or no property damage; and/or brief interruption of essential facilities or services.
(f) 
Impact of a Changing Climate.
According to the 2018 National Climate Assessment a changing climate would create new risks and exacerbate existing vulnerabilities in communities across the United States (U.S.), presenting growing challenges to human health and safety, quality of life, and the rate of economic growth. This could include more frequent and intense extreme weather and climate-related events, as well as changes in average climate conditions, which could continue to damage infrastructure, ecosystems, and social systems. The U.S. Environmental Protection Agency (EPA) concludes that a world of warmer temperatures could lead to less predictable weather patterns and rising sea levels. While impacts within and across regions may not be distributed equally, these and other impacts would threaten the reliable delivery of many community services. Although extreme weather events are caused by a variety of contributing factors, human-induced climate change is considered by a large majority of the scientific community to be one of those contributing factors.
The 2018 National Climate Assessment found that temperatures increased across almost all of the Southwest U.S. from 1901 to 2016 with the greatest increases in southern California and western Colorado. If this trend were to continue, the increase in heat and reduction of snow under a changing climate would tend to increase the duration and severity of droughts. Additionally, this could contribute to aridification (a potentially permanent change to a drier environment) through lower soil moisture, reduced snow cover and changes in the timing and efficiency of snowmelt and runoff.
The 2018 National Climate Assessment also estimated that the area burned by wildfire across the western U.S. from 1984 to 2015 was twice what would have been burned had the climate not been changing. Some of the worst wildfires in Colorado State history have occurred within the last 10 years, including the Black Forest Fire in 2013, Spring Creek Fire in 2018, and the 416 Fire in 2018.
A changing climate in Mesa County will likely induce longer summertime warm periods, earlier onset of spring snowmelt, more precipitation arriving as rain rather than snow, and longer dry periods with heavier precipitation events in between. These types of changes could exacerbate already risky wildfire conditions, place extra pressure on already stretched water providers and users, provide additional challenges to winter and summer recreation providers, as well as a decline in snowpack depth and duration which is closely linked to water availability, watershed functions and winter ecology impacting every sector important to the community.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Avalanche hazards occur mostly in mountainous regions of Colorado above 8,000 feet. The vast majority of avalanches occur during and shortly after winter storms. Avalanches occur when loading of new snow increases stress at a rate faster than strength develops, and the slope fails. While most avalanches are caused by the weight of accumulated snow, other triggers can be caused by human activities (e.g., skier, snowshoer, and snowmobiler).
(a) 
Geographic Location.
The geographic extent of this hazard in Mesa County is isolated – less than 10 percent of the County is affected.
The avalanches in Mesa County have primarily occurred on the Grand Mesa which is primarily federally owned land.
(b) 
Previous Occurrences.
According to the National Climatic Data Center Storm Events Database and the CAIC information, Mesa County has had five recorded avalanches from 1959 to 2019.
(1) 
January 30, 1999 – Nine snowmobilers were traversing the north side of the Grand Mesa at the 10,600-foot level. The snowmobiler who was third in line triggered a small hard-slab avalanche which buried him under five feet of snow ending with unsuccessful resuscitation efforts.
(2) 
February 24, 2002 – A snowmobiler triggered a soft-slab avalanche near Flat Top Mountain in extreme northeast Mesa County, about eight miles south southwest of Sunlight Ski Area. This avalanche was about 300 feet across and two feet deep, beginning at an elevation of just below the 10,200-foot level. The avalanche ran approximately 400 vertical feet. The victim was found after having been buried for approximately 30 minutes. Resuscitation efforts were unsuccessful.
(3) 
February 4, 2004 – Avalanche swept across Highway 65 at mile marker 36 on the Grand Mesa. One vehicle was buried and the road was closed in both directions until the next day. No injuries or fatalities reported; however, $5,000 in property damage was reported.
(4) 
April 1, 2005 – A backcountry skier was killed when he triggered an avalanche at about 10,560 feet above sea level on the Grand Mesa while ascending a slope. The skier was swept over some rocks and down into some trees. His companion notified 911 dispatch of the incident. CDOT employees and Mesa County Search and Rescue responded and found the victim approximately two hours after he was buried.
(5) 
March 17, 2010 – Two cross country skiers attempted to ski the Thunderbird area on the west side of the Grand Mesa. The skiers were passing through a clearing when a wall of snow above them collapsed. They were both carried an estimated 300 to 800 feet down slope. One of the skiers was dragged into several trees and seriously injured. Mesa County Search and Rescue responded and the injured skier was airlifted to the regional trauma center.
(c) 
Probability of Future Occurrence.
The probability of future occurrence for avalanches in Mesa County is considered occasional or a one to 10 percent chance of happening in the next year.
(d) 
Magnitude/Severity.
Three out of the four avalanche events recorded resulted in a death, categorizing the magnitude/severity of this hazard as critical.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Dams are manmade structures built for a variety of uses, including flood protection, power, agriculture, water supply, and recreation. Dams typically are constructed of earth, rock, concrete, or mine tailings. Two factors that influence the potential severity of a full or partial dam failure are the amount of water impounded and the density, type, and value of development and infrastructure located downstream.
Dam failures can result from any one or a combination of the following causes:
(1) 
Prolonged periods of rainfall and flooding, which result in overtopping (overtopping is the primary cause of earthen dam failure);
(2) 
Earthquake;
(3) 
Inadequate spillway capacity resulting in excess overtopping flows;
(4) 
Internal erosion caused by embankment or foundation leakage or piping or rodent activity;
(5) 
Improper design;
(6) 
Improper maintenance;
(7) 
Negligent operation;
(8) 
Failure of upstream dams on the same waterway.
(b) 
Geographic Location.
The geographic extent of this hazard in Mesa County is small – 10 to 25 percent of the County is affected.
The Colorado Division of Water Resources provided a list of dams in Mesa County as shown in Table 6 and their classification based on the potential hazard to the downstream area resulting from failure of the dam:
(1) 
Class I (High Hazard): Failure of dam would likely result in loss of life.
(2) 
Class II (Significant Hazard): Failure of dam would not cause loss of life, but would cause extensive and/or severe property damage.
Based on these classifications, there are 23 high hazard dams and 28 significant hazard dams in Mesa County. High and significant hazard dams all have emergency action plans in place.
Table 6: Class I – Class II Hazard Dams
Dam Name
Hazard Class
Year Completed
ALSBURY
1
1996
BIG CREEK #1
1
1893
BIG CREEK #3
1
1893
BONHAM-WELLS
1
1900
BULL CREEK #4
1
1901
COON CREEK #1
1
1900
COTTONWOOD #1
1
1894
COTTONWOOD #2
1
1895
COTTONWOOD #5
1
1909
HALLENBECK #1
1
1970
INDIAN WASH DET.
1
1965
JERRY CREEK #1
1
1964
JERRY CREEK #2
1
1978
JERRY CREEK DIKE 1
1
1978
JUNIATA
1
1979
KITSON
1
1911
LEON LAKE
1
1898
PARKER BASIN #1
1
1899
PARKER BASIN #3
1
1899
SOMERVILLE-McCULLAH
1
1972
UPPER HIGHLINE
1
1967
VEGA
1
1959
Y T RANCH
1
1911
ANDERSON #1
2
1963
ANDERSON #2
2
1974
BIG BEAVER
2
1947
BOLEN
2
1973
BULL BASIN #2
2
1953
BULL CREEK #5
2
1901
CASTO
2
1940
COLBY HORSE PARK
2
1956
COTTONWOOD #4
2
1896
CRAIG #1
2
1951
CRAIG #2
2
1960
DEEP CREEK #2
2
1906
FLOWING PARK
2
1973
FRUITA #1
2
1949
FRUITA #2
2
1959
GARDNER LAKE
2
1980
GOBBO #1
2
1973
GOBBO #3
2
1973
GRAND MESA #1
2
1887
GRAND MESA #8
2
1901
HALLENBECK #2
2
1943
HOGCHUTE
2
1947
MESA CREEK #1
2
1893
MESA CREEK #3
2
1890
MESA CREEK #4
2
1892
MONUMENT #1
2
1960
PALISADE CABIN
2
1956
RAPID CREEK #1
2
1934
Figure 6 is a map showing locations of the Class I and II Dams in Mesa County.
Figure 6: Map of Dams in Mesa County
(Mesa County GIS)
(c) 
Previous Occurrences.
(1) 
June 1983 – Grand Mesa Dam No. 8 overtopped and failed during spring runoff due to emergency spillway being blocked by snow and ice. Snowmelt produced high inflow to the reservoir which overtopped dam. Minor flooding downstream with damage to Highway 65 and Lands End Road. Significant damage was reported to the dam. Dam was repaired and spillway enlarged.
(2) 
Spring 1998 – Fruita No. 1 dam located at the head of North East Creek south of Glade Park failed as a result of failing downstream slope. This slope failed on two separate occasions; reservoir level was restricted until dam was rehabilitated in 2009. Because this failure happened during normal operations, actual flooding was prevented.
(3) 
1996 – Upper Highline Dam in unincorporated Mesa County (Mack) suffered settling and deformation of the dam. The dam crest settled several feet at the west end and reservoir was drained so dam could be rehabilitated. This intervention prevented failure and flooding. Significant damage reported to State-owned dam.
(4) 
1983 – Vincient No. 2 dam (above the Town of Palisade) overtopped during spring runoff and failed. When a hazard classification is given to a dam, it is done so based on the consequences of the dam’s failure absent flooding conditions, i.e., on a clear day in summer with the stream at a “normal” level. When Vincient No. 2 failed, the stream below was running bank-full from snowmelt and the resulting failure discharge jumped out of the channel and did more damage downstream than would have normally occurred. It is important to remember that a low hazard dam can still cause a significant amount of damage and possibly result in loss of life, depending on the timing of the failure. (Jackson, 2009)
(d) 
Probability of Future Occurrence.
The probability of future occurrence is occasional, meaning there is a one to 10 percent chance of occurrence in the next year or has a recurrence interval of 11 to 100 years. Due to the documented cases above, there is a possibility of future dam failures.
(e) 
Magnitude/Severity.
Depending on the hazard class of the dam, the magnitude/severity of a dam failure is listed as catastrophic. Multiple deaths, destroyed or severely damaged property, and/or interruption of essential facilities and services is possible. As indicated above, Mesa County has several Class I (High Hazard) dams which would cause loss of life upon failure of the dam.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Drought is a normal, recurrent feature of climate, although some consider it a rare and random event. It occurs in virtually all climatic zones, but characteristics vary significantly from one region to another. It originates from a deficiency of precipitation over an extended period of time, usually a season or more. (University of Nebraska Lincoln, 2009)
Due to Colorado’s semiarid conditions, drought is a natural but unpredictable occurrence in the State. The onset of drought in western Colorado counties is usually signaled by a lack of significant winter snowfall.
(b) 
Geographic Location.
The geographic location of this hazard is considered large in Mesa County, with more than 50 percent of the County affected.
(c) 
Previous Occurrence.
According to the National Climatic Data Center, Mesa County and respective towns and municipalities have experienced several drought periods over time. Since 1999 Mesa County was experiencing multi-year drought conditions and beginning in May of 2002, western Colorado was experiencing its first full month of severe to extreme drought conditions. The most intense drought classification, exceptional drought conditions, had developed. Low elevation snowpack had already melted throughout the area and many seasonal streams dried up by the end of May.
The drought began to have a major impact on agricultural interest and to a lesser degree on the outdoor recreational industry. Perhaps of most importance, the drought created a large potential for major wildfires. Below is a list of drought occurrences as recorded by the National Climatic Data Center.
(1) 
May 2002 – May was the first full month of severe to extreme drought conditions in western Colorado. The most intense drought classification, exceptional drought conditions, had developed in the southwest corner of the State by the end of the month. Low elevation snowpack had already melted throughout the area before May, with many seasonal streams dried up by the end of May. In May, the drought began to have a major impact on agricultural interests, and to a lesser degree on the outdoor recreation industry. Perhaps of most importance, the drought created a large potential for major wildfires.
(2) 
July 2003 – Severe to extreme drought conditions continued across western Colorado during the month. Although monsoon moisture did bring thunderstorms to the area, significant rainfall amounts were not widespread in coverage. Additionally, record high temperatures occurred through much of the month.
(3) 
July 2004 – Surges of subtropical moisture in monsoonal flow resulted in a few bouts of widespread precipitation across western Colorado during the month, with locally heavy rains occurring in some areas. However, this had little impact on the long-term drought situation across the area, and moderate to severe drought continued across most of western Colorado.
(4) 
July 2005 – Occasional surges of monsoonal moisture resulted in periods of thunderstorms across western Colorado during the month of July, mainly during the second half of the month. However, typical hot conditions persisted for much of the month and the rainfall that did occur had little impact on the drought conditions across the area. Northwest Colorado remained in moderate to severe drought conditions. Although the remainder of western Colorado was no longer categorized as being in a drought, multiple years of below normal precipitation continued to cause water supply concerns.
(5) 
March 2007 – Below normal precipitation through the month caused an increase in the dryness and drought conditions across western Colorado.
(6) 
March 2012 – Moderate drought conditions expanded westward into the upper reaches of the Grand Valley by the end of March while abnormally dry conditions remained in place across the western portion of the valley through March as precipitation remained well below normal.
(7) 
2018 – Severe (D2) drought conditions began to intrude over the southern portion of Mesa County by late December 2017. Early to mid January saw the severe drought encompass the entirety of Mesa County. This persisted until the end of February when the Extreme (D3) drought conditions moved into the southern portion of Mesa County. A few storms moving through the region saw this area of extreme drought be trimmed back until it rebuilt back over the entire county by early July. Throughout the summer, several sites in Mesa County saw their record warmest temperatures or had temperatures well above normal. The Grand Junction area recorded 14 days of high temperatures at or above 100 degrees in 2018 and had 90 degrees or more 90 times throughout the year. Early September saw the Exceptional (D4) drought creep into the southeast portion of Mesa County and eventually expand over the eastern portion of the County by early October. This was a result of a dismal monsoon season with prolonged hot and dry conditions over the region. However, the drought finally improved after a few wet weeks in October which eradicated the exceptional and extreme drought conditions over Mesa County. Grand Junction had 11 consecutive days of precipitation from October 1-11, 2018 with 2.53 inches total. Additionally, Grand Junction finished as the fourth wettest October on record with 2.76 inches (1.70 inches above normal for the month). By the end of 2018, most of Mesa County was in the severe drought category. Continual gradual improvement occurred during the first few months of 2019 with all traces of the drought gone in Mesa County by mid May 2019.
(d) 
Probability of Future Occurrence.
The probability of future occurrence is occasional, meaning there is a one to 10 percent chance of occurrence in next year or has a recurrence interval of 11 to 100 years. According to the Colorado Drought Mitigation and Response Plan, Colorado was in a drought for 48 of the past 115 years (1893 – 2007). Therefore a 42 percent chance exists that a drought will happen in Colorado in any given year. (J. Truby, January 2001)
(e) 
Magnitude/Severity.
The magnitude/severity of drought conditions is limited. Drought impacts in Mesa County can be wide reaching: economic, environmental, and societal. The most significant impacts in Mesa County and respective jurisdictions are related to wildfire protection and agriculture. Mesa County economy consists of a number of fruit and vegetable growers who are heavily impacted by drought conditions.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Earthquakes are defined as the sudden release of energy occurring from the collision or shifting of crustal plates on the earth’s surface or from the fracture of stressed rock formations in that crust. The release of energy results in the earth shaking, rocking, rolling, jarring and jolting; having the potential to cause minimal to great damage. Earthquakes are measured by units of magnitude, which is a logarithmic measure of earthquake size. This means that at the same distance from the earthquake, the shaking will be 10 times as large during a magnitude 5 earthquake as it would during a magnitude 4 earthquake. (EHP Web Team, 2009)
Earthquakes can cause structural damage, injury, and loss of life, as well as damage to infrastructure networks, such as water, power, communication and transportation systems. Secondary impacts can include landslides, liquefaction, fires, and dam failure.
(b) 
Geographic Location.
Colorado is comprised of areas with low to moderate potential for damaging earthquakes, based on research by geologists and geophysicists who specialize in seismology. There are about 90 potentially active faults that have been identified in Colorado, with documented movement within the last 1.6 million years. However, there are several thousand other faults that have been mapped in Colorado that have not been sufficiently studied to know whether they are capable of generating earthquakes or not.
It is not possible to accurately estimate the timing or location of future dangerous earthquakes in Colorado. The lack of an adequate network of seismometers in Colorado makes it difficult to detect and locate earthquakes. Moreover, the historical record is quite short (~150 years). Nevertheless, the available seismic hazard information can provide a basis for a reasoned and prudent approach to seismic safety. (Subcommittee, 1999)
Mesa County has a considerable amount of fault lines as shown in Figure 7 that are located within the County but has not recently experienced a significant earthquake event.
(c) 
Previous Occurrences.
Many of Colorado’s earthquakes occur in mountainous regions of the State with some having been located in the western valley and plateau region. The Colorado Geological Survey has estimated that the largest earthquake possible on the Western Slope of Colorado is magnitude 6.5. This estimate is based on studies of the fault systems in western Colorado. The two largest fault systems in western Colorado are associated with the Uncompahgre Uplift and the White River Uplift.
The areas of most concern are the Uncompahgre Plateau and Paradox Valley. The Uncompahgre has the greatest potential for producing a large natural event. The Paradox Valley has the greatest potential for creating a large manmade seismic event. Below are the two significant events that have occurred in Mesa County.
(1) 
1971 – 4.5 magnitude earthquake, Glade Park Fault (unincorporated Mesa County).
(2) 
1975 – 4.4 magnitude earthquake northeast of Fruita, Colorado (Mesa County).
(d) 
Probability of Future Occurrence.
The probability of future occurrence for an earthquake in Mesa County or neighboring jurisdictions is occasional resulting in a one to 10 percent chance of occurrence in the next year or has a recurrence interval of 11 to 100 years.
(e) 
Magnitude/Severity.
The magnitude/severity of an earthquake is limited resulting in minor injuries and illnesses, minimal property damage that does not threaten structural stability and/or interruption of essential facilities and services for less than 24 hours.
Figure 7: Faults in Mesa County
Source: Mesa County GIS
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Flooding has occurred repeatedly throughout Mesa County and will continue to occur. FEMA defines “flooding” as “a partial or complete inundation of normally dry land areas from (1) the overland flow of a lake, river, stream, ditch, etc.; (2) the unusual and rapid accumulation or runoff of surface waters; and (3) mudflows or the sudden collapse of shoreline land.” (www.training.fema.gov/EMIWeb/IS/IS394A/glossary-0306.doc)
Snowmelt flooding is characterized by moderate peak flows, large volume, and long duration, and is marked by a diurnal fluctuation in flow. Rainfall on melting snow may speed up the melting process and increase flood flow. General rain floods are caused by prolonged heavy rainfall over large areas and are characterized by high peak flows of moderate duration. Cloudburst floods characteristically have high peak flows, high velocities, short durations, and small volumes of runoff. (FEMA, Flood Insurance Study, Mesa County Colorado, 2009)
The area adjacent to a river channel is its floodplain. In its common usage, “floodplain” most often refers to that area that is inundated by the 100-year flood, the flood that has a one percent chance in any given year of being equaled or exceeded. Other types of floods include general rain floods, thunderstorm generated flash floods, alluvial fan floods, dam failure floods (see GJMC § 42.08.220, Dam failure), and local drainage floods. The 100-year flood is the national standard to which communities regulate their floodplains through the National Flood Insurance Program.
The potential for flooding can change and increase through various land use changes. A change in environment can create localized flooding problems inside and outside of natural floodplains by altering or confining watersheds or natural drainage channels. These changes are commonly created by human activities. These changes can also occur as the result of other events such as wildfires. Wildfires create hydrophobic soils, in which the soils harden preventing rainfall from being absorbed into the ground.
FEMA also defines “flash flooding” as “flood that arises very quickly, occurring suddenly, within a short time (from minutes to less than six hours), and usually is characterized by high flow velocities. Flash floods often result from intense rainfall over a small area, usually in areas of steep terrain.” (www.training.fema.gov/EMIWeb/IS/IS394A/glossary-0306.doc)
Flooding in Mesa County is caused mainly by snowmelt in the larger drainage basins and by cloudbursts over the smaller drainage basins. However, general rainstorms constitute the principal flood hazard on Roan Creek, while general rain on snowpack creates the most hazardous conditions in the basins of Plateau and Buzzard Creek. Major floods on the Colorado and Gunnison Rivers result from rapid melting of the mountain snowpack during May, June, and July and the Dolores River experiences flooding from both snowmelt and general rainstorms.
Mesa County has received a copy of the 2012 Flood Insurance Study that covers the Town of Collbran, Town of DeBeque, City of Fruita, City of Grand Junction, Mesa County unincorporated areas, and Town of Palisade. This study has developed flood risk data for various areas of the community that will be used to establish actuarial flood insurance rates. This information will also be used by Mesa County to update existing floodplain regulations as part of the Regular Phase of the National Flood Insurance Program (NFIP), and by local and regional planners to further promote sound land use and floodplain development.
The following table details information provided by the Colorado Water Conservation Board regarding the number of active flood insurance policies in Mesa County communities in 2018. With this plan update, there remains a single repetitive loss property in Mesa County (unincorporated area) (parcel no. 2697-273-00-063) with the following claims: claim no. 1: 6/8/95 in the amount of $750; claim no. 2: 7/1/99 in the amount of $2,267; and claim no. 3: 7/10/01 in the amount of $1,973. This property is partially within the FEMA regulatory floodway and partially within the regulatory special flood hazard area.
Jurisdiction
Num. Policies
Total Coverage
Claims since 1978
Total paid since 1978
Mesa County
156
$39,492,000
38
$262,065
Town of Collbran
8
$2,235,400
4
$15,827
City of Grand Junction
120
$29,238,600
20
$228,328
City of Fruita
10
$3,347,100
5
$5,047
Town of Palisade
7
$1,952,700
2
$0
Town of DeBeque
1
$105,000
0
$0
(b) 
Geographic Location.
All streams in Mesa County are either direct or indirect tributaries of the Colorado River, which traverses the north-central and northwestern sectors. From the northern County line, the river flows southwesterly for 41 miles to its confluence with the Gunnison River, thence northwesterly 27 miles, and again southwesterly for 15 miles in its remaining course in the County.
In general, the Dolores River, Gunnison River, and West Creek systems drain the western, southwestern, and south-central portions of the County. The Plateau Creek system drains the eastern sector, except for the easternmost portion, which is drained by the Divide Creek system, which flows northerly to the Colorado River in Garfield County. A group of minor creeks and washes flowing southerly from the Roan and Bookcliffs regions drain the northwestern portion of the County, and a group of similar streamways convey drainage to the river from the north-central portion.
Plateau Creek has its headwaters in the Grand Mesa National Forest, approximately 18 miles southeast of the Town of Collbran. The stream flows northwesterly from its origin near Chalk Mountain into Vega Reservoir, approximately 11 miles upstream from Collbran. Plateau Creek then continues westerly from Vega Reservoir through Collbran to its confluence with the Colorado River.
Mesa County is subject to major stream flooding caused by rapid snowmelt, usually associated with rising temperatures and flash flooding caused by rains associated with thunderstorms. Spring runoff usually reaches its peak in June and recedes to a normal flow by mid-July. Mesa County typically experiences the monsoonal weather patterns in late July and August that create the potential for flash flood events found in the steeper drainage areas of the County. It is these events that have the greatest potential for causing major flooding in Mesa County and typically involve localized flooding and debris-flow issues.
(c) 
Previous Occurrences.
Mesa County has a long history of flooding from summer cloudburst storms and from snowmelt runoff. Seven major flood events have occurred on the Colorado River, four on the Gunnison River, and four on the Dolores River. Floods occurred in 1884, 1917, 1920, 1921, 1935, 1952, 1957, 1983, and 1984 on the Colorado River; in 1884, 1920, 1921, and 1957 on the Gunnison River; and in 1884, 1909, 1911, and 1958 on the Dolores River. Most known floods in Mesa County resulted from snowmelt, sometimes augmented by general rain. The largest snowmelt flood runoff of record on the Colorado River occurred in June 1921. Heavy rain on June 14th and 15th augmented runoff to produce a peak flow of 81,000 cfs near Fruita.
Flooding from general rain occurred on the Dolores River in September 1909 and October 1911. Snowmelt flooding on the Dolores River in April 1958 inundated 1,100 acres in the Gateway area and resulted in damage estimated at $230,000.
Recorded cloudburst floods occurred on Indian Wash (Grand Junction area) in June 1958 and on West Creek (Gateway area) in July 1940. The West Creek cloudburst covered approximately 25 square miles of the drainage area and produced a peak flow estimated at 11,700 cfs.
The most recent serious floods on the Colorado River occurred in 1983 and 1984. Peak flows on the Colorado River at the State line were approximately 61,000 and 70,000 cfs in 1983 and 1984 respectively. Colorado River flood flows in the Grand Junction area inundated streets, lawns, and gardens; deposited sand, silt, and debris; and flooded basements and lower floors in residential areas in the Riverside Park, Rosevale and Connected Lakes area southwest of the City in 1983 and 1984 but have not caused significant damage since these events. The flooding events in 1984 resulted in loss of life as did the flooding event that occurred on I-70 when Bosley Wash flooded in 2008 resulting in a drowning.
The Riverside Park area has experienced repeated flood danger as the erosion and undermining of protective levees has necessitated extensive flood fighting and levee repair. These noncertified levee and storm drain system improvements serve to mitigate potential flooding.
The principal cause of flooding on Plateau Creek and Buzzard Creek is a rapidly melting heavy snowpack during May, June, and July. Rainfall on melting snow may hasten the melting process and increase flood flows. A major flood occurred on Plateau Creek in 1922. Based on the record from a stream gage on Plateau Creek located approximately six miles east of Collbran, this flood had an estimated discharge of 3,080 cfs which corresponds to a frequency in excess of 100 years.
On May 27, 2016, heavy snowmelt on the Grand Mesa during spring runoff caused an estimated 30,000 cubic meters of dirt and rock to slide off the head scarp of the West Salt Creek Landslide into the sag pond formed by the landslide. This caused a large volume of water in the sag pond to overflow the debris dam and cut a channel up to 100 feet deep and 50 feet wide down the 2.8-mile long landslide deposit. The flood waters continued down below the landslide along West Salt Creek at depths over 12 feet and then down to the larger Plateau Creek where the flood waters came up to within one foot of Rodeo Road in the Town of Collbran. The flash flood caused damage to some roads, fences, a barn and horse riding arena.
(d) 
Probability of Future Occurrence.
The probability of future occurrence is highly likely with a near 100 percent chance of occurrence next year or it happens every year. Due to the documented cases above and the information collected on events that were smaller in size, Mesa County and the various towns/municipalities will continue to deal with flood-related activities in the future.
(e) 
Magnitude/Severity.
The magnitude/severity of a flood event is limited resulting in minor injuries and illnesses, minimal property damage that does not threaten structural stability and/or interruption of essential facilities and services for less than 24 hours. Most of the flood events that have occurred in Mesa County over the past 10 years have been limited with respect to injuries and property damage. Figure 8 shows the major rivers and tributaries within Mesa County.
Figure 8: Rivers and Tributaries
(Nelson, 2009)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
A hazardous material is any item or agent (biological, chemical, physical, radiological) that has the potential to cause harm to humans, animals, or the environment, either by itself or through interaction with other factors. The release of hazardous materials can happen either by accident or as a result of criminal activity and can threaten people and natural resources in the immediate vicinity of the accident, including residences and businesses along transportation routes.
(b) 
Geographic Location.
Mesa County is a center of commerce in western Colorado and hazardous materials are commonly transported through the County by truck and rail. Designated truck routes are State Highways 139, 141, 50 and U.S. Interstate 70. The Union Pacific Railroad operates two rail lines in Mesa County. Their main line is located primarily along the Colorado River through the County. The secondary line (southern leg) branches off the main line near the confluence of the Gunnison and Colorado Rivers and is located along the Gunnison River.
It is observed that the majority of the products transported through Mesa County belong to the hazard classes of 2 (Flammable and Combustible Gases), 3 (Flammable and Combustible Liquids), 8 (Corrosive Materials), and 9 (Miscellaneous Hazardous Materials). There are currently 193 Tier II reporting fixed site facilities in Mesa County. These facilities either produce, store, and/or use hazardous materials and are required by the Environmental Protection Agency to report these quantities under Tier II reporting requirements.
(c) 
Previous Occurrences.
Two significant incidents have occurred in Mesa County as a result of illegal dumping of hazardous materials. The first incident involved illegal dumping in the Cactus Park area of Mesa County of three 150-pound cylinders of liquid chlorine with safety caps removed. This case resulted in a felony conviction of a 30-year-old male who received eight years in the Colorado State Corrections System. This case was the first successful prosecution of the “Clean Air Act” in the State of Colorado. (Reekie, 2009)
The second case occurred in 2001 and was the result of illegal discharging of ethylene glycol into the Colorado River. The facility was discharging through the conveyance of storm water system piping directly into the Colorado River. The illegal discharges resulted in a substantial “fish kill” to native aquatic life. This case resulted in a felony conviction of the corporation and individuals responsible. The environmental remediation was conducted by the Environmental Protection Agency. Remediation costs were approximately $1,500,000. The business was charged with felony charges resulting in significant fines and imprisonment. This case was the first successful prosecution of the “Clean Water Act” in the State of Colorado. (Reekie, 2009)
The Grand Junction Fire Department that serves as the Designated Emergency Response Authority for the entire planning area identified the following as significant incidents in Mesa County:
(1) 
1990 – Motor Carrier 338 carrying 70,000 pounds of liquid oxygen caused one injury and $70,000 in damage.
(2) 
1991 – Motor Carrier 331 carrying propane caused $100,000 in damage due to remediation of highway shoulder from diesel contamination.
(3) 
1991 – Illegal dumping of three 150-pound cylinders of liquid chlorine with safety caps removed in Cactus Park area.
(4) 
1992 – Two tractor trailer 40-foot cargo trailers (MC 331 carrying propane) collide causing two injuries and $200,000 in damage.
(5) 
1992 – Motor Carrier 306 with 7,000 gallons of naphtha crashes into rock wall on Highway 141. Highway closed for 36 hours. $200,000 in damage.
(6) 
1995 – Hazardous materials release at fixed facility. Nitric acid tank endothermic reaction at fixed facility. Resulted in $60,000 in damages.
(7) 
2001 – Illegal discharge of ethylene glycol into the Colorado River.
(8) 
2002 – Hazardous materials release from Amtrak derailment in Ruby Canyon with 123 passengers on board; $300,000 in property damage and $20,000 in environmental remediation.
(9) 
2008 – Hazardous materials release with two tractor trailers with coal and hydrochloric acid with property damage of $250,000 and $80,000 in environmental remediation.
(10) 
2011 – Tanker rolled 30 feet down an embankment on Highway 141 resulting in loss of two-thirds of its 7,000 gallon light crude oil cargo.
(11) 
2013 – Approximately 26 pounds of chlorine leaked at a water utility as a result of a valve not being shut properly.
(12) 
2014 – Approximately 100 pounds of ammonia leaked from a refrigeration unit at a business.
(d) 
Probability of Future Occurrence.
Highly likely – near 100 percent chance of occurrence next year or it happens every year. Hazardous materials related incidents occur in Mesa County every year. Most often these incidents involve the transportation sector and are often fuel spills or cargo that is being transported.
(e) 
Magnitude/Severity.
The magnitude/severity of a hazardous materials incident in Mesa County has been limited with impacts to the environment, property destroyed or severely damaged, and/or interruption of essential facilities and service for more than 72 hours.
Impacts in the past have been limited, but depending on the type and quantity of material released, an event could have serious consequences to the public. Humans and animals are affected through inhalation, ingestion, or direct contact with the skin. Air releases can prompt large-scale population evacuations and spills into water or onto the ground can adversely affect public water and sewer systems.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
The Colorado Geological Survey department defines landslides as the downward and outward movement of slopes composed of natural rock, soils, artificial fills, or combination thereof. Landslides move by falling, sliding, and flowing along surfaces marked by difference in soil or rock characteristics. A landslide is the result of a decrease in resisting forces that hold the earth mass in place and/or an increase in the driving forces that facilitate its movement.
Landslides as defined above include two major types: (1) rotational slides which refer to all landslides having a concave upward, curved failure surface and involving a backward rotation of the original slide mass; and (2) translational slides in which the surface of rupture along which displacement occurs is essentially planar. Either type of landslides can involve various combinations of bedrock, broken bedrock, and unconsolidated superficial material, and the displaced material in either type of slide may be either greatly deformed or nearly intact.
Rate of movement of landslides varies from very slow to very rapid. They may be extremely small in extent or measurable in miles. Volumes of material involved may range from a few cubic feet to millions of cubic yards. Landslides result from some change in the physical condition of an unstable slope area (see section of guidelines on potentially unstable slopes). Such changes may be natural or man-induced.
A rockfall is the falling of a detached mass of rock from a cliff or down a steep slope. Weathering and decomposition of geological materials produce conditions favorable to rockfalls. Rockfalls occur most frequently in mountains or other steep areas during the early spring when there is an abundance of moisture and repeated freezing and thawing. (Survey, 2004)
(b) 
Geographic Location.
The geographic location of landslides and rockfalls throughout Mesa County is isolated – which is less than 10 percent of the area.
The landslides and rockfalls that have occurred in Mesa County are most typically associated with canyons. The areas most affected by landslides-rockfalls include: Interstate 70 in DeBeque Canyon and along the Bookcliffs, Highway 65 in Plateau Canyon, Highway 141 in John Brown Canyon near Gateway, Colorado, and the area encompassing the Colorado National Monument.
The DeBeque Canyon Landslide is a major landslide complex in western Colorado that has historically impacted the east-west highway and railway corridor on the Colorado River as shown in Figures 9 and 10.
Figure 9: Mesa County Landslide Map
Source: Mesa County GIS
Figure 10: DeBeque Canyon Slide Area
(Survey, 2004)
Figure 11: Photo of DeBeque Canyon Slide Area – Interstate 70
Figure 12: Photo of DeBeque Canyon Slide Area – Interstate 70
(Photos taken by Mesa County Emergency Management – 1998 Slide in DeBeque Canyon)
Figure 13: Rockfall West of Palisade Along Interstate 70
(Photos taken by Mesa County Emergency Management, July 8, 2009)
Figure 14: Rockfall Event in DeBeque Canyon at Beaver Tail Tunnel on Interstate 70
Figure 15: Rockfall Event in DeBeque Canyon at Beaver Tail Tunnel on Interstate 70
(Photos taken by Mesa County Emergency Management 10/26/09)
(c) 
Previous Occurrences.
The DeBeque Canyon Landslide, which is considered a major landslide complex, has had three significant reactivations or ground movements during the past century. The precise date of the first major movement is unknown but occurred in the late 1890s or early 1900s. That slide movement was the largest and reportedly shifted the river channel and damaged railroad facilities on the north bank of the Colorado River.
The second noteworthy movement occurred in February 1958 when the roadway was widened for a modern two-lane highway. The widening resulted in further cutting and destabilizing of the landslide toe, with subsequent movements resulting in the heaving of the roadway 23 vertical feet. In April 1998, the third major movement occurred and caused Interstate 70, constructed in the mid-1980s, to heave 14 vertical feet. This highway also shifted five to six feet laterally towards the river during this event as shown in Figures 11 and 12. (Survey, 2004)
In 2004, rain and snow loosened several rocks resulting in several injuries to motorists traveling on Interstate 70. In 2006 a rockfall along Interstate 70 just outside of the Town of Palisade resulted in a 300-pound boulder hitting several cars traveling on Interstate 70, injuring several motorists who required medical treatment. Additional rockfall activity has occurred in the DeBeque Canyon resulting in isolated deaths and injuries.
In July of 2009 a significant rockfall occurred on the Bookcliffs approximately two miles west of the Town of Palisade; see Figure 13. What was unique about this rockfall was the amount of energy associated with it. This particular event registered a 2.6 on the Richter scale and was first thought to have been an earthquake. After hours of analysis it was determined that the event was actually a rockfall event, possibly triggered due to the moisture in the soil.
A rockfall event occurred in DeBeque Canyon near the Beaver Tail tunnel on Interstate 70. A significant amount of large boulders landed on the interstate closing all lanes of traffic for a period of time as seen in Figures 14 and 15. No injuries were reported.
The West Salt Creek Landslide occurred on May 25, 2014, near the town of Collbran in eastern Mesa County. The landslide mobilized 30,000,000 cubic meters of material and took the lives of three men. The landslide cut off West Salt Creek and the rotated slide block created a sag pond that detains the flow of West Salt Creek. This incident resulted in both local and State emergency declarations. Considerable work has been done to establish monitoring systems and understand the hazard of the remaining slide block and sag pond. Monitoring will be ongoing for a number of years. The West Salt Creek Landslide can be seen in Figures 16 and 17.
Figure 16: West Salt Creek Landslide Viewed from the East Flank of the Head Escarpment
Figure 17: West Salt Creek Landslide Change in Topography
In July, 2019, a DeBeque Canyon land owner allowed water to flow into his dry rock quarry – in violation of his permit. The water seeped to canyon walls above Interstate 70 loosening rocks and endangering motorists on I-70. The Colorado Department of Transportation spent $1,300,000 to mitigate damage to canyon walls and to install rock fence.
(d) 
Probability of Future Occurrence.
The probability of future occurrence is considered highly likely based on past events.
(e) 
Magnitude/Severity.
The magnitude/severity of a landslide-rockfall event in Mesa County is critical. Past events have resulted in isolated deaths and/or multiple injuries as well as major or long-term property damage that threatens structural stability and/or interruption of essential facilities for 24 to 72 hours.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Lightning is defined as “an abrupt, discontinuous natural electric discharge in the atmosphere.” The rising air in a thunderstorm cloud causes various types of frozen precipitation to form within the cloud. Included in these precipitation types are very small ice crystals and much larger pellets of snow and ice. The smaller ice crystals are carried upward toward the top of the clouds by the rising air while the heavier and denser pellets are either suspended by the rising air or start falling toward the ground. Collisions occur between the ice crystals and the pellets, and these collisions serve as the charging mechanism of the thunderstorm. The small ice crystals become positively charged while the pellets become negatively charged. As a result, the top of the cloud becomes positively charged and the middle to lower part of the storm becomes negatively charged. At the same time, the ground underneath the cloud becomes charged oppositely of the charges directly overhead.
When the charge difference between the ground and the cloud becomes too large, a conductive channel of air develops between the cloud and the ground, and a small amount of charge (step leader) starts moving toward the ground. When it nears the ground, an upward leader of opposite charge connects with the step leader. At that instant this connection is made, a powerful discharge occurs between the cloud and the ground. We see this discharge as a bright visible flash of lightning. (NWS, 2008)
Each year in the United States, more than 400 people are struck by lightning. On average, between 55 and 60 people are killed; hundreds of others suffer permanent neurological disabilities.
(b) 
Geographic Location.
The geographic location of this hazard is considered large as it can happen anywhere in the County. However, lightning strikes are isolated in that the area that is affected by a lightning strike is less than 10 percent of the planning area.
(c) 
Previous Occurrences.
Data from the National Lightning Network ranks Colorado second in the number of deaths (24) from 2002-2011 for deaths caused by lightning. While lightning is a regular occurrence in Mesa County, there are few documented cases where lightning has caused structural damage.
(1) 
September 13, 1996 – Lightning hit a tree and then traveled into an adjacent house causing some fire and electrical damage. Estimated damage was reported at $4,000.
(2) 
September 6, 1997 – Lightning struck a house on the north side of the Grand Mesa destroying some electrical items and blackening a wall on the side of the house.
(3) 
September 13, 1997 – Lightning struck a tree and power pole, setting the tree on fire and destroying a power transformer. Some electrical damage was also incurred at a nearby home.
(4) 
September 21, 1997 – Lightning strike of a two-story house, causing the house to catch on fire.
(5) 
September 9, 1998 – A man was injured when lightning struck a 12-foot-high pole on a trailer next to the man. The lightning also struck the man who was jolted off the trailer, landing 20 feet away. He suffered minor burns.
(6) 
August 20, 2000 – Lightning struck two horses, killing one and paralyzing the other. The two horses were found 50 feet apart from each other.
(7) 
July 7, 2013 – An intense late night thunderstorm produced locally heavy rainfall and a lot of lightning in the Grand Valley, including a lightning bolt that caused significant damage to a childcare facility.
(8) 
July 2, 2016 – A thunderstorm produced a lightning bolt which struck a girl riding an ATV near Glade Park. The girl was injured but survived.
Many of the lightning strikes that occur in Mesa County are the cause of wildland fires throughout the County and many strikes go unreported.
(d) 
Probability of Future Occurrence.
The probability of lightning strikes in Mesa County is highly likely with a near 100 percent chance of occurrence next year or it happens every year.
(e) 
Magnitude/Severity.
The magnitude/severity of lightning throughout Mesa County is limited with minor injuries and illnesses; minimal property damage that does not threaten structural stability; and/or interruption of essential facilities and services for less than 24 hours.
It is recognized that lightning can cause deaths, injuries, and property damage, including damage to buildings, communications systems, power lines, and electrical systems.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
Severe winter weather can include heavy snow, ice, wind chill, blowing snow, freezing rain, sleet, and extremely cold temperatures. Any of these conditions can immobilize our community. These conditions can strand commuters, stop supplies and disrupt power and communication sources. The cost of snow removal, damage repair, and business losses can have a significant impact on the community.
Severe winter storms are usually accompanied by high winds, creating blizzard conditions causing snow to drift, making travel dangerous. Extreme cold temperatures are often associated with winter weather and prolonged exposure can be life-threatening. The months of December, January, and February are the most likely time of the year for severe winter weather.
Grand Junction receives about two feet of snow per year and it generally falls a few inches at a time and then melts off. The ground is usually not covered in snow and there is generally no need to shovel snow constantly. The winter months dip down into the teens and occasionally lower. Most years will see a maximum low temperature for the year of about zero to five degrees Fahrenheit. The average December-January high is 39 with an average low of 16 degrees Fahrenheit. The coldest months on average in Mesa County are January and February and Mesa County’s record minimum temperature was recorded as -23 degrees Fahrenheit in 1963. (NWS, 2008)
(b) 
Geographic Location.
The geographic location of severe winter weather in Mesa County is small with approximately 25 to 50 percent of the County affected. Primarily severe winter weather is found in the higher elevations of the County and include: Grand Mesa, Colorado National Monument, and the Uncompahgre areas. The valley area of the County can see severe winter weather in snowfall, icy conditions, cold temperatures and wind.
(c) 
Previous Occurrences.
The National Climatic Data Center Storm Events Database was used to determine the 287 recorded winter weather events that included some portion of Mesa County. These events ranged from heavy snowfall to blowing and drifting snow from significant wind gusts. (Hinson, National Climatic Data Center, 2009). There have been 54 events between 2010 to 2013.
On January 9, 2017, an abnormally mild Pacific storm system produced rainfall which fell into some western Colorado valleys where trapped air with temperatures below freezing resulted in the formation of freezing rain. Ice up to half of an inch thick quickly accumulated on roads and other surfaces at the beginning to the morning commute. There were hundreds of vehicle accidents and many roads were closed due to crashed vehicles blocking those roads. There were numerous injuries to those who slipped and fell. Emergency rooms in the Grand Valley exceeded their daily admittance records with over 200 people treated for broken bones and other blunt force injuries. Schools were closed throughout the Grand Valley and many businesses were negatively impacted by either not opening, opening late, or the lack of customers.
(d) 
Probability of Future Occurrence.
The probability of future occurrence is likely with a 10 to 100 percent chance of occurrence in next year or has a recurrence interval of 10 years or less. However, it should be noted that Mesa County on average has much milder winter seasons than other parts of the State.
(e) 
Magnitude/Severity.
The magnitude and severity of severe winter weather in Mesa County is limited – resulting in minor injuries and illnesses; minimal property damage that does not threaten structural stability; and/or interruption of essential facilities and services for less than 24 hours.
Severe winter weather in Mesa County can result in property damage, localized power outages and force the closure of streets, highways, schools and businesses. Severe winter weather can escalate, creating life-threatening situations when emergency response is limited due to the conditions or when individuals are caught in the backcountry unprepared. Snow removal costs can also greatly impact local budgets.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
“Wildfire” is the term applied to any unwanted, unplanned, damaging fire burning in forest, shrub or grass and is one of the most powerful natural forces known to humans. While sometimes caused by lightning, nine out of 10 wildfires are human-caused from smoking, campfires, equipment use, and arson.
On public lands in Mesa County, 74 percent of the wildfires started are from lightning and 26 percent are human-caused. However, many of the more destructive and costly fires have been human-caused. Most of these human-caused fires are started near areas where people congregate. This can include towns, subdivisions, or campgrounds. Undoubtedly, human-caused fires on public lands have the potential to threaten human life as well as property. (Paul, 2009)
Due to fuel accumulation in the form of fallen leaves, branches, and excessive plant overgrowth in forest and wildland areas, increasing hot weather, changing weather patterns, and increased residential development in the wildland-urban interface areas, the potential for wildfires to occur has increased. The potential for major loss of property and structures has also significantly increased with the wildland-urban interface. The risk to firefighters can be high. Similar fuels/fire/terrain was responsible for 17 firefighter deaths in neighboring Garfield County. (Paul, 2009)
Based on information contained in the State of Colorado Natural Hazards Mitigation Plan, a century of aggressive fire suppression combined with cycles of drought and changing land management practices has left many of Colorado’s forests unnaturally dense and ready to burn. Furthermore, the threat of wildfire and potential losses is constantly increasing as human development and population increases and the wildland-urban interface expands.
Many other areas of Mesa County now have an increased wildfire threat in areas where fire was not a problem in the past. This is due to a combination of irrigation and the introduction of nonnative plants. Nonnative tamarisk and Russian olive have invaded drainage areas. Excess, undrained irrigation water has created thick, unbroken stands of vegetation throughout the Grand Valley. The stands of tamarisk and Russian olive burn readily and pose a threat to homes and other structures. The spring 2009 Preserve Fire on the Redlands is a good example of this kind of fire. (Paul, 2009)
(b) 
Geographic Location.
The geographic extent of this hazard in Mesa County is medium – 25 to 50 percent of the planning area affected.
(c) 
Previous Occurrences.
According to data collected from the various Fire Protection Districts, the Mesa County Wildland Fire Team, the Bureau of Land Management, and the Colorado State Forest Service, Mesa County has had several significant wildfire events that have either burned a large amount of acres, structures, or involved a multi-agency response. These significant fires include the following:
(1) 
April 3, 1956 – Human caused wildfire at the intersection of Mesa Street and U.S. Hwy 65 with three structures destroyed.
(2) 
April, 1978 – Human caused wildfire known as Mesa Creek Fire (Easter Fire) burned one home with several others damaged.
(3) 
July 1, 1989 – Lightning caused wildfire burned 1,233 acres with approximately 100 homes evacuated.
(4) 
July 31, 1995 – Lightning caused wildfire known as Triangle Fire burned 5,343 acres and forced evacuation of 50 people.
(5) 
July 4, 2000 – Lightning caused wildfire known as Cone Mountain Fire burned 4,960 acres. No homes were threatened but forced road closure of John Brown Canyon.
(6) 
June 9, 2002 – Lightning strike resulting in wildfire known as the Miracle Complex Fire that burned 3,951 acres.
(7) 
June 10, 2002 – Human caused fire known as the Dierich Creek Fire burned 3,951 acres and forced the evacuation of 57 homes.
(8) 
July 4, 2004 – Human caused fire known as the 22 1/2 Road Fire burned 110 acres and threatened 20 homes.
(9) 
July 29, 2005 – Human caused fire known as the Turkey Track Fire burned 348 acres, a camp trailer, and the fire protection district’s water tender. This fire also forced the evacuation of approximately 20 people.
(10) 
June 21, 2007 – Human caused wildfire with three homes destroyed.
(11) 
July 21, 2008 – Lightning caused fire known as the Housetop Fire burned 143 acres and threatened multiple gas wells in the area.
(12) 
August 2, 2008 – Human caused wildfire known as the 48 1/4 Road Fire with one injury and one residence partially burned.
(13) 
May 11, 2012 – Lightning caused fire known as the Brushy Mountain Fire burned approximately 170 acres. The fire started on private land and burned onto National Forest lands on the Uncompahgre Plateau.
(14) 
June 26, 2012 – Lightning caused fire known as the Pine Ridge Fire burned 13,920 acres on private and federal lands. Parts of the town of DeBeque were evacuated and the fire caused closure of I-70 and the rail line through DeBeque canyon.
(15) 
July 10, 2012 – Lightning caused fire known as the Bull Basin Fire grew rapidly being fueled by extremely dry vegetation, low relative humidity, high temperatures, and windy conditions. The fire was quickly contained to approximately 20 acres due to the availability of severity resources that were prepositioned in Mesa County.
(16) 
April 2, 2018 – Human caused urban interface fire known as the Rosevale Fire burned one home, 10 acres and forced 363 homes to be evacuated. This early season fire occurred prior to spring green-up.
(17) 
April 19, 2018 – Human caused urban interface fire known as the Skipper Island fire burned 220 acres, closed I-70 for several hours, damaged power lines impacting 2,100 power customers. A man who admitted accidentally starting the fire was sentenced to 80 hours of community service. This early season fire occurred prior to spring green-up.
(18) 
May 25, 2018 – Human caused fire in DeBeque Canyon started as a result of a vehicle fire on I-70 known as the MM46 fire burned 120 acres, closed I-70 for hours, required evacuation of Island Acres State Park.
(19) 
July 29, 2018 – Lightning caused fire, known as Bull Draw Fire, started in Montrose County and burned into Mesa County on federal and private land burned 36,549 acres. Fire was not contained until mid-October, 2018.
(20) 
July 4, 2019 – Human caused urban interface fire known as the Riverview Fire burned 10 acres dangerously close to homes under Red Flag conditions. The fire was started by a juvenile discharging illegal fireworks. The juvenile plead guilty to fourth-degree arson and sentenced to 50 hours of public service and restitution in the amount of $10,000.
(21) 
August 17, 2019 – Human caused urban interface fire known as the Peach Festival fire burned five acres adjacent to the Colorado River near orchards and vineyards. The fire was caused by the Peach Festival fireworks display. One firefighter was transported to the hospital due to heat related injuries.
(d) 
Probability of Future Occurrence.
Highly likely – Near 100 percent chance of occurrence next year or it happens every year.
(e) 
Magnitude/Severity.
Critical – Isolated deaths and/or multiple injuries and illnesses; major or long-term property damage that threatens structural stability; and/or interruption of essential facilities and services for 24 to 72 hours.
Based on data received from the Bureau of Land Management and Mesa County GIS Department, the following risk assessment has been mapped out for the planning area. Figure 18 illustrates the areas where risk is significant if a wildfire were to occur.
Figure 18: Mesa County Wildfire Risk Assessment
(Source: Bureau of Land Management)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Hazard Description.
High winds occur year round in Mesa County. In the spring and summer, high winds often accompany severe thunderstorms. These winds are typically straight-line winds, which are generally any thunderstorm wind that is not associated with rotation. It is these winds, which can exceed 80 miles per hour (mph), that represent the most common type of severe weather and are responsible for most wind damage related to thunderstorms.
(b) 
Geographic Location.
The geographic extent of this hazard in Mesa County is large – more than 50 percent of the planning area affected.
(c) 
Previous Occurrences.
Historical data from SHELDUS, NCDC Storm Data, and the National Weather Service, Grand Junction Office, reported 48 recorded wind events in Mesa County between 1974 and 2008. These wind events also include tornado events that have occurred in Mesa County. Between 2009 and 2013 there were nine recorded wind events. Nineteen events were recorded between 2015 and 2019, including a tornado on the Grand Mesa.
On July 9, 2015, a thunderstorm with rotation produced a tornado which tracked across a forest of mature aspen trees on the Grand Mesa. Many aspen trees up to a foot and a half in diameter were either uprooted or snapped off as high as 15 feet above the ground. The tornado initially produced damage to trees at the 8,400-foot level and traveled uphill to about the 8,500-foot level.
(d) 
Probability of Future Occurrence.
Likely – 10 to 100 percent chance of occurrence in the next year or has a recurrence interval of 10 years or less.
There were 48 recorded wind events in the past 34 years in Mesa County which equals 1.4 wind events every year on average, or a 100 percent chance of occurrence in any given year.
(e) 
Magnitude/Severity.
Limited – Minor injuries and illnesses; minimal property damage that does not threaten structural stability; interruption of essential facilities and services for less than 24 hours.
Windstorms in Mesa County are rarely life-threatening, but do threaten public safety, disrupt daily activities, cause damage to buildings and structures, increase the potential for other hazards (e.g., wildfire), and have adverse economic impacts from business closures and power loss. Although windstorms are likely to occur in the future, data indicates the past losses have not been significant, and the overall magnitude of this hazard is limited.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
This section summarizes the results of the hazard profiles and assigns a level of overall planning significance to each hazard of low, moderate, or high as indicated in Table 7. Significance was determined based on the hazard profile, focusing on key criteria such as geographic location, occurrences, magnitude and severity. This assessment was used by the HMPC to prioritize the hazards that present the greatest risk to the planning area. The hazards that occur infrequently or have little or no impact to the planning area were determined to be of low significance. Those determined to be of high significance were identified as priority hazards that require additional evaluation in the vulnerability assessment.
The priorities for this 2020 plan revision have not changed from the previous plan. The hazards that have been determined to be of high significance remain wildfire, flood, and landslide/rockfall. These hazards continue to be the focus in the vulnerability assessment and the focus of mitigation project proposals.
Table 7: Hazards Profile
Hazard Type
Geographic Location
Occurrences
Magnitude/ Severity
Total Score
Hazard Level
Avalanche
2
4
6
32
M
Drought
8
4
4
48
M
Earthquake
6
4
4
40
M
Expansive Soils
2
4
2
16
L
Extreme Heat
8
4
2
40
M
Wildfire
6
8
4
80
H
Flood
6
8
6
96
H
Hailstorm
4
4
2
24
L
Land Subsidence
2
4
4
24
L
Landslide/Rockfall
4
8
6
80
H
Lightning
2
8
4
48
M
Tornado
2
4
2
16
L
Windstorm
4
6
4
48
M
Winter Storm
6
6
2
48
M
Dam Failure
4
4
6
40
M
Hazardous Materials
2
8
4
48
M
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Requirement Section 201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area.
Requirement Section 201.6(c)(2)(ii)(B): [The plan should describe vulnerability in terms of an] estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate.
Requirement Section 201.6(c)(2)(ii)(C): [The plan should describe vulnerability in terms of] providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions.
The vulnerability assessment further defines and quantifies populations, buildings, critical facilities and infrastructure, and other community assets at risk to natural hazards. The vulnerability assessment for this plan followed the methodology described in the FEMA publication Understanding Your Risks – Identifying Hazards and Estimating Losses (2002).
The vulnerability assessment is based on the best available data and the overall planning significance of the hazard. Data to support the vulnerability assessment was collected from the same sources identified for the hazard identification and hazard profile sections.
The vulnerability assessment includes three sections:
(a) 
Community Asset Inventory.
This section is an inventory of assets exposed to hazards in Mesa County, including the total exposure of people and property; critical facilities and infrastructure; natural, cultural, and historic resources; and economic assets.
(b) 
Vulnerability by Hazard.
This section describes the County’s overall vulnerability to each hazard; identifies existing and future structures, critical facilities, and infrastructure in identified hazard areas; and estimates potential losses to vulnerable structures, where data is available. Only hazards of moderate or high significance, or that have identified hazard areas, are addressed in the vulnerability assessment.
(c) 
Development and Land Use Trends.
The final section analyzes trends in population growth, housing demand, and land use pattern.
In addition, a capability assessment was conducted for each jurisdiction as part of the risk assessment process. A capability assessment identifies the existing programs, policies, and plans that mitigate or could be used to mitigate risk to disasters. From a Countywide perspective the following capabilities are identified in Table 8. Jurisdiction specific information regarding capabilities is found in the Jurisdictional Annex of this plan (Article VII of this chapter).
Table 8: Capabilities Matrix
Local Mitigation Capabilities Tracker for Local and State Plan Updates
Planning and Regulatory
Yes/No
Building Codes
Yes
Building Codes Year
Yes
BCEGS Rating
Yes
Capital Improvements Program (CIP) or Plan
Yes
Community Rating System (CRS)
Yes
Community Wildfire Protection Plan (CWPP)
Yes
Comprehensive, Master, or General Plan
Yes
Economic Development Plan
Yes
Elevation Certificates
Yes
Erosion/Sediment Control Program
Yes
Floodplain Management Plan or Ordinance
Yes
Flood Insurance Study
Yes
Growth Management Ordinance
Yes
Non-Flood Hazard-Specific Ordinance or Plan (e.g., Steep Slope, Wildfire, Snow Load)
No
NFIP
Yes
Site Plan Review Requirements
Yes
Stormwater Program, Plan, or Ordinance
Yes
Zoning Ordinance
Yes
Financial
Yes/No
Has community used any of the following to fund mitigation activities:
– Levy for Specific Purposes with Voter Approval
No
– Utilities Fees
No
– System Development/Impact Development Fee
No
– General Obligation Bonds to Incur Debt
No
– Special Tax Bonds to Incur Debt
No
– Withheld Spending in Hazard-Prone Areas
No
– Stormwater Service Fees
No
– Capital Improvement Project Funding
Yes
– Community Development Block Grants
No
– Other (BLM Community Assistance Grant)
Yes
Administrative and Technical
Yes/No
Emergency Manager
Yes
Floodplain Administrator
Yes
Community Planning:
– Planner/Engineer (Land Devel)
Yes
– Planner/Engineer/Scientist (Natural Hazards)
Yes
– Engineer/Professional (Construction)
Yes
– Resiliency Planner
No
– Transportation Planner
Yes
Building Official
Yes
GIS Specialist and Capability
Yes
Grant Manager, Writer, or Specialist
Yes
Warning Systems/Services:
– General
Yes
– Flood
No
– Wildfire
No
– Tornado
No
– Geological Hazards (West Salt Creek Landslide)
Yes
Other
Education and Outreach
Yes/No
Local Citizen Groups That Communicate Hazard Risks
Yes
Firewise
No
StormReady
Yes
Other
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
The following sections assess the population, structures, critical facilities and infrastructure, and other important assets in Mesa County at risk to natural hazards.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
A critical facility may be defined as one that is essential in providing utility or direction either during the response to an emergency or during the recovery operation. Table 9 displays the inventory of critical facilities in Mesa County. The information is based on available data from the Northwest All Hazard Emergency Management Region.
Table 9: Critical Facilities and Infrastructure
Facility Type
Unincorporated Mesa County
Grand Junction
Collbran
Palisade
Fruita
DeBeque
Ambulance
7
10
3
2
3
2
Bridge
104
27
3
–
6
1
Dam
47
1
–
–
–
–
EOC
1
–
–
–
–
–
Communication Towers
103
52
1
–
2
–
Fire Station
7
5
1
1
1
1
Govt. Building
3
14
1
1
1
1
Helicopter Staging
–
1
–
–
–
–
911 Communications Center
–
1
–
–
–
–
Medical Facility
–
3
–
–
1
–
Schools
District 51
15
19
1
2
5
1
Private
2
5
Water – Wastewater
2
1
1
1
1
1
College – University
–
2
–
–
–
–
Airport
1
1
–
–
–
–
Note: Communication towers include cell towers, radio sites and TV translators. Other facilities in Mesa County, such as locations that hold concerts, sporting events, and other events that attract large numbers of people, may also be at higher risk due to concentrations of people.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Assessing the vulnerability of Mesa County to disaster also involves inventorying the natural, historic, and cultural assets of the area. This step is important for the following reasons:
(a) 
The community may decide that these types of resources warrant a greater degree of protection due to their unique and irreplaceable nature and contribution to the overall economy.
(b) 
If these resources are impacted by a disaster, knowing so ahead of time allows for more prudent care in the immediate aftermath, when the potential for additional impacts is higher.
(c) 
The rules for reconstruction, restoration, rehabilitation, and/or replacement are often different for these types of designated resources.
(d) 
Natural resources can have beneficial functions that reduce the impacts of natural hazards, such as wetlands and riparian habitat, which help absorb and attenuate floodwaters.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Natural resources are important to include in benefit-cost analyses for future projects and may be used to leverage additional funding for projects that also contribute to community goals for protecting sensitive natural resources. Awareness of natural assets can lead to opportunities for meeting multiple objectives. For instance, protecting wetlands areas protects sensitive habitat as well as attenuates and stores floodwaters. A number of natural resources exist in Mesa County, including wetlands, endangered species, and imperiled plant communities.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Wetlands are a valuable natural resource for communities, due to their benefits to water quality, wildlife protection, recreation, and education, and play an important role in hazard mitigation. Wetlands reduce flood peaks and slowly release floodwaters to downstream areas. When surface runoff is dampened, the erosive powers of the water are greatly diminished. Furthermore, the reduction in the velocity of inflowing water as it passes through a wetland helps remove sediment being transported by the water. They also provide drought relief in water-scarce areas where the relationship between water storage and stream flow regulation is vital. Figure 19 shows the wetlands that have been identified throughout Mesa County.
Figure 19: Mesa County Wetlands Areas
Source: Mesa County GIS
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
An endangered species is any species of fish, plant life, or wildlife that is in danger of extinction throughout all or most of its range. A threatened species is a species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. Both endangered and threatened species are protected by law and any future hazard mitigation projects are subject to these laws. Candidate species are plants and animals that have been proposed as endangered or threatened but are not currently listed. Figure 20 is a map showing habitats for threatened and endangered species in Mesa County. (Nelson, 2009)
Figure 20: Mesa County Habitats for Threatened and Endangered Species
The Colorado Division of Parks and Wildlife provides the following information on their website regarding wildlife species found in Mesa County that have been given special designations, see Table 10.
Table 10: Endangered Wildlife
Group
Common Name
Scientific Name
Occurrence
Abundance
Status
Amphibians
Boreal Toad
Bufo boreas
Known to occur
Unknown
State Endangered
Amphibians
Northern Leopard Frog
Rana pipiens
Known to occur
Common
State Species of Concern, Federal Review
Birds
American Peregrine Falcon
Falco peregrinus anatum
Known to occur
Rare
State Species of Concern
Birds
Bald Eagle
Haliaeetus leucocephalus
Known to occur
Casual/ Accidental
State Species of Concern
Birds
Ferruginous Hawk
Buteo regalis
Known to occur
Very Rare
State Species of Concern
Birds
Greater Sage Grouse
Centrocercus urophasianus
Known to occur
Unknown
State Species of Concern
Birds
Greater Sandhill Crane
Grus canadensis tabida
Known to occur
Very Rare
State Species of Concern
Birds
Gunnison Sage Grouse
Centrocercus minumus
Known to occur
Rare
State Species of Concern, Federal Threatened
Birds
Least Tern
Sterna antillarum
Known to occur
Unknown
Federal Endangered, State Endangered
Birds
Long-billed Curlew
Numenius americanus
Known to occur
Casual/Accidental
State Species of Concern
Birds
Mountain Plover
Charadrius montanus
Known to occur
Unknown
State Species of Concern
Birds
Plains Sharp-tailed Grouse
Tympanuchus phassianellusjamesii
Known to occur
Unknown
State Endangered
Birds
Southwestern Willow Flycatcher
Empidonax traillii extiums
Known to occur
Rare
Federal Endangered, State Endangered
Birds
Western Snowy Plover
Charadrius alexandrinus nivosus
Known to occur
Unknown
State Species of Concern
Birds
Whooping Crane
Grus americana
Known to occur
Unknown
Federal Endangered, State Endangered
Fish
Bonytail
Gila elegans
County Fish Data Not Kept by NDIS
Federal Endangered, State Endangered
Fish
Razorback Sucker
Xyrauchen texanus
County Fish Data Not Kept by NDIS
Federal Endangered, State Endangered
Fish
Humpback Chub
Gila cypha
County Fish Data Not Kept by NDIS
Federal Endangered, State Endangered
Fish
Colorado Pikeminnow
Ptychocheilus lucius
County Fish Data Not Kept by NDIS
Federal Endangered, State Endangered
Fish
Colorado Roundtail Chub
Gila robusta
County Fish Data Not Kept by NDIS
State Species of Concern
Fish
Colorado River Cutthroat Trout
Oncorhynchus clarki pleuriticus
County Fish Data Not Kept by NDIS
State Species of Concern
Mammals
Kit Fox
Vulpes macrotis
Known to occur
Very Rare
State Endangered
Mammals
Lynx
Lynx canadensis
Likely to occur
Extirpated
Federal Endangered, State Endangered
Mammals
Northern Pocket Gopher
Thomomys talpoides
Known to occur
Common
State Species of Concern
Mammals
River Otter
Lontra canedensis
Known to occur
Rare
State Threatened
Mammals
Townsend’s Big-eared Bat
Plecotus townsendii
Known to occur
Uncommon
State Species of Concern
Mammals
Wolverine
Gulo gulo
Likely to occur
Extirpated
State Endangered
Reptiles
Longnose Leopard Lizard
Gambelia wislizenii
Known to occur
Uncommon
State Species of Concern
Reptiles
Midget Faded Rattlesnake
Crotalus viridis concolor
Known to occur
Uncommon
State Species of Concern
(CODPW, 2020)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
The Colorado Natural Heritage Program (CNHP) tracks and ranks Colorado’s rare and imperiled species and habitats, and provides information and expertise on these topics to promote the conservation of Colorado’s valuable biological resources. The Statewide Potential Conservation Areas (PCA) map in Figure 21 shows CNHP’s best estimate of the primary area required to support the long-term survival of targeted species or natural communities. (About Us: Colorado Natural Heritage Program, 2009)
Figure 21: Potential Conservation Areas
(About Us: Colorado Natural Heritage Program, 2009)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Figure 22 shows the ecologically sensitive areas in Mesa County where threatened and endangered species and imperiled natural plant communities are most likely found.
Figure 22: Mesa County Ecologically Sensitive Areas
Source: Mesa County GIS
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Several national and State historic inventories were reviewed to identify historic and cultural assets in Mesa County:
(a) 
The National Register of Historic Places is the nation’s official list of cultural resources. The National Register is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect historic and archaeological resources. Properties listed include districts, sites, buildings, structures, and objects that are significant in American history, architecture, archeology, engineering, and culture. The National Register is administered by the National Park Service, which is part of the U.S. Department of the Interior.
(b) 
The Colorado State Register of Historic Properties is a listing of the State’s significant cultural resources worthy of preservation. Properties listed in the Colorado State Register include individual buildings, structures, objects, districts, and historic and archaeological sites.
(c) 
Table 11 lists the properties and districts in Mesa County that are on the National Register of Historic Places.
Table 11: National Register of Historic Places in Mesa County
Property Name
City
Location
Date Listed
Colorado National Monument Visitor Center Complex
Mesa County
Colorado National Monument
07/15/2003
Colorado River Bridge
Mesa County
DeBeque Vicinity
10/15/2002
Clifton Community Center and Church
Mesa County
Clifton
06/30/1982
Coates Creek Schoolhouse
Mesa County
Glade Park
02/03/1993
Convicts’ Bread Oven
Mesa County
Molina
12/31/1974
Crissey, Herbert and Edith, House
Palisade
218 W. 1st St.
05/18/2003
Cross Land and Fruit Company Orchards and Ranch
Mesa County
3079 F Road
03/28/1980
DeBeque House
DeBeque
233 Denver Ave.
07/28/1995
Denver and Rio Grande Western Railroad Depot
Grand Junction
119 Pitkin Ave.
09/08/1992
Devils Kitchen Picnic Shelter
Mesa County
Colorado National Monument
04/21/1994
Fruita Bridge
Mesa County
Cty. Rd. 17.50 over Colorado River
02/04/1985
Fruita Museum
Fruita
432 E. Aspen
10/10/1996
Grand Valley Diversion Dam
Mesa County
8 miles NE of Palisade
10/08/1991
Handy Chapel
Grand Junction
202 White Ave.
08/19/1994
Hotel St. Regis
Grand Junction
359 Colorado Ave.
10/22/1992
IOOF Hall
DeBeque
4th St. and Curtis Ave.
03/25/1993
Kettle-Jens House
Mesa County
498 32nd Road
05/06/1983
Land’s End Observatory
Mesa County
Land’s End Road, 10 miles W of CO 65
02/28/1997
Loma Community Hall
Mesa County
1341 Co. Rd. 13, Loma
11/22/1995
Margery Building
Grand Junction
519-527 Main Street
02/24/1993
North 7th Street Historic Residential District
Grand Junction
7th St. between Hill and White Aves.
01/05/1984
Phillips, Harry and Lilly House
Fruita
798 N. Mesa St.
11/13/1997
Pipe Line School
Mesa County
101 16.5 Rd. Glade Park
04/29/1999
Rim Rock Drive Historic District
Grand Junction
Colorado National Monument
04/21/1994
Saddlehorn Caretaker’s House and Garage
Grand Junction
Colorado National Monument
04/21/1994
Saddlehorn Comfort Station
Grand Junction
Colorado National Monument
04/21/1994
Saddlehorn Utility Area Historic District
Grand Junction
Colorado National Monument
04/21/1994
Serpents Trail
Grand Junction
Colorado National Monument
04/21/1994
U.S. Post Office
Grand Junction
400 Rood Ave.
01/31/1980
Cayton Ranger Station
Mesa County
White River National Forest, Silt Vicinity
04/27/2005
Calamity Camp
Mesa County
Gateway Vicinity
06/11/2011
TBM Avenger Aircraft N53503
Grand Junction
780 Heritage Way
11/13/2017
Stranges Grocery
Grand Junction
226 Pitkin Ave
03/20/2013
Dept of Energy Grand Junction Office
Grand Junction
2591 Legacy Way
07/26/2016
(National Register of Historic Places, 2020)
(d) 
Table 12 identifies the properties and districts in Mesa County that are on the Colorado Office of Archaeology and Historic Preservation site. Those properties listed in Table 11 were also listed on the State list.
Table 12: Mesa County Properties Listed as Archaeology and Historic Preservation Sites
Property Name
City
Location
Date Listed
Stockmens Bank
Collbran
111 Main St.
03/08/1995
Circle Park
Fruita
Fruita Park Sq.
05/14/1997
Fruita Elementary
Fruita
325 E. Aspen St.
03/10/1993
Weckel House
Mesa County
1620 Hwy. 6 and 50
03/13/1996
Driggs Mansion
Mesa County
24505 State Highway 141
09/14/2005
Grand Junction Country Club
Grand Junction
2463 Broadway
09/13/1995
Hurlburt-Knowles House
Mesa County
1151 13 Rd. Loma
08/09/2000
Harlow Gravesite
Mesa County
869 Rapid Creek Rd.
09/13/1995
Bloomfield Site
Mesa County
Whitewater Vicinity
01/20/1983
Coffman House
Mesa County
4000 US Hwy. 50
12/12/2001
Land’s End Aboriginal Site
Mesa County
Land’s End Road
03/11/1998
Raber Cow Camp
Mesa County
Land’s End Road
03/10/1993
(National and State Registers)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Economic assets at risk may include major employers or primary economic sectors, such as agriculture, whose losses or inoperability would have severe impacts on the community and its ability to recover from disaster. After a disaster, economic vitality is the engine that drives recovery. Every community has a specific set of economic drivers, which are important to understand when planning ahead to reduce disaster impacts to the economy. When major employers are unable to return to normal operations, impacts ripple throughout the community. Table 13 lists the major employers in Mesa County based on the number of employees.
Table 13: Major Employers in Mesa County
Employer
Employees
Industry
Mesa County School District #51
2,785
Education
St. Mary’s Hospital and Medical Center
2,448
Healthcare
Mesa County
1,070
Government
State of Colorado
1,012
Government
Community Hospital
1,000
Healthcare
VA Medical Center
720
Healthcare
City of Grand Junction
652
Government
Hilltop Community Resources
600
Healthcare
West Star Aviation
441
Aviation
Mind Springs Health
433
Healthcare
HopeWest
350
Healthcare
Strive
304
Nonprofit
Primary Care Partners
304
Healthcare
Family Health West
282
Healthcare
Navarro
263
Technical/Professional Services
United Companies
203
Manufacturing
StarTek, Inc.
203
Telecommunications
Capco, Inc.
200
Manufacturing
Union Pacific Railroad
175
Transportation
Coors Tek, Inc.
150
Manufacturing
The Daily Sentinel
146
Media
Reynolds Polymer Technology
125
Manufacturing
Mantey Heights Rehab and Care
100
Healthcare
(Data and Demographics: Grand Junction Economic Partnership, 2020)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Senate Bill 11-265, 6-6-11; Res. 05-10, 1-6-10)
This section through GJMC § 42.08.530 describe overall vulnerability and identify structures and estimate potential losses to buildings, infrastructure, and critical facilities located in identified hazard areas. This assessment was limited to the hazards that were considered moderate or high in planning significance, based on HMPC input and the hazard profiles. Hazards that ranked as “low significance” are not included in the vulnerability assessment. These include the following: expansive soils, hailstorm, land subsidence, and tornado.
Many of the identified hazards, particularly weather related hazards, affect the entire planning area, and specific hazard areas cannot be mapped geographically. For those hazards, which include drought, lightning, and winter weather, the vulnerability is mainly discussed in qualitative terms because data on potential losses to structures is not available.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Mesa County’s vulnerability to avalanches is moderate due to the historical events where loss of life has occurred. Thousands of people are exposed to avalanche risk in Mesa County every winter and spring due to the recreational use of backcountry areas. Motorists along highways are also at risk of injury or death if avalanches sweep across roadways.
(a) 
Existing Development.
Mesa County does not have comprehensive information or mapping of avalanche hazard areas, therefore limiting available data on specific structures at risk or estimate of potential losses to structures.
(b) 
Future Development.
Based on historic avalanche activity and lack of anticipated development in backcountry areas, there are no immediate plans to map avalanches in Mesa County.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Mesa County has a considerable amount of high hazard dams; if a failure of one of these high hazard dams occurred, it would result in loss of life. There is no specific evidence at the time this plan was written to indicate a failure of any dams in Mesa County.
Vulnerability to dam failure is greatest on the Grand Mesa where most of the dams are located and specifically the Town of Collbran which is downstream from many of the dams. A catastrophic dam failure would challenge local response capabilities and require evacuations to save lives. Impacts to life safety will depend on the timely warning of people in the area. Without immediate warning, loss of life could result as well as potentially catastrophic effects to roads, bridges, and homes.
(a) 
Existing Development.
The Mesa County Department of Emergency Management retains copies of emergency action plans for all Class I and Class II dams in the County. The Mesa County Emergency Management Office has also worked with the Grand Junction Regional Communications Center to identify potential evacuation areas if a dam failure were to occur that is built into the reverse 911 system for notification purposes. Due to ongoing security concerns of the dam operators, Mesa County Emergency Management requests that inundation maps not be made part of this public planning process.
(b) 
Future Development.
Efforts to map out additional evacuation areas that would be inundated in the event of a dam failure will continue with the Grand Junction Regional Communications Center. The County and towns should consider the dam failure hazard when permitting development downstream of the Class I and Class II dams.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Drought has been a significant issue in Mesa County. It is the one hazard that cannot be controlled yet it has devastating effects that can last for several years. Drought has several impacts to Mesa County including but not limited to: air quality, wildfires, reduction of tourism and recreation activities, and damage to the agriculture industry.
(a) 
Existing Development.
The impacts from drought are nonstructural and generally affect the economy and environment the most. A drought event normally does not impact structures and it can be difficult to identify specific hazard areas. Many of the towns use public education efforts to encourage water conservation during the summer months.
(b) 
Future Development.
Vulnerability to drought will increase as population growth increases, putting more demands on existing water supplies. Future water use planning should consider increase in population as well as potential impacts of climate change.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Past earthquake activity in Mesa County has been minimal and most earthquake activity has low magnitude and severity. Earthquake data in Mesa County is limited but some historical information is available through Colorado Mesa University.
(a) 
Existing Development.
By using data from the HAZUS-MH software, information on potential economic and social losses due to an earthquake in Mesa County can be determined. This particular information produces “what if” scenarios (e.g., determines what would happen if an earthquake of a certain magnitude occurred on a particular fault). The earthquake magnitudes used for each fault were the “maximum credible earthquake” as determined by the U.S. Geological Survey.
There are 16 Quaternary aged faults identified by the USGS in Mesa County. There are innumerable older faults that have been identified and presumably older faults which remain hidden from view. The Quaternary aged faults are associated with the Uncompahgre Plateau. The Uncompahgre Plateau extends from Grand County, Utah, northwest of Grand Junction to near the Town of Ridgway, Colorado. The Uncompahgre has as much as 640 meters of uplift. The faults associated with the uplift are in two groups, bordering both the southwest flank and northeast flank of the uplift.
The northeast flank of the Uncompahgre Plateau, near Grand Junction, contains the Redlands Fault complex. This fault shows as much as 240 meters of displacement and can be seen most vividly in the Colorado National Monument. The Colorado Geological Survey has estimated that the largest earthquake possible on the Western Slope of Colorado is magnitude 6.5.
(b) 
Using the HAZUS-MH program, Emergency Management staff and a Colorado Mesa University faculty member designed and analyzed the following earthquake scenario on the Bridgeport/Cactus Park fault complex in southern Mesa County:
(1) 
Type: Deterministic, arbitrary.
(2) 
Attenuation Function: Western U.S. Shallow Crustal Event – Nonextensional.
(3) 
Magnitude: 5.5.
(4) 
Epicenter.
(i) 
Latitude 38.875, Longitude -108.438.
(ii) 
Depth: one kilometer.
(iii) 
Width: six kilometers.
(5) 
Fault Mechanism: Reverse Slip.
(6) 
Rupture.
(i) 
Subsurface Length: 5.88844 kilometers.
(ii) 
Surface Length: 4.02717 kilometers.
(iii) 
Orientation: 120 degrees.
(iv) 
Dip Angle: 75 kilometers.
While this is not the worst-case scenario for an earthquake event in Mesa County, it is believed to be a more plausible scenario (Wolny, Martsolf, 2009). Figure 23 provides an illustration of potential ground acceleration from this scenario.
Figure 23: HAZUS Earthquake Scenario
Figure 24 shows how far reaching this type of earthquake would be felt in Mesa County and Figure 25 identifies the area with displaced homes.
Figure 24: Bridgeport Earthquake Ground Motion
Figure 25: Bridgeport Earthquake Scenario, Displaced Homes
(c) 
In calculating building damage associated with this type of earthquake, the following HAZUS definitions were used:
(1) 
Slight damage. Small plaster or gypsum board cracks at corners of doors and window openings and wall-ceiling intersections, small cracks in masonry chimneys and masonry veneer.
(2) 
Moderate damage. Larger plaster or gypsum board cracks at corners of door and window openings; small diagonal cracks across shear wall panels exhibited by small cracks in stucco and gypsum wall panels; large cracks in brick chimneys; toppling of tall masonry chimneys.
(3) 
Extensive damage. Large diagonal cracks across shear wall panels or large cracks at plywood joints; permanent lateral movement of floors and roof; toppling of most brick chimneys; cracks in foundations; splitting of wood sill plates and/or slippage of structure over foundations; partial collapse of room-over garage or other soft-story configurations; small foundation cracks.
(4) 
Complete damage. Structure may have large permanent lateral displacement, may collapse, or be in imminent danger of collapse due to cripple wall failure or the failure of lateral load resisting system; some structures may slip and fall off the foundations; large foundation cracks.
Table 14 provides an estimated number of buildings damaged throughout Mesa County and the extent of damage to the various types of structures using this scenario.
Table 14: Estimated Building Damage from Earthquake
Number of Buildings
No Damage
Slight Damage
Moderate Damage
Extensive Damage
Complete Damage
Total
Wood
28,677
2,296
384
25
0
31,382
Steel
177
10
5
1
0
193
Concrete
367
27
10
1
0
405
Precast
192
16
13
3
0
224
Reinforced Masonry
3,234
202
133
20
0
3,589
Manufactured Home
2,086
295
156
16
0
2,553
Total
34,733
2,846
701
66
0
38,346
Table 15 identifies the possible economic loss throughout Mesa County due to the number of damaged or destroyed buildings as a result of this type of earthquake.
Table 15: Direct Economic Loss
Capital Stock Losses
Structural Damage Loss
Nonstructural Damage Cost
Contents Damage Cost
Inventory Loss
$11,819,000.00
$37,667,000.00
$15,472,000.00
$539,000.00
Income Losses
Relocation Loss
Capital Related Loss
Wage Losses
Rental Income Loss
$315,000.00
$2,977,000.00
$3,944,000.00
$4,520,000.00
Total Loss
$65,497,000.00
(d) 
Much of the County’s recent development has building codes in place which reduce the risk of structural damage. However, historical buildings constructed of unreinforced masonry are most vulnerable to seismic ground shaking. Downtown Grand Junction is one of the areas most vulnerable to a seismic event due to older construction.
Similar to calculating damage to buildings, the analysis also allows us to estimate possible injuries sustained throughout Mesa County during a 5.5 magnitude earthquake. This data is shown in Table 16. HAZUS injury definitions are defined as the following:
(1) 
Severity 1. Injuries requiring basic medical aid without requiring hospitalization.
(2) 
Severity 2. Injuries requiring a greater degree of medical care and hospitalization, but not expected to progress to a life-threatening status.
(3) 
Severity 3. Injuries that pose an immediate life-threatening condition if not treated adequately and expeditiously. The majority of these injuries are the result of structural collapse and subsequent collapse or impairment of the occupants.
(4) 
Severity 4. Instantaneously killed or mortally injured.
Table 16: Possible Injuries Sustained in Earthquake
Injury Severity Level
Casualties at 2:00 a.m. event
Severity 1
Severity 2
Severity 3
Severity 4
Total
Commuting
0
0
0
0
0
Commercial
0
0
0
0
0
Educational
0
0
0
0
0
Hotels
0
0
0
0
0
Industrial
0
0
0
0
0
Other – Residential
7
1
0
0
8
Single-Family
14
2
0
0
16
Total Casualties – 2:00 a.m.
21
3
0
0
24
Casualties at 2:00 p.m. event
Severity 1
Severity 2
Severity 3
Severity 4
Total
Commuting
0
0
0
0
0
Commercial
13
2
0
0
15
Educational
3
0
0
0
3
Hotels
0
0
0
0
0
Industrial
2
0
0
0
2
Other – Residential
1
0
0
0
1
Single-Family
3
0
0
0
3
Total Casualties – 2:00 p.m.
22
2
0
0
24
Casualties at 5:00 p.m. event
Severity 1
Severity 2
Severity 3
Severity 4
Total
Commuting
0
0
0
0
0
Commercial
10
1
0
0
11
Educational
0
0
0
0
0
Hotels
0
0
0
0
0
Industrial
1
0
0
0
1
Other – Residential
3
1
0
0
4
Single-Family
5
1
0
0
6
Total Casualties – 5:00 p.m.
19
3
0
0
22
(e) 
Future Development.
All jurisdictions within Mesa County have adopted building codes. Building codes substantially reduce the costs of damage to future structures from earthquakes. It is highly recommended that a specific study be done on the liquefaction hazards found within the Grand Valley. This is the single most important unknown in assessing the vulnerability of earthquakes in Mesa County.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Senate Bill 11-265, 6-6-11; Res. 05-10, 1-6-10)
Floods affect most of the communities in Mesa County and will continue to occur in the future. Floods can be critical in their magnitude and may cause deaths and damage to property and infrastructure.
(a) 
Existing Development.
In 2005, Mesa County entered FEMA’s map modernization program to develop digital flood insurance rate maps (DFIRMS) in partnership with State and federal agencies. Mesa County has received a copy of the preliminary copies of the Digital Flood Insurance Rate Map (DFIRM) and Flood Insurance Study (FIS) report. Samples of DFIRMS are included in the community profiles for participating jurisdictions. A comprehensive collection of DFIRMS can be viewed on Mesa County’s website.
Analysis was done for each community in Mesa County to determine the proportion of value of buildings in the hazard areas that were identified by the HMPC. The GIS system was used by selecting parcels that have their center within the city or town limits, then by making a subselection of parcels that have their center within the areas subject to flooding. Structure value is based on the actual value of improvements. Specific information regarding flood losses is identified in the jurisdiction’s annex.
(b) 
Floodplain Management.
The purpose of the Mesa County Floodplain Management program is to assist property owners with any improvements in the floodplain. The County’s goal is to help minimize property damage to residents of Mesa County during flood events. Mesa County wants to ensure that life, property including natural resource values, and/or new improvements are safe during flood events and that any structures or improvements in the floodplain will not cause additional drainage problems.
Regulations are in place to ensure that proposed improvements will not cause flooding problems upstream and/or downstream. Every manmade structure or improvement constructed within the floodplain area requires a floodplain development permit prior to beginning construction. A floodplain development permit authorizes a specific activity within the regulatory floodplain while minimizing the likelihood of property damage to buildings or improvements in the event of a flood. (County, Mesa County Public Works, Stormwater Management, 2009)
The National Flood Insurance Program (NFIP) is a federal program enabling property owners in participating communities to purchase insurance as a protection against flood losses. A jurisdiction’s eligibility to participate is premised on their adoption and enforcement of state and community floodplain management regulations intended to prevent unsafe development in the floodplain, thereby reducing future flood damages. Thus, participation in the NFIP is based on an agreement between communities and the federal government. If a community adopts and enforces a floodplain management ordinance to reduce future flood risk to new construction in floodplains, the federal government will make flood insurance available within the community as a financial protection against flood losses. Currently all of the communities in and including Mesa County participate in the National Flood Insurance Program.
(c) 
Future Development.
Management of storm water is important to the communities in Mesa County. As mandated under the Clean Water Act, the U.S. Environmental Protection Agency has developed a National Pollutant Discharge Elimination System storm water permitting program. Phase II of this program addresses smaller urbanized areas, such as the Grand Valley. Currently the jurisdictions in Mesa County have identified areas where Phase II regulations are to be implemented, requiring storm water construction permits. (County, Mesa County Public Works, Stormwater Management, 2009)
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
In Mesa County, vulnerability to landslides primarily occurs along roadways, where the hazard could cause deaths or injuries. Road closures due to landslide events also affect the County economically.
(a) 
Existing Development.
Under the Mesa County Land Development Code, Chapter 7, any proposed land use or development must identify hazard areas, i.e., floodplains, drainage areas, steep slope areas, geological fault areas, and other areas hazardous to life or property. Such proposals will require an evaluation to determine the degree to which the proposed activity will:
(1) 
Expose any person, including occupants or users of the proposed use or development, to any undue natural hazard.
(2) 
Create or increase the effects of natural hazard areas or other improvements, activities or lands.
(3) 
Impact the natural environment and be unduly destructive to the natural resources of an area.
Regulations also require proposed land uses to address soil, erosion, and surface geologic characteristics of the development site through proper design, engineering and construction. (County, Mesa County Planning Division, 2014)
Potential losses for the landslide areas in Mesa County were estimated using Mesa County GIS and assessor’s data and were examined in terms of values and critical facilities at risk. Detailed information pertaining to specific jurisdictions is found in that jurisdiction’s community profile.
(b) 
Future Development.
The severity of landslide problems is directly related to the extent of human activity in hazard areas. Adverse effects can be mitigated by early recognition and avoiding incompatible land uses in these areas or by corrective engineering. The mountainous topography of the County presents considerable constraints to development, most commonly in the form of steep sloped areas. These areas are vulnerable to disturbance and can become unstable. Most of these areas are adjacent to roadway systems that are heavily used. Continued adherence to the Land Development Code is necessary.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Lightning events are likely to occur throughout Mesa County and can result in deaths and destruction of property. Consequences of lightning may have destructive effects on power and information systems. Failure of these systems would have cascading effects throughout the County and could possibly disrupt other critical infrastructure such as water treatment facilities. Because lightning can occur anywhere in the County, data was not available to identify specific structures at risk or estimate potential losses.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Existing Development.
Winter storms can create significant public safety concerns and cause significant impacts to the local economy due to a disruption in the transportation of goods. On occasion, winter storms can overwhelm snow removal efforts, transportation, livestock management and business and commercial activities.
From previous events, Mesa County Emergency Management staff has identified the County’s elderly population as a significantly vulnerable population during winter storms especially when utility outages are associated with winter storms.
(b) 
Future Development.
Population growth in the County will increase potential problems with traffic and snow removal, thereby putting pressure on local governments and emergency services. The Grand Valley does not typically experience significant winter storms; however, it has experienced utility outages associated with severe weather. Future efforts should be made to identify populations at risk and determine special needs.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
(a) 
Existing Development.
Past mitigation projects include a detailed, on the ground, wildfire hazard risk assessment for approximately 450 structures including private residences and outbuildings within the jurisdictions of Lower Valley Fire Protection District, Grand Junction Rural Fire Protection District and unincorporated Mesa County. Each structure was evaluated based on potential fuels, slope, aspect, fire disturbance regimes, access/egress, water supply, and structure ignitability. This data was compiled and incorporated into the County’s GIS system.
The GIS data shows structures that have been rated as to overall risk of wildfire, as well as those areas deemed most appropriate for wildland fire hazard mitigation efforts on both federal and non-federal lands within this area. This information is used to aid local fire departments and federal agencies in preparing fuels mitigation projects and preplanning fire prevention and protection strategies. This assessment also serves as the basis for public information and education efforts directed primarily by the Colorado State Forest Service and participating jurisdictions to encourage private property owners to participate in Firewise and other mitigation efforts to protect their property.
Mesa County Land Development Code specifically addresses development standards in hazard areas. All new development located on lands rated as medium or higher wildfire hazard shall be developed using defensible spacing standards. (County, Mesa County Planning Division, 2014)
(b) 
Future Development.
Many areas in Mesa County now have an increased wildfire threat in areas where fire was not a problem in the past. This is due to a combination of irrigation and the introduction of nonnative plants. Nonnative tamarisk and Russian olive have invaded drainage areas. Excess undrained irrigation water has created thick unbroken stands of vegetation throughout the Grand Valley. These stands of tamarisk and Russian olive burn readily and pose a threat to homes and other structures. (Paul, 2009)
Additional wildfire assessments need to be conducted across Mesa County. Several areas are at significant risk to wildland fire and more education of property owners on how to create a defensible space around their homes and other structures is needed. Once the assessments have been completed, on the ground efforts to create defensible spacing or thinning of areas with substantial overgrowth need to be completed.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15; Res. 05-10, 1-6-10)
Between 2015 to 2019, there were 422 new subdivision plats recorded in Mesa County accounting for 3,558 subdivision lots. These new subdivision lots are distributed as detailed as follows:
(a) 
City of Grand Junction: 2,332.
(b) 
City of Fruita: 402.
(c) 
Town of Palisade: 54.
(d) 
Town of DeBeque: 0.
(e) 
Town of Collbran: 0.
(f) 
Unincorporated Mesa County: 770.
The number of building permits issued for the unincorporated area of Mesa County is reflected in the following table.
2015
2016
2017
2018
2019
Commercial Permits
8
5
11
11
6
Residential Permits
190
158
184
272
232
Individual community profiles contain additional information on new development within each respective community.
(Res. 61-20, 10-7-20; Res. 32-15, 7-1-15)