The Story
By 2050, Utah’s ability to withstand and recover from natural disasters is generally not improved. We do not spend additional money or require any extra work from builders, the state, or the public. Recovery time after a disaster is very long, Utah’s economy is badly damaged, and large numbers of Utahns leave the state and never return.
We are not more resilient to earthquakes because:
- Weak buildings with unreinforced brick are not reinforced.
- Building codes are not strengthened to make new buildings more likely to be habitable.
- Schools, hospitals, and nursing homes are retrofitted very slowly.
- We continue to build in earthquake hazard areas.
- Roads, water, sewer, power, and gas lines are upgraded only when replaced.
We are also not more resilient to flooding or wildfire because:
- Storm water systems are not upgraded to accommodate larger storms.
- A large amount of scattered growth occurs on the fringe of urban areas, where homes are more vulnerable to wildfire.
- Homes on the urban fringe are not designed to be fire resistant.
Will Our Buildings Stand Up In An Earthquake?
| Problem | Solution | Results |
|---|---|---|
| Utah has 165,000 unreinforced brick buildings, which cause 55% of deaths. | Retrofit structurally weak buildings. |
|
| By 2050, the number of buildings in Utah will double; if new buildings are built to the current code, many of them will be uninhabitable after an earthquake. | Strengthen building codes. |
|
Results
In the event of a 7.0 earthquake along the Wasatch Front:
- Utah experiences 14,300 deaths and life-threatening injuries.
- 115,200 households (350,000 people) are displaced; 30,700 from post-2015 housing.
- Compared to other scenarios, restoring utilities such as water, natural gas, power, and roads takes the longest time.
- Schools, hospitals, and nursing homes are very susceptible to damage and destruction.
- Medical facilities and first responders are overwhelmed by the number of injured and amount of damage.
In the event of more severe storms:
- Urban and suburban flooding is very likely.
In the event of a wildfire:
- Compared to other scenarios, the greatest number of homes may need to be evacuated.
- Compared to other scenarios, the greatest number of homes may be at risk of being destroyed.
Background
What is disaster resilience?
Disaster resilience is the ability to withstand and quickly recover from a large-scale disaster. It requires looking beyond short-term needs to consider how we can ensure catastrophic events do not permanently disrupt our economy and way of life. The historical reality is that some areas never truly recover from natural disasters—by the time essential infrastructure returns, jobs, businesses and residents are already gone for good.
Where are we today?
Though Utah has always taken disaster preparedness seriously, we have prepared primarily for short-term disaster response. We are less prepared to respond to larger, long-term disasters. Improving our disaster resilience means preparing in ways that decrease the amount of damage and number of lives lost and allow our economy and communities to recover more quickly.
What are the top risks to the state?
Earthquakes
A large portion of Utah’s population lives near earthquake fault lines and on liquefaction areas, where soil can become like liquid quicksand during an earthquake. A powerful 7.0 earthquake is estimated to occur roughly once every 300 years along the Wasatch Fault, and the last earthquake of that size occurred about 350 years ago on the Nephi segment of the fault. A large earthquake in 2050 could cause significant damage (especially to older buildings), displace people from over 100,000 households, and cause over 14,000 deaths and life-threatening injuries.
Of particular concern is the number of high risk unreinforced masonry buildings (URMs) in the state. A URM is a building in which the main supporting walls are made of material like brick, stone, or concrete and lack adequate steel or wood structural support to withstand the shaking of a large earthquake. In Utah, most URMs were built between the 1860s and the mid-1970s. About 165,000 URMs are at risk of being damaged or destroyed by an earthquake along the Wasatch Front. By comparison, California, another state at high risk for earthquakes, has only 26,000 URMs, many of which have already been reinforced. (California prohibited the construction of URMs in the 1930s and began requiring the reinforcement of URMs in the 1980s.)
Disruption to utilities could leave people without power, water, and gas, while disruption to businesses could leave people unable to work and could jeopardize the economy. The better prepared we are to minimize damage from a large earthquake, the faster we will be able to recover.
Flooding
Flooding is a significant risk to many places in the state, and floods are becoming more common as storms become more severe. Recently, multiple neighboring states have experienced large-scale flooding from bigger-than-anticipated storms. Our stormwater systems are designed for storms smaller than we could experience in the future.
Wildfires
Wildfires have always occurred in Utah, but we are now building more homes scattered on the fringe of our urban areas. We can design homes and communities to lower the risk of catastrophic losses from wildfires by reducing how scattered our growth is, creating defensible spaces to buffer homes from fuel sources, and building with fire-resistant materials.
Source: Earthquake impact modeling performed by Utah Division of Emergency Management using the HAZUS model.
