Know Your Hazards

Hazards in Pierce County

Abandoned MinesAbandoned Mines

Abandoned underground mines were formerly used to remove coal, silver, and other minerals. These mines pose three problems for the citizens of Pierce County: gaining access is dangerous; entrance plugs made of mine waste and debris may eventually fail or prevent water flow; and hazardous gases given off by remaining coal. These documented mines are located in the Cascade foothills around the towns of Buckley, Carbonado, Wilkeson, and north of the community of Ashford. 

Avalanche Pierce County HazardAvalanche

An avalanche is a mass of loosened snow or ice that suddenly slides down a slope, growing as it descends. Avalanche season begins in November and runs through early summer for all mountain areas of the state. In Pierce County, avalanches only take place in mountainous areas, such as Mount Rainier National Park, Crystal Mountain, and other steep slopes in the Cascade Mountain Range.   

CivilUnrestCivil Disturbance

Civil unrest is the result of groups or individuals within the population feeling, rightly or wrongly, that their needs or rights are not being met, either by the society at large, a segment thereof, or the current overriding political system. When this results in community disruption to the extent that intervention is required to maintain public safety, it has become a civil disturbance. The potential for civil unrest or civil disturbance is highest in the larger cities of the County, such as Lakewood, Puyallup, and Tacoma.

Hazard_Pictograms (1)_HeatwaveClimate Change

Climate change occurs when Earth’s usual weather patterns change due to factors like an increase or decrease in surface temperature or gases released into the atmosphere. This shift in weather patterns will create dramatic changes in the local environment of Pierce County. Climate change impacts other hazards within the County. For example, as the average winter temperature slowly increases, the annual snow-pack gets smaller which leads to less water for our forests as summertime approaches and increases the risk for wildfires to occur.

DamFailureDam Failure

A dam is a barrier built across moving water to slow or stop the water’s flow. A dam failure occurs when the barrier is not able to hold back the flow of water and there is a sudden increase in the amount of water moving past the dam. In Pierce County, there are 57 dams or retention facilities either totally in Pierce County or shared jointly with another county. Many of these, even though they are located in portions of the County with a low population base, are a hazard because of the quantity of water they retain, such as Alder, La Grande, and Mud Mountain Dams.


According to Washington State law, an area is in a drought condition when: 1) the water supply for the area is below 75% of normal and 2) water uses and users in the area will likely incur undue hardships because of the water shortage. Drought is a natural part of the climate cycle. However, it can have a widespread impact on the environment and the economy. While all of Pierce County experiences drought, specific natural resources are the most impacted – rivers, streams, ponds, fish habitat, forests, and many more.

Additional Information:+ WA Department of Ecology - Drought 


An earthquake is a naturally induced shaking of the ground. It is caused by an abrupt shift of rock along a fracture in the earth’s crust called a fault. Pierce County is susceptible to three types of earthquakes: deep, crustal, and Cascadia Subduction Zone earthquakes. Earthquakes directly and indirectly affect all of Pierce County, whether that’s from ground shaking, liquefaction, or resulting landslides and tsunamis. The probability of recurrence for earthquakes in Pierce County can be found at the sites listed below.

Additional Information:+ WA Department of Natural Resources - Earthquakes 

EnergyEnergy Emergency

An Energy Emergency is a situation in which the unavailability or disruption of the supply of energy poses a clear and foreseeable danger to the public health, safety, and welfare. Energy resources include: electricity; petroleum distillates such as gasoline, diesel fuel, aviation fuel, heating oil; propane; and natural gas.This can happen anywhere and potentially everywhere in Pierce County. They most frequently come in the form of extended electrical outages due to severe weather.


An epidemic is a disease that spreads rapidly throughout a region’s or country’s population. Pandemic refers to an epidemic that has spread throughout a larger geographic area impacting multiple countries or continents. Epidemics and pandemics have in the past covered the entire County. To what extent they infect the public depends on their ease of transmittal. How serious the disease is to the individual depends on a number of factors including age, general health, life style, occupation, etc. Annually, the flu affects approximately 5 to 15% of the population.

Additional Information: + WA Department of Health - Pandemic 


A flood is a general and temporary condition of partial or complete flooding of normally dry land areas from: 1) the overflow of inland or tidal waters; 2) the unusual and rapid accumulation or runoff of surface waters from any source; or 3) mudflows or the sudden collapse of shoreline land. Flooding directly affects less than 5% of Pierce County. Flooding brings the risk of erosion where river channels can move to new locations and high waves can undermine coastal homes.

Additional Information: + Pierce County Public Works - Flooding 

HazardousMaterialsHazardous Materials

Hazardous materials are materials, which because of their chemical, physical, or biological properties, pose a potential risk to life, health, the environment, or property when not properly contained. A hazardous material release then is the release of the material from its container into the local environment. Hazardous material spills are a regular part of response organizations' operations in Pierce County. While most reported spills are relatively minor, such as small amounts of hydraulic fluid or diesel, there are occasional spills that tax response organizations.


A landslide is the gravity-driven down-slope movement of a sliding mass composed of rock, soil, and vegetation. It can pick up and include anything else that might be in its path, whether part of the natural or the developed environment. The landslide hazard areas within the County include the walls of the major river valleys, the more mountainous regions, the coastal areas, and parts of the peninsula.


While there are many different substances transported through pipelines, including sewage, water, and even beer, our focus is on the transportation arteries carrying hazardous liquids and gaseous substances. Current Pierce County pipelines include Northwest Pipeline Corp, Olympic Pipeline Company, and U.S. Oil and Refining Company. Between these they contain 80.93 miles of natural gas pipeline and 44.68 miles of liquid petroleum product pipeline.

SevereWeatherSevere Weather

Severe weather includes a variety of weather patterns that may negatively impact citizens and/or infrastructure in the County. These storms are usually characterized by strong winds frequently combined with rain, snow, sleet, hail, ice, thunder, and lightning. This also includes unusual weather disturbances, such as tornadoes or waterspouts, which appear infrequently in Pierce County. Due to variations in geographic location and elevation, certain areas of the County are more vulnerable to certain types of severe weather, including windstorms and snowstorms.


Terrorism is the unlawful use of violence and intimidation, especially against civilians, in the pursuit of social or political aims. Pierce County has areas of concentrated population, venues, and events that draw large crowds. It also has significant infrastructure that is important locally as well as nationally. The county is a key component in the Pacific Northwest transportation network that supports extensive domestic and international commerce. There are key transportation nodes and routes that cannot be easily replaced or bypassed.

TranspotationTransportation Accidents

Transportation accidents include accidents involving a method of transportation on the road, rail, air, and maritime systems within the confines of Pierce County. The various forms of transportation, covering the majority of the County, have considerable potential for accidents that could threaten Pierce County’s infrastructure, its citizens, and their livelihood. One large recent accident was the Amtrak train derailment that occurred on December 18, 2017 near the City of DuPont.

Additional Information: + National Transportation Safety Board 

Hazard_Pictograms (1)_Tsunami Seismic SeichesTsunami

A tsunami consists of a series of high-energy waves that radiate outward like pond ripples from the area in which the generating event occurred. They also build in height as they move into shallow water, just before striking the open shore or reaching the heads of bays, and then flooding the low-lying areas near the shore. Often, a quick recession of the water precedes the first wave crest. In Washington State, the Pacific Coast, Strait of Juan de Fuca, and Puget Sound are all at risk from tsunamis. In addition, large lakes and other enclosed bodies of water, like Puget Sound south of the Tacoma Narrows Bridge, could be affected by a seiche

Volcanic hazardVolcanic

A volcano is a vent in the Earth’s crust through which molten rock (lava), rock fragments, gases, and/or ash can be ejected from the Earth’s interior. Volcanic hazards within Pierce County include all hazards associated with individual volcanoes in the Cascade Mountain Range. This includes ash, landslides, lahars, pyroclastic flows (very near the mountain), and lava (on slopes of mountain). The lahar hazard covers a great deal of the County as each of the major river valleys comprises a portion of the lahar runout zone. Over 150,000 inhabitants of the White, Puyallup, and Nisqually River valleys work and reside on the deposits of prehistoric and historic debris flows.

Additional Information: + Pierce County Active Volcano 

Wildland Urban Interface FireWildland/Urban Interface Fire 

A wildland/urban interface (WUI) area is the geographic area in which structures and other human development meets or intermingles with wildland or vegetative fuels. A fire that occurs in these geographic areas is referred to as a WUI fire. There are numerous locations within Pierce County where structural developments meet and intermingle with these wildland areas. Communities in areas that are at-risk for WUI fires can find resources at the DNR link below to become a Firewise community. The Firewise education material provides techniques to reduce fire risk through actions, such as creating defensible space around homes.

Personal Preparedness

Preparedness is the foundation for building resilient communities. While Pierce County Emergency Management focuses on preparing our whole community for disasters, you also have a role to play in emergency preparedness. By planning ahead, you can increase your ability to survive and thrive in the face of disaster, everything from an earthquake to a major winter storm.


Preparedness Planning by Local Government

Pierce County Emergency Management is working to prepare for the identified hazards listed above. We plan with other government entities, non-profits, first responder agencies, and other organizations involved in preparedness efforts.

The Comprehensive Emergency Management Plan (CEMP) outlines roles and responsibilities to aid in the response coordination. The plan reviews processes and brings together key organizations/partners who provide critical services in all phases of emergency management to assess our capability to respond.

Planning is a way to improve service to communities by identifying gaps, building partnerships, and gaining clarity on the integration of private, non-profit, and volunteer groups with government.

A Hazard Mitigation Plan is a product developed by jurisdictions with the goal of reducing risk to loss of life and property by lessening the impact of disasters. These plans consist of seven sections: Process, Profile, Capabilities, Risk Assessment, Mitigation Strategies, Infrastructure, and Plan Maintenance.  We also utilize resources from our partners in our planning efforts, such as the 2017 Risk Report that FEMA developed for Pierce County.

For more information: Pierce County Emergency Management - Plans