High Risk Washington  ·  Earthquake / Volcanic Lahar

Pierce County WA

EMERGENCY PREPAREDNESS & DISASTER RISK PROFILE  ·  LAST UPDATED: Mar 2026

8/ 10
Threat Score
Population
921,173
Area
1676
sq miles
Primary Hazard
Earthquake / Volcanic Lahar
FEMA Disasters
45
federally declared

Pierce County sits directly in the lahar flow path from Mount Rainier — the most dangerous volcano in the United States. A major eruption or debris avalanche could send volcanic mudflows down the Puyallup and Carbon River valleys into densely populated Tacoma suburbs within hours with little warning time. The county also faces Cascadia Subduction Zone megathrust earthquake risk.

// Recommended Supplies

Essential gear for power outages, severe weather, and emergency situations in your area.

// Risk Intelligence

Threat Score 8 / 10    High Risk
Primary Hazard Earthquake / Volcanic Lahar
Secondary Hazard Flooding
FEMA Flood Zone Zone X (Seismic High Risk)
Federally Declared Disasters 45
Last Major Event Nisqually Earthquake (2001)
Event Frequency Major event every 4–5 years

// Emergency Operations

Emergency Mgmt Phone (253) 798-6595
Emergency Shelters 38 designated facilities
Evacuation Routes I-5 North, I-5 South, SR-512 East, SR-7 South

// County Profile

County Pierce County WA
State Washington (WA)
Population 921,173
Area 1676 sq miles
FEMA Region Zone X (Seismic High Risk)

// Major Cities

Gig Harbor WA DuPont WA Steilacoom WA University Place WA Roy WA Lakewood WA Puyallup WA Tacoma WA

// Cities in This County

// Other Washington Counties

// Nearby Infrastructure Risks

Critical infrastructure facilities within or near this area that could affect civilian safety during emergencies, conflict, or infrastructure failures.

Joint Base Lewis-McChord WA
Military Installation  ·  Tacoma  ·  US Army / US Air Force / I Corps  ·  25-mi risk zone
8/10 High
Asarco Tacoma Smelter Superfund WA
Superfund Site  ·  Ruston, WA  ·  ASARCO / EPA  ·  5-mi risk zone
8/10 High
PNW Substation Cluster Tacoma WA
Power Plant  ·  Tacoma, WA  ·  Puget Sound Energy / BPA  ·  5-mi risk zone
8/10 High
Port of Tacoma WA
Port / Marine Terminal  ·  Tacoma, WA  ·  Port of Tacoma  ·  10-mi risk zone
7/10 High
🚂
Cascades Corridor Amtrak Seattle to Portland
Rail Infrastructure  ·  DuPont, WA  ·  Amtrak / WSDOT  ·  2-mi risk zone
7/10 High
🌉
Tacoma Narrows Bridge WA
Bridge / Critical Crossing  ·  Gig Harbor, WA  ·  Washington State Department of Transportation  ·  5-mi risk zone
7/10 High

Infrastructure risk data is for emergency preparedness awareness. Facility locations are publicly known. Always follow official emergency guidance.