Benton County, Oregon Natural Disaster Risk
FEMA National Risk Index assessment · OR
MediumComposite Risk Score
National percentile: 84th
Benton County faces medium composite natural disaster risk (NRI Risk Index score 84.4, 84th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $64M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Benton County is medium, with a National Risk Index score of 84.4 out of 100 — placing it in the 84th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $503K in expected annual loss and about 4.17 events per year; earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $41M in expected annual loss and about 0.02 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $2M in expected annual loss and about 5.88 events per year. Across all hazards, FEMA estimates $64M in expected annual loss for a population of 95K.
Beyond physical exposure, Benton County has a very low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Benton County has received 15 federal disaster declarations since 1964, including 7 for severe storm events and 4 for flood events. The most recent was Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides (severe storm), declared in April 2024.
Among 36 Oregon counties, Benton County ranks #15 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 4.17 / yr | $503K |
| Earthquake | Medium | 0.02 / yr | $41M |
| Heat Wave | Medium | 5.88 / yr | $2M |
| Riverine Flood | Medium | 0.79 / yr | $19M |
| Ice Storm | Low | 0.50 / yr | $138K |
| Winter Weather | Low | 7.24 / yr | $66K |
| Lightning | Low | 4.99 / yr | $203K |
| Wildfire | Very Low | 0.00 / yr | $26K |
| Volcanic Activity | Very Low | 0.01 / yr | $0 |
| Cold Wave | Very Low | 0.05 / yr | $193K |
| Drought | Very Low | 4.85 / yr | $287 |
| Strong Wind | Very Low | 0.04 / yr | $133K |
| Tornado | Very Low | 0.04 / yr | $125K |
| Avalanche | Very Low | 0.01 / yr | $12 |
| Hail | Very Low | 0.04 / yr | $21K |
| Coastal Flood | Very Low | 0.01 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Benton County has received 15 federal disaster declarations since 1964, most recently Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides in April 2024. Most frequent causes: Severe Storm (7), Flood (4), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2024 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides |
| May 2021 | Severe Storm | Severe Winter Storm |
| September 2020 | Fire | Wildfires and Straight-Line Winds |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2014 | Severe Storm | Severe Winter Storm |
| March 2012 | Flood | Severe Winter Storm, Flooding, Landslides, and Mudslides |
| February 2007 | Severe Storm | Severe Winter Storm and Flooding |
| March 2006 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
Showing the 10 most recent of 15 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Benton County?
Benton County has a composite FEMA National Risk Index score of 84.4 out of 100, placing it in the Medium category and the 84th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Benton County?
The three highest-rated hazards are Landslide (Medium, $503K EAL), Earthquake (Medium, $41M EAL), Heat Wave (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Benton County compare to other Oregon counties?
Benton County ranks #15 of 36 Oregon counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Benton County had?
FEMA records 15 federal disaster declarations for Benton County since 1964, most often 7 for severe storm events and 4 for flood events. The most recent was Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides, declared in April 2024.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Benton County's $64M EAL is a statistical average, not a guarantee for any specific year or address.