Ketchikan Gateway Borough, Alaska Natural Disaster Risk
FEMA National Risk Index assessment · AK
Very LowComposite Risk Score
National percentile: 2th
Ketchikan Gateway Borough faces very low composite natural disaster risk (NRI Risk Index score 1.7, 2th national percentile), driven primarily by landslide and avalanche exposure. Expected annual loss across all 18 hazard types is $2M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Ketchikan Gateway Borough carries a very low composite natural disaster risk, with a National Risk Index score of 1.7 out of 100 — placing it in the 2nd national percentile and among the lowest-risk counties in the country. 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 Low risk — $42K in expected annual loss and about 10.16 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Medium risk — $457K in expected annual loss and about 0.03 events per year; and volcanic activity (eruptions producing ashfall, lava, and pyroclastic hazards) at Very Low risk — $652 in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $2M in expected annual loss for a population of 14K.
Beyond physical exposure, Ketchikan Gateway Borough has a low social vulnerability rating (how susceptible the population is to harm) and a 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: Ketchikan Gateway Borough has received 3 federal disaster declarations since 2020, including 2 for biological events and 1 for mud/landslide events. The most recent was Landslides (mud/landslide), declared in November 2024.
Among 30 Alaska counties, Ketchikan Gateway Borough ranks #26 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 10.16 / yr | $42K |
| Avalanche | Medium | 0.03 / yr | $457K |
| Volcanic Activity | Very Low | 0.00 / yr | $652 |
| Winter Weather | Low | 9.15 / yr | $78K |
| Tsunami | Very Low | 0.30 / yr | $432K |
| Earthquake | Very Low | 0.01 / yr | $94K |
| Coastal Flood | Very Low | 0.01 / yr | $3K |
| Ice Storm | Very Low | 0.01 / yr | $17K |
| Wildfire | Very Low | 0.00 / yr | $4K |
| Riverine Flood | Very Low | 0.01 / yr | $722K |
| Lightning | Very Low | 7.99 / yr | $16K |
| Tornado | Very Low | 0.00 / yr | $0 |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 5.82 / yr | $0 |
| Hail | Very Low | 0.00 / yr | $0 |
| Heat Wave | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Strong Wind | Very Low | 0.00 / yr | $0 |
Disaster History
Ketchikan Gateway Borough has received 3 federal disaster declarations since 2020, most recently Landslides in November 2024. Most frequent causes: Biological (2), Mud/Landslide (1).
| Declared | Type | Disaster |
|---|---|---|
| November 2024 | Mud/Landslide | Landslides |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Ketchikan Gateway Borough?
Ketchikan Gateway Borough has a composite FEMA National Risk Index score of 1.7 out of 100, placing it in the Very Low category and the 2th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Ketchikan Gateway Borough?
The three highest-rated hazards are Landslide (Low, $42K EAL), Avalanche (Medium, $457K EAL), Volcanic Activity (Very Low, $652 EAL). These account for most of the county's expected annual losses.
How does Ketchikan Gateway Borough compare to other Alaska counties?
Ketchikan Gateway Borough ranks #26 of 30 Alaska counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Ketchikan Gateway Borough had?
FEMA records 3 federal disaster declarations for Ketchikan Gateway Borough since 2020, most often 2 for biological events and 1 for mud/landslide events. The most recent was Landslides, declared in November 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. Ketchikan Gateway Borough's $2M EAL is a statistical average, not a guarantee for any specific year or address.