Matanuska-Susitna Borough
Alaska — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 93th
Matanuska-Susitna Borough faces medium composite natural disaster risk (NRI Risk Index score 93.3, 93th national percentile), driven primarily by avalanche and earthquake exposure. Expected annual loss across all 18 hazard types is $161M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Avalanche | Very High | 1.33 / yr | $15M |
| Earthquake | High | 0.20 / yr | $131M |
| Landslide | Medium | 91.40 / yr | $304K |
| Wildfire | Medium | 0.00 / yr | $4M |
| Winter Weather | High | 11.16 / yr | $620K |
| Volcanic Activity | Very Low | 0.02 / yr | $915 |
| Cold Wave | Low | 4.02 / yr | $2M |
| Lightning | Low | 17.98 / yr | $329K |
| Riverine Flood | Low | 0.01 / yr | $8M |
| Ice Storm | Very Low | 0.01 / yr | $14K |
| Tsunami | Very Low | 0.30 / yr | $56K |
| Hail | Very Low | 0.01 / yr | $8K |
| Tornado | Very Low | 0.00 / yr | $7 |
| Coastal Flood | Very Low | 0.01 / yr | $0 |
| Drought | Very Low | 1.14 / 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 |
Frequently Asked Questions
What is the overall natural disaster risk for Matanuska-Susitna Borough?
Matanuska-Susitna Borough has a composite FEMA National Risk Index score of 93.3 out of 100, placing it in the Medium category and the 93th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Matanuska-Susitna Borough?
The three highest-rated hazards are Avalanche (Very High, $15M EAL), Earthquake (High, $131M EAL), Landslide (Medium, $304K EAL). These account for most of the county's expected annual losses.
How does Matanuska-Susitna Borough compare to other Alaska counties?
Matanuska-Susitna Borough ranks #2 of 30 Alaska counties for overall natural disaster risk, with a medium rating.
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. Matanuska-Susitna Borough's $161M EAL is a statistical average, not a guarantee for any specific year or address.