Lucas County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
Very LowComposite Risk Score
National percentile: 30th
Lucas County faces very low composite natural disaster risk (NRI Risk Index score 29.7, 30th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Lucas County at very low composite risk, with a National Risk Index score of 29.7 out of 100 — placing it in the 30th 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.
Most of Lucas County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at High risk — $2M in expected annual loss and about 12.16 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $7K in expected annual loss and about 0.30 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $357K in expected annual loss and about 5.38 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 9K.
Beyond physical exposure, Lucas County has a high 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). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
The federal record bears this out: Lucas County has received 15 federal disaster declarations since 1973, including 6 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 99 Iowa counties, Lucas County ranks #65 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 12.16 / yr | $2M |
| Landslide | Low | 0.30 / yr | $7K |
| Hail | Low | 5.38 / yr | $357K |
| Cold Wave | Low | 4.74 / yr | $1M |
| Tornado | Low | 0.33 / yr | $1M |
| Heat Wave | Low | 7.58 / yr | $385K |
| Wildfire | Very Low | 0.00 / yr | $50K |
| Strong Wind | Low | 5.21 / yr | $469K |
| Ice Storm | Low | 0.54 / yr | $23K |
| Earthquake | Very Low | 0.00 / yr | $34K |
| Riverine Flood | Very Low | 3.21 / yr | $2M |
| Winter Weather | Very Low | 11.47 / yr | $16K |
| Lightning | Very Low | 45.10 / yr | $42K |
| Hurricane | Very Low | 0.01 / yr | $889 |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Lucas County has received 15 federal disaster declarations since 1973, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (6), Severe Storm (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Flood | Severe Storms and Flooding |
| July 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| May 2013 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| July 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| May 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| January 2008 | Severe Ice Storm | Severe Winter Storm |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| May 2004 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
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 Lucas County?
Lucas County has a composite FEMA National Risk Index score of 29.7 out of 100, placing it in the Very Low category and the 30th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lucas County?
The three highest-rated hazards are Drought (High, $2M EAL), Landslide (Low, $7K EAL), Hail (Low, $357K EAL). These account for most of the county's expected annual losses.
How does Lucas County compare to other Iowa counties?
Lucas County ranks #65 of 99 Iowa counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Lucas County had?
FEMA records 15 federal disaster declarations for Lucas County since 1973, most often 6 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic, declared in March 2020.
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. Lucas County's $8M EAL is a statistical average, not a guarantee for any specific year or address.