riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Delaware County Disaster Risk

Delaware County, Iowa

FEMA Risk Rating

Relatively Low

National Percentile

50th

of 3,144 counties

State Rank

#26

of 99 (1 = highest risk)

Flood Risk

62th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 62% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 12% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 58% of US counties

Earthquake

Seismic activity and ground shaking risk

Very Low

Higher than 25% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 19% of US counties

Risk Overview

About Natural Disaster Risk in Delaware County, Iowa

Delaware County: Moderate Risk, Flood-Focused

Delaware County scores 49.75 on the composite risk scale, placing it "Relatively Low" but modestly above Iowa's state average of 39.68. The county's risk profile centers on flood exposure at 61.74, one of the state's highest water-related risks, while tornado (58.46) presents secondary concern. This flood-dominant pattern reflects Delaware's position along the Turkey River and other significant tributaries.

Upper-Middle Ranking, Driven by Flooding

Delaware County ranks in Iowa's upper-middle tier for overall disaster risk, with its 61.74 flood score substantially exceeding the state average and positioning it among the state's most flood-exposed counties. Tornado risk at 58.46 adds secondary hazard exposure, while wildfire and earthquake risks remain below state norms. This combination creates a distinctive flooding-first risk profile within northeastern Iowa.

Flood Risk Exceeds Regional Peers

Delaware County's flood score of 61.74 substantially exceeds neighboring Dubuque (65.36—comparable), Buchanan, and Clayton counties, making Delaware a regional flooding hotspot. Tornado risks align closely with neighbors, but Delaware's water vulnerability stands apart in the immediate region. The county's riverine geography and tributary networks create above-average water hazard exposure.

Flooding Is Your Primary Concern Here

Flood risk at 61.74 dominates Delaware County's hazard profile, reflecting proximity to the Turkey River and multiple creek systems that regularly overflow during spring snowmelt and heavy rain. Tornado risk at 58.46 requires standard severe weather preparedness but remains secondary to flood planning. Wildfire risk at 12.44 is minimal and earthquake risk at 24.62 presents negligible concern for most residents.

Flood Insurance Is Essential for Delaware

If you're in or near a flood-prone area, flood insurance through the National Flood Insurance Program (NFIP) is critical—standard homeowner's policies explicitly exclude flood damage. Obtain an elevation certificate for your property and understand your local flood zone; many Delaware properties sit in mapped flood zones requiring mandatory coverage. Create a family flood evacuation plan and monitor weather alerts during spring months and heavy rain events.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Delaware County

Top Hazards by Exposure

  1. #1
    FloodPrepare
    62th percentile
  2. #2
    TornadoPrepare
    58th percentile
  3. #3
    EarthquakePrepare
    25th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Delaware County

Risk Verdict

With a national percentile rank of 50th, Delaware County faces below-average hazard exposure relative to U.S. counties as a whole. A preparedness foundation — alert registration, household communication plan, and a basic supply review — costs little and remains valuable even at Delaware County's favorable 50th percentile ranking.

Hazard Breakdown

Flood risk is Delaware County's dominant natural hazard, ranked at the 62th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 58th percentile nationally. Additional tracked hazards include earthquake (25th percentile), hurricane (19th percentile), wildfire (12th percentile).

Preparedness Context

With flood risk ranking at the 62th percentile nationally, Delaware County residents face one of the most financially damaging hazards without specialized coverage. Flood insurance through the NFIP or a private carrier is worth evaluating regardless of current mortgage requirements. Secondary tornado exposure at the 58th percentile adds a second preparedness layer; households should review coverage options and alert sign-up for both hazard types. Registering for Delaware County's county emergency alert system — typically through the county emergency management office's website — ensures households receive early warning when flood events develop faster than forecast.

Regional Context

At 10.1 points above the Iowa state average, Delaware County carries meaningfully higher natural disaster exposure than a typical Iowa county.

Is your household prepared for Delaware County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Delaware County, IA?
Delaware County has a FEMA National Risk Index rating of Relatively Low, placing it in the 50th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Delaware County?
Delaware County is evaluated for five major natural hazard types: flooding (62th percentile), tornado (58th percentile), earthquake (25th percentile), hurricane (19th percentile), wildfire (12th percentile). The highest-risk hazard is flooding at the 62th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Delaware County risk compare to the Iowa average?
Delaware County's composite risk percentile is 50th, compared to the Iowa state average of 40th percentile. The state's overall risk rating is Very Low. This means Delaware County faces higher natural disaster risk than the typical county in Iowa.
Is Delaware County at risk for flooding?
Yes, Delaware County's flooding risk is at the 62th percentile nationally. This is above the national median.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Delaware County higher risk than average?
Delaware County's composite risk score of 50th percentile is above the Iowa state average of 40th percentile. This elevated risk is driven by flooding exposure (62th percentile), along with tornado risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.