Sioux City, IA Flood Zone Lookup
Last updated: March 2026
Sioux City is located at the confluence of the Missouri and Big Sioux rivers and faces flooding from both systems. Flood control infrastructure provides protection, but extreme events still pose risks.
Woodbury County has recorded 294 NFIP flood insurance claims since 1978, totaling $1.9M in payouts. Explore the full NFIP claims data by state and county to see how this area compares nationally.
FEMA Region
Region 7
NFIP Policies
251
Woodbury County
Avg. Premium
$1,388/yr
Woodbury County
FEMA Flood Risk Profile: Woodbury County
Based on FEMA's National Risk Index, which evaluates flood risk at the county level using historical loss data, exposure, and vulnerability.
Inland Flood Risk
Relatively ModerateEst. annual loss: $18.2M
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
Federal Flood Disaster History: Woodbury County
Woodbury County has been included in 8 federal flood-related disaster declarations.
These declarations affected communities across Woodbury County, including Sioux City.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced February 2026.
NFIP Flood Insurance Claims: Woodbury County
Properties in Woodbury County have filed 294 NFIP flood insurance claims totaling $1.9M in payouts since 1978. The average claim payout is $6K.
Highest-Claim Years
1990
152 claims - $808K
2019
21 claims - $276K
2024
21 claims - $655K
Claims by Flood Zone
Source: OpenFEMA NFIP Claims API. Data sourced March 2026. See national claims data.
Flood Insurance Coverage: Woodbury County
Only roughly 1 in 167 households in Woodbury County carries NFIP flood insurance (0.6% of estimated households). With 80 recorded flood events and $23.6M in damage, most flood losses in this county are likely uninsured.
Penetration Rate
0.6%
roughly 1 in 167 households
Historical Claims Ratio
1 in 1
294 claims over 45+ years across 251 current policies
Avg. Claim Payout
$6,476
Per claim, county-wide since 1978
Historically, Woodbury County has averaged 1.2 claims for every active policy (since 1978). This compares cumulative claims against today's policy count and does not predict future claim likelihood.
Coverage data: NFIP policies as of March 2026, claims since 1978 (March 2026), population from FEMA NRI. All figures are county-wide and include Sioux City.
What Your Flood Zone Means in Sioux City
Sioux City faces flood risk primarily from river and stream overflow during heavy rainfall, snowmelt, or upstream dam releases. When rivers exceed their banks, floodwaters spread across low-lying areas mapped in AE and A zones. The most common FEMA flood zone designations in Sioux City are Zone AE, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $18.2M.
Riverine flood risk in Sioux City is driven by the proximity and elevation of properties relative to nearby waterways. Properties closer to rivers with lower ground elevations typically face higher flood insurance premiums under FEMA's Risk Rating 2.0. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.
River flood maps can change when FEMA conducts new Flood Insurance Studies or when development alters drainage patterns. Letters of Map Amendment (LOMA) can remove individual properties if the natural ground elevation was always above the Base Flood Elevation and the property was inadvertently mapped in the SFHA. Use our free lookup tool to check the current flood zone for any Sioux City address.
Repetitive Loss Properties: Woodbury County
Woodbury County has 1 properties with multiple flood insurance losses, including 0 severe repetitive loss properties. Severe repetitive loss is a subset of multiple loss, not a separate count. Data sourced March 2026.
Multiple Loss
1
2+ claims within 10 years
Severe Repetitive Loss
0
4+ claims or 2 exceeding value
Mitigated
0
Received FEMA mitigation
Source: OpenFEMA NFIP Multiple Loss Properties. Data sourced March 2026.
Recorded Flood Events: Woodbury County
NOAA has recorded 80 flood events in Woodbury County since 1996, causing $23.6M in damage.
Costliest Events
Events by Type
Source: NOAA Storm Events Database, 1996-2026. Data sourced March 2026.
Flood Mitigation: Woodbury County
FEMA has funded mitigation for 51 properties in Woodbury County, investing $243K in flood risk reduction. Common mitigation actions include acquisition (buying and demolishing flood-prone structures), elevation (raising buildings above flood level), and safe rooms (wind/storm shelters for tornado and hurricane protection).
By Action Type
Source: OpenFEMA Hazard Mitigation Assistance. Data sourced March 2026.
Sioux City, IA Flood Zone FAQ
What flood zones are in Sioux City, IA?
The most common FEMA flood zones in Sioux City are Zone AE, Zone X. Properties in these high-risk zones (SFHA) may require flood insurance with a federally regulated or government-backed mortgage.
Is flood insurance required in Sioux City?
If your Sioux City property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance. Properties in Zone X are not federally required to carry flood insurance, though coverage is still recommended since over 40% of all NFIP flood claims come from Zone X properties.
How do I check my flood zone in Sioux City?
Enter your Sioux City address in the search tool above for an instant flood zone determination. Results include your FEMA flood zone, SFHA status, base flood elevation (if available), and FIRM panel information, pulled directly from FEMA's National Flood Hazard Layer.
What type of flooding affects Sioux City?
Sioux City is primarily affected by river and stream overflow during heavy rainfall. The most common FEMA flood zone designations are Zone AE, Zone X. Use the free lookup tool above to check the specific flood zone for any Sioux City address.
Has Sioux City experienced major flooding events?
Woodbury County, where Sioux City is located, has been part of 8 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Severe Storms and Flooding in 2019. Federal disaster declarations are issued when flooding overwhelms local resources and triggers FEMA assistance programs.
How many flood insurance claims have been filed in Sioux City?
Woodbury County has recorded 294 NFIP flood insurance claims totaling $1.9M in payouts since 1978. The year with the most claims was 1990, with 152 claims and $808K in payouts. These figures cover all NFIP claims in the county, including Sioux City.
How many flood insurance policies are active in Sioux City?
Woodbury County currently has 251 active NFIP flood insurance policies with an average annual premium of $1,388. The most policies are in Zone AE (120 policies). These figures cover all active NFIP policies in the county.
How many Sioux City properties have flooded repeatedly?
Woodbury County has 1 properties with multiple flood losses on record, including 0 severe repetitive loss properties. These are properties that have experienced four or more NFIP claims of $5,000+ or two claims exceeding the building value.
Can my Sioux City property be removed from a high-risk flood zone?
Yes, if your property's natural ground elevation is above the Base Flood Elevation and FEMA inadvertently mapped it in a high-risk zone, you can apply for a Letter of Map Amendment (LOMA). A successful LOMA removes the property from the Special Flood Hazard Area, generally eliminating the federal mandatory flood insurance requirement. You will need an elevation certificate from a licensed surveyor. If a property was raised above the BFE with fill material, the process is a LOMR-F rather than a LOMA.
What is Base Flood Elevation in Sioux City?
Base Flood Elevation (BFE) is the predicted height of floodwaters during a 1% annual chance (100-year) flood, shown on FEMA maps as an elevation number in feet above sea level. In Sioux City's Zone AE areas, BFE lines appear on the FIRM as wavy contours labeled with elevation values. Properties with a lowest floor at or above the BFE typically qualify for significantly lower NFIP flood insurance premiums.
Other Iowa Cities
Understanding Flood Zones
Look Up Any Sioux City, IA Address
Enter a Sioux City, IA address to instantly check its FEMA flood zone designation, SFHA status, and insurance requirements.
Disclaimer: Flood risk data on this page is sourced from FEMA datasets including the National Risk Index, NFIP claims and policy records, disaster declarations, and the Community Rating System. These datasets were last extracted on March 2026 and may not reflect the most recent changes. This page is for informational purposes only and is not a certified flood zone determination. Always verify current flood zone status through FEMA or a licensed determination provider before making property, insurance, or lending decisions.