105 flood insurance claims·$4.0M paid·8 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Delaware County, Iowa. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding from summer thunderstorms dominates Delaware County, accounting for the vast majority of severe flood events over the last 30 years compared to general river floods. NOAA storm records document recurring heavy rainfall events, such as a major storm in July 2017 that dropped between 3 and over 8 inches of rain, and an October 2018 event where 2 to 6 inches of rain fell on saturated ground, closing roads across the county.
National Flood Insurance Program records show that flood losses extend across multiple zones, though high-risk areas bear the heaviest burden. Zone A properties account for the vast majority of claims with 88 filings, averaging $58,480 per payout and an average recorded water depth of 11 inches. Additional claims occurred outside primary hazard areas, including Zone X with 6 claims averaging $19,693 and an average water depth of 11 inches, unshaded Zone X with 3 claims averaging $35,598 and an average water depth of 8 inches, and shaded Zone X with 6 claims averaging $4,142 with 0 inches of average recorded water depth.
Homeowners and real estate agents in Zone A face the highest financial risk and should pay the closest attention, while property owners in Zone X areas must also recognize that moderate flooding can still occur.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
9% of Delaware County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
97 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 11 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2008, with 25 claims and $761,313 paid, the year of Severe Storms, Tornadoes, and Flooding.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
14 NOAA storm reports from Delaware County describe what happened, in the words of the forecasters who covered it. Read the Iowa flood stories →
18 federal disaster declarations since 1968, 8 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Jun 6, 2018 |
| Severe Storms And Flooding | Sep 21, 2016 |
| Severe Storms, Tornadoes, And Flooding | Jun 21, 2013 |
| Severe Storms, Tornadoes, And Flooding | May 19, 2013 |
| Severe Storms, Flooding, And Tornadoes | Jun 1, 2010 |
| Severe Storms, Tornadoes, And Flooding | May 25, 2008 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes, And Flooding | May 19, 2004 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
42 since 1996: 30 flash floods and 12 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | May 24, 2019 | — |
| Flash Flood | Jun 9, 2018 | — |
| Flash Flood | Oct 1, 2018 | — |
| Flash Flood | Jul 22, 2017 | $1,000 |
| Flash Flood | Jul 21, 2017 | — |
| Flood | Sep 23, 2016 | $150,000 |
| Flash Flood | Jun 19, 2014 | — |
| Flash Flood | May 29, 2013 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · May 24, 2019. A warm front lifted northward into the area Friday, May 24, sparking widespread thunderstorms in the morning/early afternoon time frame and again in the early evening. Two tornadoes were occurred in McDonough County during the early afternoon. Towards evening, another tornadic storm developed, producing two tornadoes. The first occurred in Johnson County just southwest of Iowa City, and the second in Cedar Coun…
Flash Flood · Jun 9, 2018. After an early morning flash flood event in eastern Iowa, with some damaging winds near the Mississippi River, a line of slow moving supercell thunderstorms moved southeast from northern Iowa, into portions of eastern Iowa the evening of June 9th. Damaging winds, large hail, a few tornadoes, and torrential rain accompanied the storms. This event brought flash flooding, and led to some minor to moderate river floo…
Flash Flood · Oct 1, 2018. Several rounds of showers and thunderstorms occurred along the Highway 20 corridor during the afternoon and evening hours. Spotters and Emergency Managers reported rainfall amounts of 2 to 6 inches on already saturated ground, which caused flash flooding of roads and along creeks and streams. Highway 52 in Dubuque County was closed along with roads in Delaware County and Buchanan County.
Flash Flood · Jul 22, 2017. Another round of convective storms fired along a stalled boundary and lasted overnight resulting in a major heavy rain and flooding event from 3 to over 8 inches of rain falling. Some storms become severe with damaging winds over 60 mph and isolated large hail.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Delaware County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.