1,155 flood insurance claims·$13.1M paid·2 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 Johnson County, Kansas. 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 severe summer thunderstorms dominates the flood risk in Johnson County, Kansas. Over the last 30 years, the NOAA Storm Events Database recorded 84 flash flood events resulting in 3 deaths, compared to 25 general flood events. Recent severe weather includes a heavy rainfall event on July 1, 2024, that dropped 3 to 6 inches of rain (with isolated amounts up to 7 inches) in about three hours, as well as severe thunderstorms with flash flooding on July 17, 2025.
Federal Emergency Management Agency records show that flood impacts extend beyond designated high-risk areas. Zone A properties account for 593 National Flood Insurance Program claims with an average payout of $18,238 and an average recorded water depth of 4 inches. Meanwhile, various Zone X designations account for 545 total claims, including 196 claims in Zone X with an average recorded water depth of 11 inches and an average payout of $16,157, and 289 claims in unshaded Zone X with an average payout of $7,418 and an average recorded water depth of 2 inches.
Homeowners, real estate agents, and journalists should pay the most attention to properties located within Zone A, as well as homes in Zone X designations where localized heavy rainfall frequently produces damaging water depths despite being outside traditional high-risk flood zones.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
37% of Johnson County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
942 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 4 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 1982, with 160 claims and $937,212 paid, the year of Severe Storms 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.
13 NOAA storm reports from Johnson County describe what happened, in the words of the forecasters who covered it. Read the Kansas flood stories →
12 federal disaster declarations since 1969, 2 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | Jul 14, 2023 |
| Severe Storms, Straight-line Winds, And Flooding | Jul 22, 2017 |
| Severe Winter Storms | Dec 6, 2007 |
| Hurricane Katrina Evacuation | Sep 1, 2005 |
| Severe Winter Ice Storm | Jan 29, 2002 |
| Flooding 10/31/98 | Oct 30, 1998 |
| Severe Storms, Flooding And Tornadoes | Oct 1, 1998 |
| Severe Storms & Flooding | Jun 28, 1993 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
109 since 1996: 84 flash floods and 25 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 17, 2025 | $10,000 |
| Flash Flood | Jul 17, 2025 | — |
| Flash Flood | Jul 1, 2024 | — |
| Flash Flood | Jul 14, 2023 | — |
| Flash Flood | Aug 12, 2021 | — |
| Flash Flood | May 28, 2020 | — |
| Flash Flood | Apr 30, 2019 | — |
| Flash Flood | Jul 27, 2017 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 17, 2025. A cluster of severe thunderstorms moved through portions of eastern Kansas, including the Kansas side of the KC Metro area. Numerous reports of wind damage, severe wind gusts, and flash flooding occured.
Flash Flood · Jul 1, 2024. During the morning and early afternoon hours of July 1st, heavy rainfall yielded flash flooding across much of Johnson County. A swath of 3 to 6 of rain with isolated locations up to 7 fell within about a 3 hour time period from about 930 am to 1230 pm.
Flash Flood · Jul 14, 2023. During the afternoon of July 14, 2023 a strong storm formed in northeast Kansas and eventually transformed into a strong squall line that impacted far eastern Kansas and western Missouri. This storm left a swath of wind damage mainly through the heart of the Kansas City metro area in the form of widespread tree damage. Several structures were impacted by falling trees as the storm moved through the city, and into…
Flash Flood · Aug 12, 2021. After an initial round of thunderstorms formed and moved out of the area, a second round of thunderstorms formed in the late afternoon to evening that produced some severe hail, that got up to around an inch, with some isolated golfball sized 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 Johnson 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.