4 flood insurance claims·$1.1M paid·3 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 Knox County, Missouri. 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 profile of Knox County, Missouri. According to NOAA Storm Events Database records from the last 30 years, flash floods account for 25 out of 29 total flood events, far outpacing general river floods.
Storms driven by frontal boundaries and outflow boundaries frequently produce intense rainfall over short periods. For example, storms moving across northeastern Missouri in June 2015 produced heavy rainfall and numerous reports of flash flooding across Knox and Lewis counties. Later that year, strong cold fronts and slow-moving storms triggered additional flash flooding events in May 2019 and September 2019.
National Flood Insurance Program claims data indicates that high-risk Zone A properties face the most severe threats, recording an average water depth of 48 inches and an average payout of $472,520. Properties located in Zone A, as well as moderate-to-low risk Zone X and Zone X Unshaded areas that have also recorded historical claims with average depths of 3 to 4 inches, should pay the closest attention to local flood risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
In flood insurance claims here that reported a flood depth, the average was 18 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.
25 federal disaster declarations since 1973, 3 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | Jul 29, 2023 |
| Severe Storms, Tornadoes, And Flooding | Apr 29, 2019 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | May 15, 2015 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Sep 9, 2014 |
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | May 29, 2013 |
| Severe Winter Storm | Jan 31, 2011 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms, Flooding, And Tornadoes | Jun 12, 2010 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
29 since 1996: 25 flash floods and 4 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Sep 27, 2019 | — |
| Flash Flood | May 26, 2019 | — |
| Flash Flood | Jun 26, 2015 | — |
| Flash Flood | Jun 25, 2015 | $200,000 |
| Flash Flood | Sep 10, 2014 | — |
| Flash Flood | Jun 26, 2011 | — |
| Flash Flood | Jul 12, 2011 | — |
| Flash Flood | Jul 20, 2010 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Sep 27, 2019. A strong cold front moved into the forecast area, triggering showers and thunderstorms. Some of the storms became severe producing large hail, damaging winds and flash flooding.
Flash Flood · May 26, 2019. Storms developed along an old outflow boundary across portions of northeast Missouri and west central Illinois. There were numerous reports of damaging winds and several reports of flash flooding.
Flash Flood · Jun 26, 2015. A frontal boundary was slowly sinking south across forecast area. Several rounds of storms developed and moved east along the front dumping up to 8 inches of rain in a 24 hour period from 7 am June 25th to 7 am June 26th. This caused considerable flash flooding, especially in Lincoln County Missouri and Calhoun County Illinois. There were also numerous reports of damaging winds and large hail.
Flash Flood · Jun 25, 2015. A complex of storms developed over northern Missouri and tracked to the east, dumping a lot of rain over northeastern Missouri. There were numerous reports of flash flooding over Knox and Lewis counties.
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 Knox 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.