598 flood insurance claims·$7.9M 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 Knox County, Tennessee. 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 the flood risk profile in Knox County, Tennessee, accounting for 68 events compared to 33 general flood events and one recorded flood-related death over the last 30 years. Recent occurrences illustrate this pattern, including minor flooding near the Karns and Solway areas from scattered air mass thunderstorms on August 22, 2025, and flash flooding caused by heavy rain from overnight showers and thunderstorms on August 13, 2025.
Federal Emergency Management Agency National Flood Insurance Program records show claims across multiple zones, with high-frequency losses occurring outside traditional high-risk areas. High-risk Zone A accounts for 303 claims with an average payout of $15,029 and an average recorded water depth of 7 inches. Meanwhile, Zone X recorded 139 claims with an average payout of $15,611 and an average recorded water depth of 21 inches, and Zone X_UNSHADED recorded 112 claims with an average payout of $23,950 and an average recorded water depth of 3 inches. Zone X_SHADED recorded 43 claims with an average payout of $11,314 and an average recorded water depth of 5 inches, and Zone V recorded 1 claim with a payout of $32,247 and an average recorded water depth of 9 inches.
Homeowners, real estate agents, and journalists should pay the most attention to properties in both designated high-risk flood zones and moderate-to-low risk Zone X areas, where substantial claim volumes and severe average water depths demonstrate that significant flood risks extend beyond standard high-risk boundaries.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
34% of Knox County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
459 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 8 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 2011, with 97 claims and $2.2M paid, the year of Severe Storms, Tornadoes, Straight-line Winds, and Associated Flooding and Severe Storms, Straight-line Winds, Tornadoes, And.
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.
10 NOAA storm reports from Knox County describe what happened, in the words of the forecasters who covered it. Read the Tennessee flood stories →
19 federal disaster declarations since 1973, 2 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storm | Jan 22, 2026 |
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | Apr 2, 2025 |
| Severe Storms, Straight-line Winds, And Tornado | Aug 7, 2023 |
| Severe Winter Storm | Dec 22, 2022 |
| Severe Storms, Flooding, Landslides, And Mudslides | Feb 19, 2019 |
| Severe Storms, Straight-line Winds, And Flooding | May 27, 2017 |
| Severe Winter Storm And Flooding | Feb 15, 2015 |
| Severe Storms, Straight-line Winds, Tornadoes, And | Jun 18, 2011 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
101 since 1996: 68 flash floods and 33 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 22, 2025 | — |
| Flash Flood | Aug 13, 2025 | — |
| Flash Flood | Jul 30, 2024 | — |
| Flood | Sep 28, 2024 | — |
| Flash Flood | Jul 24, 2024 | — |
| Flash Flood | Jul 22, 2024 | — |
| Flash Flood | Jun 4, 2024 | — |
| Flash Flood | Jul 20, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Aug 22, 2025. Scattered air mass thunderstorms developed over the east Tennessee mountains, Cumberland plateau, and central Tennessee valley during the afternoon and evening hours of August 22nd. These storms produced some minor flooding near the Karns and Solway areas.
Flash Flood · Aug 13, 2025. Multiple rounds of showers and thunderstorms overnight, culminated with some particularly heavy rain on the morning of August 13th in both Knox and Sullivan counties. This resulted in some flash flooding in both areas.
Flash Flood · Jul 30, 2024. An upper level shortwave coupled with strong wind fields brought multiple rounds of severe weather to East Tennessee, including two mesoscale convective systems. Flash flooding occurred in Knox county.
Flood · Sep 28, 2024. Tropical Storm Helene caps off a several day heavy rainfall event in association with a stalled closed upper low that drew a stream of tropical moisture into the area on the 25th and 26th. The arrival of Helene on the 27th yielded catastrophic flash flooding and river flooding, as well as significant wind damage as wet soils and strong wind gusts led to forest damage.
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.