20 Inland Counties With the Greatest Flood Risk

By Evan Comen  •  April 17, 2026
traffic light sign underwater
Photo by Kelly Sikkema on Unsplash

While the coastal United States is increasingly flood-prone, flood risk extends far inland. America’s rivers regularly overflow their banks, causing billions of dollars in property damage every year. Flood risk is worst along the Mississippi River corridor, while several flood-prone pockets in the banks of the Missouri and Ohio Rivers also see regular, damaging flood activity. A closer look at the data reveals the inland counties with the greatest flood risk.

To determine the inland counties with the greatest flood risk, Climate Crisis 247 reviewed data on riverine flooding from FEMA’s National Risk Index. Counties were ranked based on composite riverine flood risk score, a function of annualized, historic flood losses from 1996 to 2014. Supplemental data on total population is from the U.S. Census Bureau.

20. Guadalupe County, TX

  • Score of annual losses from riverine flooding: 99.0/100
  • Number of riverine flood events, 1996-2019: 80 events
  • Largest river: Guadalupe River
  • Total population: 178,368
  • County seat: Seguin

19. Comal County, TX

  • Score of annual losses from riverine flooding: 99.0/100
  • Number of riverine flood events, 1996-2019: 103 events
  • Largest river: Guadalupe River
  • Total population: 174,552
  • County seat: New Braunfels

18. Cook County, IL

  • Score of annual losses from riverine flooding: 99.0/100
  • Number of riverine flood events, 1996-2019: 141 events
  • Largest river: Fox River
  • Total population: 5,185,812
  • County seat: Chicago

17. Washington County, UT

  • Score of annual losses from riverine flooding: 99.1/100
  • Number of riverine flood events, 1996-2019: 145 events
  • Largest river: Virgin River
  • Total population: 189,827
  • County seat: St. George
a river running through a city at night
Photo by Stephen Crane on Unsplash

16. Bexar County, TX

  • Score of annual losses from riverine flooding: 99.2/100
  • Number of riverine flood events, 1996-2019: 190 events
  • Largest river: San Antonio River
  • Total population: 2,037,344
  • County seat: San Antonio

15. Hays County, TX

  • Score of annual losses from riverine flooding: 99.2/100
  • Number of riverine flood events, 1996-2019: 96 events
  • Largest river: Pedernales River
  • Total population: 256,429
  • County seat: San Marcos

14. San Bernardino County, CA

  • Score of annual losses from riverine flooding: 99.2/100
  • Number of riverine flood events, 1996-2019: 302 events
  • Largest river: Colorado River
  • Total population: 2,187,816
  • County seat: San Bernardino

13. Linn County, IA

  • Score of annual losses from riverine flooding: 99.3/100
  • Number of riverine flood events, 1996-2019: 60 events
  • Largest river: Iowa River
  • Total population: 229,463
  • County seat: Cedar Rapids

12. Montgomery County, TX

  • Score of annual losses from riverine flooding: 99.3/100
  • Number of riverine flood events, 1996-2019: 44 events
  • Largest river: West Fork San Jacinto River
  • Total population: 654,722
  • County seat: Conroe

11. Somerset County, NJ

  • Score of annual losses from riverine flooding: 99.4/100
  • Number of riverine flood events, 1996-2019: 165 events
  • Largest river: Passaic River
  • Total population: 346,203
  • County seat: Somerville

10. Wayne County, MI

  • Score of annual losses from riverine flooding: 99.5/100
  • Number of riverine flood events, 1996-2019: 61 events
  • Largest river: Huron River
  • Total population: 1,773,767
  • County seat: Detroit

9. Ascension Parish, LA

  • Score of annual losses from riverine flooding: 99.5/100
  • Number of riverine flood events, 1996-2019: 16 events
  • Largest river: Mississippi River
  • Total population: 128,593
  • County seat: Donaldsonville

8. Kern County, CA

  • Score of annual losses from riverine flooding: 99.5/100
  • Number of riverine flood events, 1996-2019: 132 events
  • Largest river: Kern River
  • Total population: 910,433
  • County seat: Bakersfield
A bench sitting next to a body of water
Photo by Nish Gupta on Unsplash

7. Jefferson County, AL

  • Score of annual losses from riverine flooding: 99.6/100
  • Number of riverine flood events, 1996-2019: 95 events
  • Largest river: Black Warrior River
  • Total population: 669,744
  • County seat: Birmingham

6. Washoe County, NV

  • Score of annual losses from riverine flooding: 99.7/100
  • Number of riverine flood events, 1996-2019: 33 events
  • Largest river: Truckee River
  • Total population: 491,770
  • County seat: Reno

5. Davidson County, TN

  • Score of annual losses from riverine flooding: 99.7/100
  • Number of riverine flood events, 1996-2019: 94 events
  • Largest river: Cumberland River
  • Total population: 709,846
  • County seat: Nashville

4. Livingston Parish, LA

  • Score of annual losses from riverine flooding: 99.7/100
  • Number of riverine flood events, 1996-2019: 13 events
  • Largest river: Amite River
  • Total population: 145,583
  • County seat: Livingston

3. Lafayette Parish, LA

  • Score of annual losses from riverine flooding: 99.8/100
  • Number of riverine flood events, 1996-2019: 44 events
  • Largest river: Bayou Teche
  • Total population: 245,075
  • County seat: Lafayette

2. Shelby County, TN

  • Score of annual losses from riverine flooding: 99.9/100
  • Number of riverine flood events, 1996-2019: 129 events
  • Largest river: Mississippi River
  • Total population: 922,195
  • County seat: Memphis

1.East Baton Rouge Parish, LA

  • Score of annual losses from riverine flooding: 99.9/100
  • Number of riverine flood events, 1996-2019: 31 events
  • Largest river: Mississippi River
  • Total population: 452,821
  • County seat: Baton Rouge


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