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States with the highest risk of flooding

  • States with the highest risk of flooding

    It’s spring, which means for much of the U.S., it’s flood season. Warnings and watches have been pouring in from across the country, including current ones in Ohio, Illinois, Wisconsin, Idaho, Kansas, Oregon, Missouri, and more. And that’s after earlier floods have already devastated communities this season—in Texas, two children and their mother were killed by a flash flood near a usually small creek. Some Iowa towns spent weeks underwater after the Missouri River flooded in March. Meanwhile, West Virginia and Louisiana are still struggling to recover after major floods from more than two years ago.

    While it may seem like almost all of the country is at risk for being plunged underwater at any second, the flooding risk actually varies by state. Stacker wanted to know: which states are most likely to flood? In order to determine a ranking, we harnessed 2011 data from the Federal Emergency Management Agency’s National Flood Hazard Layer and the agency’s Designated Special Flood Hazard Area (SFHA) estimates. The National Flood Hazard Layer is a national database used to calculate the percentage of each county in the U.S. that qualifies as an SFHA; SFHA regions have a 1% annual chance of flooding.

    All of the statistics were found through the CDC’s National Environmental Public Health Tracking Network. Stacker first assessed the data provided on the county level, then added up all threatened land within each county to determine how much land was under threat in each state. The resulting ranking shows the states in order, from lowest to highest, of the percentage of each within FEMA’s Designated Special Flood Hazard Area.

    Although we may continually be fighting flooding events—and even more so as the climate continues to change—we are at least able to take some steps forward in predicting and combating them. Scientists are starting to use drones, supercomputers, and sonar to predict where rivers will overflow and to help monitor flood control projects. Generally speaking, we have a glimmer of hope.

    Read on to find out how your state ranks.

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  • #51. Alaska

    Percentage of state within flood hazard area: 0.5%
    Total flood hazard area: 1,286 square miles (#42 among all states)

  • #50. Wyoming

    Percentage of state within flood hazard area: 1.6%
    Total flood hazard area: 1,462 square miles (#41 among all states)

  • #49. Hawaii

    Percentage of state within flood hazard area: 1.81%
    Total flood hazard area: 124 square miles (#50 among all states)

  • #48. Idaho

    Percentage of state within flood hazard area: 1.89%
    Total flood hazard area: 1,589 square miles (#39 among all states)

  • #47. Montana

    Percentage of state within flood hazard area: 1.89%
    Total flood hazard area: 2,485 square miles (#32 among all states)

  • #46. Colorado

    Percentage of state within flood hazard area: 2.04%
    Total flood hazard area: 1,890 square miles (#38 among all states)

  • #45. Utah

    Percentage of state within flood hazard area: 2.72%
    Total flood hazard area: 1,944 square miles (#37 among all states)

  • #44. Nevada

    Percentage of state within flood hazard area: 2.74%
    Total flood hazard area: 2,981 square miles (#28 among all states)

  • #43. New Mexico

    Percentage of state within flood hazard area: 2.76%
    Total flood hazard area: 2,966 square miles (#29 among all states)

  • #42. Oregon

    Percentage of state within flood hazard area: 3.32%
    Total flood hazard area: 3,231 square miles (#26 among all states)