Flooding in Kentucky isn’t rare; it’s expected.
In the last 15 years, Kentucky has faced 29 federally declared disasters. Most of these events have been flooding-related, and we seem to have more each coming year. Floods are by far Kentucky’s most widespread natural disaster.
Through late spring and early summer, Kentucky’s most common type of flooding, flash flooding, is most likely to occur. Flash flooding is categorized as a sudden, rapid rise of water that happens within minutes to hours after heavy rain, a storm, or another sudden water release. This can happen in as little as hours or minutes. It’s dangerous because water levels rise quickly with little warning and can sweep away people, cars, and structures.
One of Kentucky’s most significant floods was in July 2022. This catastrophic flash flood in Eastern Kentucky resulted in 45 fatalities and over half a billion dollars in property damage. According to the NWS (National Weather Service), between the dates of July 26th and 30th, rainfall amounts were over 600% percent of the normal estimated rainfall.
You can learn more about the 2022 Eastern Kentucky flood in this Daily Yonder documentary about public experiences.
Estimated Rainfall (inches): July 25-30, 2022, in Eastern Kentucky
Why is flooding so prevalent in Kentucky and causes so much damage?
Flooding is common and damaging in Kentucky because of its geography, waterways, and weather patterns. In the eastern part of the state, the steep terrain of the Appalachian Mountains causes rainwater to rush quickly into narrow valleys, creating fast-moving flash floods with little warning. At the same time, Kentucky’s dense network of rivers—like the Kentucky River and Ohio River—can overflow during heavy storms, as rainfall has become more intense in recent years. Many communities were built along these waterways, so rising water directly impacts homes and infrastructure, while factors like wet soil, land disturbance, and limited drainage systems make it harder for water to be absorbed or redirected, leading to widespread and costly damage.
Flooding can happen anywhere, not just in Eastern Kentucky or in Flood zones.
Flood zones in Kentucky are areas identified as having a higher risk of flooding, typically mapped by the Federal Emergency Management Agency (FEMA). The most common high-risk designation is the “100-year flood zone,” meaning there’s a 1% chance of flooding in any given year, and many communities along rivers like the Kentucky River and Ohio River fall into this category. Although in instances like in 2022, we have “1000-year flood events.”
In Eastern Kentucky, narrow valleys in the Appalachian Mountains create very dangerous flood zones because water rises quickly and has nowhere to spread out, leading to sudden flash floods. In simpler terms, the water has nowhere to go. Soil and rock types also play a major role. Much of the region has thin, compacted soils and underlying rock like shale and sandstone that limit how much water can soak into the ground, increasing runoff. Meanwhile, parts of Central Kentucky have limestone that can absorb some water but also contribute to uneven drainage. Because many towns were built in these low-lying areas near water, flood zones often overlap directly with residential neighborhoods. Learn more about Kentucky Flood Zones here!
Watersheds and Flooding
Another, more local aspect of flooding relates to watersheds. A watershed is an area of land where all precipitation drains to a common body of water, such as a river or lake, making it a central concept in Hydrology. Watersheds are important to flood zones because they determine how water moves across the landscape and where it comes together during heavy rainfall.
Map of Watersheds in Fayette County, KY
When rain falls within a watershed, it flows downhill into streams and rivers; if too much water collects too quickly, those waterways can overflow, creating floods in low-lying areas. The size, shape, and land use of a watershed—such as urban development or natural vegetation—can either increase or reduce flooding risk by affecting how fast water runs off or is absorbed into the ground. Because of this, agencies like FEMA use watershed data to help map and manage flood-prone areas. Here in Fayette County, we have nine major watersheds. You can find your Fayette County watershed here!
Article by: Samantha Sapp
Featured/Header Image of Article: ESRI Kentucky Flood Hazard model of Downtown, Lexington
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