Information related to flooding and floodplain management in Kentucky.
A flood is the inundation of a normally dry area caused by an increased water level in an established watercourse such as a river, stream or drainage ditch, or ponding of water at or near the point where the rain fell. Floods can occur any time during the year. However, many occur seasonally after winter snow melts or heavy spring rains.
Flash floods occur suddenly, usually within six hours of the rain event, and result from heavy localized rainfall. Flash floods can begin before the rain stops. Water levels in small streams may rise quickly in heavy rainstorms, especially near the headwaters of river basins. Heavy rains can also cause flash flooding in areas where the floodplain has been urbanized.
Dam failures, blocked culverts and bridges and backwater from larger rivers and streams can also cause both flooding and flash flooding.
Many people are killed by flash floods when driving or walking on roads and bridges that are covered by water. In fact, flash floods are the number one weather-related killer in the United States. Even six inches of fast-moving water can knock you off your feet, and a depth of only two feet of water will float many of today's automobiles. If you are in a car and water starts rising, get out and move to higher ground.
A flash flood or flood watch indicates that flash flooding or flooding is possible within the designated watch area. The watch is issued to inform the public and cooperating agencies that current and developing weather conditions may cause flooding but that its occurrence is neither certain nor imminent.
A flash flood or flood warning indicates that flash flooding or flooding is already occurring or imminent within the designated warning area. When a flash flood or flood warning is issued for your area, act quickly. Get out of areas subject to flooding and avoid areas where flooding has already occurred.
A small stream flood advisory indicates that flooding of small streams, streets and low-lying areas, such as railroad underpasses and urban storm drains, is occurring.
