Flash Floods in Ohio

The weather in Ohio is known as "consistently inconsistent;" it seems to change frequently and, sometimes, with very little warning. Flash flooding can occur very quickly when hard rains, thunderstorms and the winter snow thaw come, and especially if these elements occur over a brief period of time in the spring. Ohio's Committee for Severe Weather Awareness says flash flooding in the Buckeye State is very dangerous during all seasons of the year.

Weather Terms

• The National Weather Service (NWS) will issue a Flood Watch when the possibility of flooding exists following hard rains, damage to dams and rapidly melting or breaking snow and ice jams. The NWS may issue the flood watch up to 12 hours before the possible event; it can be in effect for several hours. The NWS will issue a Flash Flood Warning for current, potentially life-threatening conditions. River Flood Warnings which include cresting forecasts are issued for communities along high-rising rivers.

Flood Varieties

• Shallow flooding can occur in farm fields.

  Flooding typically occur when lakes, streams, creeks and rivers overflow their banks. The Ohio Emergency Management Agency (OEMA) defines several types of flooding; shallow, riverine, coastal and flash. The four types of shallow flooding keep water from draining easily; sheet flowing (the waters move downhill to cover a large area of land), urban and rural drainage overflowing (such as ditches, basements, storm sewers, levees and farm fields), and ponding (water that lies with no movement in flat areas). Riverine flooding is slow and rising, occurring when heavy rains fill and overflow Ohio's rivers. Coastal flooding can happen in the surrounding counties of Lake Erie if the waters are high and the winds are strong. Flash flooding is when the rains come swiftly, within a brief time period. Waters rise and fall quickly with little or no advanced warning.

Flash Floods

• Watch out for flooded roadways.

  OEMA says flash floods containing six or more inches of rapidly moving water can drag rocks, trees, earth and building materials from their foundations. They can create fast-moving walls of water that rise from 10 to 20 feet, sometimes higher, and can pull along trash and debris. Six inches of water can knock a person down; flooding of about two feet can destroy buildings and bridges and carry vehicles off the road.

Flash Flood Safety

• Do not drive through high waters.

  Do not try to walk, drive or swim through rapidly moving water; move to a higher ground at the first sign of flash flooding. Look out for flooding, especially in low-lying areas and under bridges. Do not drive vehicles through flooded roadways; each foot of rising water means the car effectively loses 1,500 pounds of its weight. Listen to the radio for updated weather information; keep a battery operated weather alert unit in your car.

General Flood Safety

• Because home flooding is always possibility in Ohio, contact your county's Designated Floodplain Administrator to determine if your home is in a floodplain (see reference). Assemble an emergency kit containing a battery operated radio, flashlight, bottled water, non-perishable foods and warm clothing. Create and practice an evacuation plan. Consider a purchase of flood insurance, which is not included in most home owners' policies; visit the National Flood Insurance Program (floodsmart.gov) for more information.