Floodplain Information

Floodplain area with water and mist

The Stormwater Management Program (SMP) contracted for seven watershed studies between 1998 and 2002. These studies were part of a county-wide effort to provide the following information:

  1. Identify existing and potential future flooding problems;
  2. Develop planning solutions to mitigate flooding problems;
  3. Generate new 1% chance (100 year) floodplain maps based on current conditions and fully urbanized conditions; and
  4. Develop the data required by the Federal Emergency Management Agency (FEMA) to update FEMA regulatory 1% chance floodplain maps.

Through this effort, the SMP and the cities have created a tool that will assist in providing a public service to help protect the welfare and safety of Johnson County residents and visitors.

Floodplain Mapping

The floodplain mapping is complete and was adopted by FEMA on August 3, 2009. Johnson County floodplain mapping information can be found at the following locations:

If you have questions about the floodplain information or want additional information, contact the floodplain administrator for your community.

Floodplain Map

Localized Flooding

Water in basement, home, business
For help with flooding issues in buildings and structures, please contact your city.

If you cannot determine the source of the water entering your home, contact your city hall or a plumber.

Water in yard, drives, drainage areas
If you have water pooling in your yard for long periods of time, contact your city to determine if this is a city responsibility issue or a homeowner issue.

Water standing in the streets for long periods of time, clogged/blocked inlets, culverts and bridges?
Contact your city and inform them of the situation.

Water in car, truck, vehicles
Restoring cars and vehicles that have been partially or completely submerged under water requires professional attention. Check with your dealer or look in the telephone directory for automobile service and repair firms.

Please visit our page on flood safety.