Floodplain

Development in Floodplains

The City of Johnston participates in the National Flood Insurance Program (NFIP) and has adopted regulations to manage development in floodplains. The floodplain regulations adopted by the City of Johnston establishes a flood fringe (FF) overlay district and a flood way (FW) overlay district. The regulations are found in Chapter 169 of the Zoning Ordinance, which outline permissible development in those areas. A floodplain development permit is required.

The Iowa Department of Natural Resources issues floodplain development permit also and a permit may also be required from them based upon the type of construction proposed.

To determine if your property is within the floodplain, review the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps. Copies are available at Johnston City Hall for review. Electronic copies of the maps are also available from FEMA.


Floodplain Regulations

Because of the city's floodplain regulations, residents in the city are eligible to purchase flood insurance from the National Flood Insurance Program, please contact your insurance agent about flood insurance or review this link for more information.

For additional floodplain information, please contact the Community Development Department at 515-727-7778 or by email.

Preliminary FEMA Maps Released


The current FIRM maps regulating properties within Johnston were adopted on July 19, 2000. However, over the last couple of years FEMA has been working to update all FIRM maps within Johnston based upon:

  • Re-delineation of flood hazard areas using updated topographic information, affecting all flood hazard areas within Johnston. The 2000 FIRM maps were prepared using 10 foot topographic contour data, while the preliminary maps use 2 foot topographic contour data.
  • Updated hydrologic and hydraulic analysis of portions of Little Beaver Creek, affecting flood hazard areas generally north of NW 70th Avenue and east of NW 86th Street; and,
As a result of this work, FEMA has published updated FIRM maps and an FIS for Johnston dated February 1, 2019. To continue participating in the NFIP, the City is required to officially adopt these updated maps as presented by FEMA and update our existing floodplain development regulations and Zoning Ordinance Overlay Districts prior to that date.

In order to move forward with the required City approvals resulting from the proposed FEMA maps, we have set Public Hearing dates as follows:

Planning and Zoning Commission, Monday, October 29, 2019 at 7:00 p.m.
City Council, Monday, November 5, 2019 at 7:00 p.m.

Both of the above noted meetings will be held at Johnston City Hall, 6221 Merle Hay Road. An opportunity will be available for anyone wishing to make comment about the updates, you may also address any comments to the Planning and Zoning Commission or City Council in writing by contacting me at the contact information contained below. I would suggest if you have specific questions about your individual property that you contact City Staff directly, as it will be difficult to address impacts to specific properties during the Public Hearing process.

A copy of the preliminary FIRM maps and Flood Study, and all of the information noted above, is also available for review in the Community Development Office at Johnston City Hall, located at 6221 Merle Hay Road. You may stop in anytime during regular office hours from 8 a.m. – 5 p.m. to review this information. Should you desire to discuss this information with a staff member, it is suggested that you schedule an appointment in advance by calling 515-727-7778.