First step in flood mitigation effort for Ideal Creek, Mason Creek approved by Mason City council

MASON CITY — The City Council in Mason City last night approved submitting an application for the Federal Emergency Management Agency Advanced Assistance program through the Iowa Department of Homeland Security to assist with costs associated with assessing the Ideal Creek watershed above the Eastbrooke neighborhood and in the Mason Creek watershed upstream of South Federal Avenue for a possible flood mitigation project.

Planning & Zoning Manager Tricia Sandahl says an upstream detention project would reduce the peak flow on the streams and reduce the area subject to a 100-year flood event. The council last night approved revisions to the city’s floodplain management ordinance, placing  those areas as required by FEMA into the floodplain, meaning that property owners in those areas would now have to carry flood insurance.

Sandahl says the completion of a future mitigation project would hopefully allow those areas to be removed from the floodplain.  “Our intent is to hopefully find a project that would provide enough upstream detention so we could go back into FEMA and request a letter of map revision, removing most, I think there might still be one or two structures in the floodplain, but it would certainly lessen the impact of the remap.”

Sandahl says this grant would be for preliminary work before seeking more funding for the full mitigation project.  “This application is just for site evaluation and doing the environmental assessment for that site to put the city in a position to apply for another grant to actually do the project.”

Sandahl says people in those areas will need to have flood insurance on a temporary basis until the project is completed, with the timeline putting that a number of years down the line.  “The requirement for flood insurance is at the discretion of the lender, so most likely yes. I just want to tamper expectations. This is going to be a long process. We’ll probably be finishing this up about the time we finish up the roundabouts on Highway 122.”

Potential mitigation projects could include either upstream detention and/or increasing the span of the State Highway 122 bridge over Ideal Creek in Eastbrooke, as well as decreasing the peak flow at the upstream end of the Mason Creek watershed on the west side of US Highway 65.

If the grant application is approved, 75% of the study costs would be covered by FEMA, 10% by the state, with about $33,750 being the city’s responsibility.