Floodplain Mapping

The Iowa DNR and FEMA entered into a Cooperating Technical Partners (CTP) Partnership Agreement dated August 12, 2009, with the goal of collaboratively creating and maintaining accurate, up-to-date flood hazard data for the state. This ushered in the Iowa DNR's Floodplain Mapping Program. The goal of the program is to develop digital FEMA Flood Insurance Rate Maps (FIRMs) for all 99 counties. 

The State of Iowa was awarded $15.0 million in CDBG Disaster Recovery Funds in 2009, due to the devastating floods of 2008. This funding was allocated to the Iowa DNR for the development of new floodplain maps and updating of existing maps for all of the 85 Iowa counties listed in the federal Disaster Declaration of 5/27/2008 (Declaration FEMA-1763-DR). In 2010, the state legislature mandated that the Iowa Flood Center (IFC) in Iowa City, Iowa (IFC) contract with the Iowa DNR for $10 million of the $15 million of CDBG grant funds. In March 2015, the contract with the Iowa Flood Center was amended to increase the contract amount to $12.5 million. State funding and leveraging of state resources with the Army Corps of Engineers Section 22 Public Assistance to States (PAS) program is being used to develop and update floodplain mapping for the remaining 14 non-disaster declared counties. Two Section 22 PAS agreements between the Iowa DNR and the U.S. Army Corps of Engineers have been executed: September 21, 2011 (for eleven countywide floodplain work maps); and June 28, 2012 (for one countywide floodplain work map).  Development of flood hazard data for the two remaining non-declared counties was funded with non-grant state funding. The $15 million CDBG grant has been completely expended as of December 31, 2016 – and has been closed out by the State of Iowa Economic Development Authority.  

Coincidentally, Iowa began collection of LiDAR elevation data at one (1) meter resolution (elevations to +/- 8 inches) for the entire state in 2007. This $4.3 million project, funded by several state and federal agencies and completed in 2012, provided the ability to create the flood hazard data used to generate floodplain maps for the entire state.  At the time, Iowa was one of a few states in the country to accomplish this significant data acquisition task.

In order to have the capability to provide technical and project management oversight of Iowa’s floodplain mapping program, in 2009 the Iowa DNR hired Scott Ralston, P.E., CFM, a Senior Environmental Engineer with 26 years of public and private civil engineering experience (at time of hire) to act as Floodplain Mapping Coordinator/CTP Program Manager - and Chris Kahle, a Senior GIS Analyst to manage the GIS and data management needs.

The Iowa DNR is currently performing work for forty-seven (47) regulatory countywide FIRMs and one flood study (Honey Creek in the City of Boone). Forty-one (41) of these FIRMs are being funded by the 2016 CTP grant, and six (6) are being funded by the 2017 CTP grant. Under the 2018 CTP grant, enhanced (detailed) stream reaches in 14 counties will be studied resulting in floodplain mapping for the 1% (100-year) and 0.2% (500-year) annual chance floods.

The Iowa DNR is the state coordinating agency for the National Flood Insurance Program (NFIP) and provides assistance to local communities that participate in the NFIP. Bill Cappuccio, a water resources engineer with 40-plus years of experience as the State of Iowa NFIP Coordinator, has two other staff members dedicated to working closely with NFIP participating communities to ensure their compliance with both state and NFIP requirements.