Title
APPROVAL OF A LETTER TO THE FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) REQUESTING THAT EXISTING FLOOD MODELING PROCEDURES BE USED TO COMPLETE FLOOD MAPPING ALONG NON-ACCREDITED LEVEES.
Presented by: James Weber, P.E., Deputy Director of Public Works.
RECOMMENDED ACTION: Approve the letter and authorize the Chairman to sign.
Body
There are three flood mapping initiatives currently underway within Sedgwick County. FEMA has recently approved a map revision requested by the City of Wichita that affects the Dry Creek and Calfskin creeks in northwest Wichita and adjacent Sedgwick County. The City of Wichita and Sedgwick County have been working on mapping that is associated with the accreditation of the flood control levees. FEMA has been working on periodic remapping of all of Sedgwick County.
The best maps for Sedgwick County would be produced if data from all three of these projects can be merged into a single set of updated maps. The Kansas Department of Agriculture's Division of Water Resources (DWR) is responsible for the management of flood mapping in Kansas on behalf of FEMA. Both FEMA and DWR are in agreement that a merger of the three data sets will result in the best overall maps for Sedgwick County. This work is expected to be completed in 2014.
A recent change in policy at the federal level has the potential to significantly slow down the mapping process. FEMA is working to revise its policies regarding the mapping of floodplains along streams with non-accredited levees. There are several areas in the communities of Sedgwick County that have non-accredited levees. These are generally levees that were formed as spoil banks from the excavation of channels or that were never designed to meet FEMA requirements (so called "ag" levees). They may offer some protection from small floods but do not meet the standards that would allow them to be recognized as providing protection from the 100 year flood. FEMA's current guidance would require the countywide mapping project hold up until the new policies are place and studies could be completed using the new modeling methods. It is estimated that under this scenario, new maps would not be completed and in place until 2017.
FEMA has concluded that for many communities the new policies under consideration would produce little or no new benefit. They also understand that the value of completing the maps early may exceed the possible benefits of analyzing a limited number of areas using the new modeling techniques. FEMA has offered to proceed with the mapping projects that are underway if the communities involved submit a written request to continue the projects using existing modeling techniques.
There are three general areas within Sedgwick County where mapping would be affected. There are ag levees along the Big Arkansas River west of 151st St. West, along the West Branch of Chisholm Creek (Valley Center area) and along the Cowskin Creek south of the Wichita-Valley Center Flood Control Project (Haysville area). Haysville and Valley Center have already signed similar letters and the City of Wichita staff is working to get a letter approved by their City Council.
After considering both alternatives (move forward with existing techniques or wait for new guidance) County Public Works and Code Enforcement staff recommend that the Board of County Commissioners make a formal request to FEMA to proceed with the existing modeling techniques based on the following:
1. This work has already been completed using existing methods .
2. It is unlikely that the new techniques being considered will make any significant changes to the mapping.
3. The maps could be finalized and in use in 2014 rather than 2017.
4. Property owners would benefit by using the best available information three years earlier.
A letter, based on language provided by FEMA, has been prepared for the Chairman's signature that will formally request that the maps for unincorporated Sedgwick County be prepared using the existing modeling procedure for non-accredited levees. The letter indicates that Kelly Dixon, Floodplain Manager, is the designated contact for this matter.
Alternatives: Wait for the new policy guidance and delay issuance of the countywide maps.
Financial Considerations: None
Legal Considerations: None
Policy Considerations: None
Outside Attendees: None
Multimedia Presentation: None