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FEMA_Technical Appeal of Revised Flood Plan MapsMasterpiece on the Mississippi TO: The Honorable Mayor and City Council Members FROM: Michael C. Van Milligen, City Manager SUBJECT: City of Dubuque Technical Appeal of Revised Floodplain Maps DATE: November 7, 2012 Dubuque kital All- America City II 111! 2012 The Federal Emergency Management Agency (FEMA) provided five new preliminary panels of the Flood Insurance Rate Maps and Flood Insurance Study for review by the City of Dubuque in August 2012. The Flood Insurance Rate Maps and Flood Insurance Study were revised to change the status of Dubuque's Local Flood Protection Project Levee from provisionally- accredited to accredited, and to revise the Special Flood Hazard Area to map interior drainage ponding from the accredited levee. In layperson's terms, FEMA is providing revised flood maps to the City of Dubuque that change the designation of the City's flood wall from a provisionally- accredited levee to an accredited levee. In addition, the maps have been revised to reflect new 100 -year flood elevations for the City's four detention basins located along the flood wall. The basins detain storm water from upland areas and pump it over the floodwall at such times when the normal gravity flow storm sewers have to be closed due to flooding on the Mississippi River. Planning Services Manager Laura Carstens recommends City Council approval of the City of Dubuque's technical appeal of revised floodplain maps. I concur with the recommendation and respectfully request Mayor and City Council approval. brit44 krt., italy, Michael C. Van Milligen MCVM:jh Attachment cc: Barry Lindahl, City Attorney Cindy Steinhauser, Assistant City Manager Teri Goodmann, Assistant City Manager Laura Carstens, Planning Services Manager Masterpiece on the Mississippi Dubuque bitri inmedcatih 'VIII' 2012 TO: Michael Van Milligen, City Manager FROM: Laura Carstens, Planning Services Manager .4 SUBJECT: City of Dubuque Technical Appeal of Revised Floodplain Maps DATE: November 6, 2012 INTRODUCTION This memo transmits the City of Dubuque's technical appeal of revised floodplain maps for City Council review and approval. BACKGROUND The Federal Emergency Management Agency (FEMA) provided five new preliminary panels of the Flood Insurance Rate Maps (FIRMs) and Flood Insurance Study (FIS) for review by the City of Dubuque in August 2012. The FIRMs and FIS were revised to change the status of Dubuque's Local Flood Protection Project Levee from provisionally- accredited to accredited, and to revise the Special Flood Hazard Area (SFHA) to map interior drainage ponding from the accredited levee. In layperson's terms, FEMA is providing revised flood maps to the City of Dubuque that change the designation of the City's flood wall from a provisionally- accredited levee to an accredited levee. In addition, the maps have been revised to reflect new 100 -year flood elevations for the City's four detention basins located along the flood wall. The basins detain storm water from upland areas and pump it over the floodwall at such times when the normal gravity flow storm sewers have to be closed due to flooding on the Mississippi River. DISCUSSION FEMA has revised five panels of the City's FIRMs to reflect the fact that the City's levee has been accredited and to reflect the interior (land side) drainage ponding that is associated with the operation of the levee. FEMA has also provided a Summary of Map Actions that documents previous Letters of Map Changes. This would include the Letters of Map Amendment — Out As Shown (LOMA -OAS) that Planning staff has been assisting citizens with since adoption of the new flood maps on October 18, 2011. The process for reviewing these maps is similar to that which was followed as part of the review of the new flood maps that were submitted to the City in July 2009 and City of Dubuque Technical Appeal of Revised Floodplain Maps Page 2 approved and adopted on October 18, 2011. The process for the revised maps included a non - technical review in May 2012. Planning and Engineering staff reviewed the preliminary panels and FIS Report, and transmitted non - technical errors that were found by the June 4, 2012 deadline. FEMA incorporated these recommended non - technical changes in the maps. FEMA now is initiating a statutory 90 -day appeal period because FEMA has added or modified a base flood elevation, base flood depth, and flood zone designations within Dubuque as shown on the preliminary FIRM. The 90 -day appeal period began on September 1, 2012 for submission of scientific or technical data to correct the preliminary FIRM. Planning and Engineering staff coordinated a review of the revised FIRM. As part of staff's review of these maps, it was found that the 16th Street Detention Basin does not reflect its current shape that was changed as part of the Bee Branch Creek Restoration Project. The available area for building along 16th Street was increased by utilizing dredged materials out of the 16th Street Detention Basin. As you are aware, the capacity of the 16th Street Detention Basin was not reduced as the removal of the material restored the capacity of the 16th Street Detention Basin even with a smaller water surface area. The City's consultant, CDM Smith, has been in contact with FEMA and their consultant as to the process to file a technical appeal to revise the 16th Street Detention Basin's current shape. FEMA indicated that the City should provide a new interior drainage polygon along with a letter explaining the proposed appeal. FEMA can process the request as an appeal, and then FEMA can update the FIRMs accordingly. REQUESTED ACTION The requested action is for the City Council to authorize transmittal of the attached letter from Mayor Buol as part of the City's appeal of the Preliminary Flood Insurance Rate Maps. Enclosures cc: Gus Psihoyos, City Engineer Don Vogt, Public Works Director John Klostermann, Streets & Sewers Supervisor Steve Brown, Project Manager Bob Schiesl, Assistant City Engineer Deron Muehring, Civil Engineer Dubuque THE CITY OF kdkril i 'f DTJBUQ'LJE i � III nu Masterpiece on the Mississippi Louis Rodriguez, P.E. Chief Engineering Management Branch . Federal Insurance and Mitigation Administration Federal Emergency Management Agency 500 C Street SW Washington DC 20472 Office of the Mayor City Hall 50 West 13th Street Dubuque, Iowa 52001 -4805 www.cityofdubuque.org November 20, 2012 SUBJECT: City of Dubuque Technical Appeal of FEMA Preliminary DFIRM Dear Mr. Rodriguez: This letter provides documentation from the City of Dubuque constituting a technical appeal of the preliminary copies of the revised Flood Insurance -Rate Map (FIRM) and Flood Insurance Study Report (FIS) for Dubuque County, Iowa and incorporated areas. This letter transmits information explaining the requested change and a new interior drainage polygon as an attachment. Specifically, this appeal is regarding panels 19061CO244F and 19061CO243F. In reviewing the submitted preliminary copies of the revised FIRM, the City found that the City's 16th Street Detention Basin did not reflect the current shape of the detention basin. The water surface area was modified as part of the Bee Branch Creek Restoration Project. The City of Dubuque had submitted a detailed interior drainage study as part of the 65.10 package submitted for recertification of the City's Levee. The revised water surface area of the 16th Street Detention Basin was included as part of that study. The City's request is that Panels 243 and 244 be revised to reflect the existing shape of the 16th Street Detention Basin. Thank you for your attention to this matter. Please feel free to contact Planning Services Manager Laura Carstens with any questions or for more information at 563- 589 -4210 or Icarsten@citvofdubuque.orq. Sincerely, Roy a Buol Mayor Enclosures Service People Integrity Responsibility Innovation cc: City Council Members Michael Van Milligen, City Manager Barry Lindahl, City Attorney Teri Goodmann, Assistant City Manager Laura Carstens, Planning Services Manager Gus Psihoyos, City Engineer Deron Muehring, Civil Engineer Kyle L. Kritz, Associate Planner Bill Cappuccio, Iowa Department of Natural Resources Anna O'Shea, Dubuque County Zoning Administrator /Flood Plain Administrator Emily Whitehead, STARR Service People Integrity Responsibility Innovation , l 1 1/4. '.7 , 1 'V • . ■ • o ) ' ■ • - t . . A .1,1 iklii , • . I '1' • ki I • • ' ' lift,,,, t r • , 6 . . ' , ""I' .... : '''il . ■ • if. P i. r4,f-f.e. • ii 1 _t4 ;Fe. 7, rvti VI .1 • i ... ..c . 1..r it .7 f- A -1'■ v.z, ..,,,...1 • i ! .... ! 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