Federal Emergency Management Agency Letter_DFIRM2007
TO: The Honorable Mayor and City Council Members
FROM: Michael C. Van Milligen, City Manager
SUBJECT: Correspondence with FEMA concerning Dubuque Industrial Center West
DATE: December 14, 2009
IIW Engineers & Surveyors was hired by the City of Dubuque to determine the flood
plain boundaries within the Dubuque Industrial Center West (DICW). As part of the
development of the DICW, the Middle Fork of the Catfish Creek was significantly
changed with a new detention basin as part of the Bergfeld Recreation Area. The study
establishes the new flood plain boundaries and demonstrates that the buildable lots
along the Middle Fork of the Catfish Creek have been raised to a point where they are
above the 100-year flood plain.
Planning Services Manager Laura Carstens recommends City Council approval of a
letter to the Federal Emergency Management Agency (FEMA) requested changes to
the preliminary digital flood insurance rate map for DICW.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
Mic ael C. Van Milligen
MCVM:jh
Attachment
cc: Barry Lindahl, City Attorney
Cindy Steinhauser, Assistant City Manager
Laura Carstens, Planning Services Manager
Dubuque
THE CITY OF
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Masterpiece on the Mississippi '
200
TO: Michael Van Milligen, City Manager
FROM: Laura Carstens, Planning Services Manager ~~i"`~
SUBJECT: Correspondence with FEMA concerning Dubuque Industrial Center West
DATE: December 10, 2009
INTRODUCTION
This memorandum transmits a draft letter from Mayor Roy Buol to the Federal Emergency
Management Agency (FEMA) requesting changes to the preliminary digital flood insurance
rate map (DFIRM) and providing the flood plain boundary study completed by IIW
Engineers & Surveyors on the Dubuque Industrial Center West (DICW).
DISCUSSION
IIW Engineers & Surveyors was hired by the City of Dubuque to determine the flood plain
boundaries within the DICW. As part of the development of the DICW, the Middle Fork of
the Catfish Creek was significantly changed with a new detention basin as part of the
Bergfeld Recreation Area. The study establishes the new flood plain boundaries and
demonstrates that the buildable lots along the Middle Fork of the Catfish Creek have been
raised to a point where they are above the 100-year flood plain (Zone A). The benefit of this
study is that the individual property owners will not have to have flood insurance.
Enclosed is a letter from Dennis Waugh of IIW Engineers & Surveyors outlining the study
and a disc that includes all of the pertinent study data.
RECOMMENDATION
City staff recommends transmittal of the enclosed letter, study and disc requesting that
FEMA review the study and modify the Zone A flood plain boundary delineations on the
preliminary DFIRM within the DICW.
Prepared by: Kyle L. Kritz, Associate Planner
Enclosures
cc: Gus Psihoyos, City Engineer
Deron Muehring, Civil Engineer
Kyle L. Kritz, Associate Planner
Dave Heiar, Economic Development Director
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Masterpiece on the Mississippi
Dubuque Office of the Mayor & City Council
~" City Hall
~' ~ 50 West 13~ Street
I ~. Dubuque, IA 52001-4864
www.cityofdubuque.org
200
December 21, 2009
Rick Nusz
Hydraulic Engineer
FEMA Region VII
9221 Ward Parkway Ste 300
Kansas City MO 64114
Dear Mr. Nusz:
Please find enclosed information regarding base flood determinations obtained through a
detailed study by IIW Engineers & Surveyors, P.C. for property in and around the City of
Dubuque's Dubuque Industrial Center West (DICW).
The City of Dubuque developed the DICW in the mid 1990s. As part of the development of
the industrial park, a substantial amount of grading was completed to create building pads
as well as made changes to the Middle Fork of the Catfish Creek as it runs through the
DICW. Currently there are portions of the industrial park, designated as a special flood
hazard area, Zone A, that the enclosed study completed by IIW Engineers & Surveyors
addresses. The City hired IIW Engineers & Surveyors to do the study in an effort to clearly
define the new limits of the special flood hazard area within the industrial park.
Attached to this letter is a letter from Dennis Waugh, professional engineer with IIW
Engineers & Surveyors, as well as a disc containing all the pertinent study data. Please
contact Associate Planner Kyle Kritz in the City's Planning Services Department if you need
additional information or clarification of information in this letter.
Sincerely,
Roy D. Buol
Mayor
Enclosures
cc: Watershed Concepts, 2405 Grand Blvd, Suite 1000, Kansas City MO 64108
Roger Benson, Consultant Coordination Officer, FEMA Region 7
Michael C. Van Milligen, City Manager
Laura Carstens, Planning Services Manager
Gus Psihoyos, City Engineer
Deron Muehring, Civil Engineer II
Kyle L. Kritz, Associate Planner
Anna O'Shea, Dubuque County Zoning Administrator/ Flood Plain Administrator
Bill Cappuccio, Iowa Department of Natural Resources
December 2, 2009
Kyle Kritz
City of Dubuque -Planning Services
50 West 13th St.
Dubuque, IA 52001805
Re: Base Flood Determination -Detailed Study
by IIVV Engineers & Surveyors, P.C.
Community: Dabuque County, Iowa (Uainwrporated Aress)
Community No. 190534
Property Address: Chavenefle Road & Synergy Coart, Dubugae, Iowa 52002
IIW Project No: 0500(x02
Dear Mr. Kritz:
IIW Engineers & Surveyors, P.C. has prepared a Detailed Engineering Study of the Middle
Fork Catfish Watershed located in Dubuque County, Iowa, Sections 22 through 27, T89N R1E
and Sections 19 and 30, T89N R2E, encompassing 5.48 square miles as mapped from USGS
quad maps. This letter is a description of the detailed study with a summary of the results.
The subject property is located along Chavenelle Road, east of Seippel Road and both sides of
Synergy Court in the Dubuque Industrial Center West, Dubuque, Iowa.
Hydrology
A HEC-HMS 3.0 model was developed for the watershed consisting of 9 subareas and 5 stream
reaches. The model used SCS Curve Number loss and transform methodology using TR55
procedures for Time of Concentration determination and the resultant Lag Time. Rainfall event
modeling used SCS Type II 24-hour distribution using rainfall amounts tabulated from the
Rainfall Frequency Atlas of the Midwest, Bulletin 71 by Huff and Angel. For calibration
purposes, the model was extended downstream to the closest County of Dubuque Flood
Insurance Study (FIS) on the Middle Fork Catfish Creek, section C in Table 4. With very
minor changes of CN numbers in some subareas, the model was calibrated to within 0.25% of
the tabulated data in the FIS using the original stream reaches without the constructed ponds.
After calibration the model was changed to include the reservoir characteristics of the two
constructed ponds. One pond, herein referred to as the Seippel Pond, is west of 5eippel Road on
a tributary that has a drainage area of 871 acres south of the main branch of the Middle Fork
Catfish Creek (MFCC). The other pond, herein referred to as the Bergfeld Pond, is located on
the main branch of MFCC at the southerly boundary of the Dubuque Industrial Center West
(DICW), just upstream of a railroad bridge over MFCC below the confluence of two major
tributaries, and has a total drainage area of 3507 acres, or 5.48 square miles. The model was run
for design storm events of 10-, 25-, 50-, I00-, and 500-years.
An actual flood event also provided a good calibration for the revised model. Heavy rainfall
during June 2002 resulted in major flooding on all the streams in Dubuque County. After this
event, 3 bridge replacements were made on the Little Maquoketa River, the next drainage basin
to the north of this basin. Using the F[S hydrology as a basis, HEC-RAS hydraulic analysis of
all three bridges were within 0.1' to 0.3' of the predicted 100-yeaz flood event using field
measured high water marks and detailed field surveys. The newly constructed Bergfeld Pond
has an emergency spillway elevation of 823.0.
IIW Engineers & Surveyors , P . C .
Dubuque, IA Hazel Grern, WI
1NTECRITY. EXPERTISE. SOLUTIONS.
Dennis F. Waugh, PEISE•
Charles A. Cate, PE
Gary D. Sejkora, PE
Michael A. Jansen, PF1SE
Ronald A. Balmer, PE/SE
John M.'fnnmer, P[S
Timothy I. Trancl, PE•
John F. Wandsnider, PE
Julie P. Neebel, PE
James P. Kaune, PE
Thoroes J. Oster, PLS
Wray A. Childers, PIS
Geofiry T. Blandin, PE
Mark C. Jobgen, PE
Lauren N. Ray, PE/SE•
Bradley 1. Mootz, PE/SE
Cody T. Austin, PE•
Marc D. Ruden, PE
Mark R. Fassbinder, AfA•
Michael A. Rudrn, AIA•
* LEED® AP
Civil Engineering
Structural Engineering
Environmental Engineering
Municipal Engineering
Transportation Engineering
Architectural Engineering
Land surveying
ConsWCtion services
4155 Pennsylvania Avenue
Dubuque, Iowa 52002-2628
(563)556-2464
(563) 556-781 F fax
www.iiwengr.com
Dubuque Industrial Center West -Base Flood Elevations
December 2, 2009
Page 2 of 3
The County Engineer, whose office is across Seippel Road from the pond, observed flow in the emergency
spillway that day, estimated less than a foot deep and going over for less than a half hour. The model's design
storm events has flow 0.08' deep for the 50-year event and 0.98' deep for the 100-year event. We believe this is
also good calibration data for the model.
Hydraulics
Hydraulic stage-discharge tables were developed for the two pond control structures (both drop inlet Reinforced
Concrete Box Culverts) using the Iowa DOT Culvert program, which is based on Hydraulic Design of Highway
Culverts, HDS 5, from the FHWA. Stage-storage data was obtained from topographic field survey for the
Bergfeld Pond, and design topography for the Seippel Road pond, which was based on field survey. This stage
storage and stage discharge data was entered into the HEC-HMS model, and the model iteratively run adjusting
culvert tailwater conditions based on previous runs until convergence was achieved.
After the HEC-HMS model was completed, flow data and field survey data was entered in HEC-RAS 3.1.2 to
develop a water surface profile model from Bergfeld Pond to just upstream of Seippel Road. This detailed water
surface profile provides the basis for flooding limits, elevations, and floodway determination with the Dubuque
Industrial Center West, for the FIS designated Zone A of the Middle Fork Catfish Creek (MFCC). The limits of
the detailed study include land adjacent to the Bergfeld Pond, the Seippel Pond, the reach of MFCC between the
Bergfeld Pond, just upstream of Seippel Road, and a tributary from the north that joints MFCC at the upstream
end of the RCB under Chavenelle Road.
Base Flood Elevations were determined from these models and are cummarimi ac f„n~...~•
Stream Reach or Reservoir BFE Ran e
Middle Fork Catfish Creek -Chavenelle to Sei l 831.6 to 833.0
North Tribu - S er Court to north a line 835.5
U stream of Sei 1 Road 836.8
Be eld Pond 824.0
Sei 1 Road Pond 833.4
Attached to this letter are related calculations and exhibits upon which the above recommendations are based.
IIW ENGINEERS & SURVEYORS, P.C.
I hereby certify that I have prepared this hydrologic and hydraulic analysis and that I am a duly licensed
Professional Engineer under the Laws of a State of Iowa.
~_..._~
Dennis Waugh, P.E. Iowa Registration No. 8909, renewal 12/31/11
Appendix of Attachments
Attachments
~~~~,
FS ~sooooe^~ p,~si`•
Dubuque Industrial Center West -Base Flood Elevations
December 2, 2009
Page 3 of 3
APPENDIX
• A -FIS Map on Chavenelle-Seippel reach -Dubuque County Community 1905345 Panels 80 and 85
• B -Watershed Map Exhibit
• C -HMS Lag Time and Runoff Worksheet
• D -HEC-HMS Calibration Model -100-year event (2 pages)
• El -HEC-HMS Revised Model - 100-year event (2 pages)
• E2 - HEGHMS Bergfeld Pond Summary Table - 100-year event
• F -HEC-RAS Chavenelle-Seippel FIS Model
• G -HEC-RAS Chavenelle-Seippel FIS WS Profile -Existing Conditions
• H -HEC-RASChevenelle-Seippel FIS WS Existing Conditions 10- to 500- Year Discharges (2 pages)
• I -HEC-RAS Chavenelle-Seippel FIS Floodway Encroachment -Method 2
• 7 -DICW -Existing Plan with Topography Sheet C 1.1
• K -DICW -Existing with Zone A and IIW Study Flood Overlay Limits Sheet C1.2
• L -North Synergy Court -Grading with IIW Study Flood Overlay Limits Sheet C 1.3
• M -,IIW Study Floodway Map -Chavenelle to Seippel Sheet C1.4
• PLAT LOTS 1-4 & 2-4 DICW-4T"
• PLAT LOTS 1 2 3 4 DICW
• PLAT LOTS 1 2 3 4 Synergy Court DICW-4Tx
• HEC-HMS model
• HEC-RAS model
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Dubuque Office of the Mayor & City Council
City Hall
1 ~' i 50 West 13~ Street
I I, Dubuque, IA 52001-4864
www.cityofdubuque.org
2007
December 21, 2009
Rick Nusz
Hydraulic Engineer
FEMA Region VII
9221 Ward Parkway Ste 300
Kansas City MO 64114
Dear Mr. Nusz:
Please find enclosed information regarding base flood determinations obtained through a
detailed study by IIW Engineers & Surveyors, P.C. for property in and around the City of
Dubuque's Dubuque Industrial Center West (DICW).
The City of Dubuque developed the DICW in the mid 1990s. As part of the development of
the industrial park, a substantial amount of grading was completed to create building pads
as well as made changes to the Middle Fork of the Catfish Creek as it runs through the
DICW. Currently there are portions of the industrial park, designated as a special flood
hazard area, Zone A, that the enclosed study completed by IIW Engineers & Surveyors
addresses. The City hired IIW Engineers & Surveyors to do the study in an effort to clearly
define the new limits of the special flood hazard area within the industrial park.
Attached to this letter is a letter from Dennis Waugh, professional engineer with IIW
Engineers & Surveyors, as well as a disc containing all the pertinent study data. Please
contact Associate Planner Kyle Kritz in the City's Planning Services Department if you need
additional information or clarification of information in this letter.
Sincerely,
Roy D. Buol
Mayor
Enclosures
cc: Watershed Concepts, 2405 Grand Blvd, Suite 1000, Kansas City MO 64108
Roger Benson, Consultant Coordination Officer, FEMA Region 7
Michael C. Van Milligen, City Manager
Laura Carstens, Planning Services Manager
Gus Psihoyos, City Engineer
Deron Muehring, Civil Engineer II
Kyle L. Kritz, Associate Planner
Anna O'Shea, Dubuque County Zoning Administrator/ Flood Plain Administrator
Bill Cappuccio, Iowa Department of Natural Resources