Digital Flood Insurance Rate Map DFIRMTO: The Honorable Mayor and City Council Members
FROM: Michael C. Van Milligen, City Manager
SUBJECT: Correspondence with FEMA regarding Digital Flood Insurance Rate Map
(DFIRM)
DATE: November 12, 2009
Planning Services Manager Laura Carstens is recommending approval of a letter to the
Federal Emergency Management Agency requesting changes to the Digital Flood
Insurance Rate Map (DFIRM) and stating that the City of Dubuque will not provide
additional GIS data requested by FEMA for the North End.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
Michael C. Van Milligen
MCVM:jh
Attachment
cc: Barry Lindahl, City Attorney
Cindy Steinhauser, Assistant City Manager
Laura Carstens, Planning Services Manager
THE CITY OF Dubuque
I~~LTB E i
~~
Masterpiece on the Mississippi °
200
TO: Michael Van Milligen, City Manager ~~~
FROM: Laura Carstens, Planning Services Manager ~`~5'~,-
SUBJECT: Correspondence with FEMA regarding DFIRM
DATE: November 12, 2009
INTRODUCTION
This memorandum transmits a draft letter from Mayor Buol to FEMA (Federal Emergency
Management Agency) requesting changes to the preliminary DFIRM (Digital Flood Insurance
Rate Map), and stating that the City of Dubuque will not provide additional GIS data requested
by FEMA for the North End. A set of talking points for our federal and state legislators is
enclosed. A map depicting the changes from the current to the new flood maps is enclosed also.
DISCUSSION
Previously, the City transmitted a GIS shape file prepared by engineering consultant HDR, who
worked with the City on the Drainage Basin Master Plan. The shape file reflected the area of
the North End within the new Zone A proposed by FEMA. The GIS shape file also reflected the
existence of the Carter Road detention basin completed in 2004 and the West 32"d Street
detention basin completed this spring. The accompanying project summary outlined the
engineering models and techniques used to establish the predicted storm water flooding limits.
City Engineering and Planning Services staff discussed this information with FEMA
representatives and their engineering consultants during a conference call on October 22, 2009.
We had anticipated that the provision of this information would help in the removal of some of
the properties from the regulated flood plain proposed for the North End. Unfortunately, this
does not appear to be the case. FEMA has requested that the City provide additional GIS data
from the Drainage Basin Master Plan to establish a Zone A boundary.
The City's Drainage Basin Master Plan was intended to address long standing issues with urban
storm sewer conveyance problems in this area of the community -not flooding associated with
a creek or river. These types of urban storm water problems are common throughout the U.S.
The history of localized street flooding and basement flooding experienced in the North End
does not rise to the level of being designated as a regulatory flood plain.
This data request from FEMA has been discussed by staff in the Engineering, Planning
Services, Legal and City Manager's Offices. City staff recommends that the City not provide any
further data to FEMA. We feel that we will have to appeal the DFIRM, and we do not want to be
in the unenviable position of appealing our own data.
Correspondence with FEMA regarding DFIRM
Page 2
FEMA has indicated that if the City does not provide the data, then FEMA will use the best
available data to determine a flood hazard area and it may be larger than our GIS shape file
may indicate. Our concern, however, is that any flood hazard area shown in the North End is a
mistake and recommend the City continue to ask FEMA to remove this area from the DFIRM.
The enclosed letter to FEMA states that the City is unable to supply any relevant data for the
DFIRM. The data we have supplied to date relates to our planning studies of the risk of flooding
due to capacity issues for the storm water management system in the North End. This data
does not constitute an engineering study to determine a regulatory flood plain, and we oppose
FEMA's use of this data to establish a Zone A in the North End.
The letter goes on to state that the City believes that the new Zone A shown on the preliminary
DFIRM is an error, is not supported by FEMA's Flood Insurance Study (FIS) Report for
Dubuque County, and was established using rudimentary, regression analysis which is
inappropriate for designating a flood hazard area. The letter contains additional remarks about
the history of and impacts to the North End, the City's participation in the National Flood
Insurance Program, the findings in previous and current FIS Reports for Dubuque, and the lack
of standard engineering analysis for determining the new Zone A areas. The letter requests the
removal of the new Zone A areas for these reasons.
City staff has discussed alerting our federal and state legislators to the situation we face. In
contacting other cities in Iowa, we have learned that Dubuque appears to be the only city facing
a significant increase of structures in the flood plain, from 70 to over 1,700. A series of talking
points to be shared with our federal and state legislators and their staff is enclosed.
The Iowa Department of Natural Resources (IDNR) is the state agency that has oversight for
flood plain management. The IDNR must review and approve all FIS Reports and flood studies
that will be used for regulating flood plain development. This review is to ensure that: an
adequate study was performed, IDNR's study standards are followed, different studies on the
same stream are consistent, and all map revisions to reflect stream modifications and flood
control structures are based on projects that have been approved by IDNR. IDNR potentially
could be enlisted to support our position if they agree with the City of Dubuque.
RECOMMENDATION
City staff recommends transmittal of the enclosed letter from Mayor Buol to FEMA requesting
removal of the proposed Zone A flood plain boundary delineations on the preliminary DFIRM,
and approval to share the enclosed talking points and map with our federal and state legislators.
Enclosures
cc: Gus Psihoyos, City Engineer
Deron Muehring, Civil Engineer II
Kyle L. Kritz, Associate Planner
Tim O'Brien, Assistant City Attorney
Teri Goodmann, Assistant City Manager
Office of the Mayor & City Council
THE CITY OF Dubuque City Hall m
50 West 13 Street
D V L E Dubuque,lA 52001-4864
,AFA~Ia i www.cityofdubuque.org
I I.
Mcisterpiece on the Mississippi Zoos
November 12, 2009
Rick Nusz
Hydraulic Engineer
FEMA Region VII
9221 Ward Parkway Ste 300
Kansas City MO 64114
Dear Mr. Nusz:
This letter is in response to your request for the City of Dubuque to provide data for the
Zone A covering a large portion of the North End of Dubuque on FEMA's preliminary
DFIRM (Digital Flood Insurance Rate Map).
The City of Dubuque is not comfortable supplying any additional data related to the area
currently designated as a Zone X that might be used to increase the size of the
proposed new Zone A shown in the City's North End. As indicated in previous
correspondence, the City believes that the new Zone A shown on the preliminary
DFIRM is unfounded as the storm water drainage issues are related to basement
flooding due to storm sewer and street storm water conveyance capacity limitations.
North End History and Impacts
The North End is laid out in a traditional grid street system and has been fully developed
for approximately 100 years. With the construction of the original Bee Branch storm
sewer system, many of the problems associated with storm water were resolved;
otherwise, the area would not have fully developed in its present configuration. The
historical records since the construction of the Bee Branch Storm sewer system would
suggest the only problems have been associated with storm water creating relatively
minor street flooding and water in basements. The City's latest project to rebuild the
Bee Branch storm sewer system addresses problems associated with the age of the
system and additional storm water created by development in upland areas since the
original Bee Branch storm sewer was constructed.
It is very typical for cities to design their storm sewer systems to handle the 10-year
storm. Obviously, this can be exceeded from time to time in any given year; in those
instances streets are asked to carry this additional flow. The fact that cities' storm
sewer systems can be overwhelmed by particular storm events and there is street
flooding does not render all those areas throughout the United States as being in a
regulated flood plain. Many streets in Dubuque actually have curbs that are nearly two
feet in height to allow the street to carry more storm water.
Letter to Rick Nusz, FEMA
November 17, 2009
Page 2
From the time that the City's Drainage Basin Master Plan (DBMP) was completed in
2001, the City has never indicated that there are 1,150 properties in the 100-year flood
plain. The City has simply indicated that there are 1,150 properties at risk of flood
damage during heavy rains. While the DBMP findings were based on sophisticated
models (the US Army Corps of Engineers' HEC-HMS and the US EPA's SWMM
models), it was not the intent to identify a flood plain -only quantify/qualify a drainage
issue and present potential solutions. The City has already started implementing the
solutions with the last to be completed in 2013.
The proposed designation of the North End of Dubuque as a Zone A would increase the
number of structures over 500 square feet located in special flood hazard areas from
approximately 70 to approximately 1,741. The most significant impact of having a
property in a flood plain is that new construction, new additions, and even existing
structures, which may be undergoing rehabilitation, may have to be elevated or flood
proofed as part of any substantial improvement to a property. In Zone A, where there
are no base flood elevations, an engineer must be hired to determine the base flood
elevation, in order to determine how high an addition or new structure must be elevated.
The area proposed for inclusion in the new Zone A on the North End of Dubuque
includes some of the City's oldest housing stock (dating from the late 1800s) and long-
standing businesses and industries. These neighborhoods have a higher percentage of
low to moderate income households and racial and ethnic minorities than the City as a
whole.
The City of Dubuque has focused reinvestment efforts in these neighborhoods for many
years and has installed upstream storm water management facilities to alleviate
problems with the storm water system. The delineation of these neighborhoods as a
Zone A flood hazard area will reverse the progress the City has made. The Zone A
designation will result in neighborhood disinvestment and blighting conditions.
Placing this burden on approximately 1,400 low to moderate income households in the
new Zone A is unacceptable. The burden to determine base flood elevations (BFEs)
must rest with FEMA and not the citizens of Dubuque if FEMA is determined to
designate this area as a special flood hazard area because of storm water issues.
National Flood Insurance Program in Dubuaue
The City of Dubuque was the first community in Iowa to join the National Flood
Insurance Program (NFIP) on April 2, 1971. The City's current flood maps were revised
in September 1989. These maps updated a previous set from the 1970s. The North
End of Dubuque was not shown as a special flood hazard area in either of the two
previous FIRM maps.
The City of Dubuque has been very conscientious in its application of the NFIP
requirements. The City has never approved a variance from the NFIP requirements.
The City has not allowed a single new residential structure to be built in any Special
Letter to Rick Nusz, FEMA
November 17, 2009
Page 3
Flood Hazard Area (SFHA). The only new structures built in SFHAs have been
commercial structures that have been elevated and/or flood proofed in compliance with
NFIP requirements.
Inaccuracies of Preliminary DFIRM
The inaccuracies that City staff found in the preliminary DFIRM maps will make it
difficult to enforce NFIP requirements in areas newly designated as a SFHA. The
preliminary DFIRM shows flooding heights on Kaufmann Avenue such that vehicles
would be submerged, when the 100+ year history that shows no such flooding having
ever occurred. This error will make citizens question the validity of the new maps, and
rightly so.
The City of Dubuque cannot stress enough the far reaching negative impacts to the
North End that designation as a Zone A will have. If this area had a history of flood
damage, the City would not question its designation as a special flood hazard area;
however, the written record of over 100 years does not support such a designation.
Flood Boundary Methodology
The accuracy of the preliminary DFIRM also calls into question the methodology used to
establish the flood boundaries initially. In the conference call of October 22, 2009 with
FEMA, City staff and AECOM /Watershed Concepts staff, it was stated that FEMA did
not use a standard model for the new Zone A areas. The Nebraska model, INSECT,
was used. This model depicts normal depth at cross sections. You confirmed that FEMA
was using Iowa regression analysis. It was further discussed at the conference call that
FEMA was using new modeling, and it was not done to an engineering standard that
would enable elevations to be published. You stated that FEMA has limited funding to
do an engineering study that would determine BFEs. Therefore, this burden will be
placed on citizens in the City of Dubuque who have the least means; the City finds this
unacceptable.
If FEMA does not have the funding to do an engineering study, using sufficiently
sophisticated models to produce BFEs, then no new Zone A areas should be mapped.
By failing to do more than a rudimentary planning study, FEMA fails to provide the BFEs
needed for the City to regulate development in the North End. The Zone A in the North
End, in particular, will create neighborhood disinvestment. It also will subject low and
moderate income households to costly flood insurance that they cannot afford, further
acerbating disinvestment in this historic neighborhood.
The shallow flooding experienced in the new Zone A areas on the preliminary DFIRM is
due to local drainage problems with the capacity of the City's storm sewer system.
These areas do not rise to the level of a regulatory flood plain, and should not be
mapped as A Zones by FEMA. Increasing our inventory of structures in the flood plain
from 70 to over 1,700 through non-standard mapping would be a mistake.
Letter to Rick Nusz, FEMA
November 17, 2009
Page 4
Flood Insurance Studv
By definition, a Flood Insurance Study (FIS) Report is an appraisal of a community's
flood problems, including historic floods. The City of Dubuque's FIS Report from FEMA,
revised on September 6, 1989, does not mention any flooding hazards in the North End.
The July 2009 FIS Report for Dubuque County and incorporated areas provided by
FEMA to the City of Dubuque earlier this year does not mention any flooding hazards in
the North End. On page 4, the 2009 FIS Report indicates the 1989 FIS Report for the
City of Dubuque is a reference document. On Page 5, the 2009 FIS Report described
the Scope of Study for the area studied. The report states, "the areas studied were
selected with priority given to all known flood hazard areas and areas of projected
development or proposed construction." The City of Dubuque is not included in the
following section entitled Community Description on pages 6-9. The City of Dubuque is
not listed in the next section, Principal Flood Problems, on pages 9-11.
On page 12, the City of Dubuque is identified as having no flood protection measures in
existence or proposed. The City has a floodwall and levee system along its Mississippi
Riverfront that provides protection from the 100-year and 500-year flood events.
Shouldn't this levee system be acknowledged in the 2009 FIS Report?
The 2009 FIS Report lists Engineering Methods for hydrologic analyses (pages 13-17)
and hydraulic analyses (pages 18-23). The North End is not mentioned in either of
these analytical descriptions with respect to flooding.
The 2009 FIS Report describes flood plain management applications on pages 23-25.
This section speaks to streams with respect to regulated flood plains, floodways, and
floodway fringes. Urban storm water in the North End of Dubuque is never mentioned
in this context.
Conclusion ,
The point of the NFIP is for communities to regulate floodplain development. In
Dubuque, we have an excellent record of flood plain management. The Zone A areas
shown on the preliminary DFIRM are not supported by the FIS Reports, and therefore
including them in the DFIRM would be a mistake that would burden low and moderate
income households with costly flood insurance that they cannot afford, further
acerbating disinvestment in their historic neighborhoods. The new Zone A areas should
be removed entirely from the City of Dubuque's DFIRM before the FEMA public
meeting, for the benefit of everyone.
Sincerely,
Roy D. Buol
Mayor
Request to FEMA to change the City of Dubuque's preliminary DFIRM
(Digital Flood Insurance Rate Map)
Introduction
The City of Dubuque is requesting that the Federal Emergency Management Agency (FEMA)
remove new flood areas from the preliminary DFIRM (Digital Flood Insurance Rate Map).
Without the use of standard engineering computer models, FEMA has proposed a DFIRM that
would significantly expand the number of properties in the city designated as being in a
regulated flood plain from 70 structures to over 1,700 structures! Adoption of the
proposed DFIRM would place a heavy financial burden on approximately 1,400 low to
moderate income households resulting in neighborhood disinvestment and decline.
Background
On July 15, 2009, the City of Dubuque received the preliminary DFIRM and the FIS (Flood
Insurance Study) Report as part of FEMA's Flood Map Modernization Program. The program is
designed to update on a nationwide basis the flood insurance rate maps of member
communities and counties in the National Flood Insurance Program (NFIP).
The City of Dubuque was the first community in Iowa to join the NFIP on April 2, 1971. The
City's current flood insurance rate map is from 1989. The City has regulated floodplain
development since 1990. The City of Dubuque has been very conscientious in its application of
the NFIP requirements. The City has never approved a variance from the NFIP requirements.
The City has not allowed a single new residential structure to be built in any flood hazard area.
The only new structures built in flood hazard areas have been commercial structures elevated
and/or flood proofed in compliance with the NFIP requirements.
Discussion
Enclosed is a map that indicates new flood zones for Zone A (no base flood elevations
determined) and Zone AE (base flood elevations determined) proposed by FEMA. These zones
mark the 100-year flood plain. In addition, this map shows the 500-year flood plain and Zone X.
Zone X is areas outside the 500-year flood plain and areas protected by the City's floodwall.
General Impact on Properties
The most significant impact of having a property in a flood plain is that new construction, new
additions and even the existing structures may have to be elevated or flood proofed as part of
any substantial improvement to a property. In Zone A, base flood elevations (BFEs) haven't
been determined, so the property owner first must hire an engineer to determine the BFEs in
order to determine how high an addition or a new structure must be elevated.
Flood insurance will be required by a commercial lender if the property owner refinances an
existing structure or buys a structure in a flood plain. Flood insurance for properties in a flood
plain is higher than flood insurance for properties outside a flood plain. For example, flood
insurance for a single family home with a value of $75,000 and contents valued at $30,000
would cost about $260 annually outside a flood area. This insurance rises to about $844
annually for the same home in a designated flood area -and this assumes a $2,000 deductible
for both home and contents!
Concerns with New North End Flood Zones
We are concerned with all of the new Zone A areas on the DFIRM. We are particularly
concerned about the new Zone A in the North End. The North End includes some of the city's
oldest housing (dating from the late 1800's) and long-standing businesses and industries. These
neighborhoods have a higher percentage of low to moderate households and racial and ethnic
minorities than the city as a whole.
Request to FEMA to change the City of Dubuque's preliminary DFIRM
(Digital Flood Insurance Rate Map)
The City has focused reinvestment efforts in these neighborhoods, and installed upstream storm
water management facilities to alleviate problems with the storm water system. Delineation of
these neighborhoods as a Zone A flood hazard area will reverse the progress we've made. The
Zone A designation will result in neighborhood disinvestment and blighting conditions.
Placing this burden on 1,400 property owners in the new Zone A areas is unacceptable.
Inadeauate Studv
The large Zone A for the North End reflects the City's Drainage Basin Master Plan findings on
flooding related to the Bee Branch storm sewer. The City's Drainage Basin Master Plan was
intended to address storm sewer conveyance problems -not flooding associated with a creek
or river. These types of urban storm water problems are common throughout the U.S. The
history of localized street flooding and basement flooding experienced in the North End does not
rise to the level of being designated as a regulatory flood plain.
The City's Drainage Basin Master Plan is a planning study; it did not detail precisely which
structures would be impacted. It identifies a generalized area that appears to be at risk from
storm sewer backups or overflows. We believe that FEMA is identifying a storm sewer problem
rather than a flooding issue connected with a flood plain along a stream or river.
City staff provided FEMA with data and information on planned drainage basin improvements
like the Bee Branch Creek Restoration Project as well as storm water improvements such as the
Carter Road dam and 32"d Street detention areas that address existing storm water issues.
City staff held a conference call with FEMA staff and their engineering consultants on October
22, 2009. FEMA staff acknowledged they did not use a standard model for the new Zone A
areas. They discussed that FEMA was using new modeling, and it was not done to an
engineering standard that would enable BFEs to be published. FEMA has limited funding to do
an engineering study that would determine BFEs.
We hoped this information would help remove properties from the flood plain proposed for the
North End. Unfortunately, it appears that FEMA will map the North End without adequate study.
If FEMA does not have the funding to do an engineering study correctly, using sufficiently
sophisticated models to produce BFEs, then no new flood areas should be mapped. The
burden of determining the base flood elevations (BFEs) must rest with FEMA, not the
citizens of Dubuque. The City of Dubuque requests that FEMA show all new Zone A areas
with BFEs determined, so that they are converted to Zone AE areas on the DFIRM - if in fact
these even are special flood hazard areas.
The shallow flooding experienced in the new Zone A areas on the preliminary DFIRM is due to
local drainage problems with the capacity of the City's storm sewer system. These areas do not
rise to the level of a regulatory flood plain, and should not be mapped as Zone A by FEMA.
Increasing Dubuque's inventory of structures in the flood plain from 70 to over 1,700
through non-standard mapping would be a mistake as it would place a heavy financial
burden on approximately 1,400 low to moderate income households resulting in
neighborhood disinvestment and decline.
If you have questions or need additional information, please contact Laura Carstens,
Community Flood Plain Administrator at 563.589.4210 or IcarstenCa~cityofdubugue.org.
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