Drainage Basin Master Plan 2013 AmendmentTHE CITY OF
Dui
Masterpiece on the Mississippi
TO: The Honorable Mayor and City Council Members
FROM: Michael C. Van Milligen, City Manager
SUBJECT: Drainage Basin Master Plan, 2013 Amendment
DATE: November 12, 2013
Dubuque
band
AI- America City
11111r
2007 • 2012 • 2013
In 1996, the City of Dubuque, through the Capital Improvement Project Budget,
committed to developing a City -wide stormwater management plan. The need for the
plan arose from a growing number of citizen complaints related to stormwater runoff and
the significant amount of damage to hundreds of homes in a major rainstorm in May
1999. Increasing public safety and reducing property damage are the primary goals of
the stormwater management plan.
In 1997, the City Council approved the selection of HDR Engineering, Inc. of Omaha,
NE, to develop a stormwater management plan.
In 2001, HDR Engineering, Inc. completed a Drainage Basin Master Plan for the City of
Dubuque, Iowa. The master plan evaluated flood mitigation strategies for the Bee
Branch watershed and the North Fork Catfish Creek watershed. The Drainage Basin
Master Plan identified and recommended various projects to address the recurring
flooding and property damage that first manifested itself in 1999.
A drainage basin master plan considers the entire watershed. When drainage
modifications are made in a watershed, it will affect, for better or worse, the drainage of
the entire watershed. The Drainage Basin Master Plan ensures that efforts to solve
stormwater flooding problems are cost - effective and mitigate flooding as intended,
without creating new flooding problems elsewhere.
In December of 2001, the City Council adopted the Drainage Basin Master Plan
prepared by HDR.
Since 2001, the City has implemented many of the improvements outlined in the
Drainage Basin Master Plan. But since 2001 several intense storm events have
occurred in the Dubuque metropolitan area so that revisiting the predicted hydrology
and hydraulic behavior of the drainage basins is appropriate. Based on the expected
rainfall totals understood in 2001, there have been three 100 -year storms, two 50 -year
storms, one 25 -year storm, and one 10 -year storm in the past twelve years. Finally, it is
important to consider how additional flood mitigation efforts undertaken by the City since
2001 fit with the overall effort to mitigate flooding. Therefore, HDR Engineering, Inc.
began the process of updating /amending the Drainage Basin Master Plan in the fall of
2012.
The Drainage Basin Master Plan adopted in 2001 focused on two watersheds: the Bee
Branch Watershed and the North Fork of the Catfish Creek Watershed. More than half
of Dubuque residents live in these two watersheds with thousands more who travel to
work within the watersheds. These two watersheds, which encompass one third of the
City by area, have been repeatedly hit the hardest by flooding. Therefore, the
improvements to mitigate flooding identified in 2001 were located within these two
watersheds.
The 2013 Drainage Basin Master Plan Amendment does not replace the 2001 Drainage
Basin Master Plan. Instead, it builds upon its foundation. While many of the
improvements outlined in the amendment are again concentrated within the Bee Branch
Watershed, the 2013 Amendment starts to look outside the North Fork Catfish Creek
and Bee Branch Watersheds, and begins to consider areas seemingly protected from
the Mississippi River by the City's floodwall /levee system.
The Catfish Creek Watershed Management Authority was formed in 2012. It is
comprised of representatives from the City of Dubuque, Dubuque County, the City of
Asbury, the City of Peosta, the City of Centralia, and the Dubuque Soil and Water
Conservation District. The purpose of the Catfish Creek Watershed Management
Authority is to work together to solve water quality and flooding problems within the
watershed. Through the development of a Watershed Management Plan for the entire
Catfish Creek Watershed, it is expected that improvements within the Catfish Creek
Watershed will be proposed and possibly administered through the Catfish Creek
Watershed Management Authority.
Multiple Bee Branch Watershed improvements are recommended.
Civil Engineer Deron Muehring recommends City Council adoption of the 2013
Amendment to the Drainage Basin Master Plan.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
MCVM:jh
Attachment
Michael C. Van Milligen
2
cc: Barry Lindahl, City Attorney
Cindy Steinhauser, Assistant City Manager
Teri Goodmann, Assistant City Manager
Deron Muehring, Civil Engineer
Gus Psihoyos, City Engineer
3
THE CITY OF
DuB
E
Masterpiece on the Mississippi
TO: Michael C. Van Milligen, City Manager
FROM: Deron Muehring, Civil Engineer)
DATE: November 12, 2013
SUBJECT: Drainage Basin Master Plan, 2013 Amendment
Dubuque
All_AmeticaC ly
II �r
2007 • 2012 • 2013
INTRODUCTION
The purpose of this memorandum is to request adoption of the 2013 Amendment to the
Drainage Basin Master Plan.
BACKGROUND
In 1996, the City of Dubuque, through the Capital Improvement Project Budget,
committed to developing a City -wide stormwater management plan. The need for the
plan arose from a growing number of citizen complaints related to stormwater runoff and
the significant amount of damage to hundreds of homes in a major rainstorm in May,
1999. Increasing public safety and reducing property damage are the primary goals of
the stormwater management plan.
In 1997, the City Council approved the selection of HDR Engineering, Inc. of Omaha,
NE (HDR) to develop a stormwater management plan.
In 2001, HDR Engineering, Inc. (HDR) completed a Drainage Basin Master Plan
(DBMP) for the City of Dubuque, Iowa. The master plan evaluated flood mitigation
strategies for the Bee Branch watershed and the North Fork Catfish Creek watershed.
The DBMP identified and recommended various projects to address the recurring
flooding and property damage that first manifested itself in 1999.
A drainage basin master plan considers the entire watershed. When drainage
modifications are made in a watershed, it will affect, for better or worse, the drainage of
the entire watershed. The Drainage Basin Master Plan ensures that efforts to solve
stormwater flooding problems are cost - effective and mitigate flooding as intended
without creating new flooding problems elsewhere.
In December of 2001, the City Council passed Resolution 549 -01 adopting the Drainage
Basin Master Plan prepared by HDR.
DISCUSSION
Since 2001, the City has implemented many of the improvements outlined in the
Drainage Basin Master Plan. But since 2001 several intense, storm events have
occurred in the Dubuque metropolitan area so that revisiting the predicted hydrology
and hydraulic behavior of the drainage basins is appropriate. Based on the expected
rainfall totals understood in 2001, there have been three 100 -year storms, two 50 -year
storms, one 25 -year storm, and one 10 -year storm in the past twelve years. Finally, it is
important to consider how additional flood mitigation efforts undertaken by the City since
2001 fit with the overall effort to mitigate flooding. Therefore, HDR Engineering, Inc.
began the process of updating /amending the Drainage Basin Master Plan in the fall of
2012.
The Drainage Basin Master Plan adopted in 2001 focused on two watersheds: the Bee
Branch Watershed and the North Fork of the Catfish Creek Watershed. More than half
of Dubuque residents live in these two watersheds with thousands more who travel to
work within the watersheds. These two watersheds, which encompass one third of the
City by area, have been repeatedly hit the hardest by flooding. Therefore, the
improvements to mitigate flooding identified in 2001 were located within these two
watersheds.
The 2013 Drainage Basin Master Plan Amendment (2013 Amendment) does not
replace the 2001 Drainage Basin Master Plan. Instead, it builds upon its foundation.
And while many of the improvements outlined in the amendment are again concentrated
within the Bee Branch Watershed, the 2013 Amendment starts to look outside the North
Fork Catfish Creek and Bee Branch Watersheds, begins to consider areas seemingly
protected from the Mississippi River by the City's floodwall /levee system.
North Fork Catfish Creek Watershed Improvements
Within the North Fork Catfish Creek Drainage Basin, conveyance and detention
improvements were defined in the 2001 DBMP. Detention was expanded and improved
at Northwest Arterial and upstream of Pennsylvania Avenue. In addition, conveyance
improvements were implemented along the North Fork Catfish Creek between the
Northwest Arterial and Pennsylvania Avenue. The 2013 Amendment does not identify
any additional improvements within the North Fork Catfish Creek Drainage Basin.
The Catfish Creek Watershed Management Authority (CCWMA) was formed in 2012. It
is comprised of representatives from the City of Dubuque, Dubuque County, the City of
Asbury, the City of Peosta, the City of Centralia, and the Dubuque Soil and Water
Conservation District. The purpose of the CCWMA is to work together to solve water
quality and flooding problems within the watershed. Through the development of a
Watershed Management Plan for the entire Catfish Creek Watershed, it is expected that
improvements within the Catfish Creek Watershed will be proposed and possibly
administered through the CCWMA.
Bee Branch Watershed Improvements
Within the Bee Branch Drainage Basin, conveyance and detention improvements were
outlined in the 2001 DBMP. Detention has been provided along Carter Road and the
pre- existing West 32nd Street Detention Basin was expanded. In the 2001 DBMP, it
was proposed that a portion of the existing Bee Branch storm sewer trunk line that runs
between 15th Street and W. 32nd Street be replaced with an open channel. This channel,
or open waterway, would begin at the 16th Street Detention CeII, located near the
Page 1 2
Mississippi River, and would proceed upstream to 24th Street. A phased approach
separated the Bee Branch storm sewer into "Lower" and "Upper" creek restoration
segments. The Lower Bee Branch Creek Restoration extends from the 16th Street
Detention Cell to the Canadian Pacific Railway (CP Railway) and the Upper Bee Branch
Creek Restoration extends from the CP Railway crossing north, terminating around 24th
Street.
The 2013 Drainage Basin Master Plan Amendment incorporates the refined engineering
and design work associated with the development of the Carter Road and W. 32nd
Street Detention Basins, as well as, the Bee Branch Creek Restoration. It also outlines
additional improvements within the Bee Branch Watershed, some to address localized
flooding and some to augment the overall plan to prevent the repeated, extreme flash
flooding experienced in the Bee Branch Watershed over the past dozen years.
22nd Street Storm Sewer Improvements
The shortcoming of the existing 22nd Street storm sewer /street drainage system is that
22nd Street becomes "like a river" across Central Avenue (US Highway 52), White,
Jackson, and Washington Streets. Motorists have become stranded in their cars at
22nd and Elm Streets, while other motorists have been forced to abandon their stalled
cars in the street. Floodwaters have repeatedly overloaded the storm sewer system and
blown the covers off manholes, creating geysers several feet high.
Since 2001, the H &H modeling for the Kaufmann Avenue Drainage Subarea has been
refined as part of the 2004 Bee Branch Creek Alignment Study and further refined
during development of the final design of the Bee Branch Creek Restoration Project. At
an estimated cost of $3.2 million, a 10- foot -wide by 6 -foot high reinforced concrete box
(RCB) storm sewer along 22nd Street from Central Avenue (US Highway 52) to EIm
Street is recommended to prevent flooding conditions repeatedly experienced along
22nd Street.
17th Street Storm Sewer Improvements
The 2001 DBMP identified locations where the existing storm sewer hydraulic capacity
was lacking. A problem area was identified at the base of Locust and 17th Streets. The
grade flattens along the street and storm sewer at this intersection, creating flooding in
this area. In addition, stormwater flows rapidly down 17th Street. The flow must cross
Central Avenue (US Highway 52), and White, Jackson, and Washington Streets. The
2013 Amendment recommends replacement storm sewer be constructed in the area of
Locust and 17th Streets to provide additional conveyance capacity for the downstream
portion of the Locust Street Drainage Subarea. The storm sewer would be constructed
from Dorgan Place to approximately EIm Street, discharging into the Bee Branch Creek
Restoration Project. Construction of the storm sewer will require the complete
reconstruction of 17th Street and utilities located along the corridor. The estimated cost
of the work is estimated to be $6.8 million.
Page 1 3
North End Storm Sewer Improvements
Repetitive flooding occurs in the "North End" of the Washington Street Subarea
between White and Elm Streets on 25th to 30th Streets during heavy rains due to
inadequate drainage capacity. With the completion of the Lower Bee Branch Creek
Restoration Project, the need for additional storm sewer and catch basins in the vicinity
of the existing Bee Branch storm sewer trunk line can be further refined. With the
construction of the Bee Branch Creek Restoration, improvements to the North End
storm sewer will provide increased capacity and reduce flooding of streets and adjacent
properties. These improvements include replacing and upsizing the lateral storm sewers
along the Bee Branch trunk line. The North End Storm Sewer improvements would be
along 25th, 26th, 27th, 28th, 29th, and 30th Streets between White and Elm Streets.
The estimated cost to upgrade the storm sewer systems along 25th, 26th 27th 28th 29th
and 30th Streets is $1 million.
16th Street Flood Gate Improvements
The flood control gates and pump station located at the 16th Street Detention Cell
where floodwaters exit the Bee Branch Watershed and flow into the Mississippi River
are in need of rehabilitation. The flood gates were installed in the 1950s and modified by
the U.S. Army Corps of Engineers (USACE) in the late 1960s as part of the construction
of the John C. Culver Floodwall, the floodwall /levee system that protects the City from
the Mississippi River. During gravity flow, the twin 12- foot -wide by 12- foot -high flood
gates are open; conversely, during flood events, the flood gates are closed to prevent
the Mississippi River from flooding the landward side of the levee. The 2013
Amendment outlines an alternative flood gate design that would allow interior
floodwaters to pass into the Mississippi River when the gates are closed and a positive
hydraulic gradient occurs. Essentially, when the depth of floodwaters on the City side of
the gate exceed the depth of floodwaters in the Mississippi River, floodwaters from the
City will automatically begin to flow into the Mississippi. The estimated cost to replace
the existing gate structure with the enhanced design is $2.2 million.
Impervious Area Reduction (Pervious Pavement Systems)
Pervious pavement reduces localized flooding and can significantly reduce negative
downstream impacts by decreasing the volume of runoff and runoff rate, both of which
contribute to the flash flooding experienced within the Bee Branch Watershed. Pervious
pavement conveys runoff into the ground closer to where it originates. Compared to
conventional pavements, pervious pavement systems convey stormwater into the
ground instead of shedding it quickly to downstream properties. The 2013 Amendment
recognizes the replacement of an impervious street system with a pervious street
pavement system in the Historic Millwork District. It also recognizes the conversion of
eight (8) alleys within the Bee Branch Watershed to pervious pavement systems and
the plan to reconstruct 73 additional. Bee Branch Watershed alleys over a 3 -year period
so that a third of the alleys in the Bee Branch Drainage Basin will have been converted
to systems that convey stormwater into the ground. Finally, the 2013 Amendment
recommends converting all 240 alleys within the Bee Branch Watershed to pervious
pavement systems. Once complete, the pervious pavement systems will reduce the
runoff volume to the Mississippi River by approximately 50 percent. On an annual basis,
Page 14
conversion of the alleys into pervious pavement systems will result in approximately 2.5
million gallons of stormwater to be conveyed into the ground versus being quickly shed
to the flood prone area in the Bee Branch Watershed. The 2013 Amendment
recommends converting the alleys over a 20 -year period or as funding is available. The
cost to convert the alleys to pervious pavement systems, provide safety and security
and to relocate /reconstruct underground utilities is estimated to be $43.3 million.
Other Flood Mitigation Improvements
Water Treatment Plant Floodproofinq
The plant supplies potable water to Bee Branch Drainage Basin residents and
businesses. It also provides a sufficient quantity and the necessary pressure for fire
protection and suppression. Due to the possible loss of fire fighting capabilities and
potable drinking water as the result of a flood either as a result of interior drainage
flooding or a breach /failure of the John C. Culver Floodwall, the 2013 Amendment
recommends that the facility be provided its own floodwall protection system. The
estimated cost to construct the floodwall system around the perimeter of the potable
water treatment facility is $3.4 million.
Levee Breach Breach /Failure Analysis
In addition to the projects identified within the Bee Branch Drainage Basin, additional
improvements associated with the federally constructed, City operated and maintained
John C. Culver Floodwall may be appropriate. The levee /floodwall system reduces the
risk of Mississippi River flooding in portions of the City. Two projects have been
identified for the John C. Culver Floodwall include a levee breach analysis and a levee
functional assessment.
Knowing the affects of a levee breach or failure is a component of understanding a
levee system's risk. An evaluation of the affects of a possible Mississippi River levee
breach along the City's levee system is necessary to understand the likelihood and the
consequences of a levee failure. Mitigation strategies can then be developed to avoid or
minimize the impacts of a potential levee failure. The results of a levee breach analysis
can be used to supplement a flood risk management plan in order to promote public
safety.
The John C. Culver Floodwall was constructed by the US Army Corp of Engineers
(USACE) between 1968 and 1973. Since the construction of the levee /floodwall system,
numerous physical modifications and technical advances have occurred. The 2013
Drainage Basin master Plan recommends an assessment be conducted to recognize
the current levee's level of flood risk reduction and compliance with current criteria and
conditions. This information will help the City to determine what, if any, design and
operational modifications need to be incorporated to the John C. Culver Floodwall.
RECOMMENDATION
I recommend adopting the 2013 Drainage Basin Master Plan Amendment.
Page 1 5
BUDGET IMPACT
Adoption of the 2013 Drainage Basin Master Plan Amendment (2013 Amendment) does
not impact the budget directly. While the 2013 Amendment outlines several capital
improvements, the budget impact will be related to when individual improvements are
programmed into a Capital Improvement Program Budget.
REQUESTED ACTION
I respectfully request adoption of the attached resolution adopting the 2013 Drainage
Basin Master Plan Amendment prepared by HDR Engineering, Inc.
Prepared by Deron Muehring, Civil Engineer
attach.
Cc: Barry Lindahl, City Attorney
Gus Psihoyos, City Engineer
Don Vogt, Public Works Director
Page 16
Prepared by: Deron Muehring, City Hall, 50 W 13th Street, Dubuque IA 52001 563 - 589 -4270
RESOLUTION NO. 335 -13
ADOPTING THE CITY OF DUBUQUE 2013 DRAINAGE BASIN MASTER PLAN
AMENDMENT
Whereas, the City of Dubuque (City) is committed to developing a stormwater
management master plan; and
Whereas, the City of Dubuque retained the firm of HDR Engineering, Inc. (HDR) to
produce a drainage basin master plan; and
Whereas, the City Council of the City of Dubuque adopted a drainage basin master
plan authored by HDR in 2001; and
Whereas, the City of Dubuque hired HDR in 2012 to amend the drainage basin
master plan; and
Whereas, the HDR has authored the 2013 Drainage Basin Master Plan Amendment
(2013 Amendment); and
Whereas, the 2013 Amendment does not replace but augments the Drainage Basin
Master Plan adopted in 2001; and
Whereas, the 2013 Amendment addresses flooding problems and issues in the City
of Dubuque and recommends certain public improvements to implement the plan.
NOW THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF
DUBUQUE, IOWA AS FOLLOWS:
The That the City of Dubuque 2013 Drainage Basin Master Plan Amendment prepared
by HDR Engineering, Inc., is hereby adopted.
Passed, approved and adopted this 18th day of November, 2013.
Attest:
Amp- ApP7,,,iii
Kevi r 'Firnstah , City erk
dD
Roy D. Buo , Mayor
APPENDIX B: COMPLETED PROJECT COST SUMMARIES
Page Left Intentionally Blank
Table B -1A - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Burden Street Improvements
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $60,000
2 Construction $900,000
TOTAL $960,000
Notes:
1) Engineering costs obtained from the April 12, 2001 memo requesting project acceptance from Council.
2) Construction costs obtained from the April 12, 2001 memo requesting project acceptance from Council.
Table B -1B - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Burden Street Storm Sewer Improvements
No Description Unit Unit Cost Quantity Item Cost
1 Engineering
$8,000
2 Construction
$120,000
TOTAL $128,000
SUBTOTAL INFLATION FACTOR 1.52
G RAND TOTAL $190,000
Notes:
1) Total engineering cost was estimated to be the total engineering cost multiplied by the fraction calculated by
dividing the storm sewer portion of the construction cost by the total construction cost.
2) Construction costs obtained from the April 12, 2001 memo requesting project acceptance from Council.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from April 2001.
4) Construction costs are rounded to the nearest ten thousand.
Table B -2 - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Locust Street Improvements
No Description Unit Unit Cost Quantity Item Cost
1 Engineering
$9,000
2 Construction
$270,000
TOTAL $279,000
SUBTOTAL INFLATION FACTOR 1.43
G RAN D TOTAL $400,000
Notes:
1) Engineering costs obtained from the July 2, 2003 memo requesting project acceptance from Council.
2) Construction costs obtained from the July 2, 2003 memo requesting project acceptance from Council.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from July 2003.
Table B -3 - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Carter Road Detention Cell
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $190,000
2 Property Acquisition - -- - -- - -- $140,000
3 Construction - -- - -- - -- $690,000
4 Early Completion Bonus - -- - -- $60,000
SUBTOTAL $1,080,000
SUBTOTAL INFLATION FACTOR 1.30
GRAND TOTAL $1,410,000
Notes:
1) Engineering costs obtained from the November 29, 2004 memo requesting project acceptance from Council.
2) Property acquisition costs obtained from the November 29, 2004 memo requesting project acceptance from
Council.
3) Construction costs obtained from the November 29, 2004 memo requesting project acceptance from Council.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from November 2004.
Table B -4 - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Windsor Street Relief Storm Sewer Project
No Description Unit Unit Cost Quantity Item Cost
1 Engineering
$9,000
2 Construction
$170,000
TOTAL $179,000
SUBTOTAL INFLATION FACTOR 1.11
G RAN D TOTAL $200,000
Notes:
1) Engineering costs obtained from the November 10, 2008 memo requesting project acceptance from Council.
2) Construction costs obtained from the November 10, 2008 memo requesting project acceptance from Council.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from November 2008.
Table B -5 - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
West 32nd Street Detention Cell
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $300,000
2 Property Acquisition - -- - -- - -- $2,150,000
3 Construction - -- - -- - -- $1,710,000
TOTAL $4,160,000
SUBTOTAL INFLATION FACTOR 1.10
GRAND TOTAL $4,590,000
Notes:
1) Engineering costs obtained from the December 1, 2009 memo requesting project acceptance from Council.
2) Property acquisition costs obtained from the December 1, 2009 memo requesting project acceptance from
Council.
3) Construction costs obtained from the December 1, 2009 memo requesting project acceptance from Council.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from December 2009.
Table B -6 - Final Construction Cost
North Fork Catfish Creek Drainage Basin Improvements:
North Fork Catfish Creek Stormwater and Sanitary Improvements - Phase I
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $152,000
2 Property Acquisition - -- - -- - -- $25,000
3 Construction - -- - -- - -- $720,000
TOTAL $897,000
SUBTOTAL INFLATION FACTOR 1.09
GRAND TOTAL $980,000
Notes:
1) Engineering costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
2) Property acquisition costs obtained from the October 22, 2010 memo requesting project acceptance from
Council.
3) Construction costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from October 2010.
Table B -7 - Final Construction Cost
North Fork Catfish Creek Drainage Basin Improvements:
North Fork Catfish Creek Stormwater and Sanitary Improvements - Phase II
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $158,000
2 Property Acquisition - -- - -- - -- $6,000
3 Construction - -- - -- - -- $1,052,000
TOTAL $1,216,000
SUBTOTAL INFLATION FACTOR 1.09
GRAND TOTAL $1,320,000
Notes:
1) Engineering costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
2) Property acquisition costs obtained from the October 22, 2010 memo requesting project acceptance from
Council.
3) Construction costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from October 2010.
Table B -8 - Final Construction Cost
North Fork Catfish Creek Drainage Basin Improvements:
North Fork Catfish Creek Stormwater and Sanitary Improvements - Phase III
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $204,000
2 Property Acquisition - -- - -- - -- $17,000
3 Construction - -- - -- - -- $1,626,000
TOTAL $1,847,000
SUBTOTAL INFLATION FACTOR 1.09
GRAND TOTAL $2,010,000
Notes:
1) Engineering costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
2) Property acquisition costs obtained from the October 22, 2010 memo requesting project acceptance from
Council.
3) Construction costs obtained from the October 22, 2010 memo requesting project acceptance from Council.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from October 2010.
Table B -9 - Final Construction Cost
North Fork Catfish Creek Drainage Basin Improvements:
Northwest Arterial Detention Basin Improvements
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $0
2 Property Acquisition - -- - -- - -- $0
3 Construction - -- - -- - -- $201,000
TOTAL $201,000
SUBTOTAL INFLATION FACTOR 1.09
GRAND TOTAL $220,000
Notes:
1) Construction costs obtained from Deron Muehring on July 24, 2013.
2) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from October 2010.
Table B -10 - Final Construction Cost
North Fork Catfish Creek Drainage Basin Improvements:
Pennsylvania Avenue Concrete Wall
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $0
2 Property Acquisition - -- - -- - -- $0
3 Construction - -- - -- - -- $71,000
TOTAL $71,000
SUBTOTAL INFLATION FACTOR 1.09
GRAND TOTAL $80,000
Notes:
1) Construction costs obtained from Deron Muehring on July 24, 2013.
2) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from October 2010.
Table B -11- Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Lower Bee Branch Channel
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $1,390,000
2 Property Acquisition $2,620,000
3 Construction $11,240,000
TOTAL $15,250,000
SUBTOTAL INFLATION FACTOR 1.05
G RAND TOTAL $15,960,000
Notes:
1) Engineering costs obtained from the August 10, 2010 memo requesting award approval from Council.
2) Property acquisition costs obtained from Bee Branch (Jobs grant application.
3) Construction costs obtained from the September 10, 2011 pay request from Tschiggfrie Excavating.
4) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from September 2011.
Table B -12 - Final Construction Cost
Bee Branch Storm Sewer Trunkline Improvements:
Historic Millworks Complete Streets Project
No Description Unit Unit Cost Quantity Item Cost
1 Engineering $610,000
2 Construction - -- - -- - -- $6,690,000
3 Unused Materials - -- - -- - -- $120,000
4 Construction Inspection - -- - -- - -- $440,000
5 Testing, Environmental, Audits - -- - -- - -- $120,000
TOTAL $7,980,000
SUBTOTAL INFLATION FACTOR 1.04
GRAND TOTAL $8,300,000
Notes:
1) Engineering costs obtained from the January 24, 2012 memo requesting project acceptance from Council.
2) Construction costs obtained from the January 24, 2012 memo requesting project acceptance from Council.
3) Unused materials costs obtained from the January 24, 2012 memo requesting project acceptance from
Council.
4) Construction inspection costs obtained from the January 24, 2012 memo requesting project acceptance from
Council.
5) Testing, environmental and audit costs obtained from the January 24, 2012 memo requesting project
acceptance from Council.
6) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The
escalation factors are a ratio of the CCI for June 2013 against the CCI from January 2012.
APPENDIX C: PROPOSED PROJECT OPINIONS OF PROBABLE
CONSTRUCTION COST
Page Left Intentionally Blank
Table C -1- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
16th Street Detention Basin Flood Gates
No Description Item Cost
1 Construction $1,650,000
2 Design & Engineering $250,000
3 Contingency $250,000
SUBTOTAL $ 2,150,000
SUBTOTAL INFLATION FACTOR 1.03
GRAND TOTA L $ 2,210,000
Notes:
1) Construction cost was obtained from a combination of the CIP report for FY 2014 through FY
2018 and the November 2008 Strand Technical Memo No. 1.
2) Engineering cost was estimated to be 15% of the construction cost.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index
(CCI). The escalation factors are a ratio of the CCI for June 2013 against the CCI from March 2012.
4) Construction cost has been rounded to the nearest ten thousand.
Table C -2- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
Valeria Street Project
No Description Item Cost
1 Construction $34,000
2 Design & Engineering $6,000
3 Contingency $4,000
SUBTOTAL $44,000
SUBTOTAL INFLATION FACTOR 1.02
GRAND TOTAL $45,000
Notes:
1) Construction cost was obtained from the August 20, 2012 Kaufmann - Valeria Flood
Reduction Analysis memo.
2) Engineering cost was obtained from the August 20, 2012 Kaufmann - Valeria Flood
Reduction Analysis memo.
3) Contingency cost was obtained from the August 20, 2012 Kaufmann - Valeria Flood
Reduction Analysis memo.
4) Escalation factors are based upon the Engineering News Record (EN R) Construction
Cost Index (CCI). The escalation factors are a ratio of the CCI for June 2013 against the
CCI from August 2012.
Table C -3- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
Upper Bee Branch Channel Restoration
No Description Item Cost
1 Construction $39,100,000
2 Design & Engineering $5,900,000
3 Contingency $2,000,000
4 Property Acquisitions $11,900,000
SUBTOTAL $58,900,000
SUBTOTAL INFLATION FACTOR 1.00
GRAND TOTAL $58,900,000
Notes:
1) Construction cost for the open channel was obtained from the 2013 cost estimate provided by the
design engineer of record (Strand & Associates).
2) Engineering cost was estimated to be 15% of the construction cost.
3) Contingency was estimated to be 5% of the construction cost.
4) Land acquisition cost estimates from Office of the City Engineer. Costs include acquisition,
relocation benefits, and site clearing (structure removal).
5) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index
(CCI). The escalation factors are a ratio of the CCI for June 2013 against the CCI from April 2013.
Table C -4- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
North End Storm Sewer Improvements
No Description Item Cost
1 Construction
$930,000
2 Design & Engineering
$60,000
SUBTOTAL $990,000
SUBTOTAL INFLATION FACTOR 1.03
GRAND TOTAL $1,020,000
Notes:
1) Construction cost was obtained from the CIP report for FY 2013 through FY 2017.
2) Engineering cost was obtained from the CIP report for FY 2013 through FY 2017.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost
Index (CCI). The escalation factors are a ratio of the CCI for June 2013 against the CCI from
March 2012.
4) Construction cost has been rounded to the nearest ten thousand.
Table C -5- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
22nd Street Storm Sewer
No Description Item Cost
1 Construction $2,610,000
2 Design & Engineering $260,000
3 Contingency $260,000
4 Property /ROW Acquisition $10,000
SUBTOTAL $3,140,000
SUBTOTAL INFLATION FACTOR 1.03
GRAND TOTAL $3,230,000
Notes:
1) Construction cost was obtained from the City.
2) Engineering cost was obtained from the CIP report for FY 2013 through FY 2017.
3) Escalation factors are based upon the Engineering News Record (EN R) Construction Cost Index
(CCI). The escalation factors are a ratio of the CCI for June 2013 against the CCI from March 2012.
4) Construction cost has been rounded to the nearest ten thousand.
Table C -6- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
17th Street Storm Sewer
No Description Item Cost
1 Construction $5,640,000
2 Design & Engineering $560,000
3 Contingency $560,000
4 Property /ROW Acquisition $15,000
SUBTOTAL $6,775,000
SUBTOTAL INFLATION FACTOR 1.00
GRAND TOTAL $6,780,000
Notes:
1) Costs obtained from the Office of the City Engineer.
2) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost
Index (CCI). The escalation factors are a ratio of the CCI for June 2013 against the CCI from
March 2012.
3) Construction cost has been rounded to the nearest ten thousand.
Table C -7- Preliminary Opinion of Probable Construction Cost
Bee Branch Watershed Improvements:
Impervious Area Reduction
No Description Item Cost
1 Construction $37,260,000
2 Design & Engineering $3,730,000
3 Contingency
$1,860,000
SUBTOTAL $42,850,000
SUBTOTAL INFLATION FACTOR 1.01
GRAND TOTAL $43,300,000
Notes:
1) Construction cost based on February 12, 2013 letter from the City to the Iowa Department of Natural
Resources and historic costs to construct pervious alleys.
2) Construction cost estimate to reconstruct the 237 impervious alleys in the Bee Branch watershed with
pervious pavement systems.
3) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI).
The escalation factors are a ratio of the CCI for June 2013 against the CCI from February 2013.
Table C -8- Preliminary Opinion of Probable Construction Cost
Dubuque Drainage Basin Master Plan Amendment:
Water Treatment Plant Floodproofing
No Description Unit Unit Cost Quantity Item Cost
1 Construction LS 7% 1 $2,100,000
2 Design & Engineering LS 2% 1 $530,000
3 Contingency LS $10,500 1 $530,000
4 Property /ROW Acquisitions AC $6,300 0.5 $210,000
SUBTOTAL $3,370,000
SUBTOTAL INFLATION FACTOR 1.00
GRAND TOTAL $3,370,000
Notes:
1) Escalation factors are based upon the Engineering News Record (ENR) Construction Cost Index (CCI). The escalation factors are a ratio of the
CCI fortune 2013 against the CCI from June 2013. Since there is no difference in month and year there is no inflation for this project.
2) Construction cost has been rounded to the nearest ten thousand.
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Page Left Intentionally Blank
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -1
Impervious Surface Reduction — Proposed Alley Reconstruction
Year 1 (Calendar Year 2013)
Parallel Bounding Streets
Beginning Point of
Alley
Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Lincoln Ave and Providence St
605 Lincoln Ave
Windsor Ave
2,640
E 22 °d St and Regent St
Prince St
Queen St
4,480
Prince St and Queen St
2240 Prince St
Regent St
4,480
Prince St and Queen St
Regent St
E 24th St
4,320
Queen St and Windsor Ave
Regent St
E 24th St
3,200
Windsor Ave and Stafford St
Merz St
Ries St
8,240
Burden St and Balke St
Link St
Strauss St
5,280
Burden St and Balke St
Strauss St
Lawther St
4,400
Burden St and Balke St
Lawther St
Goethe St
4,400
Burden St and Balke St
Goethe St
Groveland P1
7,040
Merz St and Ries St
Pleasant St
Windsor Ave
3,200
Edison St and Merz St
Stafford St
Windsor Ave
2,560
Maple St and Cedar St
E 14th St
E 15th St
4,560
Central Ave and White St
E 24th St
E 25th St
6,960
White St and Jackson St
E 24th St
E 25th St
3,200
W Locust St and Almond St
Ellis St
Foye St
15,120
Rhomberg Ave and Lincoln Ave
Johnson St
Windsor Ave
6,080
Rhomberg Ave and Lincoln Ave
Windsor Ave
Stafford St
6,240
Rhomberg Ave and Lincoln Ave
Stafford St
Humboldt St
6,320
Rhomberg Ave and Lincoln Ave
Humboldt St
Schiller St
6,000
Rhomberg Ave and Lincoln Ave
Schiller St
Farley St
5,520
Rhomberg Ave and Lincoln Ave
Farley St
Fengler St
4,800
Rhomberg Ave and Lincoln Ave
Fengler St
Ann St
6,640
Rhomberg Ave and Lincoln Ave
Ann St
Dock St
5,840
Rhomberg Ave and Lincoln Ave
Dock St
Marshall St
5,920
Garfield Ave and Rhomberg Ave
Marshall St
Decatur St
5,920
Garfield Ave and Rhomberg Ave
Decatur St
Hamilton St
7,040
Total (SF):
150,400
Note:
1. Information on proposed alley projects was obtained from the February 12, 2013, letter from the City of Dubuque to the Iowa
Department of Natural Resources, responding to comments with regard to the proposed pervious pavement reconstruction.
City of Dubuque, Iowa
Appendix D
D -1
Drainage Basin Master Plan Amendment
Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -2
Impervious Surface Reduction — Proposed Alley Reconstruction
Year 2 (Calendar Year 2014)
Parallel Bounding Streets
Beginning Point of
Alley
Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Francis St and Valeria St
Kaufmann Ave
W 23rd St
7,920
Kaufmann Ave and W 23 "d St
Francis St
Valeria St
2,640
Lowell St and Clarke Dr
Paul St
Foye St
8,080
Lowell St and Clarke Dr
Foye St
Schroeder St
4,160
Schroeder St and Harold St
Clarke Dr
Lowell St
6,480
W 17th St and Angella St
Cox St
Catherine St
11,680
W l lth St and Chestnut St
Prairie St
Walnut St
3,600
Mt. Pleasant St and Wood St
Loras Blvd
Park St
15,200
Adair St and N Grandview Ave
Loras Blvd
Fillmore St
4,400
Adair St and N Grandview Ave
Fillmore St
Decorah St
4,320
Adair St and N Grandview Ave
Decorah St
Delaware St
6,320
N Grandview Ave and Atlantic St
Custer St
Loras Blvd
6,960
N Grandview Ave and Atlantic St
Loras Blvd
Fillmore St
4,400
N Grandview Ave and Atlantic St
Fillmore St
Decorah St
4,320
N Grandview Ave and Atlantic St
Decorah St
Delaware St
4,320
Green St and N Grandview Ave
Avoca St
N Algona St
4,960
University Ave and Delhi St
University Ave
N Grandview Ave
6,400
Ventura Dr and Broadway St
Pleasant View Dr
Putnam St
10,880
Fulton St and Kane St
King St
Monroe St
8,000
Ashton P1 and Avoca St
Decorah St
Delaware St
4,320
Asbury Rd and Finley St
Poplar St
Bunker Hill Rd
7,120
Jackson St and Washington St
E 25th St
E 26th St
13,920
Total (SF):
150,400
Note:
1. Information on proposed alley projects was obtained from the February 12, 2013, letter from the City of Dubuque to the Iowa
Department of Natural Resources, responding to comments with regard to the proposed pervious pavement reconstruction.
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -2 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -3
Impervious Surface Reduction — Proposed Alley Reconstruction
Year 3 (Calendar Year 2015)
Parallel Bounding Streets
Beginning Point of
Alley
Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Green St and Rosedale Ave
Avoca St
Asbury Rd
10,160
Rhomberg Ave and Lincoln Ave
Kniest St
Johnson St
7,200
Garfield Ave and Rhomberg Ave
Kniest St
Johnson St
7,200
Dorgan Pl
W 17th St
Ellis St
13,000
White St and Jackson St
E 16th St
E 17th St
4,480
White St and Jackson St
E 18th St
E 19th St
4,480
White St and Jackson St
E 19th St
E 20th St
3,600
White St and Jackson St
E 20th St
E 214 St
6,080
White St and Jackson St
E 214 St
E 22nd St
7,360
Washington St and Elm St
E 27th St
E 28th St
9,920
Iowa St and Central Ave
W 10th St
W 11th St
4,320
Iowa St and Central Ave
W 11th St
W 12th St
4,480
Washington St and Elm St
E 22" St
E 24th St
12,960
Washington St and Elm St
E 24th St
E 25th St
9,600
Central Ave and White St
E 9th St
E 10th St
4,240
Central Ave and White St
E 10th St
E 11th St
4,240
White St and Jackson St
E 10th St
E 11th St
4,240
White St and Jackson St
E 13th St
E 14th St
4,480
White St and Jackson St
E 14th St
E 15th St
4,480
Jackson St and Washington St
E 12th St
E 13th St
4,560
Jackson St and Washington St
E 13th St
E 14th St
4,480
Jackson St and Washington St
E 14th St
E 15th St
4,480
Jackson St and Washington St
E 15th St
E 16th St
4,560
Washington St and Elm St
E 11th St
E 12th St
4,560
Total (SF):
149,160
Note:
1. Information on proposed alley projects was obtained from the February 12, 2013, letter from the City of Dubuque to the Iowa
Department of Natural Resources, responding to comments with regard to the proposed pervious pavement reconstruction.
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -3 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Adair St and Wood St
Fillmore St
Loras Blvd
6,400
Alta P1 and N Algona St
Fillmore St
Loras Blvd
4,400
Alta P1 and N Algona St
Decorah St
Fillmore St
4,320
Alta P1 and N Algona St
Delaware St
Decorah St
4,320
Alta P1 and N Algona St
Green St
Delaware St
5,440
Alta Vista St and Belmont St
Loras Blvd
Rose St
7,840
Alta Vista St and Center P1
Rose St
University Ave
11,520
Asbury Rd and St Ambrose St
Rosedale Ave
Asbury Rd
3,040
Ashton P1 and Alta P1
Delaware St
Decorah St
4,400
Atlantic St and N Grandview Ave
Dexster St
Delaware St
4,320
Auburn St and Atlantic St
Fillmore St
Loras Blvd
4,400
Auburn St and Atlantic St
Decorah St
Fillmore St
4,400
Auburn St and Atlantic St
Delaware St
Decorah St
4,400
Auburn St and Atlantic St
Dexster St
Delaware St
4,320
Auburn St and Atlantic St
N Grandview Ave
Dexter St
2,400
Belmont St and Cummins St
Loras Blvd
Rose St
8,320
Bluff St and Locust St
W 10th St
W 9th St
4,240
Bluff St and Locust St
W 10th St
North
2,080
Broadway St and Traut Terr
Diagonal St
Broadway St
6,160
Brunswick St and Balke St
Strauss St
Link St
3,600
Brunswick St and Balke St
Lawther St
South
2,960
Burden St and Argyle St
Goethe St
Lawther St
4,320
Burden St and Argyle St
Groveland P1
Goethe St
3,760
Burden St and Hedley Ct
Lawther St
Strauss St
4,320
Caledonia P1 and Hill St
Hill St
north
4,000
Total (SF):
119,680
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -4 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Center P1 and Race St
Rose St
W llth St
4,960
Center P1 and Race St
Rose St
W llth St
5,440
Center P1 and Wilson St
W 1 lth St
University Ave
5,760
Central Ave and White St
E 8th St
E 7th St
4,480
Central Ave and White St
E 15th St
E 14th St
4,480
Central Ave and White St
E 16th St
E 15th St
4,480
Central Ave and White St
E 16th St
E 17th St
4,480
Central Ave and White St
E 18th St
E 17th St
4,480
Clarke Dr and Rosedale Ave
St Ambrose St
N Grandview Ave
10,000
Cottage P1 and Lowell St
Woodworth St
East
5,280
Cottage P1 and Lowell St
Abbott St
Woodworth St
5,760
Cox St and Walnut St
Cox St
Chestnut St
6,080
Custer St and University Ave
Auburn St
Atlantic St
6,720
Custer St and University Ave
N Algona St
Auburn St
3,360
Davenport St and Lemon St
Stoltz St
South
2,080
Davenport St and Lemon St
Saunders St
Stoltz St
3,200
Davenport St and Lemon St
Saunders St
South
3,040
Davis St and Euclid St
Sheridan Rd
East
7,840
Diamond St and Milwaukee St
Central Ave
Jackson St
6,320
Edina St and Vernon St
Glen Oak St
Alta Vista St
4,000
Edith St and O'Neill St
Burden St
Sheridan St
8,960
Elm St and Pine St
E 12th St
E 13th St
4,560
Elm St and Pine St
E 13th St
E 14th St
4,480
Elm St and Pine St
E 18th St
E 17th St
4,320
Euclid St and Harlan St
Sheridan Rd
EAST
7,840
Total (SF):
132,400
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -5 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Francis St and Central Ave
W 23rd St
Kaufmann Ave
8,320
Glen Oak St and Alta Vista St
Edina St
Vernon St
5,200
Glen Oak St and Alta Vista St
Edina St
north
7,840
Goethe St and Lawther St
Sheridan Rd
east
7,520
Green St and Cherry St
Asbury Rd
Avoca St
7,040
Harlan St and Goethe St
Sheridan Rd
east
7,600
Hill St and W 3rd St
Hill St
W 3rd St
10,080
Iowa St and Central Ave
W 15th St
Loras Blvd
4,480
Iowa St and Central Ave
W 16th St
W 15th St
4,480
Iowa St and Central Ave
W 16th St
W 17th St
4,480
Jackson St and Washington St
E 20th St
E 19th St
3,600
Jackson St and Washington St
E 21ST St
E 20th St
6,560
Jackson St and Washington St
E 22nd St
E 21ST St
7,200
Jackson St and Washington St
E 24th St
E 22nd St
15,680
Jackson St and Washington St
E 27th St
E 26th St
9,920
Jackson St and Washington St
E 28th St
E 27th St
10,000
Jackson St and Washington St
E 29th St
E 28th St
9,920
Jackson St and Washington St
E 30th St
E 29th St
9,920
Jackson St and Washington St
E 16th St
E 17th St
4,480
Jackson St and Washington St
E 19th St
E 18th St
5,200
Jackson St and Washington St
E 18th St
E 17th St
4,480
Kane St and Kaufmann Ave
Kaufmann Ave
Kaufmann Ave
8,640
Kane St and Muscatine St
Putnam St
Muscatine St
7,360
Lemon St and Central Ave
W 32nd St
W 30th St
14,400
Lincoln Ave and Rhomberg Ave
Hamilton St
Decatur St
6,880
Total (SF):
191,280
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -6 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Lincoln Ave and Rhomberg Ave
Decatur St
Marshall St
5,840
Locust St and Main St
W 9th St
W 8th St
4,240
Locust St and Main St
W 10th St
W 9th St
4,480
Locust St and Main St
W 1 lth St
W 10th St
4,480
Locust St and Main St
W 12th St
W 1 lth St
4,400
Locust St and Main St
W 13th St
W 12th St
4,480
Locust St and Main St
Loras Blvd
W 13th St
4,480
Locust St and Main St
W 15th St
Loras Blvd
4,480
Locust St and Main St
E 16th St
E 15th St
4,480
Loras Blvd and Arlington St
Prairie St
Dell St
10,400
Main St and Iowa St
W 9th St
W 8th St
3,520
Main St and Iowa St
W 10th St
W 9th St
4,480
Main St and Iowa St
W 1 lth St
W 10th St
4,480
Main St and Iowa St
W 12th St
W 1 lth St
4,480
Main St and Iowa St
W 13th St
W 12th St
4,480
Main St and Iowa St
Loras Blvd
W 13th St
4,480
Main St and Iowa St
W 15th St
Loras Blvd
4,480
Merz St and Edison St
Merz St
south
10,880
Milwaukee St and E 32nd St
Central Ave
Jackson St
6,320
Mt Pleasant St and Glen Oak St
Loras Blvd
south
3,840
Muscatine St and Davenport St
Sabula St
W 28th St
4,320
Muscatine St and Davenport St
Primrose St
Sabula St
5,280
Muscatine St and Davenport St
National St
Primrose St
5,120
Muscatine St and Davenport St
Stoltz St
National St
4,160
Muscatine St and Broadway St
Putnam St
Gay St
6,800
Total (SF):
132,400
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -7 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
N Algona St and Auburn St
Fillmore St
Loras Blvd
4,400
N Algona St and Auburn St
Decorah St
Fillmore St
4,320
N Algona St and Auburn St
Delaware St
Decorah St
4,320
N Algona St and Auburn St
Dexster St
Delaware St
4,320
N Algona St and Auburn St
N Grandview Ave
Dexter St
3,760
N Booth St and Alta Vista St
Loras Blvd
Martha St
5,920
Nevada St and Alpine St
University Ave
South
9,920
O'Neill St and Groveland P1
Burden St
Sheridan St
9,040
O'Neill St and Groveland P1
Brunswick St
Burden St
11,840
Park St and VERNON St
Glen Oak St
Vernon St
5,760
Pine St and Maple St
E 15th St
E 14th St
4,560
Pine St and Maple St
E 16th St
E 15th St
4,480
Pleasant St and Merz St
Viola St
Merz St
8,240
Providence St and Lincoln Ave
Stafford St
Windsor Ave
6,160
Putnam St and Muscatine St
Primrose St
Sabula St
5,280
Putnam St and Muscatine St
National St
Primrose St
5,120
Putnam St and Muscatine St
Stoltz St
National St
4,000
Queen St and Windsor Ave
Edward St
E 24th St
8,960
Queen St and Windsor Ave
Henry St
Edward St
4,000
Queen St and Windsor Ave
Pfotzer St
Henry St
4,400
Queen St and Windsor Ave
Sutter St
Pfotzer St
4,400
Queen St and Windsor Ave
Clinton St
Sutter St
8,480
Queen St and Windsor Ave
Queen St
Clinton St
4,480
Race St and Walnut St
Rose St
W llth St
4,880
Regent St and E 22nd St
Stafford St
Windsor Ave
5,440
Total (SF):
146,480
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -8 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Rhomberg Ave and Garfield Ave
Windsor Ave
Johnson St
6,160
Rhomberg Ave and Garfield Ave
Stafford St
Windsor Ave
6,400
Rhomberg Ave and Garfield Ave
Humbodt St
Stafford St
6,400
Rhomberg Ave and Garfield Ave
Schiller St
Humboldt St
6,160
Rhomberg Ave and Garfield Ave
Farley St
Schiller St
5,600
Rhomberg Ave and Garfield Ave
Dock St
Ann St
6,080
Rhomberg Ave and Garfield Ave
Ann St
Fengler St
6,880
Rhomberg Ave and Garfield Ave
Fengler St
Farley St
4,960
Rose St and W 1 lth St
Center P1
Race St
2,640
Ruby St and Diamond St
Central Ave
Jackson St
6,240
St Ambrose St and Avoca St
Rosedale Ave
south
5,280
Sheridan Rd and Windsor Ave
Goethe St
south
2,080
Sheridan Rd and Windsor Ave
Harlan St
Goethe St
4,000
Sheridan Rd and Windsor Ave
Euclid St
Harlan St
4,000
Sheridan Rd and Windsor Ave
Davis St
Euclid St
4,000
Stafford St and Althauser St
Merz St
Edison St
5,760
Strauss St and Burden St
Burden St
Windsor Ave
8,320
University Ave and Oxford St
Alta Vista St
Yale Ct
7,840
University Ave and W 5th St
Nevada St
Alpine St
4,320
University Ave and W 8th St
Wilson St
east
3,920
Vernon St and Loras Blvd
Vernon St
Glen Oak St
5,760
W 1 lth St and Jefferson St
Spruce St
Olive St
5,760
W 1 lth St and Jefferson St
Walnut St
Spruce St
5,760
W 16th St and W 15th St
Cornell St
east
2,480
W 5th St and W 3RD St
Melrose Terr
Winona St
4,720
Total (SF):
131,520
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -9 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
W 5th St and W 3rd St
Winona St
Hill St
3,520
W 5th St and W 3rd St
Winona St
Hill St
6,400
W 5th St and W 4th St
Burch St
Summit St
5,120
W 8th St and Hill St
Caledonia St
west
4,800
W Locust St and Main St
E 16th St
E 17th St
4,560
Washington St and Elm St
E 12th St
E 13th St
4,480
Washington St and Elm St
E 13th St
E 14th St
4,480
Washington St and Elm St
E 15th St
E 14th St
4560
Washington St and Elm St
E 16th St
E 17th St
4,480
Washington St and Elm St
E 29th St
E 28th St
9,920
Washington St and Elm St
E 30th St
E 29th St
9,920
Washington St and Elm St
E 19th St
E 18th St
5,200
Washington St and Elm St
E 26th St
E 25th St
15,040
Washington St and Elm St
E 16th St
E 15th St
4,560
White St and Jackson St
E 16th St
E 15th St
4,640
White St and Jackson St
E 18th St
E 17th St
4,480
White St and Jackson St
E 12th St
E llth St
4,480
White St and Jackson St
E 12th St
E 13th St
4,560
White St and Jackson St
E 10th St
E 9th St
4,400
Wilson St and Caledonia P1
W 8th St
Wilson St
12,400
Wilson St and Walnut St
University Ave
north
1,920
Windsor Ave and Stafford St
E 24th St
E 22nd St
7,040
Winona St and Hill St
W 5th St
W 3rd St
5,920
Providence St and Lincoln Ave
Windsor Ave
south
2,640
E 24th St and E 22ND St
Queen St
Prince St
4,480
Total (SF):
144,000
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -10 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Prince St and Queen St
Regent St
south
4,480
Prince St and Queen St
E 24th St
Regent St
4,320
Queen St and Windsor Ave
E 24th St
Regent St
3,200
Windsor Ave and Stafford St
Ries St
Merz St
8,240
Balke St and Burden St
Strauss St
Link St
5,280
Balke St and Burden St
Lawther St
Strauss St
4,400
Balke St and Burden St
Goethe St
Lather St
4,400
Balke St and Burden St
Groveland P1
Goethe St
7,040
Ries St and Merz St
Stafford St
west
3,200
Windsor Ave and Stafford St
Merz St
south
2,560
Maple St and Cedar St
E 15th St
E 14th St
4,560
Central Ave and White St
E 25th St
White St
6,960
White St and Jackson St
E 25th St
White St
3,200
Almond St and W Locust St
Foye St
Ellis St
15,120
Lincoln Ave and Rhomberg Ave
Windsor Ave
Johnson St
6,080
Lincoln Ave and Rhomberg Ave
Stafford St
Windsor Ave
6,240
Lincoln Ave and Rhomberg Ave
Humboldt St
Stafford St
6,320
Lincoln Ave and Rhomberg Ave
Schiller St
Humboldt St
6,000
Lincoln Ave and Rhomberg Ave
Farley St
Schiller St
5,520
Lincoln Ave and Rhomberg Ave
Fengler St
Farley St
4,800
Lincoln Ave and Rhomberg Ave
Ann St
Fengler St
6,640
Lincoln Ave and Rhomberg Ave
Dock St
Ann St
5,840
Lincoln Ave and Rhomberg Ave
Marshall St
Dock St
5,920
Rhomberg Ave and Garfield Ave
Decatur St
Marshall St
5,920
Rhomberg Ave and Garfield Ave
Hamilton St
Decatur St
7,040
Total (SF):
143,280
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
D -11
Drainage Basin Master Plan Amendment
Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
Valeria St and Francis St
W 23rd St
Kaufmann Ave
7,920
W 23rd St and Kaufmann Ave
Valeria St
east
2,640
Lowell St and Clarke Dr
Foye St
Paul St
8,080
Lowell St and Clarke Dr
Schroeder St
Foye St
4,160
Harold St and Schroeder St
Lowell St
Clarke Dr
6,480
Angella St and W 17th St
Cox St
east
11,680
Chestnut St and W llth St
Walnut St
Prairie St
3,600
Wood St and Mt Pleasant St
Wood St
Loras Blvd
15,200
N Grandview Ave and Adair St
Fillmore St
Loras Blvd
4,400
N Grandview Ave and Adair St
Decorah St
Fillmore St
4,320
N Grandview Ave and Adair St
Delaware St
Decorah St
6,320
Atlantic St and N Grandview Ave
Loras Blvd
Custer St
6,960
Atlantic St and N Grandview Ave
Fillmore St
Loras Blvd
4,400
Atlantic St and N Grandview Ave
Decorah St
Fillmore St
4,320
Atlantic St and N Grandview Ave
Delaware St
Decorah St
4,320
N Grandview Ave and Green St
Avoca St
east
4,960
University Ave and Delhi St
University Ave
N Grandview Ave
6,400
Broadway St and Pleasant View Dr
Broadway St
Ventura Dr
10,880
Kane St and Fulton St
Monroe St
south
8,000
Avoca St and Ashton P1
Delaware St
Decorah St
4,320
Jackson St and Washington St
E 26th St
E 25th St
13,920
Rosedale Ave and Green St
Asbury Rd
Avoca St
10,160
Lincoln Ave and Rhomberg Ave
Johnson St
south
7,200
Rhomberg Ave and Garfield Ave
Johnson St
south
7,200
Ellis St and Madison St
Ellis St
W 17th St
10,400
Total (SF):
178,240
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa
Appendix D
Drainage Basin Master Plan Amendment
D -12 Fall 2013
APPENDIX D: IMPERVIOUS SURFACE REDUCTION ALLEY
RECONSTRUCTION PHASING
Table D -4
Impervious Surface Reduction - Proposed Alley Reconstruction
Year 4 and Beyond (Calendar Year 2016 and Beyond)
Parallel Bounding Streets
Beginning Point of
Alley Reconstruction
End Point of Alley
Reconstruction
Approximate
Pervious
Pavement
Square
Footage (SF)
White St and Jackson St
E 16th St
E 17th St
4,480
White St and Jackson St
E 19th St
E 18th St
4,480
White St and Jackson St
E 20th St
E 19th St
3,600
White St and Jackson St
E 21ST St
E 20th St
6,080
White St and Jackson St
E 22ND St
E 21ST St
7,360
Washington St and Elm St
E 28th St
E 27th St
9,920
Iowa St and Central Ave
W llth St
W 10th St
4,320
Iowa St and Central Ave
W 12th St
W 1 lth St
4,480
Washington St and Elm St
Washington St
Washington St
12,960
Washington St and Elm St
E 25th St
Washington St
9,600
Central Ave and White St
E 10th St
E 9th St
4,240
Central Ave and White St
E 10th St
E 1lth St
4,240
White St and Jackson St
E 10th St
E 1lth St
4,240
White St and Jackson St
E 13th St
E 14th St
4,480
White St and Jackson St
E 15th St
E 14th St
4,480
Jackson St and Washington St
E 12th St
E 13th St
4,560
Jackson St and Washington St
E 13th St
E 14th St
4,480
Jackson St and Washington St
E 15th St
E 14th St
4,480
Jackson St and Washington St
E 16th St
E 15th St
4,560
Washington St and Elm St
E 12th St
E 1lth St
4,560
Total (SF):
111,600
Note:
1. Information obtained from Dubuque Area Geographical Information System (DAGIS).
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Appendix D
D -13 Fall 2013
Page Left Intentionally Blank
Legend
CityLimits
RiversLakes
Drainage Basins
L
L
Bee Branch Basin
Caffish Creek Basin
Cloie Branch Basin
Eagle Point Basin
Granger Creek Basin
Hamm Island Basin
Ice Harbor Basin
Lower Little Maquoketa River Basin
Maus Park Basin
Middle Fork Caffish Creek Basin
North Fork Catfish Creek Basin
Roosevelt Basin
Sageville Creek Basin
Shiras Basin
South Fork Caffish Creek Basin
1
0
2
SCALE IN MILES
Mississippi River
Lower Little
Maquoketa1
1River Basin
Cloie Branch
Basin
o-,- Sageville 1
Creek Basin)
r N Y
South Fork Catfish
Creek Basin
J
North Fork Cattish ',\
Creek
1
'�52,9%oosv0c Shiras
Basin
J
l \,
Roosevelt
i \ Basin ;7\
/ 1/
Be e Branch Basin
u�MaHt+i- - >.
•-.. i
% xsr
ll,
./
/ Jf
ii
1'\
r'Hamm`
Wisconsin
Illinois /
k Catfish �� t'
Basin 1 iN
NISiV V
'
Fork
v+ Lka,.r.. _n 11
f v
11 �. \ Maus `,
x-.11 y \• Park
Basin /��
Ice
Harbor r
Basin
/ r
I �
� 9
\\
Granger �\
r,
s1 - -- — — —
-•(
Catfish Creek
Basin
Sou
Du
Creek Basin
ue Area Geo
Drainage Basins
Within City Limits
ISCMOF
DUBL
n�,.rrolw�,yr City of Dubuque, Iowa
ra
hical Information S stem AGIS dated 2009
DATE
Drainage Basin Master Plan
2013
FIGURE
1 -1A
SPRING VALLEY RD
Legend
Bee Branch Drainage Basin Limits
1, CARTER RD. DET. BASIN
2, W. 32ND ST. DET. BASIN
3.1, LOWER BEE BRANCH CREEK
3.2, 16TH ST. DET. CELL
4, W. LOCUST ST. STM SEWER
5, BURDEN ST. STM SEWER
1,000
0
SCALE IN FEET
2,000
6, WINDSOR ST. STM. SEWER
7, MILLWORK DISTRICT
8.1, PERVIOUS ALLEY
8.2, PERVIOUS ALLEY
8.3, PERVIOUS ALLEY
8.4, PERVIOUS ALLEY
8.5, PERVIOUS ALLEY
8.6, PERVIOUS ALLEY
8.7, PERVIOUS ALLEY
8.8, PERVIOUS ALLEY
Dubu.ue Area Geo.ra.hicaiInformation S stem (DAGIS). dated 2009
Bee Branch Drainage Basin
Projects Completed Since 2001
BE Drainage Basin Master Plan
m
artefrnw i, Nx.g»
tssir::
City of Dubuque, Iowa
DATE
2013
FIGURE
2 -1A
E
1
6 5K
A. or 1-4-‘t,
�3
J2 s4 tP�
of
A
SPRING VALLEY RD
t no t
lines .1%
se t
u
•
se
1,000
Legend
Bee Branch Drainage Basin
Streets
Pervious Streets
Alleys
Pervious Alleys
Pervious Parking
0
SCALE IN FEET
2,000
FAIRWAY DR
Soil Permeability
Water
<0.06 in /hr
0.06 -0.20 in /hr
0.06 -2.0 in /hr
0.6 -2.0 in /hr
2.0 -6.0 in /hr
6.0 -20.0 in /hr
/to
0
x
m y
g
at'
ro�
sa•-t LOWELL Sr
I--1
CLARKS DR �\ .`�
�yy LOCUST Sr ���.,•
-440191PPA 14 %IC x‘ X \ \ x ,b,
t A ‘,X
v4, A ..0°'.* X 1 N.
w'srhsr :
Ys.
Note:
Soil permeability rates from US Department of Agriculture, Natural
Resources Conservation Service (NRCS), Soil Survey of Dubuque
County Iowa, 1985.
hDa
Source: Dubu . ue A tea Geo.m i•reai imon»ation S stem
Bee Branch Drainage Basin
Soil Permeability (USDA NRCS)
DustDrainage Basin Master Plan
Q� t:
Ationn,. ma. Athoas City of Dubuque. Iowa
DATE
2013
FGU RE
2 -2A
LOCUST S7
FAIRWAY DR
Legend
Bee Branch Drainage Basin Limits
Flood Zone
Zone A
Zone X (Protected by Levee)
1,000
0
2,000
SCALE IN FEET
FEMA Flood Zone Descriptions
Zone A: Areas subject to a 1- percent- annual- chance of flooding or a 26% chance of flooding in a 30 -year
period. Because detailed analyses are not performed for such areas; no depths or base flood
elevations are provided within these zones.
Zone X: Area protected by levees from the 1- percent- annual- chance flood event.
hDa
Source: Doha a ue A tea Geo re • h. al Information S stem
Bee Branch Drainage Basin
FEMA Floodplain (Proposed 2009)
DUBU E
,.�,..�.. City of Dubuque, Iowa
Drainage Basin Master Plan
DATE
2013
FGURE
2 -3A
1,000
Legend
Bee Branch Drainage Basin Limits
Year of Building Construction (# of Structures)
1850 -1860 (12)
1861 -1870 (28)
1871 -1880 (128)
1881 -1890 (87)
1891 -1900 (423)
1901 - 1910(107) (785)
1911 -1920 (181)
1921 -1930 (83)
1931 -1940 (24)
1941 -1950 (34)
1951 -1960 (39)
1961 -1970 (21)
1971 -1980 (10)
1981 -1990 (1)
1991 -2000 (5)
2001-2010 (29)
2011 -2013 (2)
Unknown(159) (588)
1
0
SCALE IN FEET
2,000
NOTES:
1. The buildings identified are limited to those within the flood -prone area
determined by FEMA in 2009.
2. Of the 1,373 buildings, 785 (57 %) are greater than 100 years old.
Source: Dubu a ue A tea Geo re • bicai information S
tem
ha 1
Bee Branch Drainage Basin
Historic Nature of Buildings in Flood -
Prone Area
D uc ijE Drainage Basin Master Plan
Masreaas a. M i City of Dubuque, Iowa
DATE
2013
F RE
2 -4A
LOWELL,3r _.
1;
Th-
chT en
c)t
gR
CO
Legend
Bee Branch Drainage Basin Limits
Flood Zone (FEMA 2009)
Zone A
Zone X (Protected by Levee)
A Businesses in Flood -Prone Area
1,000
0
2,000
SCALE IN FEET
FEMA Flood Zone Descriptions
ZoneA: Areas subject to a 1- percent - annual - chance of flooding or a 26% chance of flooding in a 30 -year
period. Because detailed analyses are not performed for such areas; no depths or base flood
elevations are provided within these zones.
Zone X: Area protected by levees from the 1- percent- annual- chance flood event.
Source: Dubuque Area Geographical lnfamation System gram dated 9009
Bee Branch Drainage Basin
Businesses in Flood -Prone Area
DU BU E
,.�,..�.. City of Dubuque, Iowa
Drainage Basin Master Plan
DATE
2013
FCU RE
2 -5A
Th-
chT en
or
<
co
Legend
Bee Branch Drainage Basin Limits
Flood Zone
Zone A
Zone X (Protected by Levee)
1,000
0
2,000
SCALE IN FEET
FEMA Flood Zone Descriptions
ZoneA: Areas subject to a 1- percent - annual - chance of flooding or a 26% chance of flooding in a 30 -year
period. Because detailed analyses are not performed for such areas; no depths or base flood
elevations are provided within these zones.
Zone X: Area protected by levees from the 1- percent- annual- chance flood event.
hDa
Source: Dube a ue A tea Geo re • Alegi Information S ste m
Bee Branch Drainage Basin
FEMA Floodplain (Proposed 2009)
D u E Drainage Basin Master Plan
,.n,..�.. City of Dubuque, Iowa
DATE
2013
fN URE
2 -6A
1
a
q tiIt°- Ki
01 '
1.
f\ u %. SPRING VALLEY RD n'
WAL.tk_
3
W � �
! Nit
zj n
Rips isitia tic
ascet.MC VE4" c
ze
14
2
•cc
U
Legend FAIRWAYDR i i �' w
s
0 P
Bee Branch Drainage Basin Limits qs �OSk9Av�
Flood Zone ■p
0
LOWELL sr
CLARK£ DR T--
Ny LOCUST S7
1,000
X Protected by Levee
'A
AE
0
2.000
SCALE IN FEET
tioartsn Ave
1 t .cN
W5TNs7 to-
FEMA Flood Zone Descriptions
Zone A: Areas subject to a 1- percent - annual - chance of flooding or a 26% chance of flooding in a 30 -year
period. Because detailed analyses are not performed for such areas, no depths or base flood
elevations are provided within these zones.
ZoneAE: Areas subject to a 1- percent- annual- chance of flooding or a 26% chance of flooding in a 30 -year
period. Detailed analyses was performed so that base flood elevations are provided.
Zone X: Area protected by levees from 1- percent - annual- chance of flood event.
3R
s
ha 1
Source: Dube a ue A tea Geo re • Meal Info +m ation S ste
Bee Branch Drainage Basin
FEMA Floodplain (Effective 10118111)
marvu
DUB E
M.I,SWWWfr,.,,. City of Dubuque, Iowa
Drainage Basin Master Plan
DATE
2013
F RE
2 -7A
1
7
i
c
Legend
Bee Branch Drainage Basin
Streets
1,000
0
2,000
SCALE IN FEET
ha 1
Source: Dubuque Area Geoaraphicallnformaton SVStem (DA GIS). dated 2009
Bee Branch Drainage Basin
Watershed Limits
DUBL t �"t:E Drainage Basin Master Plan
City of Dubuque, Iowa
DATE
2013
FIGURE
4-1A
F' \PRO.IFCTS\Stnrm and Sanitar,Stnrm \f)rainanP Ragin MagtPr Plan \Mangy \RPP Rrannh \NatPrgh
/
• ST I Ili ic 0
SUBAREA PP golUSIL
/ W 32ND ST all
r- . - _ \IS
1
AL�F,n ' I
171:
r
W
�.
2)O
WASHINGTON: ST Oti
HAMILTON ST
v.
SUBAREA ti
1 — 73)
ZS
SA\ f
1 1
KERPER BLVD
SUBAREA M
�C./).
CD Cn
S v_)
0-0
m
r
i
'` r PO
AAP
KAUFMA
Legend
Bee Branch Watershed Limits
— — Drainage Network
1,000
0
2,000
SCALE IN FEET
Notes:
i
r
NN' AVE
SUBAREA
FAIRWAY DR
J
LOWELL ST
CLARKE Oft
J
l
J J
J f
+4\
H SST ` 1 J'76-4t1fkid41:1111T
SUBAREA
•
J LOCUST ST _
▪ J
� I
iLi
Jv,W LOCUST ST
SUBAREA
• G
ST
SUBAREA
CD
le?/46.1 �R
KERPER
BAREA
/ 7A 5 00 N� � n D C \ 0 O 1
O 7 ) N
7 �O i IP
NA Nr r
i
(1) 8th Street Subarea diverts into the 16th Street Detention Cell when the
Mississippi River is at stage 598.5
(2) Hamilton Street and Dock Street subareas divert into 16th Street Detention
Cell when the Mississippi River is at stage 603.5 and 600.5 respectively
•
W 3RD ST
ha 1
Source: Dubu.ue Area Geo.ra.hical Information S stem (DAGIS), dated 2009
Bee Branch Drainage Basin
Drainage Basin Subareas
THE CI O
D
B
Drainage Basin Master Plan
m.sterpieceo. the Mississippi) City of Dubuque, Iowa
DATE
2013
FIGURE
4 -2A
Rac in hilaclnr PUnUdanc11At n,nd CIC
F.IPCFI.IF1,1,1Rfnrm and Can AanACfnrm
Bee Branch Creek
Monitoring
West 32nd Street
Detention Basin
,iy 32ND ST
Legend
lllllllll�
W 32nd Street Subarea
Streets
Flood Mitigation Improvements
Bee Branch Creek (On -going Monitoring)
Carter Road Detention Basin (Complete)
W. 32nd Street Detention Basin (Complete)
1,000
0
D
CD
S -
r
rrl 1-
9� -11 N -a �� K G‘ " IRA v
cE A
, -P
j ? O. Y
n 1- r-
= Qv 31' -F,
. 0 P` .0Ai � a w
MEGWGAALLN ES7 O O m e Q
�1
c1A d
Jr)
m ROS p ` . �'GFSTMORE DR
>-
CO - 'KAUFMANN Ail
kie��YOR 0 s..
„$$ Q ■•
. ?f =.1 LINDA S
'1,94i. . K4 Re.
N ST
2,000
SCALE IN FEET
ha 1
Source: Dubu.ue Area Geo ra.hicai information S stem (DAG /S). dated 2009
West 32nd Street Subarea
Flood Mitigation Improvements
riccrro, C,,
Atule,p«. un /.r .�,,.:r ,r,:,, City of Dubuque, Iowa
Drainage Basin Master Plan
DATE
2013
FIGURE
4-3A
f 1PROJFCTS1Stoim and SanitanASto,m1Dfainna. Basin Mastn PIanWarKIKautmann
Valeria /Kaufmann
Storm Sewer
FAIRWAY DR
Pervious Alleys
Legend
Drainage Subarea Boundary
Streets
Flood Mitigation Improvements
Pervious Alleys
Valeria /Kaufmann Storm Sewer
500
0
SCALE IN FEET
1,000
- ItNGS'S4'
Su, ' f�, f�i�ttilwi+
ha 1
Source: Dubu.ue Area Geo. ra.hical Information S stem (DAGIS), dated 2009
Kaufmann Ave Subarea
Flood Mitigation Improvements
r lccGYO,
D L
Drainage Basin Master Plan
M >fr y:ru ac Yet MndA:iCpi City of Dubuque, Iowa
DATE
2013
FIGURE
4-4A
no Rao in knaofar PUn\M ,..M n
F \PRf1.IFf:TC \Cfnrm and Can AariAC}nrm
Legend
QDrainage Subarea Boundary
Streets
Flood Mitigation Improvements
17th Street Storm Sewer
W Locust Street Storm Sewer
Pervious Alleys
500
0
1,000
SCALE IN FEET
W. Locust Street
Storm Sewer
VINALMOND ST q
d
-- c soy
hD: 1
Pervious
Alleys
17th Street
Storm Sewer
Source: Dubu.ue Area Geo ra.hicai information S stem (DAG /S). dated 2009
Locust Subarea
Flood Mitigation Improvements
rtsc .YOF
DUEL
City of Dubuque, Iowa
Drainage Basin Master Plan
DATE
2013
FIGURE
4-5A
.a6 ,, .m a
Legend
Drainage Subarea Boundary
Railroad
Streets
Bee Branch Storm Sewer (Buried Creek)
Flood Mitigation Improvements
17th Street Storm Sewer
22nd Street Storm Sewer
Burden Street Storm Sewer (Complete)
Lower Bee Branch Creek (Complete)
North End Storm Sewers
Upper Bee Branch Bridges
Upper Bee Branch Creek
Upper Bee Branch Culverts
UUindsorAvenue Storm Sewer (Complete)
Pervious Alleys
Pervious Alleys (Complete)
• giDiNEILL -S'TIv
GROVEL-AND PL-Z�
IPervious Alleys
IUpper Bee Branch
Kaufmann Subarea Inflow
Notes:
1. Cenrtal Business District North Subarea includes Washington, Windsor, Hamilton,
Dock, and Upper Kerper subbasins.
2. Hamilton and Dock subareas are diverted into the 16th Street Detention Basin when
the Mississippi River is above EL 603.5 and 600.5 respectively.
500
0
1,000
SCALE IN FEET
1 22nd Street Storm Sewer
Pervious Alleys
(Complete)
•
Locust Subarea Inflow
Jai
Subarea Location
kr"
ha 1
17th Street
Storm Sewer
Lower Bee Branch I
Source: D?u, ,:: ue Area Geographical l.D fo;r af;o; System. ,'D.. G; SJ dated 2009
Central Business District - North Subare
Flood Mitigation Improvements
rircrvor C,,
DUBLF
AM,Mrpzn ur R^ .H•si.
7E Drainage Basin Master Plan
—,: City of Dubuque, Iowa
DATE
2013
FIGuRE
4-6A
F \PRf1.IF1:TC\Cfnrm and Can AanARtnrmthrainana Rac in Macfer PUnUdanc V. ant Ric Ificf C rrned
500
Legend
Drainage Subarea Boundary
Railroad
Streets
Flood Mitigation Improvements
in 16th Street Detention CeII Gates
16th Street Detention CeII (Complete)
Bee Branch Creek (Complete)
Historic Millwork District Pervious Streets (Complete)
Pervious Alleys
— Pervious Alleys (Complete)
Bee Branch
Creek
16th Street
Detention CeII
16th Street Detention
CeII Gates
Pervious Alleys
(Complete)
1
L
Millwork District
Pervious Streets
4,
{
L'
Notes:
1. Central Business District Subarea includes 8th, 11th, and 14th Street Subareas.
2. 8th Street Subarea diverts into 16th Street Detention cell when the Mississippi River is above 598.5.
■ t
0
1,000
SCALE IN FEET
ha 1
Source: Dubu.ue Area Geo ra.hicai information S stem (DAG /S). dated 2009
Central Business District-South Subarea
Flood Mitigation Improvements
r -16 GM OF
DUBL"ft
Drainage Basin Master Plan
City of Dubuque, Iowa
DATE
2013
FIGURE
4-7A
4
A
}
E
Legend
=Bee Branch Watershed Limits
Bee Branch Sewer Trunk Line
Open Channel (Bee Branch Creek)
600
0
1,200
SCALE IN FEET
ha 1
Source: Dubu a ue Area Geo • ra•,/ac ,/ Information S stem
Bee Branch Drainage Basin
Bee Branch Sewer Trunk Line
& Open Channel
D Bu uc rE
fl ainn- vMM.syn
Drainage Basin Master Plan
City of Dubuque, Iowa
DATE
2013
FIGURE
4 -8A
City of Dubuque, Iowa
2013 Drainage Basin Master Plan Amendment
THE CITY OF
Dui
Masterpiece on the Mississippi
FFDFDt ONE COMPANY
Many Solutions®
HDR Engineering, Inc.
8404 Indian Hills Drive
Omaha, NE 68114
Page Left Intentionally Blank
TABLE OF CONTENTS
TABLE OF CONTENTS
1.0 INTRODUCTION 1 -1
1.1 ORGANIZATION OF THIS DRAINAGE BASIN MASTER PLAN AMENDMENT1 -1
2.0 BACKGROUND AND METHODOLOGY 2 -1
2.7 DRAINAGE BASIN HYDROLOGIC AND HYDRAULIC CHANGES 2 -1
2.7.1 Storm Changes 2 -1
2.7.2 Bee Branch Drainage Basin Flooding 2 -3
2.7.3 Presidential Disaster Declarations 2 -4
2.8 CHANGES TO THE STORMWATER MANAGEMENT PROGRAM 2 -7
2.8.1 Stormwater Projects Completed Since 2001 2 -8
2.8.2 Stormwater Management Utility 2 -9
2.8.3 National Pollutant Discharge Elimination System (NPDES) Permit 2 -10
2.8.4 Impervious Surface Reduction 2 -11
2.8.5 Lot Source Reduction 2 -13
2.8.6 City Requirements for Stormwater Treatment and Detention 2 -13
2.8.7 FEMA Floodplain Revisions 2 -14
2.9 METHODOLOGY 2 -15
3.0 NORTH FORK CATFISH CREEK DRAINAGE BASIN 3 -1
3.8 STORMWATER PROJECTS COMPLETED SINCE 2001 3 -1
3.9 CHANGES WITHIN THE NORTH FORK CATFISH CREEK DRAINAGE BASIN 3 -2
4.0 BEE BRANCH DRAINAGE BASIN 4 -1
4.1 GENERAL DRAINAGE BASIN DESCRIPTION 4 -1
4.2 WEST 32ND STREET DRAINAGE SUBAREA 4 -1
4.2.4 Problem Areas 4 -1
4.2.5 Development of Alternative Solutions 4 -2
4.2.6 Recommendations for Improvement Alternatives 4 -2
4.2.7 Project Phasing 4 -2
4.2.8 Completed Project Implementation 4 -3
4.3 KAUFMANN AVENUE DRAINAGE SUBAREA 4 -3
4.3.4 Problem Areas 4 -3
4.3.5 Development of Alternative Solutions 4 -5
4.3.6 Recommendations for Improvement Alternatives 4 -5
4.3.7 Project Phasing 4 -6
4.3.8 Completed Project Implementation 4 -6
4.4 LOCUST STREET DRAINAGE SUBAREA 4 -7
4.4.4 Problem Areas 4 -7
4.4.5 Development of Alternative Solutions 4 -7
4.4.6 Recommendations for Improvement Alternatives 4 -8
4.4.7 Project Phasing 4 -8
4.4.8 Completed Project Implementation 4 -8
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Table of Contents i Fa112013
TABLE OF CONTENTS
4.5 CENTRAL BUSINESS DISTRICT — NORTH SUBAREAS 4 -8
4.5.8 Completed Project Implementation 4 -9
4.6 CENTRAL BUSINESS DISTRICT SUBAREAS 4 -9
4.6.8 Completed Project Implementation 4 -9
4.7 BEE BRANCH STORM SEWER TRUNK LINE AND OPEN CHANNEL (BEE
BRANCH CREEK RESTORATION) 4 -10
4.7.1 Problem Areas 4 -10
4.7.2 Development of Alternative Solutions 4 -11
4.7.3 Recommendations for Improvement Alternatives 4 -17
4.7.4 Project Phasing 4 -18
4.7.5 Completed Project Implementation 4 -19
4.8 IMPERVIOUS AREA REDUCTION 4 -20
4.8.1 Pervious Street Pavement Systems 4 -21
4.8.2 Pervious Alley Pavement System 4 -22
4.8.3 Project Phasing 4 -22
4.9 NEW STORMWATER MANAGEMENT PROJECTS 4 -23
4.9.1 Water Treatment Plant Floodproofing 4 -23
4.10 SUMMARY OF COMPLETED PROJECTS IN THE BEE BRANCH DRAINAGE
BASIN 4 -24
4.11 OTHER DUBUQUE FLOOD RISK REDUCTION PROJECTS 4 -26
4.11.1 Levee Breach Analysis 4 -26
4.11.2 Levee Functional Assessment 4 -26
5.0 FINANCING DRAINAGE IMPROVEMENTS AND OPERATIONS 5 -1
5.3 CAPITAL FUNDING 5 -1
5.3.4 Grants 5 -1
5.3.6 State Revolving Fund (SRF) Loan Program 5 -2
5.5 MUNICIPAL DRAINAGE UTILITIES 5 -2
LIST OF TABLES'
Table 2.9 Magnitude and Frequency of Theoretical Rainfall Amounts for Selected Storm Periods in
Northeast Iowa From 1992 Atlas 2 -1
Table 2.10 Comparison of Predicted Rainfall Amounts for 24 -Hour Duration Storm Events at
Selected Recurrence Intervals 2 -2
Summary of Storm Event Rainfall in Dubuque Between 1999 and 2011 2 -3
Summary of Presidential Disaster Declarations in Dubuque County 1953 - 1998 2 -5
Summary of Presidential Disaster Declarations in Dubuque County 1999 - 2011 2 -5
West 32v' Street Drainage Subarea Recommended Improvements Summary 4 -2
Kaufmann Avenue Drainage Subarea Recommended Improvements Summary 4 -6
Locust Street Drainage Subarea Recommended Improvements Summary 4 -8
Table 2.11
Table 2.12
Table 2.13
Table 4.9A
Table 4.15A
Table 4.30
Table numbers are numbered consecutively from the 2001 Drainage Basin Master Plan. Tables with an "A° are additional
information used to supplement the 2001 tables.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Table ofContents ii Fa112013
TABLE OF CONTENTS
Table 4.31 Bee Branch Drainage Subarea Recommended Improvements Summary 4 -19
Table 4.32 Bee Branch Drainage Basin Recommended Improvements Summary 4 -22
Table 4.33 Other Stormwater Management Projects Recommended Improvements Summary 4 -24
Table 4.34 Completed Project Cost Summary 4 -25
PHOTOS
Photo 1 Surcharging Storm Sewer Manhole on 22nd Street
Photo 2 Residents Wading Through Rushing Floodwaters
Photo 3 Stalled Cars on 17th Street during Flash Flooding in 2011
Photo 4 Impervious, Flood -prone Historic Millwork District Street Prior to Federal TIGER Grant
Complete Streets Improvement Project
Photo 5 Historic Millwork District Pervious Pavement System that Conveys Stormwater into the
Underlying Soil
Figure 1 -1A
Figure 2 -1A
Figure 2 -2A
Figure 2 -3A
Figure 2 -4A
Figure 2 -5A
Figure 2 -6A
Figure 2 -7A
Figure 4 -1A
Figure 4 -2A
Figure 4 -3A
Figure 4 -4A
Figure 4 -5A
Figure 4 -6A
Figure 4 -7A
Figure 4 -8A
Append
Append
Append
Append
xA
xB
xC
xD
LIST OF FIGURES2 (LOCATED AFTER TEXT)
Drainage Basins Within City Limits
Stormwater Projects Completed Since 2001
Bee Branch Drainage Basin Soil Permeability (USDA, NRCS)
Bee Branch Drainage Basin FEMA Floodplain (Proposed 2009)
Bee Branch Drainage Basin Historic Nature of Buildings in Flood -Prone Area
Bee Branch Drainage Basin Businesses in Flood -Prone Area
Bee Branch Drainage Basin Appealed FEMA Floodplain
Bee Branch Drainage Basin FEMA Floodplain (Effective October 18, 2011)
Bee Branch Drainage Basin Watershed Limits
Bee Branch Drainage Basin Drainage Basin Subareas
West 32 "d Street Subarea Flood Mitigation Improvements
Kaufmann Subarea Flood Mitigation Improvements
Locust Subarea Flood Mitigation Improvements
Central Business District — North Subarea Flood Mitigation Improvements
Central Business District — South Subarea Flood Mitigation Improvements
Bee Branch Drainage Basin Drainage Basin Bee Branch Trunk Line and Open Channel
APPENDICES (LOCATED AFTER FIGURES)
Opinion of Probable Construction Costs Appendix (See 2001 DBMP)
Completed Project Cost Summaries
Proposed Projects Opinion of Probable Construction Cost
Impervious Surface Reduction Alley Reconstruction Phasing
2 Figure numbers are numbered with an "A" to reflect their
elegance to this 2013 Drainage Basin Master Plan Amendment.
City of Dubuque, Iowa
Drainage Basin Master Plan Amendment
Table of Contents iii Fa112013
Page Left Intentionally Blank
INTRODUCTION
1.0 INTRODUCTION
The City of Dubuque (City) retained HDR Engineering, Inc. to complete an amendment to the 2001
Drainage Basin Master Plan (2001 DBMP). This amendment is called the 2013 Drainage Basin Master
Plan Amendment (2013 DBMP). This updated master plan documents the stormwater accomplishments
since the implementation of the 2001 DBMP, illustrates the current status of stormwater
projects /programs within the City, and identifies stormwater improvements that will address existing and
future drainage needs in the City's drainage basins.
Many of the recommended projects outlined in the 2001 DBMP has been implemented or are in the
process of being implemented. This amendment documents the changes in the North Fork Catfish Creek
and Bee Branch Drainage Basins studied as part of the 2001 DBMP as well as city -wide endeavors
related to stormwater management and flood damage mitigation. Figure 1 -1A shows the various drainage
basins within the City limits.
Although this 2013 DBMP focuses on the Bee Branch Drainage Basin, some projects extend outside the
drainage boundaries of the Bee Branch Drainage Basin. The City projects /programs are not limited to the
Bee Branch Drainage Basin and can be implemented in the adjacent drainage basins.
1.1 Organization of this Drainage Basin Master Plan Amendment
This 2013 DBMP is intended to update, but not replace, the 2001 DBMP. Therefore, this document is
divided into the following five sections, consistent with the 2001 document:
• Section 1.0, Introduction, introduces this 2013 DBMP.
• Section 2.0, Background and Methodology, documents stormwater management changes that
have occurred in the drainage basins since 2001 and describes the methodology used to develop
this 2013 DBMP.
• Section 3.0, North Fork Catfish Creek Drainage Basin, documents stormwater projects that have
been completed since 2001 and changes within the North Fork Catfish Creek Drainage Basin.
• Section 4.0, Bee Branch Drainage Basin, updates the discussions of the problem areas, alternative
solutions, and recommendations for improvement for each drainage subarea.
• Section 5.0, Financing Drainage Improvements and Operations, presents capital funding
opportunities, including the City's stormwater utility.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Introduction
1 -1 Fall 2013
Page Left Intentionally Blank
BACKGROUND AND METHODOLOGY
2.0 BACKGROUND AND METHODOLOGY
This section contains new text to document changes that have occurred in the drainage basins and the City
since 2001, and to describe the methodology used to develop this 2013 DBMP.
Amend 2001 DBMP Section 2.0 with new Sections 2.7 through 2.9 as follows:
2.7 Drainage Basin Hydrologic and Hydraulic Changes
Since the 2001 DBMP was completed, the hydrology and hydraulic behavior of the City's drainage basins
have undergone changes. Frequent, intense storm events had resulted in an increase in flooding, and an
increase in the frequency of federally declared disasters. The following sections describe the hydrologic
and hydraulic changes in more detail.
2.7.1 Storm Changes
In the 12 years since the 2001 DBMP was released, several intense storm events have occurred in the
Dubuque metropolitan area. By analyzing past rainfall events, statistics about rainfall recurrence can be
determined for standard return periods or frequencies, such as the amount of rainfall that statistically
occurs every 100 years. Table 2.9 outlines the magnitude and frequency of theoretical rainfall amounts
reflected in the 1992 Rainfall Frequency Atlas of the Midwest, prepared by Floyd A. Huff and James R.
Angela (1992 Atlas), for selected storm periods in northeast Iowa, which includes the Dubuque area. As
the probability of occurrence decreases, the rainfall amounts increase for a given duration. The
probability of a 100 -year storm or greater occurring in any given year is 1/100 or 1 percent. According to
the 1992 Atlas, there have been three 100 -year storm events, two 50 -year storm events, one 25 -year storm
event, and one 10 -year storm event since 2001.
Table 2.9
Magnitude and Frequency of Theoretical Rainfall Amounts for Selected Storm Periods in
Northeast Iowa From 1992 Atlas
Duration
(hours)
Rainfall (inches) for Indicated Recurrence Interval or Frequency (Years)
10
25
50
100
1
2.03
2.40
2.69
2.99
2
2.50
2.96
3.32
3.69
3
2.76
3.27
3.67
4.07
6
3.23
3.83
4.30
4.77
12
3.75
4.45
4.99
5.53
18
4.05
4.80
5.39
5.98
24
4.31
5.11
5.73
6.36
48
4.69
5.62
6.34
7.09
72
5.14
6.19
7.00
7.84
Note: Rainfall frequency amounts are from the 1992 Rainfall Frequency Atlas of the Illidwest (Huff and Angel).
3 The 1992 Atlas is based on rainfall data for a period of record between 1948 and 1992.
City of Dubuque, Iowa
Background and Methodology
Drainage Basin Master Plan Amendment
2 -1 Fall 2013
BACKGROUND AND METHODOLOGY
In April 2013, the National Oceanic and Atmospheric Administration (NOAA)4 published precipitation
frequency estimates for the state of Iowa. The precipitation estimates were calculated for a variety of
frequencies and durations. The analysis used statistical calculations on annual maximum series generated
from over 4,800 stations. The stations in Iowa that were used to generate the precipitation frequency
estimates have variable rainfall periods of record that were utilized in the analysis, spanning from 1893 to
2010. NOAA did not use a standard period of record for its analysis, but rather it conducted the analysis
using available records. The available records vary for various durations. Table 2.10 compares predicted
rainfall amounts for 24 -hour duration storm events for the 1992 Atlas and 2013 NOAA data. The 1992
Atlas data are for northeast Iowa, while the NOAA data are based on point -based frequency estimates for
a specific point in Dubuque, Iowa (latitude = 42.4968, longitude = - 90.6693). The probability of
occurrence of a less frequent storm has increased, and the 2013 NOAA 100 -year storm depth has
increased 20 percent from the 1992 Atlas rainfall amount. With the evaluation of more intense rainfall
data, the probability of occurrence of higher rainfall amounts has increased. The rainfall depth that was
predicted to occur once every 100 years is now predicted to occur once every 50 years.
Table 2.10
Comparison of Predicted Rainfall Amounts for 24 -Hour Duration Storm Events at
Selected Recurrence Intervals
Frequency
(Years)
Rainfall Amounts (inches)
Rainfall
Percentage
Increase
1992 Atlas'
2013 NOAA2
10
4.31
4.43
3
25
5.11
5.55
9
50
5.73
6.54
14
100
6.36
7.65
20
Notes:
1. Rainfall amounts are from the 1992 Rainfall Frequency Atlas of the Midwest (Huff and Angel).
2. Rainfall amounts are taken from NOAA Atlas 14, Precipitation - Frequency Atlas of the United States, Volume 8. NOAA National
Weather Service website at http: //hdsc.nws.noaa.gov/hdsc /pfds/
Table 2.11 summarizes rainfall amounts in Dubuque between 1999 and 2011, with an estimate of the
storm's statistical frequency of occurrence. In May 1999, a rainstorm dropped 3 inches of rain in 90
minutes. The subsequent damage resulted in the first in a series of seven Presidential disaster declarations
over a 12 -year period. In 2001, the record for rainfall recorded in a 24 -hour period was 6.4 inches. This
amount was equaled in 2002 and later surpassed in 2011. During the months of May and June 2008, a
record total rainfall of 15.7 inches fell in Dubuque. In August 2002, the 35- year -old record for most rain
in a 24 -hour period was matched, and in July 2011, the 24 -hour record was surpassed when 10.6 inches of
rain fell, with 10.2 inches falling in a 12 -hour period.
4 2013 NOAA Atlas 14 data are based on daily rainfall data with an average of 68 years of data used for frequency estimates.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -2 Fall 2013
BACKGROUND AND METHODOLOGY
Table 2.11
Summary of Storm Event Rainfall in Dubuque Between 1999 and 2011
Date of Storm Event
Rainfall 1
(inches)
Recording
Rainfall Duration
(hours)
1992 Atlas
Frequency
2013 NOAA
Frequency
May 16, 1999
3.0
1.5
> 25 -year
— 50 -year
June 3 -5, 2002
6.4
48
> 50 -year
> 50 -year
August 21 -22, 2002
8.9
24
> 100 -year
> 200 -year
May 21 -23, 2004
3.9
48
> 5 -year
> 2 -year
July 18, 2007
5.1
48
> 10 -year
— 10 -year
July 22 -23, 2010
7.4
48
> 100 -year
> 25 -year
July 27 -28, 2011
10.2
12
> 100 -year
> 500 -year
Note: Rainfall information was obtained from the National Weather Service, National Climatic Data Center and U.S. Geological
Survey.
2.7.2 Bee Branch Drainage Basin Flooding
Historically, the Mississippi River has flooded the City's low -lying riverfront areas several times over the
past 150 years. After the record flood of 1965, a concerted effort by local, state, and federal officials to
construct a levee system was initiated. In 1973, a 6.4- mile -long earthen levee and concrete floodwall
system, known as the John C. Culver Floodwall, was completed along the Mississippi River. In addition,
with more 100 -year storm events occurring more frequently, flash flooding has become an even greater
public health, safety, and economic issue for the City. Unlike Mississippi River flooding, flash flooding
occurs with little or no warning time, with water levels rising and flowing at extremely fast rates.
Floods are the second most common and widespread of all- natural disasters, second only to fire. The
National Climatic Data Center lists 65 flood events in Dubuque County from January 1, 1950, through
December 31, 2012. Prior to 1973, the flooding experienced by the City was related to the Mississippi
River. With construction of the aforementioned floodwall, disasters related to the Mississippi River have
largely been avoided. However, there have been six disasters since 1999 unrelated to the Mississippi
River. These disasters have been a result of localized, intense rainstorms in the Dubuque area. One of the
most destructive flash floods in the City occurred on May 16, 1999, with $16 million in property damage.
The 2010 State of Iowa Hazard Mitigation Plan estimates that Dubuque County has an annual loss of
$10,566,235 due to flooding.
More recently, in July 2011, the City experienced a significant flash flood event. According to the
National Climatic Data Center, during the early evening hours on July 27, 2011, showers and
thunderstorms developed and continued to redevelop and move over the City for approximately 18 hours.
Record - setting rainfall totals of 7 to 15 inches resulted in flash flooding of much of the area. The City
experienced significant street flooding, causing sewer covers to be blown off or washed downstream with
the floodwaters. The hardest hit areas of the City included the vicinities of St. Mary's Catholic Church,
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -3 Fall 2013
BACKGROUND AND METHODOLOGY
Elm Street, and the Historic Millwork District, all of which are located in the Bee Branch Drainage
Basin s
2.7.3 Presidential Disaster Declarations
Presidential disaster declarations are issued when emergency conditions are beyond the recovery
capabilities of local and state governments. Since the first Presidential disaster declaration in the U.S. was
issued in 1953, disasters have been declared for a variety of reasons, including: acts of terrorism, extreme
weather events, droughts and flooding. The damage caused by the event is a primary metric that
determines if a Presidential disaster declaration is issued.
There are multiple prerequisites to a Presidential disaster declaration. A governor must first consult with
local government officials to determine that the recovery appears to be beyond the combined resources of
both the local and state governments. The governor must then certify that the severity and magnitude of
the disaster does in fact exceed local and state capabilities. A preliminary damage assessment team is then
assembled, comprised of personnel from the Federal Emergency Management Agency (FEMA), the
state's emergency management agency, county and local officials, and the U.S. Small Business
Administration (SBA). The team begins by reviewing the types of damage and emergency costs incurred
by local and state governments and the impact on critical facilities such as public utilities, hospitals,
schools, and fire and police departments. The damage assessment team also looks at the effect of the
event on individuals and businesses, including the number of homes and businesses damaged, the number
of people displaced, and the threat to health and safety caused by the storm event. During the assessment,
the team collects estimates of the expenses and damages, and reports its finding. FEMA assesses a
number of factors to determine the severity, magnitude, and impact of the emergency conditions. FEMA's
recommendation to the President for federal disaster assistance considers other factors, such as the
following:
• Amount and type of damage (number of homes destroyed or with major damage)
• Impact on infrastructure and critical facilities
• Imminent threats to public health and safety
• Impacts on essential government services
• Concentration of damage6
Since 1953, when the first Presidential disaster declaration in the U.S. was issued, until 1998, seven
disasters were declared for Dubuque County due to flood damage, the first in 1969 and the last in 1993, as
shown in Table 2.12. As discussed in Section 2.7.2, early Dubuque flooding was related to a combination
of Mississippi River flooding and/or relatively minor rainfall events. With the completion of the John C.
Culver Floodwall in 1973, the City of Dubuque has prevented multiple disasters related to Mississippi
River flooding.
5 Information in this section was provided by the City of Dubuque, Iowa.
6 Information in this section was obtained from FEMA's website.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -4 Fall 2013
BACKGROUND AND METHODOLOGY
Table 2.12
Summary of Presidential Disaster Declarations in Dubuque County
1953 - 1998
Date of Declaration
Disaster
Number
Reason for Declaration
Cause of Damage
April 25, 1969
259
Flooding
Mississippi River stage at 21.7
August 14, 1969
269
Flooding and heavy rain
3.2 inches of rain in 48 hours
August 18, 1972
348
Flooding and severe storms
3.0 inches of rain in 24 hours
September 26, 1972
354
Flooding and severe storms
2.2 inches of rain in 5 hours
May 23, 1973
386
Flooding and severe storms
Mississippi River stage at 20.3
June 24, 1974
443
Flooding and severe storms
Mississippi River stage at 15.2,
2.0 inches of rain in 10 hours
July 10, 1993
996
Flooding and severe storms
Mississippi River stage at 22.3,
3.9 inches of rain in 24 hours
Notes:
1. The information provided above was obtained from the FEMA, Iowa Homeland Security and Emergency Management, and the
Iowa Emergency Management Association websites.
2. The Mississippi River flood stage is 17.0 feet at River Mile 579.9 located on the right bank at the foot of 4th Street in Dubuque
adjacent to the right abutment of the Illinois Central Railroad bridge.
3. The floodwall construction was completed m 1973.
Starting in 1999, statistically rare and intense local storm events have repeatedly caused damage above
the threshold required for Presidential disaster declarations. Seven Presidential disaster declarations
occurred between 1999 and 2011, as shown in Table 2.13.
Table 2.13
Summary of Presidential Disaster Declarations in Dubuque County
1999 - 2011
Date of
Declaration
Disaster
Num ber
Reason for Declaration
Cause of Damage
May 21, 1999
1277
Flooding, severe storms, tornadoes
3 inches of rain in 1.5 hours
May 2, 2001
1367
Flooding, severe storms, tornadoes
Mississippi River stage at 23.7
June 19, 2002
1420
Flooding and storms
4.9 inches of rain in 24 hours
June 2, 2004
1518
Flooding, severe storms, tornadoes
3.9 inches of rain in 48 hours
May 27, 2008
1763
Flooding, severe storms, tornadoes
15.7 inches of rain in 2 months
August 14, 2010
1930
Flooding, severe storms, tornadoes
4.8 inches of rain in 12 hours
August 30, 2011
4018
Flooding, severe storms, tornadoes
10.2 inches of rain in 12 hours
Notes:
1. The information provided above was obtained from the FEMA and Iowa Homeland Security and Emergency Management
websites.
2. The Mississippi River flood stage is 17.0 feet at River Mile 579.9 located on the right bank at the foot of 4th Street in Dubuque
adjacent to the right abutment of the Illinois Central Railroad bridge.
As a result of the storms and floods experienced in Dubuque and nine surrounding counties in May 1999,
a Presidential disaster declaration was issued. FEMA reported that as a result of the storms and flooding:
• 2,743 victims registered for assistance.
City of Dubuque, Iowa
Background and Methodology 2 -5
Drainage Basin Master Plan Amendment
Fall 2013
BACKGROUND AND METHODOLOGY
• $3.6 million was set aside for temporary housing, minor housing repairs, and other private
disaster related expenses.
• $6.5 million in disaster loans were approved by the SBA.
• $435,000 was obligated under the federal Public Assistance program.
On May 2, 2001, a Presidential disaster declaration was issued for flooding, severe storms, and tornadoes
that damaged private property starting on April 8, 2001. As of June 7, 2001, over $2 million had been
approved in grants and low interest loans through federal disaster assistance. No other detailed
information was available for this disaster declaration.
On June 19, 2002, a Presidential disaster declaration was issued for flooding on June 3 and June 4 in
eastern Iowa. Radar indications estimated that as much as 8 to 10 inches of rain fell during that period.
Dubuque received a total of 6.4 inches of rain, with 4.9 inches recorded in 24 hours. The National
Climatic Data Center reported that "the counties hit hardest were Delaware and Dubuque. This heavy rain
resulted in widespread and significant flash flooding" and public property damage of $2.1 million in
Dubuque County.' According to the National Weather Service, "flash flooding caused significant
property damage to homes and businesses. Rainfall rates of over 2 inches per hour were recorded... with
$7.2 million of property damage. "8 It was reported in the Telegraph Herald that the Director of Dubuque
County Disaster Services, Tom Berger, toured flood damaged areas including "'well over 200' homes in
the Dubuque area. "9 Based on the National Flood Insurance Program Bureau and Statistical Agent Iowa
loss report, as presented by the U.S. Geological Survey (USGS), the reported damage (building and
contents) per Dubuque household was $6,900.10 Businesses were damaged as well.
On June 2, 2004, a Presidential disaster declaration was issued for severe storms with tornadoes and
flooding. As reported by USGS, a series of thunderstorms that crossed north - central and northeast Iowa
on May 21 -23 caused flash flooding across northeast Iowa. Intense rain occurred in the late evening of
May 21 to sunrise on May 22, followed by intense rain on the late evening of May 22 to the early
morning of May 23.11 FEMA officials reported that 4,813 individuals registered for assistance, and that
more than $11 million of aid had been approved for individuals, families, and businesses in Iowa.12
The Presidential disaster declaration on May 27, 2008, that included Dubuque also included much of
Iowa. As reported by USGS, "precipitation from December 2007 through May 2008 was the second
wettest on record from 1895 to 2008. Notably, the precipitation in eastern Iowa and southern Wisconsin
was characterized by extremely wet conditions that normally occur less than 2.5 percent of the time. "13 In
Dubuque, the 15.7 inches of total rain for May and June measured by the NOAA National Climatic Data
' NOAA National Climatic Data Center, Storm Events Database, NOAA National Climatic Data Center website,
http: / /www.ncdc.noaa.gov /stormevents/ , accessed April 8, 2013.
8 National Weather Service Weather Forecast Office (Quad Cities, IA/IL), "East Central Iowa and Northwest Illinois
Flooding — June 4, 2002," National Weather Service website, http: / /www.crh.noaa.gov /dvn/ ?n= 06042002 cwaflood ,
accessed April 5, 2013.
9 Erin Coyle. "Storms unleash flooding — Dubuque hit by record rainfall," Telegraph Herald 5 June 2002.
10 USGS, "Flood of June 4 -5, 2002 in the Maquoketa River Basin, East - Central Iowa," Open -File Report 2004 -1250.
11 USGS, "Flood of May 23, 2004 in the Turkey and Maquoketa River Basins, Northeast Iowa," Open -File Report 2006 -1 067.
12 FEMA, "Combined Disaster Aid for Iowa Reaches $13 Million," Press release, 27 July 2004.
13 USGS, "Floods of May and June 2008 in Iowa," Open -File Report 2010 -1096.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -6 Fall 2013
BACKGROUND AND METHODOLOGY
Center was the highest total since recording began in 1951. More than $800.4 million in federal assistance
was provided, with more than $133.7 million going to 31,484 households.14
A Presidential disaster declaration was issued on August 14, 2010, for Dubuque as a result of a rainfall
event on July 22 and 23. Heavy rain, which fell in 12 hours, resulted in flash flooding. About 15 inches of
water was flowing in various streets in Dubuque as torrential rains continued." According to Police
Lieutenant Scott Baxter, "the fierce water flow ... created dangerous conditions. He said that at least one
person tried walking through deep water and nearly fell into a storm sewer (manhole) left uncovered by a
blown manhole (lid). "16 Numerous homes experienced property damage from the storms, including
flooded basements. The City's Fire Department and Public Works Department helped pump out more
than 100 basements, the majority of which are in the City's north end.17 Claims for public property
damage in Dubuque totaled more than $891,000.18
The Presidential disaster declaration issued on August 30, 2011, was the result of a storm event that
stalled over northeast Iowa in July 2011. According to the National Weather Service, "thunderstorms
developed repeatedly on the back of the storm and then `trained' across the same areas. The heaviest rain
fell from near Dyersville, IA to Dubuque, IA. Rainfall totals reached record levels in Dubuque and
extreme flash flooding resulted.i19 It was reported that u p to 15 inches of rain fell ... within a 12 -hour
period on July 27 and 28, causing flash flooding that tore up roads and bridges, flooded homes and
businesses, and claimed two lives.2° Public property damage in Dubuque totaled more than $3.1 million.21
Families who live along Elm Street within the Bee Branch Drainage Basin surveyed the damage as they
waited for the fire department to come pump the water from their homes. The City of Dubuque Fire
Department pumped out 254 basements in the hours and days following the rainstorm.
Within the past decade, Presidential disaster declarations as a result of severe storms and flooding have
occurred in eastern Iowa, Dubuque County, and the City. Although damage amounts are not published
for the City, millions of dollars have been spent providing public assistance to flood victims and
providing monies to restore public infrastructure. With the occurrence of more intense rainfall events,
effective stormwater projects /programs are necessary to avoid, minimize, and mitigate flooding.
2.8 Changes to the Stormwater Management Program
Since the development of the 2001 DBMP, stormwater- related projects /programs have been completed.
These accomplishments are summarized in the subsequent sections.
14 FEMA, "Governor Culver, FEMA officials announce Iowans have received more than $800 million in total assistance,"
Press release, 12 November 2008.
15 NOAA National Climatic Data Center, Storm Events Database, NOAA National Climatic Data Center website,
http:// www.ncdc.noaa.gov /stormevents/, accessed April 8, 2013.
16 Courtney Blanchard. "Storm swamps tri- states," Telegraph Herald, 24 July 2010.
17 Kera Mashek. "Dubuque continues flood clean-up," KWWL, 28 July 2010.
18 USGS, "Floods of July 23 -26, 2010, in the Little Maquoketa and Maquoketa River Basins, Northeast Iowa," Open -File
Report 2006 -1067.
19 NOAA National Climatic Data Center, Forecast Office, "Historic Heavy Rain and Flash Flooding in Dubuque and Jo
Daviess Counties, 07/27 - 07/28/2011," NOAA National Climatic Data Center, Forecast Office website,
http: / /www.crh.noaa.govldvn/ ?n =event 072711 dubuqueflashfloocl, accessed April 9, 2013.
20 Kurt Ullrich. "Depth of damage still sinking in " Telegraph Herald, 2 August 2011.
21 Andy Piper. "Storm's precision adds insult to injury," Telegraph Herald, 12 August 2011.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -7 Fall 2013
BACKGROUND AND METHODOLOGY
2.8.1 Stormwater Projects Completed Since 2001
Within the Bee Branch Drainage Basin, conveyance and detention improvements were defined in the
2001 DBMP. Detention was provided along Carter Road, and the existing West 32nd Street Detention
Basin was expanded. In the 2001 DBMP, it was proposed that a portion of the existing Bee Branch storm
sewer trunk line be replaced with an open channel. This channel would begin at the 16th Street Detention
Cell, located near the Mississippi River, and would proceed upstream to near 24th Street. A phased
approach separated the Bee Branch storm sewer into "Lower" and "Upper" creek restoration segments.
The Lower Bee Branch Creek Restoration extends from the 16th Street Detention Cell to the Canadian
Pacific Railway22 (CP Railway), and construction of the restored creek and floodplain area was
substantially complete in 2011. The Upper Bee Branch Creek Restoration will continue north of the CP
Railway crossing and terminate at 24th Street. Land acquisition is near completion for the Upper Bee
Branch Creek Restoration, with construction scheduled to begin in the spring of 2014.
Table 2.14 summarizes the 2001 DBMP projects that have been completed, and Table 2.15 summarizes
other conveyance and storage improvement projects that were not specifically identified in the 2001
DBMP but have been implemented. These other projects are described in more detail within the
individual subarea discussions in Section 4.0. Figure 2 -1A shows the locations of the implemented
projects.
Table 2.14
2001 DBMP Completed Projects
2001 DBMP
Project
Identifier
Location
Implementation Summary
Approximate
Project Cost
W32 -DET -2
Carter Road
Construction of Carter Road Detention
Basin. Construction was completed in
2004.
$1.4 million
W32 -DET -3
West 32nd Street
Detention Basin
Expansion of existing detention basin.
Construction was completed in 2009.
$4.6 million
BB -1, Lower
Bee Branch
Creek
Restoration
16th Street Detention
Cell to 19th Street
Restoration of Bee Branch Creek from
16th Street Detention Cell to CP Railway
(19th Street) included property acquisition,
demolition, and construction. Construction
was substantially completed in fall 2011.
Final project acceptance is pending.
$15.9 million2
Notes:
1. Project cost includes engineering, property acquisition, construction, and legal fees (as necessary). Project costs escalated to
current dollars (June 2013) using the Engineering News Record (ENR) 20 -city average Construction Cost Indices.
2. Final project cost has not been established by the City of Dubuque City Council. Cost does not include the additional $1.6
million in planned appurtenances.
22
Formerly known as Dakota, Minnesota and Eastern Railroad (DM &E) which consolidated with Iowa, Chicago and Eastern
Railroad (IC &E) in 2002. DM &E and IC &E were acquired by Canadian Pacific Railroad in 2008.
City of Dubuque, Iowa
Background and Methodology 2 -8
Drainage Basin Master Plan Amendment
Fall 2013
BACKGROUND AND METHODOLOGY
Table 2.15
Other Completed Conveyance and Storage Improvement Projects
Project Name
Location
Implementation Summary
Approximate
Project Cost'
Locust Street
Improvements
Locust Street
between Rosedale
Avenue and
Kirkwood Street
Reconstruction of Locust Street included
replacement of the existing storm sewer
system with 48 -inch diameter reinforced
concrete pipe. Construction was
completed in 2003.
$0.4 million
Burden Street
Reconstruction
Burden Street
Reconstruction of Burden Street included
the installation of a storm sewer system.
Construction was completed in 2001.
$0.2 million2
Windsor
Avenue Relief
Storm Sewer
Windsor Avenue
from Burden Street to
Sutter Street
Construction included the installation of a
42 -inch diameter storm sewer system
extending from Burden Street to Sutter
Street. Construction was completed in
2008.
$0.2 million
Historic
Millwork
District
Within boundary of
White Street,
Highways 151/61,
and 11th Street
Construction included reconstruction of
the street system with pervious pavement
and other complete street elements.
Construction was completed in 2012.
$8.3 million
Impervious Area
Reduction
Various alleys and
Washington Street
Parking Lot
Construction included replacement of
impervious alley and parking surfaces
with pervious pavement technologies
within the Bee Branch Drainage Basin.
Construction started in 2009. To date,
eight alleys and one parking lot are
complete.
$1.2 million3
Notes:
1. Project cost includes engineering, property acquisition, construction, and legal fees (as necessary). Project costs escalated to
current dollars (June 2013) using the ENR 20 -city average Construction Cost Indices.
2. This cost is for only the storm sewer construction. Total project cost was — $1 million.)
3. Represents the costs as of October 2013.
2.8.2 Stormwater Management Utility
The City created a Stormwater Management Utility on February 27, 2003. The Stormwater Management
Utility is a unit within the City that manages stormwater through public right -of -way and property owned
by the City. The Stormwater Management Utility generates its revenue solely through a user fee, which is
used to cover the costs of stormwater management activities, including individual projects, stormwater
programs, and compliance with the National Pollutant Discharge Elimination System (NPDES) program
within the corporate limits of the City. Operation and maintenance of stormwater systems are funded via
the general fund and not the stormwater management utility.
The stormwater utility fee is billed by way of the City utility bill and is based on the measurement of a
property's impervious ground coverage. Impervious area means the number of square feet of hard -
surfaced areas. Instead of attempting to maintain a current, accurate measurement of the impervious area
of the approximately 20,000 residential properties, the City charges the majority of single family homes
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -9 Fall 2013
BACKGROUND AND METHODOLOGY
for one billing unit, or one Single Family Unit (SFU), per month. As part of the development of the
stormwater utility fee, it was determined that the average single family residential (SFR) property in the
City has approximately 2,917 square feet of impervious area. Therefore, 2,917 square feet of impervious
area are associated with one SFU.
At its inception, the stormwater utility fee was $1.29 per month per SFU as stormwater management
activities were funded in part with property tax and sales tax funds. The stormwater utility ordinance was
amended in 2008 to become a self - supported utility and the SFU rates were revised accordingly. The
charge in 2013 is $5.60 per month per SFU. In order to build upon the equity of the fee structure, a tiered
system was established so that SFR parcels with impervious area 1.5 times more than the SFU impervious
area are charged 1.5 SFUs. SFR parcels that have impervious area that is less than half of the SFU
impervious area pay 0.5 SFUs. The SFU for a non - residential property is based on the actual, measured
impervious area of the parcel. The SFUs are determined by dividing the total measured impervious area
by the impervious area associated with one SFU, or 2,917 square feet. The monthly fee for non - residential
properties is then determined by multiplying the number of SFUs by the rate per SFU.
No properties are exempt from paying the stormwater utility fee. The stormwater utility fee generated
between $0.6 and $0.7 million dollars in its inaugural year, and is projected to generate approximately
$3.2 million for Fiscal Year (FY) 2013.23
2.8.3 National Pollutant Discharge Elimination System (NPDES) Permit
The City's current NPDES permit (Permit No. 31- 26 -0 -04) was issued on November 30, 2009, by the
Iowa Department of Natural Resources (IDNR). The City is permitted as a Phase II Municipal Separate
Storm Sewer System (MS4). Phase II MS4s are designated as small regulated cities or counties. The City
is regulated to prevent and manage stormwater pollution, to the extent practicable, in accordance with the
implementation of six best management practices (BMPs) and measurable goals. These six BMPs
include:
• Public Education and Outreach on Stormwater Impacts — The City complies with this requirement
by distributing a stormwater education brochure, operating a telephone hotline for reporting
stormwater- related problems, hosting a website for communicating stormwater- related topics and
interaction between residents and the City, labeling storm drains, and conducting a public
education program.
• Public Involvement and Participation — The City complies with this requirement by holding
meetings with an environmental advisory committee comprised of community stakeholders and
by working with various groups to monitor water quality and collect water quality data at
stormwater outfalls.
• Illicit Discharge Detection and Elimination — The City complies with this requirement by
enforcing an illicit discharge prohibition ordinance, implementing an illicit discharge detection
and elimination program, and enforcing a pet waste ordinance requiring pet owners to remove
and dispose of their pet's waste immediately upon deposition on public property.
23
Information in this section was obtained from the City of Dubuque Code of Ordinances 13 -4, last amended on February 28,
2013, and from the City of Dubuque's website ( http:// www. cityofdubuque .org /index.aspx ?NID =877).
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -10 Fall 2013
BACKGROUND AND METHODOLOGY
• Construction Site Stormwater Runoff Control — The City complies with this requirement by
enforcing a construction site runoff control ordinance, conducting a construction site review and
inspection program including plan review and site inspections for specific permit provisions,
inspecting runoff control BMPs for proper maintenance, and providing or sponsoring a contractor
workshop that educates consultants and contractors on the implementation of erosion and
sedimentation control BMPs on site.
• Post - construction Stormwater Management — The City complies with this requirement by
enforcing a post - construction site runoff control policy ordinance, requiring review and approval
of post - construction runoff control BMP design prior to construction, inspecting runoff control
BMPs for proper maintenance, implementing a drainage basin assessment program that includes
flood reduction and water quality improvement measures, and providing or sponsoring a low
impact development (LID) workshop to educate developers about LID techniques for stormwater
runoff quality improvement.
• Pollution Prevention/Good Housekeeping — The City complies with this requirement by operating
and maintaining the City's MS4 system (including street sweeping; inspecting storm sewers,
catch basins, and detention basins; and maintaining them as appropriate), managing municipal
application and storage of pesticides and fertilizers to reduce pollutant discharge, implementing a
training program for municipal employees on practices to reduce stormwater pollution, and
assessing and implementing BMPs at City facilities to reduce stormwater pollutants.
As part of the permit requirements, the City is required to submit an annual report that documents the
City's status on each of the six above - mentioned requirements, monitoring data, the City's expenditures
related to the implementation of permit requirements, and a summary of permit enforcement activities.24
2.8.4 Impervious Surface Reduction
Urbanization in the City and surrounding areas has resulted in a steady shift from natural landscapes to
impervious surfaces such as roads, driveways, parking lots, sidewalks, and rooftops. This increase in
impervious cover is directly correlated to an increase in stormwater runoff volumes, an increase in flow
rates, and a substantially increased frequency of moderate flooding. It has been estimated that a flood
event occurring once in 100 years could occur as frequently as once every 5 years in the same drainage
basin if impervious area within the drainage basin is increased to 25 percent. Similarly, a total impervious
cover of 65 percent in the same drainage basin could make the flood event occur every year. Increases in
the peak flow of runoff can result from even moderate amounts of drainage basin development, such as 5
to 10 percent impervious area.25 As outlined in the Iowa Stormwater Management Manual (ISMM),
impervious pavements can produce two- thirds of the excess runoff in an urban area as the runoff volume
is increased and the time of concentration is decreased, resulting in increased peak rates of runoff. In
short, impervious area directly correlates to flooding.
24 Information on the NPDES system was obtained from NPDES Permit No. 31- 26 -0 -04 issued by IDNR on November 30,
2009, governing the City of Dubuque and the following receiving water courses: Little Maquoketa, Cloie Branch, Granger
Creek, South Fork Catfish Creek, Middle Fork Catfish Creek, North Fork Catfish Creek, Catfish Creek, Bee Branch and the
Mississippi River. This current permit expires on November 20, 2014.
25 R.D. Klein, "Urbanization and Stream Quality Impairment," Water Resources Bulletin, 15(4): p.953 (1979).
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -11 Fall 2013
BACKGROUND AND METHODOLOGY
Conventional approaches to stormwater management can attempt to address increased runoff and prevent
flooding and flood damage; however, in many cases, conventional approaches may exacerbate flooding
downstream. The National Research Council (NRC) has explored the limitations of traditional approaches
to stormwater management, such as large, centralized detention basins that reduce peak runoff flows but
do not reduce overall runoff volumes. The NRC advocates for stormwater management approaches that
restore hydrologic functions through techniques such as pervious pavement, which conveys runoff into
the ground closer to where it originates rather than conveying it quickly downstream. Compared to
conventional pavements, pervious pavement conveys stormwater into the ground instead of sheet flowing
off the surface 26
Pervious pavement can reduce localized flooding and significantly reduce negative downstream impacts
in a way that conventional approaches are less able to do.27 This would decrease the volume of runoff and
the runoff rate, both of which contribute to the flash flooding experienced within the Bee Branch
Drainage Basin. Some findings have shown that pervious pavement can convey 80 percent of rain into the
ground.28 Increasing infiltration can substantially reduce the overall amount of stormwater and can reduce
flooding and flooding - related impacts such as decreased property values and tax revenue associated with
flooding, damages to public infrastructure and associated repair costs, and damages to private and public
property 29
To reduce runoff volumes and flow rates within the Bee Branch Drainage Basin, and to convey runoff
into the ground versus conveying it quickly downstream, the City has started reducing the percentage of
impervious areas on public right -of -way and on City property by increasing the conveyance of
stormwater into the ground by reconstructing impervious alleys and streets within the drainage basin with
pervious pavement systems.
There are three main types of pervious pavement designs: pervious asphalt, pervious concrete, and
permeable interlocking concrete pavement systems. These three systems have high initial surface
infiltration rates and can immediately infiltrate and store rainfall and runoff from high intensity
rainstorms. According to ISMM, the typical surface infiltration rates for these pavements exceed 200 to
250 inches per hour. This is several orders of magnitude higher than all of the rainfall intensities
encountered in the upper Midwest. These high infiltration rates are also 2 to 3 orders of magnitude higher
than most of the soils found in the Bee Branch Drainage Basin which have soil permeability rates ranging
from 0.06 to 20.0 inches per hour.3° As shown in Figure 2 -2A, all alleys and the vast majority of streets
within the drainage basin are over soils with permeability rates greater than 0.5 inch per hour, the
minimum permeability of subsoils required for a pervious pavement system to be able to convey
stormwater into the ground.31 In addition to the permeability of the subsoils, the slope of the pavement
system can preclude a pervious pavement system as an effective stormwater management system.
26 Iowa Department of Natural Resources. "Iowa Stormwater Management Manual" (Version 3; October 28, 2009).
27 National Research Council. "Urban Stormwater Management in the United States" (2008).
28 From Booth, Leavitt, and Peterson (1996). `The University of Washington Permeable Pavement Demonstration Project:
Background and First -Year Field Results." The Water Center at the University of Washington, Seattle, WA.
29 Joint report by American Rivers, the Water Environment Federation, the American Society of Landscape Architects and
ECONorthwest "Banking on Green ", April 2012.
32 USDA -Soil Conservation Service. "Soil Survey of Dubuque County Iowa" (1985).
31 Stephen Jones, PE. "Site Evaluation for Porous Pavements." Presentation given at ASCE Geotechnical Conference (2009).
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -12 Fall 2013
BACKGROUND AND METHODOLOGY
Prior to drainage basin -wide implementation, a pilot project was undertaken to identify the viability of
pervious pavement systems as well as to determine construction materials and design preferences. The
Green Alley Pilot Project involved the reconstruction of two asphalt alleys between White and Jackson
Streets running from 11th to 12th Streets and from 12th to 13th Streets. The two alleys allowed for
evaluating two systems: brick pavers and pervious asphalt. The alley running from llth to 12th Streets
was paved with brick pavers using a high- strength, permeable interlocking concrete pavement, and the
alley running from 12th to 13th Streets was paved with pervious asphalt. As a part of another pilot project
to evaluate pervious concrete, a City -owned parking lot was paved using pervious concrete.
Based on the experiences and knowledge gained from the Green Alley Pilot Project, completed in 2010,
the City determined that pervious alleys are viable within the Bee Branch Drainage Basin as a stormwater
management system. In addition, permeable interlocking concrete pavement is the best value in terms of
its life -cycle costs (including construction cost, maintenance costs, durability, and design life). As of
June 2013, the City has rehabilitated 8 alleys with 40,720 square feet of pervious pavement systems.
In addition to the elimination of impervious alleys, the City has also completed a pilot pervious street
pavement system as part of the Historic Millwork District Complete Streets Project. This project included
the reconstruction of underground utilities, roadway sub -base, concrete streets, concrete sidewalks,
pervious pavers in some of the parking areas, and re -use of existing brick pavers in streetscape areas. The
project was completed in 2012 with financial assistance from a U.S. Department of Transportation
(USDOT) Transportation Investment Generating Economic Recovery (TIGER) grant and from a private
contribution 32 To date, the pervious street system has proven to be a viable pavement choice for streets.
When streets are scheduled for reconstruction, the viability of replacing the impervious street pavement
with a pervious pavement system will be investigated as part of the design process. In general, however,
streets are less viable as pervious pavement systems due to limitations related to traffic volumes, traffic
loads, turning movements, and environmental issues.
2.8.5 Lot Source Reduction
Another way to mitigate flooding is to reduce the concentration and volume of runoff from individual
properties. To that end, the City has implemented a cost share program to promote the installation of rain
gardens and the stabilization of stream banks. This program helps defray costs for individual property
owners to implement rain gardens or stabilize stream banks located on their property. The assistance is
limited to providing materials for the projects and it cannot exceed more than half of the total cost of the
project. Applications for assistance are evaluated by City staff on a case -by -case basis, and awards are
contingent on available funding 33
2.8.6 City Requirements for Stormwater Treatment and Detention
The City has implemented the Unified Development Code (UDC), which is a combination of the City's
32 Information on the Millworks District project was obtained from the January 24, 2012 Historic Millwork District Complete
Street Project Final Project Acceptance Memo.
33 Information on lot source reduction programs were obtained from the City of Dubuque public education pamphlet on
Stormwater Quality improvement.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -13 Fall 2013
BACKGROUND AND METHODOLOGY
zoning ordinance, subdivision regulations, historic preservation ordinance, and portions of the building
code. The UDC includes requirements for sustainable subdivision development tools in Section 11 -10.
The UDC also includes a sustainable site development requirement to use two or more Low Impact
development (LID) or other Best Management Practice (BMP) tools approved by the City engineer, as
specified in Section 13 -3.3 of the UDC. The allowable tools for use on a site development include the
following:
• Reduced lot grading
• Check dams
• French drains or soak away pits
• Green roofs
• Microbasins
• Permeable pavement
• Rainwater harvesting systems
• Sidewalks and drives sloped toward open
space
• Bioswales
• Native plantings
• Open water features
• Rain gardens
• Swales
• Trees and other plantings
• Tree filters
• Vegetative buffers
The primary purpose of these features is to encourage more infiltration and/or filtration of stormwater
runoff, thereby reducing the amount of stormwater exiting the site. Reducing stormwater runoff at the
source helps to better manage downstream flooding. These features also can improve the quality of the
stormwater runoff.
In addition to the UDC LID requirements, City policy codified by an ordinance requires detention
requirements for new development greater than 1 acre in size. The post - development peak runoff rate for
the 2 -, 10 -, and 100 -year storm event cannot exceed the pre - development peak runoff rate. The operation
and maintenance of the detention facilities located on non - residential land is the responsibility of the
property owner. On residential development, the developer is responsible for the construction of the
detention facility, and the City may, by ordinance, assume operation and maintenance responsibility and
then assess costs to the subdivision residents.
2.8.7 FEMA Floodplain Revisions
At the time of the 2001 DBMP, the effective Flood Insurance Rate Maps (FIRMs) for the City (dated
September 6, 1989) showed shaded and unshaded Zone X zones within the area of the Central Business
District — North Subarea and the Central Business District Subarea. Shaded Zone X zones indicate the
500 -year floodplain. There was no floodplain designation along the Bee Branch. In 2009, FEMA updated
its analysis for these subareas and published draft maps for the City's review. See Figure 2 -3A for a
graphical depiction of FEMA's draft floodplain maps from 2009. These maps showed the Central
Business District — North, Central Business District, and portions of the Kaufmann Avenue and West 32n1
Street Subareas within the 1- percent annual chance (100 -year) floodplain.
Following the publication of FEMA's draft floodplain maps in 2009, the City investigated the buildings
present within the revised floodplain boundary as well as potential impacts of flood insurance
requirements within the revised floodplain boundary. Figures 2 -4A and 2 -5A reflect the buildings and the
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -14 Fall 2013
BACKGROUND AND METHODOLOGY
historic nature of those buildings that were included in the 2009 proposed floodplain boundary. Based on
information from the City Assessor's Office, 85 percent of the impacted properties include potentially
eligible buildings for listing on the National Register of Historic Places, the official list of the Nation's
historic places worthy of preservation. In fact, 57 percent of the 1,373 buildings are more than 100 years
old.
But this boundary did not incorporate the flood attenuation benefits associated with the construction of
the Carter Road Detention Basin and the expansion of the West 32 °d Street Detention Basin. The City
initiated an appeal process to adjust the proposed floodplain boundary. The City appealed these maps and
showed revised inundation boundaries by incorporating the effects of the Carter Road and West 32 °d
Street detention projects. This resulted in a smaller floodplain boundary, as shown in Figure 2 -6A, than
FEMA showed in its proposed boundary. FEMA accepted the revised information, further revised the
floodplain boundary, and published revised maps that became effective on October 18, 2011, as shown in
Figure 2 -7A.
2.9 Methodology
The proposed project identification and recommendations presented in this 2013 DBMP were completed
using the following methodology:
• Limited hydrologic and hydraulic (H &H) modeling was completed, either as part of separate
efforts by City staff or under separate task work orders, to analyze projects presented herein.
• Project evaluation was conducted on a qualitative basis.
• Cost opinions presented herein are based on 2013 dollars. Costs have been adjusted from the time
of implementation or estimation.
• City staff provided input in the descriptions of completed projects and in the identification of
proposed projects.
• The 2013 DBMP was prepared as part of a collaborative effort on the part of HDR and the City.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Background and Methodology
2 -15 Fall 2013
Page Left Intentionally Blank
NORTH FORK CATFISH CREEK DRAINAGE BASIN
3.0 NORTH FORK CATFISH CREEK DRAINAGE BASIN
This section contains new text to document stormwater projects that have been completed since 2001 and
changes within the North Fork Catfish Creek Drainage Basin.
Amend 2001 DBMP Section 3.0 with new Sections 3.8 and 3.9 as follows:
3.8 Stormwater Projects Completed Since 2001
Within the North Fork Catfish Creek Drainage Basin, conveyance and detention improvements were
defined in the 2001 DBMP. Detention was expanded and improved at Northwest Arterial and upstream of
Pennsylvania Avenue. In addition, conveyance improvements were implemented along the North Fork
Catfish Creek between Northwest Arterial and Pennsylvania Avenue. Table 3.11 summarizes the 2001
DBMP projects within the North Fork Catfish Creek Drainage Basin that have been completed.
Table 3.11
2001 DBMP Completed Projects
)O1 DBMP Project
�� Identifier
Location
Implementation Summary
Approximate
Project Cost
NF -ST -7
Northwest
Arterial
Excavated upstream detention and built
two -stage outlet structure.
$0.2 million
NF -ST -4
Pennsylvania
Avenue
Built concrete structural wall.
$0.08 million
North Fork Catfish
Creek Stormwater and
Sanitary Improvements
— Phase I
University to
Kensington2
Excavated the channel to a trapezoidal
channel with a bottom width of 25 feet
and side slopes to 3H:1V.
$1.0 million
North Fork Catfish
Creek Stormwater and
Sanitary Improvements
— Phase II
Pennsylvania
Avenue and
JFK to
Keystones
Excavated the channel to a trapezoidal
channel with a bottom width of either 10
feet or 25 feet and side slopes of 3H:1V.
$1.3 million
North Fork Catfish
Creek Stormwater and
Sanitary Improvements
— Phase III
Keystone to
Northwest
Arterial4
Excavated the channel to a trapezoidal
channel with a bottom width of 10 feet
and side slopes of 3H:1V. This project
also included the removal of the existing
storm sewer and replacement with a triple
10- foot -wide by 8- foot -high reinforced
concrete box (RCB).
$2.0 million
Total Estimated Capital Cost:
$4.58 million
Notes:
1. Project cost includes engineering, property acquisition, construction, and legal fees (as necessary). Project costs escalated to
current dollars (June 2013) using the Engineering News Record (ENR) 20 -city average Construction Cost Indices.
2. This project is downstream of the North Fork Catfish Creek reaches identified in the 2001 DBMP.
3. This project covers a portion of the North Fork Catfish Creek reaches identified in the 2001 DBMP as the Keyway to
Pennsylvania Avenue reach and the Rosemont to Keyway reach.
4. This project covers a portion of the North Fork Catfish Creek reaches identified in the 2001 DBMP as the Northwest Arterial to
Keyway reach.
City of Dubuque, Iowa
North Fork Catfish Creek Drainage Basin 3 -1
Drainage Basin Master Plan Amendment
Fall 2013
NORTH FORK CATFISH CREEK DRAINAGE BASIN
3.9 Changes Within the North Fork Catfish Creek Drainage Basin
No other project improvements have been completed or identified in the North Fork Catfish Creek
Drainage Basin. Since the acceptance of the 2001 DBMP, the Catfish Creek Watershed Management
Authority (CCWMA) has been developed. The CCWMA was formed during the summer of 2012 and is
comprised of the City of Dubuque, Dubuque County, the City of Asbury, the City of Peosta, the City of
Centralia, and the Dubuque Soil and Water Conservation District. The purpose of the CCWMA is to work
together to solve water quality and flooding problems within the watershed. Through the completion of a
Watershed Management Plan and other initiatives, it is expected that proposed projects within the
watershed will be proposed and administered through the CCWMA.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
North Fork Catfish Creek Drainage Basin
3 -2 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.0 BEE BRANCH DRAINAGE BASIN
The discussion of the Bee Branch Drainage Basin in the 2001 DBMP is hereby updated in this 2013
DBMP. Text is being added to update discussions on the problem areas, alternative solutions,
recommendations for improvement, and project phasing for the following drainage subareas that comprise
the Bee Branch Drainage Basin:
• West 32nd Street
• Kaufmann Avenue
• Locust Street
• Central Business District — North
• Central Business District
• Bee Branch Storm Sewer Trunk Line
Figure 4 -1A shows the extent of the Bee Branch Drainage Basin, and Figure 4 -2A shows a graphical
depiction of the individual subareas within the Bee Branch Drainage Basin.
Each drainage basin subsection below includes an identification of problem areas, conceptual
improvement plans to mitigate flooding in the problem areas, and capital cost estimates for each
improvement project.
4.1 General Drainage Basin Description
No change from 2001 DBMP.
4.2 West 32nd Street Drainage Subarea
The West 32nd Street Drainage Subarea is located in the upper portion of the Bee Branch Drainage Basin,
is approximately 1.9 square miles in size, and drains into the West 32" Street Detention Basin. See
Section 4.2.1 of the 2001 DBMP for more detail on the description of the West 32" Street Drainage
Subarea.
Amend 2001 DBMP Section 4.2 by adding the following text to the end of each designated subsection as
follows:
4.2.4 Problem Areas
City staff has identified the open channel drainageway from the outlet of the Carter Road Detention Basin
to the upstream end of the West 32" Street Detention Basin as being in need of monitoring for potential
instability and need for potential stabilization. In some locations, sediment was eroded from the side
slopes of the channel, creating steep and near vertical banks. As a sediment management strategy, a
baseline condition of the stream banks was completed in 2008 by surveying typical cross - sections
between the two detention basins. Stream channels that have degraded to a point where the banks are no
longer stable, resulting in incision or bank deterioration, hamper the stream's flood control capacity.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -1 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.2.5 Development of Alternative Solutions
One alternative considered for stabilizing the stream banks between the Carter Road Detention Basin and
the West 32nd Street Detention Basin was the enclosure of the stream into a culvert system. Similar to
what was originally done with the Bee Branch storm sewer trunk line, the open channel would be
replaced with a storm sewer system. This option would result in the potential for adverse wetland impacts
and would require lateral storm sewers along the alignment.
Another alternative considered was to restore the channel with the construction of grade stabilization
structures to reduce the channel grade and prevent erosion, and to modify the channel cross - section to
restore capacity and provide stable slopes.
4.2.6 Recommendations for Improvement Alternatives
It is recommended that the existing stream channel alignment between the Carter Road Detention Basin
and the West 32nd Street Detention Basin be monitored and, if necessary, restored. On a regular time
interval, such as every 3 years, the baseline cross - sections defined in 2008 should be surveyed and
evaluated for any change in slope and shape. With the construction of the Carter Road Detention Basin,
the average flow rates have been reduced and the impact on the degrading stream minimized. See Figure
4 -3A for the location of the proposed stream monitoring project.
4.2.7 Project Phasing
The recommendation for the West 32nd Street Drainage Subarea is stream monitoring along the Bee
Branch between the Carter Road Detention Basin and the West 32nd Street Detention Basin. The
recommended improvement is summarized in Table 4.9A.
Table 4.9A
West 32nd Street Drainage Subarea
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated
Cos- 0-
Bee Branch — Along
Carter Road and West
32nd Street
Monitor stream banks.
$5,000
Total Estimated Capital Cost:
$5,000
Note:
1. Estimated annual cost includes time associated with performing field inspections and gathering data necessary to detect charges
year to year.
Amend 2001 DBMP Section 4.2 with new subsection 4.2.8 as follows:
City of Dubuque, Iowa
Bee Branch Drainage Basin 4 -2
Drainage Basin Master Plan Amendment
Fall 2013
BEE BRANCH DRAINAGE BASIN
4.2.8 Completed Project Implementation
Since the completion of the 2001 DBMP, the existing West 32" Street Detention Basin was expanded and
the Carter Road Detention Basin was constructed. The stormwater facilities are described below.
The West 32nd Street Detention Basin project included the expansion of an existing detention facility,
acquisition of property, the construction of two wet ponds, incorporation of aquatic vegetation in the
upstream wet pond, and planting of wild flowers and prairie grasses. The two -cell detention basin was
sized to control the 100 -year, 24 -hour rain event; however, the design includes the ability to reduce
discharge rates from more frequent storm events as well. Additional necessary improvements that were
constructed as part of the project include the replacement of the bridge under West 32" Street just east of
Wildwood with a twin 9- foot -wide by 8- foot -high box culvert, and construction of 328 feet of 24 -inch
diameter ductile iron sanitary sewer; 66 -, 96- and 108 -inch large diameter storm sewer; 2,200 feet of
6- foot -wide sidewalk along West 32" Street; a stone shoulder along West 32" Street where no curb and
gutter existed; a parking lane for four vehicles along West 32" Street; and a gate structure for
maintenance purposes of the wet pond. See Appendix B for an update to the total project cost.34
The Carter Road Detention Basin project included the construction of an earthen dam approximately
350 feet long and 40 feet high, with a principal outlet consisting of a 15 -inch diameter drawdown pipe
and a 24 -inch diameter gated drainage structure. The secondary, or auxiliary, outlet is a 48 -inch diameter
riser pipe that is approximately 37 feet high. A 350 -foot long asphalt road provides access to the outlet
structure for operation and maintenance purposes. The existing sanitary sewer was rebuilt as part of this
project due to the additional embankment depth associated with the dam. See Appendix B for an update to
the total project cost.35
See Figure 4 -3A for the location of West 32" Street and Carter Road Detention Basins projects.
4.3 Kaufmann Avenue Drainage Subarea
The Kaufmann Avenue Drainage Subarea is in the west- central portion of the Bee Branch Drainage Basin
and is approximately 1.3 square miles in size. Drainage is predominantly in an easterly direction,
discharging into the Bee Branch storm sewer trunk line. See Section 4.3.1 of the 2001 DBMP for more
detail on the description of the Kaufmann Avenue Drainage Subarea.
Amend 2001 DBMP Section 4.3 by adding the following text to the end of each designated subsection as
follows:
4.3.4 Problem Areas
The 2001 DBMP identified locations where the existing storm sewer hydraulic capacity was not in
34 Information on the West 32nd Street Detention project was obtained from the February 12, 2008, City of Dubuque memo
requesting authorization of the public bidding procedure and from the December 1, 2009, City of Dubuque project
acceptance memo.
35 Information on the Carter Road Detention Basin project was obtained from the August 29, 2003, City of Dubuque memo
requesting bid award and from the November 29, 2004, City of Dubuque project acceptance memo.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -3 Fall 2013
BEE BRANCH DRAINAGE BASIN
compliance with the City's drainage standards /criteria in Table 4.14. The expansion of the capacity of
storm sewer inlets and pipes would significantly reduce flooding of streets and adjacent properties within
the Kaufmann Avenue Drainage Subarea. While streets and overland flow routes are an integral part of
the storm drainage system, they should convey runoff without flooding buildings. Two locations within
the Kaufmann Avenue Drainage Subarea were identified by City staff for priority replacement: Valeria
Street and 22" Street.
Valeria Street
The residents located along the 400 block of Kaufmann Avenue and Valeria Street has experienced
persistent flooding over the last two decades. Storm events with rainfall of 3 inches or greater have
resulted in surcharge of the storm sewer system, caused overtopping of the curb, and resulted in runoff
flowing between the homes causing water to pond behind 15 single family units. The City discussed this
issue with the residents in the area and determined that flooding in this area has occurred three to four
times since 2001. Removal of accumulated runoff due to flooding of this area must either evaporate or be
pumped out by residents.36
22nd Street Storm Sewer
From the 2001 DBMP, a hydraulic capacity analysis of the Kaufmann Avenue (22nd Street) storm sewer
revealed that the existing storm sewer is insufficient to convey a 2 -year rain event. The hydraulic model
indicated that a 108 -inch diameter storm sewer would be required to safely convey the 10 -year storm with
minimal street flow, as shown in the 2001 DBMP, Table 4.14.
The shortcoming of the existing 22" Street storm sewer /street drainage system is that 22" Street becomes
"like a river" across Central Avenue (US Highway 52), White, Jackson, and Washington Streets.
Motorists have become stranded in their cars at 22°d and Elm Streets, while other motorists have been
forced to abandon their stalled cars in the street. Stormwater flows have repeatedly overloaded the storm
sewer system and blown the covers off manholes, creating geysers several feet high. Photo 1 shows a
surcharged storm sewer, and Photo 2 shows residents wading in floodwaters.
Photo 1: Surcharging Storm Sewer Manhole
on 22nd Street
Photo 2: Residents Wading Through Rushing
Floodwaters
36 Information presented on the Valeria Street project was obtained from an August 20, 2012, City of Dubuque memo titled
Kaufmann - Valeria Flood Reduction Analysis from Todd Shoemaker, PE, CFM to Deron Muehring and Gus Psihoyos, City of
Dubuque Engineering Department.
City of Dubuque, Iowa
Bee Branch Drainage Basin
Drainage Basin Master Plan Amendment
4 -4 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.3.5 Development of Alternative Solutions
Alternative solutions to the Valeria Street and 22 "d Street problem areas were developed, as discussed in
the following sections.
Valeria Street
Alternative solutions that were considered for the mitigation of the backyard ponding along Valeria Street
included the installation of a pump station for floodwater conveyance and/or a storm sewer alternative for
connecting this low area with the adjacent existing storm sewer system. The pump station was not
considered feasible due to the installation cost, ownership questions due to placement of the station, and
the long -term operation and maintenance cost. Storm sewer alternatives were analyzed with three
different sizes of pipes: 12 -inch diameter, 18 -inch diameter, and 24 -inch diameter RCP. Two inlet
structures would be used to capture the runoff, and the storm sewer pipe would then convey the
stormwater to the existing storm sewer system located along Kaufmann Avenue.
22 "d Street Storm Sewer
Alternatives to relieve the 22 "d Street storm sewer system included expanding the Bee Branch open
channel to accommodate the Kaufman Avenue Drainage Subarea stormwater runoff. This alternative
would require additional property acquisition and would sever traffic connectivity access through the City
by eliminating 22 "d Street, which serves as a critical east -west corridor across the City.
4.3.6 Recommendations for Improvement Alternatives
Valeria Street
It is recommended that the storm sewer project at Kaufmann Avenue and Valeria Street be constructed.
The proposed project would add two catch basins, approximately 170 feet of 24 -inch diameter RCP, a
backflow preventer, and a connection to the existing storm sewer system along Kaufmann Avenue. The
backflow preventer would be used to prevent additional ponding behind these single family homes when
the downstream storm sewer system is surcharged. It is further recommended that this project not be
constructed until the Upper Bee Branch project has been completed to allow sufficient capacity
downstream. See Appendix C for the breakdown in project elements and proposed cost for this
alternative.
22nd Street Storm Sewer
Since 2001, the H &H modeling for the Kaufmann Avenue Drainage Subarea has been refined as part of
the 2004 Bee Branch Creek Alignment Study37 and further refined during development of the final design
of the Bee Branch Creek Restoration Project. The H &H analysis38 showed that a 10- foot -wide by 6 -foot-
high reinforced concrete box (RCB) storm sewer along 22 "d Street from Central Avenue (US Highway
52) to Elm Street will prevent flooding conditions repeatedly experienced along 22nd Street. As a part of
the Bee Branch Creek Restoration Project, a portion of the existing Bee Branch storm sewer system will
be removed between 22 "d and 24th Streets, and it will be replaced by the restoration of the Bee Branch
37 Engineering work was performed by CDM Smith (Milwaukee, WI).
38 H &H analysis was performed by Strand & Associates (Madison, WI) as part of the Bee Branch Creek Restoration Project
design.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -5 Fall 2013
BEE BRANCH DRAINAGE BASIN
Creek and associated floodplain. The Bee Branch storm sewer will remain in place and viable as a relief
storm sewer south from 22nd Street. The proposed 10- foot -wide by 6- foot -high RCB storm sewer will
connect to the portion of the Bee Branch sewer to remain and restrict flow from entering the proposed
Bee Branch Creek Restoration Project. Due to the size of the proposed storm sewer, complete
reconstruction of 22nd Street and the relocation of traffic, sanitary sewer, and water supply infrastructure
would need to be completed. See Appendix C for the breakdown in project elements and proposed cost
for this alternative.
See Figure 4 -4A for the location of the Valeria Street and 22" Street Storm Sewer projects.
4.3.7 Project Phasing
The recommendation for the Kaufmann Avenue Drainage Subarea is the proposed 24 -inch storm sewer
system along the backyards of Valeria Street and the 22" Street Storm Sewer. The recommended
improvement is summarized in Table 4.15A.
Table 4.15A
Kaufmann Avenue Drainage Subarea
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated 1
Capital Cost
1
Valeria Street/Kaufmann
Storm Sewer
Install 24 -inch diameter storm sewer with two
catch basins.
$0.05 million
2
22nd Street Storm Sewer
Install 920 linear feet of 10- foot -wide by 6-
foot -high storm sewer with catch basins
between Central Avenue (US Highway 52) to
the existing Bee Branch storm sewer system
at Elm Street.
$3.2 million
Total Estimated Capital Cost:
$3.25 million
Note:
1. Estimated capital costs are in current (June 2013) dollars.
Amend 2001 DBMP Section 4.3 with new subsection 4.3.8 as follows:
4.3.8 Completed Project Implementation
In the 2001 DBMP, the only recommendation for the Kaufmann Avenue Drainage Subarea was the
construction of the Grandview /Kaufmann Detention Basin. This detention basin was determined to be
infeasible due to the potential roadway closure, traffic impacts in the area, public safety impacts
associated with the proposed project, and anticipated public opinion. This proposed detention basin would
adversely affect the transportation system in the area. The Grandview/Kaufmann Detention Basin is not
likely to be implemented; therefore, it was eliminated from further consideration.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -6 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.4 Locust Street Drainage Subarea
The Locust Street Drainage Subarea is in the upper portion of the Bee Branch Drainage Basin, is
approximately 0.9 square mile in size, and drains into the Bee Branch storm sewer which connects to the
Lower Bee Branch Creek Restoration Project. See Section 4.4.1 of the 2001 DBMP for more detail on
the description of the Locust Street Drainage Subarea.
Amend 2001 DB_ IP Section 4.4 by adding the following text to the end of each designated subsection as
follows:
4.4.4 Problem Areas
The 2001 DB MP identified locations where the existing
storm sewer hydraulic capacity was not in compliance with
the City's drainage standards/criteria in Table 4.17. The
increased capacity of storm sewer inlets and pipes would
significantly reduce flooding of streets and adjacent
properties within the Locust Street Drainage Subarea.
A problem area has been identified at the base of Locust
and 17th Streets. The grade flattens along the street and storm
sewer at this intersection, creating flooding in this area. In
addition, stormwater flows rapidly down 17th Street. The flow must cross Central Avenue (US Highway
52), and White, Jackson, and Washington Streets. Photo 3 shows the depth of stormwater against stalled
cars on 17th Street west of Central Avenue. There is too much water flowing in the streets as evidenced in
Photo 3, as there is a lack of sufficient conveyance capacity draining to the Lower Bee Branch Creek
Restoration Proj ect.
Photo 3: Stalled Cars on 17th Street during
Flash Flooding in 2011
4.4.5 Development of Alternative Solutions
Alternatives considered for the problem area at Locust and 17th Streets included: 1) a relief storm sewer
system, 2) an open channel system, and 3) an upsized storm sewer system in the downstream reach.
From the 2001 DBMP, a hydraulic capacity analysis of the 16th Street and Cedar Street storm sewer
revealed that the existing storm sewer is insufficient to convey a 2 -year rain event. The hydraulic model
indicated that a 72 -inch diameter relief storm sewer was required to safely convey the 10 -year storm with
minimal street flow, as shown in the 2001 DBMP, Table 4.17.
An open channel would have significant impact at this intersection and areas further south and east. The
road right -of -way is limited in this area and would require acquisition of a significant number of
commercial and residential properties to accommodate the channel.
An upsized storm sewer system could be limited by the low grade change in the area of the Locust and
17th Streets intersection.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4-7 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.4.6 Recommendations for Improvement Alternatives
It is recommended that a replacement storm sewer be constructed in the area of Locust and 17th Streets to
provide additional conveyance capacity for the downstream portion of the Locust Street Drainage
Subarea. The storm sewer would be constructed from Dorgan Place to approximately Elm Street,
discharging into the Bee Branch Creek Restoration Project. The existing 72 -inch diameter stone sewer
would be replaced or augmented with a proposed 84 -inch diameter storm sewer. See Figure 4 -5A for the
Locust and 17th Streets Replacement Storm Sewer projects.
4.4.7 Project Phasing
The recommendation for the Locust Street Drainage Subarea is to provide for a replacement 84 -inch
diameter storm sewer system along 17th Street. The recommended improvement is summarized in
Table 4.30.
Table 4.30
Locust Street Drainage Subarea
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated 1
Capital Cost
1
17th Street
Replacement Storm
Sewer Project
Install 2,750 LF of 84 -inch diameter storm
sewer with area inlets from Ellis Street to east
of Elm Street.
$6.8 million
Total Estimated Capital Cost:
$6.8 million
Note:
1. Estimated capital costs include contingencies (25 %) to account for estimated quantities, unit price adjustments, and miscellaneous
work - related items. An additional 15% was included for administrative, legal, and engineering costs. Right -of -way, operation
and maintenance, and mitigation costs were not included.
Amend 2001 DBMP Section 4.4 with new subsection 4.4.8 as follows:
4.4.8 Completed Project Implementation
Locust Street was improved from Rosedale Avenue to Kirkwood Street as part of a street improvement
project. This Rosedale /Kirkwood project involved improving storm sewer capacity to a 48 -inch diameter
storm sewer and extending the existing 36 -inch diameter storm sewer along Rosedale Avenue. See
Appendix B for more detailed project costs.
4.5 Central Business District — North Subareas
The Central Business District — North Subareas are in the center portion of the Bee Branch Drainage
Basin and total approximately 1.9 square miles in size. These subareas encompass the previously defined
Washington Street, Windsor Avenue, Hamilton Street, Dock Street, and Upper Kerper Subareas. The
Washington Street and Windsor Avenue Drainage Subareas drain into the Bee Branch storm sewer trunk
line. Storm flows in the Hamilton and Dock Subareas are diverted to the Mississippi River under gravity
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -8 Fall 2013
BEE BRANCH DRAINAGE BASIN
conditions and into the 16th Street Detention Cell when high water levels on the Mississippi River restrict
gravity flow. The Upper Kerper Subarea drains directly into the 16th Street Detention Cell. Additional
improvements to the Bee Branch storm sewer trunk line and creek restoration are discussed in Section
4.7, below. See Section 4.5.1 of the 2001 DBMP for more detail on the description of the Central
Business District — North Subareas.
Amend 2001 DBMP Section 4.5 with new subsection 4.5.8 as follows:
4.5.8 Completed Project Implementation
Two relief storm sewer projects have been constructed in the Central Business District — North Subareas,
as discussed below.
Burden Street Reconstruction Project
To help improve stormwater runoff conveyance efficiency and reduce localized flooding, storm sewer
improvements associated with the Burden Street reconstruction project were completed. Storm sewer
ranging in size from 15 -inch diameter to 36 -inch diameter RCP was installed along Burden Street from
Hogrefe Avenue to Windsor Avenue. See Appendix B for more detailed project costs.
Windsor Avenue Storm Sewer Extension Project
A 42 -inch diameter storm sewer was constructed along Windsor Avenue from Burden Street to Sutter
Street. This storm sewer extension connects the storm sewer installed along Burden Street with the
existing 48 -inch diameter storm sewer along Sutter Street. These improvements were constructed to
facilitate storm drainage along Windsor Avenue and the intersection of 22 ", Elm Street, and Kniest
Streets. See Appendix B for more detailed project costs.
See Figure 4 -6A for the Burden Street Reconstruction and Windsor Avenue Storm Sewer Extension
projects.
4.6 Central Business District Subareas
The Central Business District Subareas are in the lower portion of the Bee Branch Drainage Basin and are
approximately 0.9 square mile in size. These subareas encompass the previously defined 8th 11th, and 14th
Streets, and Lower Kerper Drainage Subareas. Stormwater drains from these subareas into the 16th Street
Detention Cell. The 8th Street Subarea discharges to the Mississippi River under gravity conditions and
into the 16th Street Detention Cell when gravity flow is prohibited. See Section 4.6.1 of the 2001 DBMP
for more detail on the description of the Central Business District Subareas.
Amend 2001 DBMP Section 4.6 with new subsection 4.6.8 as follows:
4.6.8 Completed Project Implementation
With federal funding in the form of a TIGER grant, the City was able to redevelop a portion of this area,
known as the Historic Millwork District, including the first pervious street system designed and built
within the City. The project resulted in a decrease in directly connected impervious surface and a decrease
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -9 Fall 2013
BEE BRANCH DRAINAGE BASIN
in impervious surface, allowing for infiltration and decreased runoff. Conveying stormwater into the
ground through the pervious pavement system aids in reducing the threat of flooding and mitigates flood
damage in the area.
In addition to the directly connected impervious surface and impervious surface reductions associated
with the Historic Millwork District project, additional reduction benefits were realized with the re-
construction of alleys in the area using pervious pavement systems. Additional information on the
pervious pavement elements can be found in Sections 2.8.4 and 4.8. See Figure 4 -7A for the Historic
Millwork District project.
Amend the title of Section 4.7 to match the following:
4.7 Bee Branch Storm Sewer Trunk Line and Open Channel (Bee
Branch Creek Restoration)
The 2001 DBMP recommended a combination of storage and conveyance to mitigate the impacts of the
100 -year storm event. This included constructing the Carter Road Detention Basin, expanding the West
32nd Street Detention Basin, increasing the capacity of the 16th Street Detention Cell, and restoring the
Bee Branch trunk line to a large open channel floodway from the 16th Street Detention Cell upstream to
24th Street. The flood control channel is described in the 2001 DBMP as Phase I and Phase II. These
phases later became the Lower and Upper Bee Branch Creek Restoration Projects.
In addition to implementing drainage improvements reflected in the 2001 DBMP, advancing engineering
designs, and further investigating problem areas; drainage deficiencies have been documented and studied
and solutions /improvements identified.
Amend 2001 DBMP Section 4.7 with new subsection 4.7.1 as follows, and renumber existing subsections
4.7.1 through 4.7.3 as subsections 4.7.2 through 4.7.4:
4.7.1 Problem Areas
Upper Bee Branch Creek Restoration (Open Waterway)
With the substantial completion of the Lower Bee Branch Restoration Project in 2011, which extends
upstream from the l6th Street Detention Cell to the eastern edge of the CP Railway property, the
construction of the Upper Bee Branch Creek Restoration Project can begin. As identified in the 2001
DBMP, the existing Bee Branch storm sewer trunk line has insufficient drainage capacity to handle the
100 -year storm event. As evaluated in the 2001 DBMP and the 2004 Bee Branch Creek Restoration
Alignment Study, and as refined in the 2009 design of the Lower Bee Branch Creek Restoration, the
Upper Bee Branch Creek Restoration Project is an open channel and flood plain area that would extend
from downstream of the CP Railway property to 24th Street.
Existing 16t" Street Detention CeII Gates
The flood control gates and pump station located at the l6th Street Detention Cell are in need of
rehabilitation. The l6th Street Detention Cell discharges into a cutoff channel of the Mississippi River
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -10 Fall 2013
BEE BRANCH DRAINAGE BASIN
through twin 12- foot -wide by 12- foot -high concrete box culverts under normal river stages. The flood
gates were installed in the 1950s and modified by the U.S. Army Corps of Engineers (USACE) in the late
1960s as part of the construction of the John C. Culver Floodwall, the floodwall /levee system that
protects the City from the Mississippi River. . During gravity flow, the twin 12- foot -wide by 12- foot -high
flood gates are open; conversely, during flood events, the flood gates are closed to prevent the Mississippi
River from flooding the landward side of the levee. During the rainstorm in July 2011, the Mississippi
River was above flood stage, and the flood gates were closed. What resulted was interior flood depths
higher than the level of the Mississippi River. The flood gates were manually opened long enough to
allow the respective water elevations to equalize.
The functionality of the existing flood gates at the 16th Street Detention Cell has been investigated by the
City. The engineering investigation and associated data collection effort also revealed that the existing
12- foot -wide by 12- foot -high flood gate system has sustained damage over the past 30 years. Corrosion
of the gates and damage to the concrete wing walls on the upstream and downstream sides of the gates
have been documented 39
North End Storm Sewer
Repetitive flooding occurs in the "North End" of the Washington Street Subarea between White and Elm
Streets on 25th to 30th Streets during heavy rains due to inadequate drainage capacity. With the
completion of the Lower Bee Branch Creek Restoration Project, the need for additional storm sewer and
catch basins in the vicinity of the existing Bee Branch storm sewer trunk line can be further refined.
Amend 2001 DBMP Section 4.7 by adding the following text to the end of each designated subsection as
follows:
4.7.2 Development of Alternative Solutions
Upper Bee Branch Creek Restoration (Open Waterway)
Since the idea of the Bee Branch Creek Restoration Project was first presented in 2001, the City has
actively engaged the public, sharing information and asking for public input.
In May 2003, the City kicked off the Bee Branch Creek Alignment Study. The main objective was to
work with impacted residents, in the form of a citizen advisory committee, to ensure that the
recommended alignment location and waterway design were based on input from the neighborhoods
impacted by the proposed open waterway. The Bee Branch Citizen Advisory Committee (BBCAC)
provided input with regard to the social and economic concerns and the needs of the impacted
neighborhoods. It helped establish the criteria that would be used to evaluate alternative
alignments /preliminary designs for the open waterway, and ultimately the BBCAC made an
alignment/preliminary design recommendation to the City Council. Collectively, the 16- member
committee was made up of impacted Bee Branch Drainage Basin residents, impacted property owners,
senior citizens, a developer, a State representative, and a Dubuque Board of Realtors member. In addition
to the 16 citizens who participated in the BBCAC meetings, hundreds of citizens living in the flood -prone
39
Information on flood gates obtained from the Engineering Capital Improvements Plan (CIP) project write -up for Bee Branch
Flood Control Pumping Station Gates Replacement Project.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -11 Fall 2013
BEE BRANCH DRAINAGE BASIN
neighborhoods were informed about the project through a series of Bee Branch Alignment Study
Newsletters that were mailed to them.
On March 30, 2004, the BBCAC co- hosted a public meeting at a neighborhood elementary school. The
meeting included an open house, project background presentation, question- and - answer period, and
public input session. Approximately 70 citizens attended the meeting. The meeting provided citizens with
the information they sought and provided the BBCAC, engineers, and City staff a better understanding of
citizens' concerns with the proposed Bee Branch Creek Restoration Project.
In addition to the afore - mentioned public meeting, several other presentations were given by City staff.
The project elements were presented multiple times to the following organizations:
• North End Neighborhood Association • City Expo
• Point Neighborhood Association • Lion's Club
• Washington Street Neighborhood • Masons
Council • Morning Optimist Club
• North End Neighborhood Resource Fair
The BBCAC's preferred alignment for the open channel was presented in a letter from the BBCAC
Chairperson to the City Council dated June 30, 2004. The City selected BBCAC's preferred alignment
because it best met the top three criteria established by the BBCAC: 1) preserve commercial and non-
commercial services, 2) minimize residential property acquisitions, and 3) minimize the project cost. The
preferred alignment impacted 65 residential homes and 15 non - residential buildings. More information
regarding the alternatives analysis that was conducted, resulting in this preferred alignment, is presented
below.
As part of the alternatives analysis performed in the October 2004 Bee Branch Creek Restoration
Alignment Study, two main alternatives were considered for the Bee Branch. Both alternatives included an
open waterway from the l6th Street Detention Cell to the CP Railway tracks just south of Garfield
Avenue. One alternative included a culvert from the CP Railway tracks to 24th Street while the other
extended the open waterway from the CP Railway tracks to 24th Street. These two alternatives are
described in further detail below.
Culvert Analysis
Based on analysis of the culvert alternative, in order for a culvert to convey the necessary flow, dual
concrete arch pipes between 36- and 42 -feet in width would be required. This would result in a 150 -foot-
wide project corridor. The construction of the twin concrete pipe arch concept would require the
reconstruction of road intersections over the pipe alignment.
Open Channel Analysis
For analysis of the open channel alternative, the open channel was assumed to consist of a 25- foot -wide
low flow channel, a 120- to 130 - foot -wide flood control channel, and an approximately 30- foot -wide
overbank area. This results in a total corridor of 180 feet. The construction of this open channel would
require the construction of bridges to maintain traffic connectivity and road reconstruction to
accommodate the open channel.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -12 Fall 2013
BEE BRANCH DRAINAGE BASIN
As stated above, the open channel alignment alternative was selected as the preferred alternative. In
August 2008, the City hired an engineering consulting firm to prepare the final design of the Bee Branch
Creek Restoration Project. As part of the design process, a landscape committee was formed that consists
of City staff as well as citizens from the North End and Washington Street Neighborhood Associations.
The purpose of the Bee Branch Landscape Design Advisory Committee was to facilitate the development
of a landscaping plan based on the input and direction of citizens and local businesses. Committee
meetings were conducted to discuss the previous and upcoming citizen workshops, discuss landscape
design issues as they impact or relate to individual committee members and the neighborhood or
department they represent, and advise the design consultant team.
As part of the design process, the City hosted a series of workshops to gather citizen input. A press
release was issued before each workshop, and over 2,000 postcards were sent to households in targeted
neighborhoods. At the first workshop, held in October 2008, citizens were asked to identify their hopes
and fears for the project. In addition, citizens were asked to provide input on the various potential
landscape features, bridges, and secondary uses (for example, pathways, and locations for park benches,
and playground equipment). At the second workshop held in November 2008 and continued in January
2009, the design team presented conceptual drawings that began to address the citizens' hopes and fears
for the project as well as their landscape preferences. At the third workshop, in February 2009, the design
concept, developed based on citizen direction, was presented to the public for comment.
Several modifications to the 2004 Bee Branch Creek Restoration Project design were incorporated the
final design. A partial list of these design modifications is provided below:
• The Bee Branch Creek Channel was extended approximately 1,500 feet from US Highways
151 /61 to Kerper Boulevard through the existing 16th Street Detention Cell; thereby, increasing
the Phase I channel length from approximately 2,000 feet to approximately 3,500 feet.
• Excavated soil generated by the Project would be placed within the footprint of the existing 16th
Street Detention Cell, resulting in the creation of an approximate 8 -acre parcel along 16th Street
that can be developed at a later date.
• The 16th Street Detention Cell shoreline adjacent to East 12th Street was realigned to provide a
less linear and more natural appearance.
• The structural design of the proposed roadway bridges at Sycamore Street and 16th Street was
changed from precast concrete CON /SPAN® -type structures to cast -in -place concrete structures.
• The Sycamore Street structure was modified from a 48- foot -wide by 11- foot -high precast arch
culvert to a cast -in- place, 109 -foot long, three -span flat -slab bridge with an arch facing. Similarly,
the 16th Street structure was modified from an 11- foot -high by 48- foot -wide precast arch culvert
to a cast -in- place, 110 -foot long, three -span flat -slab bridge with an arch facing.
• The structural design of the roadway bridges at Rhomberg Avenue and 22nd Street changed from
precast concrete CON /SPAN ® -type structures to cast -in -place concrete structures.
• The Rhomberg Avenue and 22nd Street structures were modified from 11- foot -high by 48 -foot-
wide precast arch culverts to cast -in- place, 90 -foot long, three -span flat -slab bridges with arch
facing.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -13 Fall 2013
BEE BRANCH DRAINAGE BASIN
• The typical channel cross - section has changed from using a vegetated floodway channel with a
25- foot -wide low -flow channel to a permanent wet pool for the full width of the floodway
channel. The width of the floodway channel varies from 65 to 145 feet.
• A level control structure was added upstream of the proposed CP Railway crossing.4°
One of the more significant changes is related to conveying the stormwater through the railroad property.
Originally, this was proposed as a pre -cast bridge, but other alternatives were investigated due to the
complications of building a conveyance structure through an active railroad yard with two main line
tracks and a half -dozen yard tracks. The alignment established in the 2004 Bee Branch Creek Alignment
Study determined that the yard office building would be acquired by the City and removed. A proposed
alternative alignment was evaluated.
The original alignment required the acquisition of CP Railway property from Garfield Avenue to the CP
Railway right -of -way, removal and replacement of the CP Railway yard office, and crossing of as many
as 10 tracks with multiple switches. By comparison, the proposed alternative alignment requires the
acquisition of all or a portion of the Dubuque Furniture & Flooring (430 Garfield Avenue) property, and
permanent and temporary construction easements from CP Railway and A -1 Crane.
Track operations, including the mainline and yard tracks, must be maintained during construction based
on criteria established by CP Railway. The extent of track modifications depends on whether the structure
type requires phasing to maintain track operations. Track phasing for open -cut and trenchless construction
options were evaluated. Track phasing for open -cut construction of the bridge structure on the original
alignment requires upgrading the tracks and switches in excess of $5 million to meet CP Railway
requirements. Track phasing for trenchless construction of the culverts on the proposed alternate
alignment is anticipated to be limited to periodic adjustment if active monitoring reveals unacceptable
movement.
Several alternatives were analyzed, as follows:
Alternative 1: 141 -foot long Three -Span Steel Bridge. Alternative 1 includes the construction of
a bridge that would pass the flow from the Upper Bee Branch to the Lower Bee Branch under the
CP Railway tracks. The existing twin 10- foot -high by 12- foot -wide box culverts would remain in
place, conveying only stormwater from the existing Bee Branch storm sewer under the CP
Railway tracks. The initial plans for the proposed bridge crossing included a 141 - foot -long
bridge with a width of 87 feet 2 inches. The 141 -foot long three -span steel bridge option provided
6.01 and 5.16 feet of freeboard below the bridge low chord elevation for the 50- and 100 -year
storm event, respectively. The hydraulic performance of the bridge exceeds the CP Railway
hydraulic design criteria for bridges (that is, 2.0 feet and 0.0 feet for a 50- and 100 -year storm
event, respectively). This alternative also would improve hydraulic performance of the existing
twin 10- foot -high by 12- foot -wide box culvert by providing 5.52 and 3.36 feet of freeboard below
the crown of the existing twin culverts at the upstream and downstream end, respectively, for a
50 -year storm event. For a 100 -year storm event, 4.67 and 2.53 feet of freeboard would be
40 Strand & Associates, Technical Memo 2, Status Update of Bee Branch Hydraulic Design.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -14 Fall 2013
BEE BRANCH DRAINAGE BASIN
provided below the crown of the existing twin culverts at the upstream and downstream end,
respectively.
Alternative 2: Four 9.5 -foot diameter Steel Culverts. Alternative 2 involves constructing new
culverts under the CP Railway tracks and combining them with the existing twin 10 -foot-
high by 12- foot -wide box culverts under the CP Railway tracks to convey both the Bee
Branch storm sewer and the flow from the Upper Bee Branch to the Lower Bee Branch.
Alternative 2 e involved boring and jacking four 9.5 -foot diameter steel culverts under the CP
Railway tracks Unlike Alternative 1, the existing Bee Branch box culverts would discharge into
an open channel that conveys upstream flows from the storm sewer and channel flows.
The upstream and downstream invert elevations of the new culverts would be 590.0 and 589.39,
respectively. This alternative included the construction of a concrete junction chamber at the
upstream end of the railroad culverts. Four 10 -foot high by 10 -foot wide box culverts would
extend upstream (north) from the junction chamber to the north side of Garfield Avenue. The
existing Bee Branch culvert would connect into a proposed junction chamber.
Hydraulic modeling results indicated that the proposed culverts would meet the CP Railway
hydraulic design criteria for culverts (that is, 50 -year hydraulic grade line (HGL) at or below the
culvert crown and 100 -year HGL no more than 1.0 foot above the culvert crown). Comparing
hydraulic modeling results to Alternative 1, similar improvement to the hydraulic performance of
the existing twin box culverts would be realized.
Alternative 3: Six 6.5 -foot diameter Steel Culverts. This crossing alternative involved boring and
jacking six 6.5 -foot diameter steel culverts under the CP Railway tracks. The upstream and
downstream invert elevations of the culverts would be 589.9 and 589.4, respectively. Alternative
3 also incorporated a concrete junction chamber at the upstream end of the railroad culverts and
involves four 10 -foot high by 10 -foot wide box culverts under Garfield Avenue.
Hydraulic modeling results indicated that the proposed culverts would not meet the CP Railway
hydraulic design criteria for culverts (that is, 50 -year HGL at or below the culvert crown and 100 -
year HGL no more than 1 foot above the culvert crown). The hydraulic performance
improvement realized by the existing twin box culverts would be similar to the crossing
improvements under Alternatives 1 and 2.
Alternative 4: Seven 6.5 -foot diameter Steel Culverts. A sensitivity analysis was performed to
estimate the change in hydraulic performance of adding another 6.5 -foot diameter steel culvert to
the Alternative 3 crossing. Similar to Alternatives 2 and 3, Alternative 4 incorporated a concrete
junction chamber at the upstream end of the railroad culverts and involves four 10 -foot high by
10 -foot wide box culverts under Garfield Avenue.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -15 Fall 2013
BEE BRANCH DRAINAGE BASIN
Based on the results of this analysis, the 50- and 100 -year storm event HGL elevation in the
existing Bee Branch near Rhomberg Avenue was lowered by 0.23 and 0.27 feet, respectively.
The 50- and 100 -year storm event HGL elevation in the existing Bee Branch near 22nd Street
would be lowered by 0.1 and 0.2 feet, respectively.
Alternative 5: Five 9.5 -foot diameter Steel Culverts. Alternative 5 was developed in an effort to
achieve Upper Bee Branch hydraulic performance at the Rhomberg Avenue and 22nd Street
bridges that is at least equivalent to that of Alternative 1 (that is, a 141 -foot long three -span steel
railroad bridge). Alternative 5 would be similar to Alternative 2, but it included an additional 9.5-
foot diameter culvert under the CP and involves construction of five 10 -foot high by 12 -foot wide
box culverts under Garfield Avenue.
Hydraulic modeling results indicated that Upper Bee Branch 100 -year storm event HGL
elevations at the Rhomberg Avenue and 22nd Street bridges are both 0.1 feet lower when
compared to the Alternative 1 hydraulic modeling results.41
Existing 16th Street Detention CeII Gates
Potential solutions to repair or replace the damaged existing flood gates at the 16th Street Detention Cell
outfall include the replacement or rehabilitation of the flood gates, and replacement or rehabilitation of
the pump station. An alternative design was developed that would allow interior floodwaters to
automatically pass into the Mississippi River when a positive hydraulic gradient occurs.
The design alternative would provide increased protection for a 100 -year storm event occurring in the Bee
Branch Drainage Basin during a "Gates Closed" operating condition. To attain this higher level of flood
damage reduction, six 96 -inch diameter rubber duckbill style check valves would be implemented
immediately downstream of the existing twin 12- foot -high by 12- foot -wide box culverts at Kerper
Boulevard. The six rubber duckbill style check valves would be mounted on the downstream side of a
new flared concrete structure constructed onto the ends of the existing twin 12- foot -high by 12- foot -wide
box culverts.
North End Storm Sewer
Potential solutions to the flooding of the streets and properties along the buried Bee Branch storm sewer
trunk line from 24th Street to 32" Street are limited to those providing increased conveyance. One option
would be to extend the open waterway (restoration of the buried Bee Branch Creek) north from 24th Street
to 32" Street. This would entail a significant increase in residential and commercial property acquisition
and come at a considerable cost to the City. Another potential option would be to construct underground
vault storage systems, which might provide relief but would also entail significant property acquisition
and disturb a significant portion of the area that is highly urbanized and developed with historic buildings.
A third option would be to construct relief or replacement storm sewers with additional storm sewer
intakes to ensure that the area remains well drained during severe weather and heavy rains.
41 Strand & Associates, Technical Memo 5, Alternatives Analysis of Canadian Pacific Railway Crossing Options.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -16 Fall 2013
BEE BRANCH DRAINAGE BASIN
The extent of acquisition and construction cost for the channel expansion and underground vault systems
are incredibly cost prohibitive (that is, $30 million to $60 million), and would likely result in unfavorable
public opinion. The construction of a relief storm sewer system is limited to a utility corridor that is more
easily managed in an urban setting than either previously identified option. It would provide the same
flood damage reduction as the other options but at a small fraction of the cost ($1 million).
The design of the North End Storm Sewer system is based on ensuring that the maximum amount of
stormwater can be conveyed from the area through the existing Bee Branch Storm Sewer Trunk Line (Bee
Branch Sewer). The H &H model created as part of the 2001 DBMP and further refined as part of the
2004 Bee Branch Creek Alignment Study indicates that the conveyance capacity of the Bee Branch Sewer
varies, it is limited to 320 cubic feet per second (cfs) north of 24th Street. To prevent the stormwater from
collecting and flooding any particular area, and recognizing the uniformity of the entire area to be
drained, the optimum design involves additional storm sewer conveyance capacity and additional storm
sewer intakes along 25tH, 26th, 27tH, 28th, 29th, and 30th Streets running generally between White and Elm
Streets. Each street system would intercept and convey approximately 55 cfs to the Bee Branch Sewer,
requiring a network of 15 -, 18 -, 24 -, and 30 -inch diameter storm sewer conduits with 106 storm sewer
intakes.
4.7.3 Recommendations for Improvement Alternatives
Upper Bee Branch Creek Restoration (Open Waterway)
The construction of the Bee Branch Creek Restoration Project is intended to re- create historic flood
control conveyance through the City while reducing flood damages. The existing Bee Branch storm
sewer trunk line will remain in service between 22nd Street and the Lower Bee Branch Creek to
supplement the channel' s capacity.42
As of October 2013, the Lower Bee Branch Creek Restoration Project is substantially complete, and the
Upper Bee Branch Creek Restoration Project is under design. The construction of the Upper Bee Branch
Creek Restoration Project will be bounded by 24th Street, the southern edge of the CP Railway property
just south of Garfield Avenue, and Kniest, Prince, and Elm Streets. This project will entail the
construction of large diameter culverts under the CP Railway yard and an open channel upstream of the
railroad tracks. The portion of the alignment under the railroad, located just south of Garfield Avenue,
will consist of five 9.5 -foot diameter culverts. It is anticipated that construction will occur using a
trenchless installation method to reduce the impact on railroad operations. Construction is anticipated to
begin in the spring of 2014. The western edge of the open channel between the railroad and 22nd Street
will be along Kniest Street. The open channel will generally be centered along Elm Street between
22nd and 24th Streets. The project will include property acquisition (both partial and full), roadway
reconfigurations, construction of bridge crossings at Rhomberg Avenue and 22nd Street, and a headwall at
24th Street at the connection to the existing Bee Branch storm sewer.
42
Information in this section was obtained from the October 2004 Final Bee Branch Creek Restoration Alignment Study; the
August 11, 2010, memo from City Staff to City Council recommending bid award for the Lower Bee Branch Creek; and the
February 8, 2013, Upper Bee Branch Creek Restoration Project Technical Memorandum No. 5 — Alternatives Analysis for
Canadian Pacific Railway (CPR) crossing options.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -17 Fall 2013
BEE BRANCH DRAINAGE BASIN
Existing 16t" Street Detention CeII Gates
It is recommended that the flood gates be replaced and a few other improvements associated with the
outfall structure be made in accordance with the observations during a 2012 inspection. Due to the age of
the structure, it is recommended that the flood gates, closure structure, concrete wing walls, and lifting
mechanisms be replaced as part of the larger project. It is recommended that the pump station discharge
pipes be equipped with automatic air release valves and check valves. Finally, it is recommended that six
96 -inch diameter rubber duckbill style check valves be installed immediately downstream of the existing
twin 12- foot -high by 12- foot -wide box culverts at Kerper Boulevard. The six rubber duckbill style check
valves would be mounted on the downstream side of a new flared concrete structure constructed onto the
ends of the existing twin 12- foot -high by 12- foot -wide box culverts. While the existing slide gates would
not be routinely used during "Gates Closed" operating conditions, they could be used for emergency
backup situations if one of the rubber duckbill style check valves becomes obstructed with debris.
Implementation of the rubber duckbill style check valves would automatically provide significant
additional gravity flow capacity through the existing twin 12- foot -high by 12- foot -wide box culverts
when positive head is available during a "Gates Closed" operating condition. By incorporating these
elements into this project, the condition of the pump station would be upgraded to current USACE
standards and provide increased flood damage reduction within the Bee Branch Drainage Basin. Any
modifications to the operation of or work affecting the pump station requires the review, input, and
approval of USACE.
North End Storm Sewer
With the construction of the Bee Branch Creek Restoration Project, improvements to the North End storm
sewer would provide increased capacity and reduce flooding of streets and adjacent properties. These
improvements include replacing and upsizing the lateral storm sewers along the Bee Branch trunk line.
The North End Storm Sewer improvements would be along 25th, 26tH, 27th, 28tH, 29th, and 30th Streets
between White and Elm Streets. The storm sewer along each street would intercept and convey
approximately 55 cfs to the Bee Branch Sewer, requiring a network of 15 -, 18 -, 24 -, and 30 -inch diameter
storm sewer conduits with 106 storm sewer inlets.43
See Figure 4 -8A for the location of the Upper Bee Branch Channel Restoration, 16th Street Detention Cell
Flood Gate Replacement, and North End Storm Sewer projects.
4.7.4 Project Phasing
Table 4.31 updates the project priority list, including storm sewer trunk line area improvements with
respect to the creek restoration, flood gate, and North End storm sewer. These improvements are
prioritized on the basis of flood damage reduction.
43 Information in this section was obtained from the City CIP project write -up for the North End Storm Sewer Improvements.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -18 Fall 2013
BEE BRANCH DRAINAGE BASIN
Table 4.31
Bee Branch Drainage Subarea
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated
Capital Cost'
1
Upper Bee Branch
Creek Restoration
Construct five trenchless 9.5 -foot diameter
culverts under the railroad and open channel from
the railroad just south of Garfield Avenue to
24th Street with two bridge structures, a headwall
structure, and street reconfigurations.
$58.9 million
2
l6th Street Detention
Cell Flood Gate
Replacement
Replace damaged flood gates with concrete wing
walls and lifting mechanisms, construct automatic
air release and check valves on pump station
discharge piping, and add six rubber duckbill style
check valves mounted on the downstream side of
a new flared concrete structure.
$2.2 million
3
North End Storm
Sewer
Improvements
Upgrade the lateral storm sewer system to connect
to the Bee Branch storm sewer trunk line between
25th Street and 30th Street.
$1.0 million
Total Estimated Capital Cost:
$62.1 million
Note:
1. Estimated capital costs are based on current (June 2013) dollars.
Amend 2001 DBMP Section 4.7 with new subsection 4.7.5 as follows:
4.7.5 Completed Project Implementation
The Bee Branch Creek Restoration Project is a drainage basin -wide project involving the daylighting and
restoration of a creek through the City from 24th Street to the 16th Street Detention Cell, and selective
removal of existing portions of the Bee Branch storm sewer that would be exposed as a result of the open
channel project.
The Lower Bee Branch Creek Restoration Project is the first of three phases of this project. The 2,100 -
foot long channel project extending from the 16th Street Detention Cell to the west across Sycamore,
Cedar, and Maple Streets before extending north across 16th Street and along the western portion of the
former Dubuque Packing Company site to the railroad tracks just south of Garfield Avenue. The channel
was constructed with a 76 -foot bottom width, and a maintenance access /hiking /biking path was included
along the channel with lighting and security features. The construction of the channel included a 100 -foot
long bridge at Sycamore Street, a 110 -foot long bridge at 16th Street, and a headwall where the existing
storm sewer outfalls into the open channel. The project also included reconstruction of sanitary sewer,
construction of new storm sewer, and dredging of the 16th Street Detention Cell. Construction was
substantially completed in the fall of 2011. Final project acceptance is pending.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -19 Fall 2013
BEE BRANCH DRAINAGE BASIN
The City implemented a public involvement strategy as part of this project to accommodate public input
and consider social and economic concerns of those residents being impacted. As discussed in
Section 4.7.2, the BBCAC was established as part of the public involvement strategy. A public meeting
was held, and several neighborhood meetings were held to discuss the project need, the project
alternatives, and address citizen concerns. The BBCAC was comprised of 16 citizens and represented a
cross - section of residents that would be affected by the project. The BBCAC met six times at meetings
open to the public between September 2003 and June 2004. The committee generated a letter in June
2004 summarizing its recommendations. These recommendations include the following:
• A piped alternative was preferable to the open channel alignment. However, the BBCAC
conceded that if the piped alternative was deemed too expensive, the open channel (daylighting)
alignment was preferable to doing nothing.
• The committee recommended that a moratorium be established over both alignments until the
alignment analysis was completed in more detail. Following analysis and selection of the
preferred alternative, it was recommended that construction commence as soon as possible.
• The committee recommended that an erosion control ordinance be enacted, that stormwater
runoff reduction BMPs be encouraged for development within the City, and that the City pursue
drainage basin -level management practices with other applicable jurisdictions.
Once the open channel design was selected as the alternative of choice, the design team was selected by
the City to proceed with the design of the Lower Bee Branch open channel from the 16th Street Detention
Cell to the CP Railway property just south of Garfield Avenue. As part of the design process for this
project, public input was solicited for project features such as the recreational trail and landscaping plan
originally envisioned in the alignment study. As a result of this public participation process, a series of
amenities to enhance the project were identified, including the recreational trail, lighting, benches, an
amphitheater, and special facades for the bridge crossings over the channel. These amenities were
considered essential to the public's acceptance and overall success of the project. To help fund the
project, the City successfully pursued multiple grant funds to supplement the established stormwater
utility fund. Awarded grants include the I -Jobs II grant and the Vision Iowa River Enhancement
Community Attraction and Tourism (RECAT) grant, generating approximately $6.2 million in additional
funding. See Figure 4 -8A for the location of the Lower Bee Branch Channel Restoration project.
Amend 2001 DBMP with new Sections 4.8 and 4.9 as follows:
4.8 Impervious Area Reduction
As illustrated in Table 2.10, predicted rainfall totals for the City have increased by as much as 20 percent.
Impervious area reduction is critical to address the predicted and increasingly intense rainstorms
witnessed in the City since 2001. All alleys are located over soils with properties allowing for the
infiltration of stormwater. These soils have permeability rates above the 0.5 inch per hour (minimum
value criterion in ISMM), and nearly a third of the alleys are constructed over soils with permeability
rates between 2.0 and 6.0 inches per hour. The subsections below describe two pervious pavement
projects the City has implemented.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -20 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.8.1 Pervious Street Pavement Systems
In 2012, the City completed a TIGER - grant - funded project that included the replacement of an
impervious street system with a pervious street pavement system within the Historic Millwork District.
Photo 4 shows the nature of the streets prior to the project. Photo 5 shows the pervious pavement system
that will convey stormwater into the underlying soil.
Photo 4: Impervious, Flood -prone Historic Millwork District
Street Prior to Federal TIGER Grant Complete
Streets Improvement Project
Photo 5: Historic Millwork District Pervious Pavement System
that Conveys Stormwater into the Underlying Soil
The project was constructed over a 2 -year period and included the reconstruction of 10th Street from
Jackson to Elm Streets, Washington Street from 9th to 11th Streets, Jackson Street from 7th to 11th Streets,
utility upgrades on 11th Street from Jackson to Elm Streets, streetscaping on 9th Street from Washington to
Main Streets, streetscaping on 10th Street from Jackson to Main Streets, and the construction of a hike and
bike trail from 5th to 7th Streets along the Jackson Street corridor. Other project improvements included
the following44:
• Reconstruction/replacement of approximately 1,200 feet of 12 -inch diameter mainline sewer
• Reconstruction of 11 deteriorated brick sanitary sewer manholes
• Replacement of private sanitary sewer laterals
• Reconstruction of approximately 5,100 linear feet of water main, mainline valves, 19 fire
hydrants, and replacement of lead water services
• Construction of approximately 3,400 linear feet of new storm sewer, 16 manholes, and 63 catch
basins to improve the stormwater conveyance in the area
• Installation of fiber optics and telecommunications conduit infrastructure
• Replacement of existing sidewalks
• Removal of two underground fuel oil tanks
• Installation of pervious pavers in parking areas
• Re -use of existing brick pavers in streetscape areas
As streets near the end of their life, the possibility of transforming into a pervious pavement system will
be evaluated. Considerations will include traffic volumes, street grade, and the nature of the underlying
soil. Several good candidates are East 14th, East 15th, East 16th, Sycamore, Cedar, and Maple Streets in the
44 Information for this section was obtained from the Dubuque Warehouse District Recommendations for Revitalization
(undated) and the January 24, 2012, memorandum from City Staff to City Council recommending project acceptance.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -21 Fall 2013
BEE BRANCH DRAINAGE BASIN
vicinity of the completed Lower Bee Branch Creek Restoration Project. Based on NRCS soil information,
the underlying soils in this area have permeability rates of over 6.0 inches per hour.
4.8.2 Pervious Alley Pavement System
There are 245 alleys within the Bee Branch Drainage Basin. Computer models WinSLAMM and P8 were
used to simulate the benefit of converting alleys into pervious pavement systems. P8 was used to
determine the runoff volume and WinSLAMM was used to determine the volume abstraction percentages.
WinSLAMM was chosen because it includes a specific calculation routine for pervious pavement, and it
is based on actual field observations, with minimal reliance on theoretical processes that have not been
adequately documented or confirmed in the field. The models predict reconstruction of the alleys with
pervious pavement systems would reduce the runoff volume to the Mississippi River by approximately 50
percent45. When fully constructed, approximately 2.5 million gallons of stormwater will be conveyed into
the ground and be diverted from the Bee Branch Creek and Mississippi River on an annual basis. The
City has completed the reconstruction of eight (8) alleys. Using federal financial assistance, design is
underway to reconstruct 73 alleys over a 3 -year period so that a third of the alleys in the Bee Branch
Drainage Basin will have been converted to systems that convey stormwater into the ground 46 The
remaining alleys are to be converted into similar conveyance systems over a 20 -year period as funding is
available. Figure 2 -2A shows the location of the Bee Branch Drainage Basin alleys.
Tables D -1 through D -4 in Appendix D list the alleys that are proposed to be reconstructed by year, with
the anticipated square footage of pervious pavement.
4.8.3 Project Phasing
There is a direct correlation between impervious area and the runoff generated as a result of a rainstorm.
The decreased runoff realized by replacing impervious alleys within the Bee Branch Drainage Basin with
pervious alleys will help offset the increased rainfall predicted by the 2013 NOAA rainfall analysis.
Table 4.32 identifies the recommended impervious alleys within the Bee Branch Drainage Basin.
Table 4.32
Bee Branch Drainage Basin
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated 1
Capital Cost
1
Bee Branch
Drainage Basin
Reconstruct the 237 impervious alleys within the
Bee Branch Drainage Basin as pervious alleys to
convey stormwater into the ground.
$43.3 million
Total Estimated Capital Cost:
$43.3 million
Note:
1. Estimated capital costs based on current (June 2013) dollars.
45 Models do not use a design storm. WimSLAMM and P8 models simulate actual, continuous, annual rainfall. Total
infiltration is based on the total annual runoff volume.
46 Information on the impervious surface reduction projects was obtained from February 2013 correspondence with the Iowa
Department of Natural Resources SRF Coordinator regarding the Dubuque CWSRF Project No. GNS13 -1.
City of Dubuque, Iowa
Bee Branch Drainage Basin 4 -22
Drainage Basin Master Plan Amendment
Fall 2013
BEE BRANCH DRAINAGE BASIN
4.9 New Stormwater Management Projects
The 2001 DBMP identified stormwater management projects within the North Fork Catfish Creek and
Bee Branch Drainage Basins. In addition to the projects identified in the 2001 DBMP, the City has
identified other projects for flood damage reduction located outside of the Bee Branch Drainage Basin.
One such project is floodproofing at the City's water plant located along the Mississippi River.
4.9.1 Water Treatment Plant Floodproofing
4.9.1.1 Development of Alternative Solutions
The City's water treatment plant is located at the northeast corner of Rhomberg Avenue and Hawthorne
Street between the CP Railway property and the John C. Culver Floodwa1147. The plant supplies potable
water to Bee Branch Drainage Basin residents and businesses. It also provides a sufficient quantity and
necessary pressure for fire protection and suppression. There are concerns of losing fire fighting
capabilities potable drinking water as the result of a flood either as a result of interior drainage flooding or
a breach in the John C. Culver Floodwall.
In response to these concerns, an evaluation of a conceptual structural floodproofing strategy was
conducted as a part of this drainage master plan amendment. The City is interested in a structural solution
that incorporates a combination of permanent and temporary floodproofing measures. The evaluation
used available Light Detection and Ranging (LiDAR) topographic data, aerial images of the area, and
information on typical earthen berm and floodwall requirements. The City desires to have 6 feet of
additional protection around the water treatment plant which can be achieved by either an earthen berm or
floodwall. A 6 -foot high earthen berm would consist of side slopes of 4H:1V, a 10 -foot top width, and a
58 -foot bottom width. The floodwall would be a minimum of 1 foot thick, with an approximate 12 -foot
wide foundation slab. The width of the floodwall foundation slab can be reduced by adding sheet pile
reinforcing. A floodwall would occupy a smaller footprint and have less of an impact on adjacent
properties than an earthen levee.
A potential alignment for the floodwall is along an apparent property line as defined by a fence, as shown
in Figure 4 -9A. Using this alignment, the floodwall would parallel the railroad tracks to the southeast and
follow the existing fence. The alignment intersects three access points to the water treatment plant
facility: two access points directly off of Hawthorne Street and one from the parking lot for the Sutton
Pool. When the floodwall is constructed, openings will be left for the three access points to the water
treatment plant. Instead of flood gates, temporary closure measures will be used in the access locations
during flooding. Temporary measures may include collapsible reusable wire mesh, fabric -lined baskets
that can be installed and filled with sand, then emptied, removed, and stored when no longer needed. The
City's existing baskets are 4 feet high and 3 feet high. In order to achieve 6 feet of protection at the access
points, two rows of baskets would be stacked, one on top of the other, across the width of the access
47
John C. Culver System was federally constructed, but locally operated by the City and protects the City of Dubuque from
Mississippi River flooding. The System consists of over 20,000 feet of earthen levees and 7,100 feet of floodwalls along the
entire Dubuque riverfront. The system also includes a navigable opening into Dubuque Harbor, three pump stations and
three primary ponding facilities.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -23 Fall 2013
BEE BRANCH DRAINAGE BASIN
points. For stability, the bottom row would be double wide, with two baskets set side -by -side, and a row
of single baskets placed on top of the bottom row.
4.9.1.2 Recommendations for Improvement Alternatives
It is recommended that the water treatment plant be equipped with a permanent concrete floodwall along
the existing alignment of the property fence, with the ability to deploy temporary measures at the access
point openings. The floodwall crest will be 6 feet aboveground and is recommended to have a T -wall
footing. Due to the floodwall construction, stormwater modifications will need to be designed and
constructed. Gravity stormwater pipes will be equipped with backflow prevention devices to prevent
ponding water from collecting within the floodproofed area. Stormwater conveyance systems otherwise
impacted would need to be replaced with pumping capacity to pump directly to the Mississippi River. For
the purposes of this analysis, a detailed interior drainage analysis was not completed to determine the
exact pump station capacity. Based upon experience with levee systems, an approximate cost was
utilized to approximate the cost.
4.9.1.3 Project Summary
Table 4.33 provides a project summary and conceptual level cost opinion for construction of the
permanent floodwall system for the City's only potable water treatment plant. The conceptual cost
opinion does not include the cost of temporary measures to be deployed during a flood event.
Table 4.33
Other Stormwater Management Projects
Recommended Improvements Summary
Drainage
Basin
Priority
Location
Recommended Improvements
Estimated
Capital
Cost"
1
Potable Water Treatment
Plant Floodproofing
Construct 2,600 -foot long± floodwall with
footing, trench drain, site restoration, and
stormwater improvements.
$3.4 million
Total Estimated Capital Cost:
$3.4 million
Note:
1. Estimated capital costs include contingencies (25 %) to account for estimated quantities, unit price adjustments, and miscellaneous
work - related items. An additional 25% was included for administrative, legal, and engineering costs. Right -of -way, operation
and maintenance, and mitigation costs were not included. Costs are based on Iowa Department of Transportation 2013 unit prices.
4.10 Summary of Completed Projects in the Bee Branch Drainage
Basin
Within the Bee Branch Drainage Basin, conveyance and detention improvements were defined in the
2001 DBMP. Detention was provided along Carter Road, and the existing West 32nd Street Detention
Basin was expanded. The open channel alternative that would replace a portion of the Bee Branch storm
sewer trunk line as first prepared in the 2001 DBMP was selected for implementation. This channel
begins at the 16th Street Detention Cell, located near the Mississippi River, and proceeds upstream to near
24th Street. A phased approach separates the Bee Branch storm sewer into "Lower" and "Upper"
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -24 Fall 2013
BEE BRANCH DRAINAGE BASIN
segments. The Lower Bee Branch Creek Restoration extends from the 16th Street Detention Cell to the
CP Railway property, and construction of the creek and flood plain area was substantially completed in
2011. The Upper Bee Branch Creek Restoration will continue north of the CP Railway crossing and
terminate at 24th Street. Land acquisition is near completion for the Upper Bee Branch Creek Restoration,
with construction scheduled to begin in the spring of 2014.
Table 4.34 summarizes the 2001 DBMP projects and other conveyance projects that that have been
completed since the 2001 DBMP was issued.
Table 4.34
Completed Project Cost Summary
Project Name
Project
Completion
Year
Project Summary'
Total Cost2
Burden Street Storm
Sewer Improvements
2001
Installed storm sewer along Burden Street
from Hogrefe to Windsor Avenues,
ranging in size from 15 to 36 inches in
diameter.
$0.2 million
Locust Street
Improvements
2003
Reconstructed Locust Street between
Rosedale Avenue and Kirkwood Street,
and upsized the storm sewer.
$0.4 million
Carter Road
Detention Basin
2004
Constructed earthen dam with two
principal outlets, one auxiliary outlet, and
other associated infrastructure
improvements.
$1.4 million
Windsor Avenue
Relief Storm Sewer
Project
2008
Installed 42 -inch diameter storm sewer
along Windsor Avenue between Burden
and Sutter Streets.
$0.2 million
West 32 °d Street
Detention Basin
2009
Expanded detention to include wet ponds,
outfall structure modifications, and other
related infrastructure improvements.
$4.6 million
Lower Bee Branch
Creek Restoration
2011
Included 2,100 feet of open channel,
selective demolition of existing storm
sewer, and other associated infrastructure
improvements.
$15.9 million3
Historic Millwork
District Project
1 2012
Replaced parking areas with pervious
pavement, reused brick pavers in
streetscaping areas, and included other
infrastructure improvements.
$8.3 million
Total Capital Cost:
$31.0 million
Notes:
1. Information provided above was obtained from sources that include the Project Acceptance Memo, input from City staff, project
grant applications and correspondence, and other project - related documentation.
2. Project costs were escalated to current dollars (June 2013) using the ENR 20 -city average Construction Cost Indices.
3. Final project cost has not been established by the City of Dubuque City Council. Cost does not include the additional $1.6 million
in planned appurtenances.
City of Dubuque, Iowa
Bee Branch Drainage Basin
Drainage Basin Master Plan Amendment
4 -25 Fall 2013
BEE BRANCH DRAINAGE BASIN
4.11 Other Dubuque Flood Risk Reduction Projects
In addition to the projects identified within the Bee Branch Drainage Basin, additional improvements
associated with the federally constructed, City operated and maintained John C. Culver Floodwall may be
appropriate. The levee/floodwall system reduces the risk of Mississippi River flooding in portions of the
City. Two projects have been identified for the John C. Culver Floodwall include a levee breach analysis
and a levee functional assessment. These projects are described in more detail in the following sections.
4.11.1 Levee Breach Analysis
As acknowledged by the USACE Levee Safety Program and within the recommendations generated from
the National Committee on Levee Safety, identification of levee risk is a critical issue. Knowing the
affects of a levee breach or failure is a component of understanding a levee system's risk. An evaluation
of the affects of a possible Mississippi River levee breach along the City's levee system is necessary to
understand the likelihood and the consequences of a levee failure. Mitigation strategies can then be
developed to avoid or minimize the impacts of a potential levee failure. The results of a levee breach
analysis can be used to supplement a flood risk management plan in order to promote public safety.
4.11.2 Levee Functional Assessment
The John C. Culver Floodwall was constructed by the USACE between 1968 and 1973. Since the
construction of this levee/floodwall system, numerous physical modifications and technical advances
have occurred. Some of these changes include:
• levee and floodwall criteria and design
• additional emphasis placed on federal levee safety program and local awareness to better
understand, manage, and reduce flood risks with levees
• national impacts associated with Hurricane Katrina
• variable flood frequency water surface elevations for the Mississippi River
• increase operation and maintenance responsibilities of the local levee Sponsors
• urbanization impact on the interior drainage system
It is recommended that an assessment be conducted to recognize the current levee's level of flood risk
reduction and compliance with current criteria and conditions. This information will help the City to
determine what, if any, design and operational modifications need to be incorporated to the John C.
Culver Floodwall.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
4 -26 Fall 2013
FINANCING DRAINAGE IMPROVEMENTS AND OPERATIONS
5.0 FINANCING DRAINAGE IMPROVEMENTS AND OPERATIONS
5.3 Capital Funding
5.3.4 Grants
Amend 2001 DBMP Section 5.3.4 with new subsections 5.3.4.1 and 5.3.4.2 as follows:
5.3.4.1 State of Iowa I -JOBS II Funding
In 2010, the Iowa Legislature appropriated $30 million from FY 2011 revenue bonds to the I -JOBS Board
of Directors for a Disaster Prevention Grant Program to assist or to provide additional funds to cities and
counties. The money was intended to assist cities and counties in the development and completion of
public construction projects relating to disaster prevention, including construction, replacement, or
reconstruction of local public buildings in a manner that would mitigate damages from future disasters,
including flooding. Because the Bee Branch Creek Restoration Project is a disaster prevention project, it
was a natural candidate for the grant program.
On July 1, 2010, the City submitted a Notice of Intent to Apply for $7.3 million in I -JOBS II Disaster
Prevention Grant Program funds for the Lower Bee Branch Creek Restoration Project, the first phase of
the Bee Branch Creek Restoration Project. The Lower Bee Branch Creek Restoration Project is the
section from the 16th Street Detention Cell to the CP Railway property just south of Garfield Avenue.
On July 15, 2010, the Iowa Finance Authority notified the City that it was eligible to apply for funds from
the program for the Lower Bee Branch Creek Restoration Project and invited the City to complete an
online application.
On September 15, 2010, the I -JOBS Board of Directors awarded a total of $30 million to 23 projects in 21
Iowa counties. Of those awardees, the City of Dubuque received $3,965,500 for the Lower Bee Branch
Creek Restoration Project, one of the largest awards.
5.3.4.2 Green Project Reserve Capitalization Grants
The federal FY 2010 Appropriation Law (P.L. 111 -88) included the requirement that "for fiscal year
2010, to the extent there are sufficient eligible project applications, not less than 20 percent of the funds
made available under this title to each State for Clean Water State Revolving Fund capitalization grants
and not less than 20 percent of the funds made available under this title to each State for Drinking Water
State Revolving Fund capitalization grants shall be used by the State for projects to address green
infrastructure, water or energy efficiency improvements, or other environmentally innovative activities."
These four categories of projects are the components of the Green Project Reserve (GPR). U.S.
Environmental Protection Agency (EPA) used an inclusive approach to determine what is and is not a
"green" water project and established that creek daylighting is a Categorical (Green Infrastructure)
Project.
Because the Bee Branch Creek Restoration Project is consistent with EPA's definition of a "green"
project, in July 2010 the City submitted an application for $14.8 million in State Revolving Fund
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
5 -1 Fall 2013
FINANCING DRAINAGE IMPROVEMENTS AND OPERATIONS
(SRF) /GPR funding. The City's application for the Upper Bee Branch Creek Restoration Project was
approved and is included on the Iowa State Revolving Fund Program Intended Use Plans (IUP) with 30
percent loan forgiveness, or $4.43 million.
Amend 2001 DBMP Section 5.3 with new subsection 5.3.6 as follows:
5.3.6 State Revolving Fund (SRF) Loan Program
Established by the federal Clean Water Act amendments of 1987, the Clean Water State Revolving Fund
(CWSRF) Program provided a new approach to providing funding assistance for water pollution
abatement projects. The primary benefit of SRF loans is that the interest rate is predictable, if not already
known, and many times is below the market rate. It also allows for a longer repayment schedule.
Congress designed the CWSRF Program to allow states to structure their programs creatively to best
serve their needs. States are given the flexibility to offer a variety of assistance options, including low
interest loans, refinancing, purchasing or guaranteeing local debt, and purchasing bond insurance. States
also set loan terms, including interest rates (from zero percent to market rate), repayment periods, and
many other loan features. The CWSRF Program has been used to fund both the construction of
wastewater treatment facilities and nonpoint source water quality improvement/protection projects. In
1990, only 1 percent of loan agreements made were for nonpoint source projects. Since then, however, the
number of loans made for nonpoint source projects has increased substantially.
The City was able to secure CWSRF loan funds for both the West 32 °d Street Detention Basin and the
Lower Bee Branch Creek Restoration Project. CWSRF loan funds also has been approved for use on the
Upper Bee Branch Creek Restoration Project.
5.5 Municipal Drainage Utilities
Amend 2001 DBMP Section 5.5 by adding text to the end of the section as follows:
In April 2002, the Dubuque City Council authorized City staff to investigate the formation and
implementation of a stormwater management utility. The objective was to determine how the City can or
should fund the construction, operation, and maintenance of the public stormwater drainage system and
the improvements outlined in the 2001 DBMP.
A 30- member Citizen Advisory Council (CAC) was appointed by the City Council. The CAC's
responsibilities included representing various areas of constituent interest, acting as advisor, assisting in
informing the community, and developing a recommendation for the City Council. The following
organizations were represented on the CAC:
• Archdiocese of Dubuque
• Bluff Street Neighborhood
• Clarke College
• Community Development Block Grant
Advisory Commission
• Finley Hospital
• Flexsteel Industries
• Greater Dubuque Development Corporation
• Historic Bluffs Neighborhood Association
• Holy Family Schools
City of Dubuque, Iowa
Bee Branch Drainage Basin
Drainage Basin Master Plan Amendment
5 -2 Fall 2013
FINANCING DRAINAGE IMPROVEMENTS AND OPERATIONS
• Developer's Roundtable
• Downtown Neighborhood Council
• Dubuque Area Chamber of Commerce
• Dubuque Area Congregations United
1st Congregational Church of Christ
• Dubuque Board of Realtors
• Dubuque Community Schools
• Dubuque Homebuilders Association
• Dubuque Main Street Ltd.
• Electrical Workers Local 704
• Environmental Stewardship Advisory
Commission
• Impacted Citizen
• Landlord Association
• Long Range Planning Advisory Commission
• Loras College
• Medical Associates Clinic
• Mercy Hospital
• North End Neighborhood Association
• United Auto Workers
• University of Dubuque
• Washington Neighborhood Council
• West Side Business Association
Between June 2002 and January 2003, the CAC held eight meetings to address the basic elements of
stormwater management, discuss future stormwater requirements, evaluate funding options, and develop
its recommendation. In addressing future stormwater requirements, the CAC considered the impact of
new federal regulations, existing maintenance requirements, and increased future maintenance needs due
to growth and aging of the City's stormwater system.
Numerous financing options were discussed, including a stormwater management utility, the general
fund, local sales tax, Dubuque Racing Association (DRA) funds, reallocation of existing budget authority,
and various combinations of those options. The CAC ultimately recommended a combination of a
stormwater management utility, existing general fund and local sale tax contributions, and additional
DRA funds.
On December 2, 2002, a set of consensus recommendations developed by the CAC were presented to the
City Council. The CAC recommended that:
1. The City should implement a major capital improvement program (CIP) to address identified
drainage problems as soon as possible. The magnitude of the CIP should start with a target of
$24.5 million and be reviewed annually.
2. The City should fund its stormwater management program from a number of sources (all existing
funding sources), including a new stormwater utility fee.
3. The City should contribute to the stormwater management program at current funding levels and
should identify additional funds, such as federal grants, to keep the stormwater utility fee as low
as possible.
The City created a stormwater management utility on February 27, 2003. When created, the stormwater
utility fee was $1.29 per month per SFU as stormwater management activities were funded in part with
property tax and sales tax funds. The stormwater utility ordinance was amended in 2008 to become a self -
supported utility and the SFU rates were revised accordingly. The charge in 2013 is $5.60 per month per
SFU, which ranks the second highest of the more than 30 stormwater utilities in the state.
City of Dubuque, Iowa Drainage Basin Master Plan Amendment
Bee Branch Drainage Basin
5 -3 Fall 2013
Page Left Intentionally Blank