Stormwater Mgm Pl Ltr 12 13 01MEMORANDUM
December 13, 2001
TO:
FROM:
SUBJECT:
The Honorable Mayor and City Council Members
Michael C. Van Miliigen, City Manager
Stormwater Management Plan
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
that need was intensified with 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 o¥ the Stormwater Management Plan.
HDR Engineering, lncl of Omaha,' Nebraska, was the selected consulting engineering
firm to produce Dubuque's Stormwater Management Plan. The Stormwater
Management Plan consists of four elements: -
1. A Drainage Basin Master Plan that addresses flooding problems and issues in
specific watershed basins;
2. A Stormwater Drainage Criteria Manual that guides development to prevent new
drainage p¢oblems and reduce pollution associated-with stormwater runoff;
3. A set of ordinances and policies that specifically address stormwater'runoff
-issues; and
4. A skeleton National Pollution Discharge Elimination System Phase II permit
application to be reft.ned by City staff.
To achieve the primary objective of increasing public safety and reducing property
damage related to stormwater runoff, the following steps were followed:
1. Determine the capacity of the existing drainage system for the 10-, .50-, ' 00- and
500-yea{ return period storm events under future drainage basin characteristics;
Develop hydrologic and hydraulic models using aerial topog!-aphic system
mapping using the Dubuque Area Geographical I.nformatbn System (DAGiS)-for
major drainage Segments within each watershed;
Identify areas where public safety is comprised and property damage occurs due
to stormwater runoff; and .
Identify funding sou.rces that might be available to construct the recommended
drainage improvements identified by the Basin Master Plan.
Assistant City Engineer Gus Psihoyos and Civil Engineer Deron Muehdng are
recommending adoption of the Drainage Basin Master Plan, as previously presented to
the Mayor and City Council in a public Work Session, and subsequently presented to
interested parties. The Plan recommends $24.1 million in construction projects for
improvements that will remove over 1,200 homes and businesses from risk of flood
damage from heavy rainfall events. The improvements include:
1. North Fork Catfish 'Creek Basin improvements - $2,135,300
2. West 32"d Street Sub-basin improvements - $4~898,000
3. Bee Branch Creek restoration - $17,1.00,000
The recommended modifications to the Northwest Arterial Detention Basin have been
previously approved and were implemented, this fiscal year.
The most significant cost item in this recommendation is the $17.1 million for the Bee
. Branch Creek RestoratiOn Project. The creation of an open channel, beginning at 24t".
and Elm Streets, and extending to the 16t~ Street Detention Basin, would eliminate the
risk of flood damage to 970 homes and businesses. The cost of the channel includes
the purchase of approximately 70 homes and businesses.
Historically, the Bee Branch Creek meandered through the north end. Over the years
the creek was lined by limestone, eventually covered, and transformed into the existing
Bee Branch Storm Sewer. The proposes channel is, in reality, the restoration of the
Bee Branch Creek. With a 76' bottom width, the channel would be designed with mildly
slopir~g landscaped banks. It is anticipated that a 150' green corridor would be required
for the channei. The exact alignment of the channel is yet to be determined. Part of
this recommendation includes issuing a request for proposals for a corridqr study to
establish the alignment of the Bee Branch Basin Flood Control Channel recommended
in this report.
An alternative to constructing this cha~nel was studied and it was determined that five
additional underground storm sewer systems, the size of the existing Bee Branch Storm
Sewer, which is 20' wide and 12' high at its largest point, would need to be constructed
at a cost exceeding $90 million. Therefore, this underground option is not being
recommended.
The City of Dubuque does not currently have [he funding capacity to pay for these
improvements, totaling over $24 million. Therefore, through the City's Fiscal Year 2003
budgeting process, the Council will be receiving a recommendation to form a
stormwater utility to fund the stormwater activities of the City, and in addition, the City
wilt need to pursue federal funding in support of these projects.
I concur with the recommendations and respectfully request Mayor and City Council
approval.
I further respectfully request that the Long Range Planning Advisory Commission be
assigned to lead a community planning effort to implement the Stormwater
Management Plan, working to mitigate any impacts on individuals and neighborhoods,
and providing input on the formation of a Stormwater Management Utility to finance the
implementation of the plan. Part of the direction of the Long Range Planning Advisory
Commission would be to formulate a City Interest Group that will be comprised of
potentially-impacted property owners and businesses, as well as representatives from
such areas as neighborhood associations, the Environmental Stewardship Advisory
Commission, the Housing Commission, the Community Development Advisory
Commission, school, real estate, health officials, civic leaders and church organizations.
The key staff members I will be assigning to work with the commission are Planning
Services Manager Laura Carstens, Housing and Community Development Director
David Harris and Assistant City Engineer Gus Psihoyos.
MCVM.rjh
Attachment
cc: Barry Lindahl, Corporation Counsel
Cindy Steinhauser, Assistant City Manager
Laura Carstens, Planning Services Manager
David Harris, Housing and Community Development Director
Gus Psihoyos, Assistant City Engineer
Deron Muehring, Civil Engineer