HomeMy WebLinkAboutAECOM - Virden Creek Floodwall - 8/20/2018 _ AECOM 319-232-6531 tel
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CITY OF WATERLOO
VIRDEN CREEK FLOODWALL
U.S. HIGHWAY 63 TO 4TH STREET
SUPPLEMENTAL AGREEMENT NO. 2
WHEREAS, a Professional Services Agreement was entered into between City of Waterloo, Iowa,
(Client), and AECOM Technical Services, Inc. (ATS), of Waterloo, Iowa, dated June 27, 2011, for
increasing the flood protection level of the Virden Creek channel and earthen levee from U.S.
Highway 63 to Gates Park near 4th Street in Waterloo, Iowa; and
WHEREAS, the Client and ATS entered into Supplemental Agreement No. 1 on December 11,
2017, for additional design, including collecting additional stream channel data, completing a
hydrologic review of the project area and preparing a hydraulic model of the stream using the new
data; and
WHEREAS, the Client and ATS now desire to enter into Supplemental Agreement No. 2 for
additional structural design.
NOW THEREFORE, it is mutually agreed to amend the original Professional Services Agreement
as follows:
I. Project Description
AECOM completed hydraulic modeling for the Virden Creek floodwalls as part of
Supplemental Agreement No. 1. This work involved recreating the FIS modeling in HEC-
RAS. The recreated or corrected effective model used the same hydrology as the original
model. However, based on the updated topography and hydraulic modeling outputs, there
were some differences (both increases and decreases) from the published Base Flood
Elevations (BFEs) shown in the FIS. The increase in the BFEs shown in the corrected
effective modeling required additional structural design to the floodwalls that were initially
based on the published BFE values.
II. Scope of Services
The Scope of Services for this supplemental agreement will encompass and include
detailed work, services, materials, equipment, personnel and supplies necessary to
complete the remaining structural design of the Virden Creek floodwalls. Quality control
reviews are also included for this additional design work. The following identifies tasks
leading to the completion of the additional work in this supplemental agreement:
Task 1 - Additional Structural Design and Plan Revisions. Floodwalls will be designed using
Corps of Engineers standards to accommodate the updated base flood elevations for
Virden Creek. This will require structural revisions to be designed and incorporated in the
plan set.
Task 2 - Quality Control Review and Administration. This task includes quality control
review by senior technical staff not directly involved in the updated structural design. This
task also includes project coordination for the plan revisions.
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III. Compensation
Compensation for the above services will be on an hourly basis in accordance with Part VI
of the original agreement and shall be integrated with the fees in the original agreement and
Supplemental Agreement No. 1. The estimated fee is Twenty-Five Thousand Dollars
($25,000.00).
IV. In all other respects, the obligations of the Client and the Consultant shall remain as
specified in the Professional Services Agreement dated June 27, 2011.
IN WITNESS WHEREOF, the parties hereto have executed this Supplemental Agreement No. 2 as
of the dates shown below:
AECOM TECHNICAL SERVICES, INC.
L
2
By Date August 14, 2018
Douglas W. Schindel, P.E.
Associate Vice President
APPROVED FOR CITY OF WATERLOO
By: Date �90 ao R'
Quentin Hart
Mayor
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