HomeMy WebLinkAboutAECOM - Supp Amnt #1 - Cont. 1062 Sup 1 Sunnyside Creek ImprovementsAECOM
AECOM 319-232-6531 tel
501 Sycamore Street 319-232-0271 fax
Suite 222
Waterloo, Iowa 50703
www.aecom.com
CITY OF WATERLOO, IOWA
CONTRACT NO. 1062
SUNNYSIDE CREEK IMPROVEMENTS
WET DETENTION POND AND CHANNEL
STABILIZATION PROJECT
SUPPLEMENTAL AGREEMENT NO. 1
WHEREAS, a Professional Services Agreement was entered into between the City of Waterloo (Client),
715 Mulberry Street, Waterloo, Iowa, and AECOM Technical Services, Inc. (ATS), 501 Sycamore Street,
Suite 222, Waterloo, Iowa, dated March 7, 2022, for design of a wet detention pond located between
Highway 20 and West San Marnan drive; and
WHEREAS, the Client and ATS now desire to enter into Supplemental Agreement No. 1 for updated
modeling, development of preliminary and final platting, and temporary/permanent easements for the
proposed wet detention pond and channel improvement areas.
NOW THEREFORE, it is mutually agreed to amend the original Professional Service Agreement as follows:
I. PROJECT DESCRIPTION
The Sunnyside Creek Improvement Project involves construction of a wet detention pond located
between Highway 20 and West San Marnan Drive, generally centered on the main channel of
Sunnyside Creek. The project also includes bank channel stabilization of approximately 1,050 feet
of the existing Sunnyside Creek channel located downstream of the proposed basin (between San
Marnan Drive and Westchester Drive).
According to the Black Hawk County Flood Insurance Study (FIS) and the effective Flood Insurance
Rate Maps (FIRMs) for Black Hawk County, the project is located in a Zone A floodplain, which
means the 100-year floodplain was developed based on approximate methods and a detailed
analysis resulting in base flood elevation determinations has not been completed. As part of this
project, a detailed analysis will be completed for the wet detention basin design and required
regulatory permitting.
This supplemental agreement will include additional hydraulic modeling downstream of the
detention basin in addition to property acquisition and easement documents for the detention pond.
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 review, update and extend
the existing detailed HEC-RAS modeling for the length of Sunnyside Creek from the proposed
detention basin to the confluence with Black Hawk Creek. The updated modeling will utilize the
current hydrologic information for the Sunnyside Watershed and include a review of the duplicate
effective FIS model of Sunnyside Creek, development of a corrected effective and proposed
conditions model incorporating the basin and channel improvements. The modeling work will
require additional spot survey along the channel to verify structure sizing and channel
characteristics from Westchester Road to Martin Road. A topographic survey will be completed
near the overflow section of Marnie Avenue (south of Dizdarevic Construction) shown in the current
FIS. A letter report and updated flood plain/floodway mapping (if required) will be developed
summarizing the updated modeling. Regulatory applications, including the Iowa DNR Flood Plain
Permit application and the FEMA Letter of Map Revision (LOMR), will be developed and submitted
AECOM
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as necessary if modeling updates require changes to the effective FIS base flood elevations
(BFEs), flood plain or floodway mapping.
In addition to the updated modeling, this supplemental agreement includes preparation of property
acquisition plats and temporary/permanent easements for the proposed wet detention pond and
channel improvement areas.
The Scope of Services is further defined as follows:
Design Survey (Tasks 1-3)
The following identifies tasks leading to the completion of the topographical survey required for the
project, including field survey, base mapping, cross sectioning of Sunnyside Creek and utility
locates.
Task 1 - Data Collection
Task 2 - Survey and Base Mapping
a. Channel cross sections (12) and structure sizing verification (7) from Westchester Drive to
Martin Road.
b. Approximate one -acre continuous topography near current FIS overflow section location near
Marnie Avenue south of Disdarevic Construction.
Task 3 - Survey Note Reduction and DTM Development
Hydrologic and Hydraulic Review and Modeling (Tasks 4-6)
These tasks include updating the HEC-RAS duplicate effective modeling based on updated
topography and hydrology. The modeling will be used to determine possible BFE, floodplain and
floodway changes for Sunnyside Creek.
Task 4 - Review Existing Sunnyside Duplicate Effective FIS Model
Task 5 - Develop Corrected Effective and Proposed Conditions Hydraulic Models Based on
Updated Topography
Task 6 - Develop a Hydrologic and Hydraulic Summary Report, Updated Flood Plain/Floodway
Mapping (if Required) Suitable for Regulatory Agency Review
Regulatory Permitting (Task 7)
This task includes preparation and submittal of regulatory permitting documents (Iowa DNR Flood
Plain and FEMA LOMR), if required, based on updated Sunnyside Creek H&H Modeling. The
following identifies tasks leading to the completion of the Regulatory Permitting.
Task 7 - Permitting (IDNR, FEMA)
Preparation of Acquisition Plats and Temporary/Permanent Easements (Tasks 8-11)
These tasks include preparation of acquisition plats, as well as temporary and permanent
easements, for the proposed wet pond detention basin and channel stabilization project.
Permanent ROW/easements are anticipated to be required for the basin construction and
temporary easements/right-of-entry documents are anticipated for the channel stabilization.
Task 8 - Preparation of Preliminary Acquisition Plats (1) and Legal Description
Task 9 - Preparation of Final Acquisition Plats (1) and Legal Description
AECOM
Task 10 - Preparation of Temporary Easements/Right of Entry Documents (7)
Task 11 - Property Owner Research
Exclusions:
The following items are not included, but may be added by supplemental agreement:
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• Acquisition Services and Closing Services
• Regulatory Permit Fees
• Design Improvements to Sunnyside Creek Downstream of Westchester Road
• Conditional Letter of Map Revision (CLOMR) Based on Proposed Design Improvements
Downstream of Westchester Road
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. The estimated
fee is Thirty -Nine Thousand Five Hundred Dollars ($39,500.00).
IV. In all other respects, the obligations of the Client and the Consultant shall remain as specified in
the Professional Services Agreement dated March 7, 2022.
IN WITNESS WHEREOF, the parties hereto have executed this Supplemental Agreement No. 1 as of the
dates shown below:
APPROVED FOR CITY OF WATERLOO
By: By: i '. ViQuert crrA641
Printed Name: Quentin Hart
APPROVED FOR AECOM
Printed Name: Douglas W. Schindel, P.E
Title: Mayor Title: Vice President
Date:
5/15/2023
Date: May 8, 2023
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