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TO: Mayor Richard C. Irvin
FROM: Robert Leible, Superintendent of Water Production
DATE: March 14, 2024
SUBJECT:
A resolution authorizing Crawford, Murphy & Tilly to provide professional engineering services to update the city's water distribution system hydraulic model in an amount not-to-exceed of $200,000.00.
PURPOSE:
To obtain City Council authorization to enter into an agreement for professional engineering services with Crawford, Murphy & Tilly (CMT), Aurora, IL for a comprehensive update to the city's existing hydraulic model for the city's Public Works/ Engineering Department and the Water Production Division.
BACKGROUND:
A hydraulic model (HM) is a computer software program that is customized for a specific water distribution system based on many factors including installed water mains, storage tanks, valves, operating pressures, population, water demand and water billing consumption data. The value of hydraulic modeling is significant. The analysis that can be derived from a HM can be used to improve customer experience if there are issues related to pressure, quantity, or water quality. Hydraulic modeling supports the water utility by determining how demographic growth or new customer types will affect pressure and flow in the distribution system. Planning of infrastructure replacement, i.e., watermains or storage tanks is enhanced via modeling so that replacements and/or repairs ensure that the system will perform as needed for years to come. A real world example of a hydraulic model result is the correct sizing of water mains to ensure appropriate fire flow to an area or facility.
DISCUSSION:
The city most recently completed an update to the HM in 2016 and prior to that in 2005, both by CMT. As with any model, the results are only as good as the programmed inputs to the model. Since the last update, many conditions that affect the accuracy and performance of the model have changed including population, water demands in the existing pressure zones, and increased development throughout the city. More detailed information is provided in the attached Standard Agreement of Professional Services - Exhibit A.
A proposal from CMT to perform the necessary Scope of Services as outlined in Exhibit A includes data collection activities, review/update historical water demands, update hydraulic model, calibration of both steady state and extended period simulation models, update/run both steady state and extended period modeling scenarios and preparation of a final report.
Compensation of CMT will be on a time and expense basis, with a not-to-exceed amount of $200,000.00. The anticipated project schedule is approximately from April 1, 2024, with a pre-final report due October 1, 2024, and a final report due November 15, 2024.
A budget transfer has been submitted to provide funding in account 510-4058-511-32-07 from the 2024 fiscal budget.
IMPACT STATEMENT:
Failure to update the hydraulic model will prevent accurate water service and availability evaluations for potential new residential, commercial, and industrial development.
RECOMMENDATIONS:
That a resolution authorizing Crawford, Murphy & Tilly to provide professional engineering services for the update of the city's hydraulic model, in an amount not-to-exceed of $200,000.00 be approved by the Mayor and City Council. It is further recommended that this matter be submitted to the Infrastructure and Technology Committee for review and recommendation.
cc: Finance Committee
CITY OF AURORA, ILLINOIS
RESOLUTION NO. _________
DATE OF PASSAGE ________________
title
A Resolution authorizing Crawford, Murphy & Tilly to provide professional engineering services to update the city's water distribution system hydraulic model in an amount not-to-exceed of $200,000.00.
body
WHEREAS, the City of Aurora has a population of more than 25,000 persons and is, therefore, a home rule unit under subsection (a) of Section 6 of Article VII of the Illinois Constitution of 1970; and
WHEREAS, subject to said Section, a home rule unit may exercise any power and perform any function pertaining to its government and affairs for the protection of the public health, safety, morals, and welfare; and
WHEREAS, there is a need for professional engineering consulting services to update the city's water distribution system hydraulic model; and
WHEREAS, Crawford, Murphy & Tilly has successfully performed this service in previous years for the city; and
WHEREAS, Crawford, Murphy & Tilly has provided a proposal in the not-to-exceed amount of $200,000.00 to provide the necessary professional engineering services for the subject project on a time and expense basis; and
WHEREAS, Sec 2-336 (a) allows for this contract to be approved; and
WHEREAS, a budget transfer has been submitted to provide funding in account 510-4058-511-32-07 from the 2024 fiscal budget.
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Aurora, Illinois, as follows: that the Purchasing Director is hereby authorized to execute a professional services agreement with Crawford, Murphy & Tilly for professional engineering consulting services to complete an update to the city's water distribution system hydraulic model, for the Public Works/Engineering Department and Water Production Division, on a time and expense basis for an amount not-to-exceed $200,000.00.