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TO: Mayor John Laesch
FROM: John Hoffmann, PE, Engineering Coordinator
DATE: March 23, 2026
SUBJECT:
A resolution authorizing the Director of Purchasing to execute a contract with Crawford, Murphy and Tilly, Aurora, IL, in the amount of $238,100 for water main flushing.
PURPOSE:
To maintain water main quality throughout the water distribution system.
BACKGROUND:
Regular maintenance of the water distribution system is necessary to keep the system working well. One component of the maintenance program is water main flushing.
The velocity of the water flowing through most water mains is usually low, therefore as time passes any solids in the water tend to settle at the bottom of the pipe. Though harmless, these solids can be stirred up when there is an increase in flow velocity from events such as main breaks or hydrant use.
The City’s current water system hydraulic model was developed by Crawford, Murphy, & Tilly, Inc. (CMT) utilizing the WaterGEMS modelling software in 2005. The hydraulic model is used to analyze distribution flow, pressure, water age, fire flow, and impact to pumping capacity. Using this information, CMT designed the City’s flushing program from 2012 to 2015.
Since then, the City has retained various contracts with CMT to incorporate distribution system changes that occur yearly because of water main installation or repair programs and new development projects. This includes a major model update in 2017 to reflect changes to the system’s supply and storage capacities.
CMT’s in-depth knowledge of the hydraulic model also makes CMT uniquely qualified to professionally service the flushing program. The model is used to determine appropriate flushing velocities needed to remove sediment from water main segments across the City, the required valve closures needed to achieve said velocities, and estimate the water demand impact of the flushing program on storage and supply capacities.
This contract, which is attached as Exhibit 1 - CMT Contract, will provide for the services of one staff member full-time and second person part time from CMT to direct the program. The remaining 4 team members required each day will come from the Water and Sewer Maintenance Division. It is estimated that during the four months that the flushing is ongoing, approximately 20% of the system will be flushed, those areas are shown on pages 8 and 9 of the exhibit.
A separate $20,000 task has been identified within this contract to update the water model annually to reflect new development improvements. The project developer will reimburse the City for these updates, ensuring the City’s water model remains current and accurate.
DISCUSSION:
The water main flushing ($238,100) will be funded with account 510-4063-511-38-68 which has a 2026 budget amount of $242,500. A budget transfer will be submitted if necessary.
IMPACT STATEMENT:
Generally, the impact is minimal, however users may notice a slight discoloration of water during and for a short time after the flushing procedures. Motorists may be stopped intermittently while the crews are working, and some lane closures are to be anticipated. The City will use localized signs alerting residents to the fact that flushing is ongoing and will use the City's social media outlets to alert the general public. Any users that could be more adversely impacted are given specific notice to allow them time to modify any processes that may be affected due to the temporary change in the water.
RECOMMENDATIONS:
I request the proposed resolution be adopted.
cc: Infrastructure and Technology Committee
CITY OF AURORA, ILLINOIS
RESOLUTION NO. _________
DATE OF PASSAGE ________________
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A Resolution to authorize the Director of Purchasing to execute a contract with Crawford, Murphy & Tilly, Aurora, IL, in the amount of $238,100 for water main flushing.
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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, water main flushing is a regular maintenance activity required to maintain the quality of the City's water; and
WHEREAS, the City generally flushes 20% of the water distribution system annually; and
WHEREAS, Crawford, Murphy & Tilly is uniquely qualified to assist the City with these operations due to their knowledge of the system and having developed the City's water model; and
WHEREAS, Per City of Aurora Code of Ordinances, Article 5, Section 2-335 (c), City Council may award; and
WHEREAS, this contract in the amount of $238,100 will be funded with account 510-4063-511-38-68 which has a 2026 budget amount of $242,500; and
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Aurora, Illinois, as follows: the Director of Purchasing is authorized to execute a contract with Crawford, Murphy & Tilly, Aurora, IL in the amount of $238,100 for water main flushing.