HomeMy WebLinkAboutA025 - April 28, 2026, Regular Meeting of the Ames City CouncilITEM #:29
DATE:04-28-26
DEPT:PW
SUBJECT:EMERGENCY 30-INCH RAW WATER LINE REPAIR CONTRACT
AMENDMENT
COUNCIL ACTION FORM
BACKGROUND:
On March 15, 2026, City staff became aware of an exposed raw water main on the east side
of the Skunk River between SE 16th Street and Lincoln Way. This main conveys water from
supply wells to the Water Treatment Plant. On April16, 2026, continued bank erosion caused
the main to deflect over four feet and begin to fall into the Skunk River. The attached memo
provides further documentation of the condition and supports the determination that this
situation constitutes an emergency repair.
To address the immediate risk and prevent further damage, the City issued a Purchase Order
to On Track Construction, LLC (Nevada, IA) on April 17, 2026, in the amount of $21,570. This
initial work was within staff authorization limits and allowed for rapid mobilization to stabilize
the bank and mitigate further deterioration of the 30-inch raw water line.
Following stabilization efforts, additional work has been identified as necessary to fully protect
the pipe and restore long-term stability. On Track Construction has submitted a request
for an additional $93,018 to import and place suitable backfill and riprap. Due to the
emergency nature of this repair and the need to proceed without delay to prevent failure of
critical infrastructure, staff is recommending approval of the contract amendment. This
Council action is to approve this additional scope of work to temporarily protect the raw
water line while a permanent solution is designed and permitted.
Funding for this emergency work will be taken from the balance in the Water Utility Fund.
Additional work still remains that will require permitting with the Iowa Department of Natural
Resources (DNR) and Army Core of Engineers (ACOE) to permanently provide protection for
this critical piece of infrastructure. Public Works staff will continue to work alongside Water and
Pollution Control staff to accelerate the permanent repair.
ALTERNATIVES:
1. Approve a contract amendment of $93,018 for a total contract of $114,588 with On Track
Construction, LLC of Nevada, IA.
2. Direct staff to investigate other options.
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CITY MANAGER'S RECOMMENDED ACTION:
The 30-inch raw water main provides approximately 20% of the raw water supply to the
Water Treatment Plant for treatment and distribution of potable water to the City of
Ames. Due to the emergency nature of this repair and the rapid deterioration of site
conditions, it is critical that stabilization and protection measures be completed without
delay to prevent failure of this critical infrastructure. Approval of the contract
amendment will allow the contractor to complete the necessary repairs in a timely
manner and restore reliable operation of the raw water system. Therefore, it is the
recommendation of the City Manager that the City Council approve Alternate 1, as described
above.
ATTACHMENT(S):
2026.04.16 Emergency Repair Work - Raw Water Line.pdf
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515.239.5101 main
515.239.5142 fax
515 Clark Ave.
Ames, IA 50010
www.CityofAmes.org
MEMO
From: Mindy Bryngelson, PE, Municipal Engineer
Date: April 16, 2026
Subject: Emergency Streambank Stabilization and Repairs for 30” Raw Water Line
A 30-inch raw water line was installed in 2008 to improve raw water supply to the Water
Treatment Plant from wells located at the Hunziker Youth Sports Complex on the east side
of the South Skunk River. At the time of installation, the riverbank was approximately 90
feet west of the pipeline. Since that time, the river has migrated significantly eastward
toward the pipe.
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A project to protect the raw water line was included in the Capital Improvements Plan for
FY 2027/28. However, due to accelerated streambank erosion, staff began advancing this
project.
In mid-March 2026, staff identified that a segment of the 30 -inch raw water main between
Southeast 16th Street and East Lincoln Way had become exposed due to streambank
erosion. Staff coordinated with the Iowa Department of Natural Resources and the U.S.
Army Corps of Engineers, who confirmed that repair work could proceed under Nationwide
Permits #3 and #13. The Iowa DNR further indicated that the City may complete the work
and submit as-built permitting documentation if post-construction modeling demonstrates
no rise in the floodplain.
The City engaged WHKS to perform survey, design, hydraulic modeling, preparation of
construction documents, and permitting services. While awaiting lower river levels to
complete survey work, staff continued to monitor conditions at the site.
Conditions have deteriorated rapidly over the past month:
• March 16, 2026: Pipe exposed but supported
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• April 15, 2026: Loss of support beneath the pipe and measurable deflection
observed
o
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• April 16, 2026: Continued bank failure resulted in additional erosion, soil collapse
onto the pipe, and portions of the pipe falling below river leve l
o
Based on field observations and the attached independent engineering evaluation
prepared by WHKS, the condition of the raw water main presents an immediate risk of
failure due to ongoing erosion, loss of soil support, and pipe deflection. Failure of this
infrastructure would disrupt the City’s raw water supply to the Water Treatment Plant and
could pose risks to public health, safety, and the surrounding environment.
The condition has progressed rapidly over a short period of time, and delay associated
with completing a standard public bidding process would increase the likelihood of failure
and the severity of resulting impacts.
For these reasons, staff recommends that the work necessary to stabilize the streambank
and restore structural support to the raw water main be treated as an emergency repair.
This designation is limited to the work required to address the immediate risk and restore
safe and reliable operation of the utility infrastructure.
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