Title
Resolution to Approve Construction Contract Change Order No. 1 with Gerace Construction Company, Inc. for the Barton Dam Air Shaft Repairs Project ($74,900.00) and to Appropriate Funding (8 Votes Required)
Memorandum
This memorandum and resolution requests approval to award contract change order No. 1 for the Barton Dam Air Shaft Repairs to Gerace Construction Company, Inc. (Gerace) ($74,900.00). Change order No. 1 will add to the scope of services in the Geddes Dam Gate Recoating and Repairs Project (Resolution R-19-195; 5/6/19; $828,000.00) to repair issues in the Barton Dam Air Shaft.
The Barton Dam is one of the two hydroelectric power generating facilities owned by the City of Ann Arbor (City). The hydroelectric facility generates approximately 4,200 MWh/year and typically contributes revenue of over $300,000.00 to the City per year. The Barton Dam was originally constructed in 1912. It is classified as a high hazard dam and is regulated by the Federal Energy Regulatory Commission (FERC).
The interior of the dam is entered by a concrete access shaft, approximately 30-feet deep, located at the end of the dam. The bottom of the access shaft is experiencing concrete deterioration, with significant concrete loss to the wall thickness. Water is currently leaking through the deterioration. The deterioration was noted as part of the FERC Dam Safety Inspection in 2018 and is considered a safety concern. The Inspection Report recommended to install temporary risk reduction measures while planning a permanent repair.
As part of Resolution R-19-195, the City awarded the Geddes Dam Gate Recoating and Repairs Project to Gerace Construction Company, Inc. (Gerace) on May 6, 2019. Gerace's area of expertise is dam repairs and they have performed work on many of the City's dam projects, including the Barton Dam Concrete Repairs in 2011. Gerace possesses the expertise to complete the design of the temporary repair system, and to construct the repairs. Th...
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