Focus Area: Infrastructure (Engineering)
Staff Contact: Mary Jaeger / Nate Baldwin
Subject: Report on the authorization of the 135th Street Retaining Wall Project, PN 3-G-010-24.
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TITLE:
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Report on the authorization of the 135th Street Retaining Wall Project, PN 3-G-010-24.
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Summary:
This project would replace the retaining wall along the south side of 135th Street between Brougham Drive and Arapaho Drive. The existing retaining wall is a modular block type wall, approximately 750 feet long and up to 7.5 feet tall, and is leaning forward throughout the entire length, up to 1" per foot.
In 2021, the City hired a structural engineering firm to conduct a condition assessment of the retaining wall. The wall system was found to be leaning forward throughout the entire length, up to 1" per foot. Fences and utility boxes behind the wall are also leaning towards the north. The wall, soil, fences, etc. appear to be slowly rotating forward as one large mass. The wall system is expected to continue rotating forward slowly until it fails or is either repaired or replaced. Replacement vs. repair costs were evaluated, and it was determined that it would be cheaper to replace the wall rather than attempt to repair it.
The estimated cost for this project is $2,020,000 including design, utility relocations, staff time, construction and inspection.
This project is tentatively scheduled for design in Spring 2024, utility relocations in Fall 2024, and construction in Spring 2025.
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Financial Impact:
Funding for the 135th Street Retaining Wall Project, as approved in the 2024-2028 Capital Improvement Plan, includes:
GO Bonds $2,020,000
Total $2,020,000
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Action Needed:
No action is requested at this time. Staff will return to Council on January 23, 2024, to request approval for authorization of the project.
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Attachment(s):
A. Project Location Map
B. Project Fact Sheet
C. CIP Sheet