TO: Mayor and Members of City Council
THRU: Michael Gibson, Interim Assistant City Manager
FROM: Sheila Thomas-Ambat, Public Services Director
DATE: September 8, 2026
RE:Title
Stamper Road Culvert Failure & Road Closure
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COUNCIL DISTRICT(S):
Council District(s)
2
b
Relationship To Strategic Plan:
Goal 1: Safe and Secure Community
Objective 1.1: To fully prepare for emergency and disaster response
Objective 1.2: To ensure traffic and pedestrian safety
Executive Summary:
Council is being asked to provide consensus to proceed with a Capital Project Ordinance to initiate the design of repairs to Stamper Road. The project is necessary due to the partial failure of the existing culvert, which has resulted in the closure of Stamper Road.
Background:
On July 24, 2026, the existing culvert on Stamper Road experienced a failure after trees located along the downstream embankment fell, damaging the downstream slope. The damage to the embankment caused the downstream headwall to separate from the culvert, compromising the integrity of the culvert.
Following the initial failure, subsequent storm events have caused additional erosion of the downstream embankment, resulting in further separation and deterioration of sections of the culvert. The continued erosion has increased the risk of additional structural failure and roadway damage. As a precautionary measure and to protect the safety of the traveling public, Stamper Road is currently closed to traffic.
The City is proposing to proceed with the design of repairs to the culvert and associated roadway infrastructure to address the current deficiencies and determine the appropriate long-term repair solution.
Issues/Analysis:
The failure of the Stamper Road culvert presents several immediate and long-term concerns that warrant proceeding immediately with the design of a permanent repair solution.
• Continued Roadway Deterioration: Soil has continued to wash out from beneath the roadway, resulting in voids beneath the existing pavement. Without stabilization and repair, continued erosion is expected to further undermine the roadway and increase the potential for a more significant roadway failure.
• Risk to Water and Sewer Infrastructure: Public Works Commission (PWC) water and sewer infrastructure is located within the roadway corridor and could be impacted if the roadway or underlying embankment experiences a more extensive failure. A continued loss of roadway support could expose or damage these utilities.
• Permitting and Regulatory Challenges: The project will require design considerations and permitting associated with work within a floodway and potentially wetlands. A no-rise analysis and associated floodplain permitting will also likely be required. These requirements may affect the final repair design and project schedule.
• Design Services: The City has reached out to Gradient, a local engineering firm, to develop a scope of work for the design through the City's Stormwater Systems On-Call contract. The anticipated design period is approximately 6-8 months following issuance of a Notice to Proceed (NTP). This timeframe includes design development and obtaining the necessary permits and regulatory approvals.
• Construction Schedule: Once the design and permitting are complete and construction funding is identified, construction is anticipated to require an additional 6-8 months, depending on the final repair solution, material availability, site conditions, and permitting requirements.
• Significant Culvert Depth and Construction Complexity: The existing culvert is located more than 20 feet below the roadway, which will significantly increase the complexity and cost of the repair. Excavation at this depth will require appropriate temporary excavation protection and consideration of groundwater, slope stability, access, and worker safety. The depth of the culvert may also require specialized construction methods and equipment, which could affect the final design, construction cost, and project schedule.
• Funding: Stormwater Enterprise Fund revenues have been identified to fund the design phase and potentially address any easement acquisition needs that may be required. These items are estimated at a cost of $300,000. Construction funding has not yet been identified and will need to be secured following completion of the design and development of a construction cost estimate.
Given the continued erosion and the potential for additional roadway and utility impacts, moving forward with the design will allow the City to better define the required repairs, address permitting requirements, establish a construction cost, and identify appropriate funding for construction.
Budget Impact:
There is no anticipated impact to the General Fund associated with the proposed design phase. Funding for the design is proposed from available Stormwater Enterprise Fund budget previously allocated to completed projects. Sufficient funding is currently available within the Stormwater Enterprise Fund to proceed with the design, and no appropriation from Stormwater Fund balance is anticipated for the design phase.
Funding for construction has not yet been identified. Upon completion of the design and development of a construction cost estimate, staff will evaluate available funding sources and return with a recommendation for funding the construction phase.
identified.
Options:
1. Provide consensus to proceed with a Capital Project Ordinance to initiate the design for repairs to Stamper Road.
2. Do not provide consensus to initiate the design for repairs to Stamper Road and provide staff with additional guidance.
Recommended Action::Recommended Action
Council provide consensus to proceed with a Capital Project Ordinance to initiate the design for repairs to Stamper Road.
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Attachments:
Stamper Road Culvert Failure and Road Closure ppt.