TO: Mayor and Members of City Council
THRU: Michael Gibson, Interim Assistant City Manager
FROM: Sheila Thomas-Ambat, Public Services Director
DATE: August 10, 2026
RE:Title
Authorization to Execute a Professional Service Contract for the Design of College Lakes Dam Improvements
Title
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COUNCIL DISTRICT(S):
Council District(s)
1
b
Relationship To Strategic Plan:
Goal 1: Safe and Secure Community
Goal 3: High-Quality Built Environment
Goal 4: Desirable Place to Live, Work, and Recreate
Executive Summary:
Council is requested to authorize the execution of a $1,658,000 professional services contract for the design of the College Lake Dam Improvements.
This qualification-based selection of Schnabel Engineering South, PC utilizes the City’s On-Call Professional Engineering Services for Dam-Related Projects.
Background:
College Lake Dam is a City maintained dam that is currently in a breached condition, with the original spillway having been modified to function as a culvert, thereby preventing the impoundment of water behind the structure. Following damage sustained during Hurricane Florence in 2018, repairs were recommended to address the immediate deficiencies. The Post-Hurricane Florence Dam Assessments Memorandum (2018) identified two long-term alternatives for the City's consideration:
1. Fully breach or remove the dam. This alternative would eliminate the operational costs and risks associated with maintaining the dam but would require downstream mitigation improvements to address the resulting hydraulic impacts.
2. Redesign and reconstruct the dam. This alternative would require construction of a spillway configuration that complies with North Carolina Dam Safety regulations, including the ability to safely pass the one-third Probable Maximum Precipitation (1/3 PMP) design storm.
Subsequent hydraulic and watershed analyses were completed as part of the Carvers Creek Watershed Study. The study findings were presented to City Council during the April 7, 2025, Work Session, where Council reached consensus directing staff to proceed with a project to rehabilitate College Lake Dam as a dry detention dam that complies with current North Carolina Dam Safety requirements. Funding for the planning, design, and implementation of this project was appropriated in the FY2026 and FY2027 budgets.
Issues/Analysis:
Fully breaching the dam would eliminate the operational costs and risks associated with continued ownership and maintenance of the facility. However, this alternative would result in increased downstream flooding impacts to roadways and adjacent properties, requiring mitigation measures to offset the additional flood risk.
Several downstream mitigation alternatives were evaluated, including culvert capacity improvements and the construction of floodplain storage. Each alternative was analyzed based on hydraulic performance, constructability, environmental considerations, and planning-level cost estimates to identify the most practical and economically feasible solution.
For the dam rehabilitation alternative, a conceptual spillway configuration was developed for College Lake Dam to satisfy North Carolina Dam Safety requirements, including the ability to safely pass the required design storm. The downstream hydraulic impacts of the proposed dry dam were evaluated using the same performance metrics applied to the fully breached alternatives to provide a consistent comparison. A planning level construction cost estimate was also developed based on preliminary geotechnical investigation and soil boring results.
Based on the engineering analysis, the rehabilitation of College Lake Dam as a dry detention dam was determined to be the most cost-effective long-term alternative. This option achieves compliance with current North Carolina Dam Safety requirements while minimizing downstream flooding impacts and avoiding the substantially higher costs associated with the downstream mitigation improvements that would be required if the dam were permanently breached.
Budget Impact:
There is no impact on the General Fund. Funding for this professional service contract is utilizing Stormwater Enterprise funds appropriated from the FY2026 & FY2027 budgets.
Options:
1. Authorize the execution of a professional services contract in the amount of $1,658,000 for the design of the College Lake Dam Improvements to the consulting firm Schnabel Engineering South, PC.
2. Do not authorize the execution of a professional services contract in the amount of $1,658,000 for the design of the College Lake Dam Improvements to the consulting firm Schnabel Engineering South, PC and provide further direction to staff.
Recommended Action::Recommended Action
Council authorizes the execution of a professional services contract in the amount of $1,658,000 for the design of the College Lake Dam Improvements to the consulting firm Schnabel Engineering South, PC.
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Attachments:
WA #1_SESPC_College Lake Dam