Cane Creek Dam and Spillway Roller Gate Rehabilitation

Richard Hazen, the firm’s founder, proposed the construction of Cane Creek Reservoir in a 1969 water supply planning report to the University of North Carolina at Chapel Hill. Mr. Hazen recommended the proposed project as the optimal alternative to meet the growing water demand of what became, in 1977, the service area of the Orange Water and Sewer Authority (OWASA).

Completed in 1989, the three billion gallon reservoir supplies approximately 80% of the water to the Chapel Hill-Carrboro service area. For the dam and reservoir project, Hazen and Sawyer provided comprehensive engineering services from initial studies through design, environmental permitting, and construction and post-construction services. The dam is a 72-foot high zoned earthfill embankment that contains 170,000 cubic yards of fill. It is classified as a Large, High Hazard Potential structure. The principal spillway is a gated structure, with seven vertical roller gates that are operated when required to increase spillway capacity. The dam is provided with an emergency spillway to provide additional hydraulic capacity for floods in excess of the 200-year event. It is furnished with a fuse plug that is designed to erode in a controlled manner to maximize spillway capacity during extreme floods.

Project Outcomes and Benefits

• Cane Creek Reservoir is a reliable high quality water source for the OWASA service area.
• The gated principal spillway minimized land impacts and acquisition within the reservoir pool by maintaining flood surcharge to within five feet of normal pool.
• The emergency spillway served as an economic source for fill materials for the dam construction and for increasing spillway capacity. The emergency spillway fuse plug, which has never been activated, further reduced spillway construction costs.
• As a part of the EPA services, Hazen assisted OWASA in staging a tabletop exercise, which was attended by local and state emergency management officials.