#SchnabelSpotlights: West Fork Eno River Reservoir

The West Fork Eno River Reservoir has been serving as Hillsborough, North Carolina’s primary water supply since 2000. The team at Schnabel Engineering recently tackled Phase 2 of its expansion, facing unique challenges posed by the spillway configuration:

  • A 70-degree bend in the spillway chute
  • Transition from 215 to 60 feet width causing flow depth issues
  • Insufficient wall heights and an eight-inch-thick chute slab

To address these issues, we developed a cutting-edge 3D computational fluid dynamics (CFD) model which estimated spillway performance under various flood conditions. This helped us make critical design decisions, including the selection of a more compact Piano Key (PK) weir over alternatives like labyrinth and ogee weirs.

The PK weir allowed for a 45% reduction in the width of the control section, ensuring efficient passage of the spillway design flood. In line with our commitment to sustainability, we re-used existing structures, reducing demolition debris by 50%. The repurposed concrete debris served as riprap for slope protection, minimizing landfill impact and decreasing the demand on local resources.

Key modifications for dam safety included control section layout revisions, a steel sheet pile cutoff wall, increased chute wall heights, and a reinforced concrete overlay on the spillway chute floor.

Schnabel’s innovative solutions and commitment to sustainability made the West Fork Eno River Reservoir Phase 2 expansion a success. We’re proud to contribute to resilient and eco-friendly infrastructure that serves to protect the water supply for the Hillsborough community.

Read more about the project

Big thanks to our team including AtkinsRéalis, Raleigh NC for Permitting Support, Thalle Construction Company, Inc., Hillsborough, NC as General Contractor, and the Town of Hillsborough, NC.

Schnabel’s innovative solutions and commitment to sustainability made this project a success.