Duke Energy
Feature Project
Blewett Falls Spillway Modifications
Duke Energy required improvements to address stability concerns identified under Federal Energy Regulatory Commission (FERC) requirements and to enhance long-term operational reliability of the spillway. Specifically, the client needed to stabilize the existing concrete spillway structure through a new rock anchor system and replace the aging wooden flashboard system with a modern spillway gate system that would be safer, more reliable, and significantly easier to operate and maintain under highly variable river flow conditions. Stabilization and gate replacement activities would be complicated by the flashy nature of the Pee Dee River and the limited reservoir storage at Blewett Falls, which required careful planning and design considerations to safely execute construction with highly variable flow conditions.
Services Provided
- Dam Safety & Water Infrastructure Engineering
- Dam & Spillway Inspections and Design
- Stability Analysis
- Bid Specifications & Drawings
- Construction Services
Our Approach:
Kleinschmidt Associates was the Engineer of Record for both the spillway anchoring system and the new inflatable crest gate system. Kleinschmidt provided detailed design and construction oversight of the drilling, installation, and testing for 129 epoxy-coated post-tensioned rock anchors. Kleinschmidt also sized the new 1,300+ linear feet of Obermeyer pneumatic crest gates to meet FERC spillway flow capacity requirements. Kleinschmidt helped create construction efficiencies by integrating the rock anchor layout with the new crest gate system and concrete rehabilitation. Kleinschmidt supported the project through design, permitting, contractor bidding, and construction, with full-time onsite engineering support.
Value Provided:
The anchoring system was selected and designed for its ability to stabilize the dam, allow compliance with updated dam safety standards, and integrate with the automated pneumatic crest gate system. The design enabled phased construction along the length of the dam, allowing work to proceed in a safe and timely manner despite the river’s flashy flow conditions. The project addressed both structural and environmental objectives, resulting in a modernized spillway system.
