Duke Energy Carolinas Proposes Embankment Seismic Stability Improvements at Catawba-Wateree Hydro Project

Duke Energy Carolinas, LLC has submitted a Non-Capacity License Amendment application to the Federal Energy Regulatory Commission (FERC) for the Catawba-Wateree Hydro Project's planned construction of a stability berm at the Mountain Island Development. The embankment seismic stability improvements (ESSI) are necessary to meet FERC-required safety standards for seismic stability. The project was designed in close coordination with the FERC Division of Dam Safety and Inspections - Atlanta Regional Office and was issued by FERC's Division of Hydropower Administration and Compliance on March 4, 2024.

Key Takeaways:

• The Catawba-Wateree Hydro Project's embankment seismic stability improvements (ESSI) involve the construction of a compacted earth-fill counterweight stability berm along the downstream slope of the existing embankment dam.
• The ESSI project is designed to meet FERC-required safety standards for seismic stability and was issued by FERC's Division of Hydropower Administration and Compliance on March 4, 2024.
• Due to extreme weather conditions, Duke Energy intends to place concrete at night to ensure that pouring conditions and the approved thermal control plan are met.
• A concrete pump and crane will be utilized to transfer and place the concrete, with crane operations conducted during daylight hours to minimize noise.
• Concrete pours will occur one or two times a week for approximately 8-10 weeks starting August 8, 2025, with schedules adjusted to accommodate daytime pours when feasible.
• Duke Energy is providing notification of this plan to the NC Department of Environmental Quality, Division of Water Resources, the NC Wildlife Resources Commission, and the U.S. Fish and Wildlife Service.

Statistics:

• The proposed embankment seismic stability improvements are necessary to meet FERCRequired safety standards for seismic stability.
• The project is expected to take 8-10 weeks to complete, starting August 8, 2025.
• Concrete will be placed at night due to extreme weather conditions, with daytime temperatures ranging from upper-80s to mid-90s.
• A concrete pump and crane will be utilized to transfer and place the concrete.
• The crane will operate during daylight hours to minimize noise.

Sources:

• Duke Energy Carolinas, LLC (2022). Non-Capacity License Amendment Application, Catawba-Wateree Hydroelectric Project No. P-2232-855.
• Federal Energy Regulatory Commission (2024). Division of Hydropower Administration and Compliance, Order, Issue Date: March 4, 2024.
• Notification letter from Duke Energy Carolinas, LLC to the Federal Energy Regulatory Commission, dated August 1, 2025.