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United States. Federal Energy Regulatory Commission

Deviation from Ramping Rate Limits at Carmen-Smith Hydroelectric Project

Strategic Insights

— 2 min read

The Eugene Water & Electric Board (EWEB) has submitted a 30-day report to the Federal Energy Regulatory Commission (FERC) regarding a deviation from the ramping rate limits at the Carmen-Smith Hydroelectric Project in Oregon. The deviation occurred on April 23, 2025, when the hourly ramping rate limit was exceeded due to flow transition issues during low load operations at the Trail Bridge Plant.

As per Article 401 of the EWEB's license for the Carmen-Smith Hydroelectric Project, the board is required to notify and report any deviations from operating requirements. In this case, the deviation was caused by the failure of the generating unit to maintain smooth operation in terms of vibration/cavitation at loads below 2 MW, resulting in a brief downramp that exceeded the hourly ramping rate limit.

The board has notified the agency representatives of the Fish Working Group and has invited them to submit comments, concerns, and questions regarding the exceedance by May 21, 2025. The board has also taken corrective actions to prevent similar events in the future and has implemented measures to reduce the likelihood of similar events.

Key Takeaways:

  • The EWEB submitted a 30-day report to FERC regarding a deviation from the ramping rate limits at the Carmen-Smith Hydroelectric Project.
  • The deviation occurred on April 23, 2025, due to flow transition issues during low load operations at the Trail Bridge Plant.
  • The hourly ramping rate limit was exceeded, with a calculated rate of -0.34 foot, while the limit is +/- 0.2 foot.
  • The weekly ramping rate limit was also exceeded, with a calculated rate of -0.39 foot, while the limit is +/- 0.3 foot.
  • The daily ramping rate limit was not exceeded.
  • The EWEB has notified the agency representatives of the Fish Working Group and has invited them to submit comments, concerns, and questions regarding the exceedance.
  • The EWEB has taken corrective actions to prevent similar events in the future and has implemented measures to reduce the likelihood of similar events.

Statistics:

  • Hourly ramping rate limit: +/- 0.2 foot
  • Weekly ramping rate limit: +/- 0.3 foot
  • Daily ramping rate limit: +/- 0.3 foot
  • Calculated hourly ramping rate during deviation: -0.34 foot
  • Calculated weekly ramping rate during deviation: -0.39 foot
  • Duration of deviation: approximately 10 minutes

Sources:

  • Federal Energy Regulatory Commission
  • Eugene Water & Electric Board
  • Article 401, Notifying and Reporting Deviations from Operating Requirements, Carmen-Smith Hydroelectric Project License
  • Oregon Department of Environmental Quality Water Quality Certification (Appendix A to the license)
  • USGS gage data (Accession No. 20250502-5216)

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