Dam Breach Incident
A breach of the Upper Reservoir rim dike of the Taum Sauk Pumped Storage Project occurred on December 14, 2005 releasing the upper reservoir. FERC staff initiated an immediate evaluation and analysis to first establish the reason for the dike breach and second, determine the appropriate repair to re-establish the project. In addition to an investigation by a team of FERC engineers, an independent panel of consultants will be convened to evaluate and oversee both the forensic evaluation and the design of the project repair. The scope of the action plan for the investigation is as follows:
- Staff engineers were immediately dispatched to site to ensure the safety of the lower dam and obtain initial information concerning the breach of the upper reservoir embankment dam.
- By letter dated December 15, 2005, the licensee, Ameren UE, was directed to submit a detailed report in accordance with Paragraph 12.10(a) of the Commission's regulations, which includes the details of the incident and information needed to assess the cause of the incident and the appropriate remedial action.
- A FERC project team has been convened to perform a forensic evaluation of the incident and to review the investigations, analysis, design and construction required to re-establish the upper reservoir, and to address corresponding environmental concerns.
- FERC has established an independent panel of expert engineering consultants to perform a forensic evaluation of the incident and to review the investigation, analysis, design and construction required to re-establish the upper reservoir.
- FERC will fully coordinate with the State of Missouri dam safety and environmental agencies during the forensic investigation and the design activities of any remedial measures to re-establish the upper reservoir.
- FERC will evaluate the licensee's compliance with all applicable requirements.
- Review the design report, construction plans and specifications, and construction records.
- A forensic evaluation of the breach of the reservoir rim dike and the project operation will be performed, including an evaluation by engineering consultants to determine the specific failure mode.
- A foundation exploratory program will be required to obtain data and information for remedial action.
- The forensic evaluation will include a critical review of the effectiveness of the Emergency Action Plan (EAP).
- Ameren UE will be required to convene an Independent Board of Consultants to oversee the investigations, analyses, design and construction of the remedial measures needed to re-establish the upper reservoir.
- The results will be shared with the Interagency Committee on Dam Safety (ICODS) whose members include Federal agencies that own, operate or regulate dams as well as the National Dam Safety Review Board which provide grants for State dam safety programs.