Taum Sauk Pumped Storage Project (No. P-2277),
Dam Breach Incident

December 20, 2007 - FERC rules on rehearing of the August 15, 2007 letter order authorizing licensee to start reconstruction and repair of the project's upper reservoir Decision August 15, 2007 - Construction, with Conditions, authorized for Taum Sauk Upper Reservoir Reconstruction Fact Sheet | Letter August 14, 2007 - FERC staff issues Final Environmental Assessment

Incident Description
On December 14, 2005 at approximately 5:20 AM CST the northwest corner of the Taum Sauk Pumped Storage Project No. 2277 upper reservoir rim dike failed resulting in a release of the upper reservoir. The reservoir was reported to have drained in about ½ hour. Approximately 4,300 Acre-feet of storage was released. The breach flow passed into East Fork of Black River (the river upstream of the lower Taum Sauk Dam) through a State park and campground area and into the lower reservoir. The Lower Taum Sauk Dam was reported to be overtopped and did not sustain damage. Upon leaving the Lower Taum Sauk Dam area, the high flows proceeded downstream of the Black River to the town of Lesterville, MO, located about 3.5 miles downstream from the Lower Dam. The incremental rise in the river level was about 2 feet which remained within the banks of the river.

• The Stipulation and Consent Agreement Between FERC and Ameren, October 2006 - Appendix A: Dam Safety Program
• Close of Comment Period for Taum Sauk Independent Panel of Consultants Report, July 20, 2006
• FERC Independent Panel of Consultants (IPOC) Report, May 25, 2006
• News Release, May 25, 2006
• FERC Staff Report, April 28, 2006
• AmerenUE Consultant's Report, April 7, 2006
• News Release, December 21, 2005