FERC continues its investigation into Taum Sauk reservoir failure

This photo shows the breach in the Taum Sauk upper reservoir dam. The breach occurred in the early morning of Dec. 14, 2005. The upper reservoir emptied withing a 12-minute time from, but damage from the flooding water was minimal and localized.

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So, for those who had family members or friends affected by or are just interested in the latest developments with the investigation, the Federal Energy Regulatory Commission (FERC) is offering that information with just a click of the mouse.

The FERC has listed the status of the investigation on their website, at www.ferc.gov. Visitors to the website have only to click on the Taum Sauk breach icon at the top right-hand corner of the screen for an update on the investigation into the breach.

The Taum Sauk Pumped Storage Project No. 2277--owned by AmerenUE--is a 1.5 billion gallon reservoir that covers 50 acres in Reynolds County and feeds a 440-megawatt pump storage hydroelectric plant.

There are two reservoirs, an upper and lower, that run the plant. The lower reservoir covers 300 acres on the Black River and is pumped into the upper reservoir at night when electrical costs are low. That water is then released from the upper reservoir to produce electricity to supply peak power needs during the day.

At approximately 5:20 a.m. Wednesday, Dec. 14, the upper reservoir dike failed, resulting in the release of the upper reservoir. The flow from the breach passed into the east fork of Black River through Johnson Shut-Ins State Park and Campground Area before returning to the lower reservoir area.

According to AmerenUE President and Chief Executive Officer Gary Rainwater, the pumping procedure is automated, so no one was at the plant when the breach occurred.

"Preliminary investigations suggest the overflow washed away rock filler materials which caused one berm on the northwest side of the reservoir to fail along a 600-foot length," said Rainwater in a previous interview with the Daily Statesman. "We got a report that the upper reservoir was full at 5:12 a.m. but at 5:24 a.m. we got an alarm that it was empty."

The family of Johnson Shut-Ins State Park Superintendent Jerry Toops were washed away with the overflow and their home was knocked off its foundation. Each of Toops' three children--ages 5, 3, and 7 months--were hospitalized following the event but have since all been released.

The park itself has been shut down until further notice because of damage created by the overflow. The town of Lesterville, located 10 miles south of the Taum Sauk reservoir, and Highway N were also evacuated as a precaution in case of heavy flooding.

According to FERC's website, FERC dam safety inspectors performed site inspections on Dec. 14 and 15 and determined that the lower dam was indeed safe, allowing very little water to overflow. The purpose of FERC's investigation is to establish the reason for the dike breach and to determine the appropriate repair to re-establish the project, has had no history of problems and has received inspections regularly from both the FERC and an outside contractor since it was built in 1963.

Some actions that have currently been taken and are listed on the FERC website include:

* Staff engineers were immediately dispatched to the site to ensure the safety of the lower dam and obtain initial information concerning the breach of the upper reservoir embankment dam.

* 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.

* 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.

* The forensic evaluation will include a critical review of the effectiveness of the Emergency Action Plan (EAP).

* AmerenUE will be required to convene an Independent Board of Consultants to oversee the investigations, analyses, design and construction of remedial measures needed to re-establish the upper reservoir.

FERC regulates and oversees energy industries in the economic, environmental and safety interests of the American public and strives to ensure reliable, affordable energy through reliance on competition and effective regulation.

The Taum Sauk hydroelectric plant will remain out of service pending repair of the breach areas.