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Taum Sauk Upper Dam Restoration Project

Award Description

In December of 2005, a 700 foot section of the dam surrounding the Taum Sauk Upper Reservoir failed and released 1.4 billion gallons of water down Profit Mountain and into Johnson's Shut-Ins State Park in Annapolis, Missouri. AmerenUE assumed responsibility for the breach. After a period of investigation and planning, AmerenUE decided to rebuild the reservoir and formed a team for the rebuild.

Paul C. Rizzo Associates, Inc. of Pittsburgh, PA was named the Engineer of Record and Construction Manager. In addition, a joint venture partnership was formed between Fred Weber, Inc. of St. Louis, MO and ASI Constructors Inc., of Pueblo, CO that would rebuild the reservoir.

Since much of the old dam remained in place, it was decided that rock used to construct the original dam could be used as aggregate for the newly designed RCC dam. Ozark Constructors made the decision to set up a total of five on-site batch plants. Two would be located inside the old dam and three would be located outside the old dam. Four would produce the RCC mix and one would produce the conventional concrete. All five batch plants could run simultaneously throughout the project. Approximately 10,000 to 12,000 cubic yards of concrete per day was averaged by all five of the plants.

As work continued on the excavation, rock from the existing dam was hauled to a crushing operation which processed the material into two stockpiles which would then be used in the RCC mix. Approximately 6 million tons of the existing rock was re-crushed and utilized, resulting in minimal waste, and eliminated the need to haul off any materials from the site.

In addition to using the existing materials, flyash recovered from a waste pond at a coal fired power plant owned by AmerenUE was used in the new RCC mix. Approximately 100 pounds of Meramec flyash was used in every cubic yard of RCC, resulting in the use of 160,000 tons of flyash. This product was previously a waste product stored in a waste ash pond. Through testing and processing, a way was found to recycle the flyash for use in the RCC mix, thereby creating a renewable resource out of a waste product.

Eventually, 2.8 million cubic yards of RCC, 160,000 tons of flyash and 300,000 cubic yards of conventional concrete would be used to rebuild the dam.

The Taum Sauk Upper Dam Rebuild has received numerous awards for innovation in design and solving design challenges including the Award of Excellence in the Constructed Project from The United States Society on Dams (USSD) and is a finalist for the Outstanding Civil Engineering Achievement Award from the American Society of Civil Engineers.

Project Participants

Owner - Ameren Services, Sunset Hills, MO
Structural Engineer - Paul C Rizzo Associates, Pittsburgh, PA
Concrete Contractor - Fred Weber Inc., Maryland Heights, MO
Concrete Producer - Fred Weber Inc., Maryland Heights, MO
Other - ASI Constructors Inc., Pueblo West, CO

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