Design of the new upper reservoir for Taum Sauk, USA

The rockfill dyke, constructed in 1963 to form the upper reservoir at the Taum Sauk pumped-storage project near Lesterville, Missouri, USA, failed suddenly on 14 December, 2005. The upper reservoir is currently being rebuilt, on schedule, as a 2.06 ¥ 106m3 RCC dam in compliance with FERC Regulations and Missouri environmental permitting regulations. As the project is the largest RCC project to be constructed in the USA and has a symmetrical cross-section with relatively low strength RCC, numerous design issues arose during the design process. This paper summarizes these, and discusses the evolution of the design through discussions with the FERC, State of Missouri and two Boards of Consultants.