Dam Failure Case Study: Taum Sauk Dam (Missouri, 2005)

DamFailures.Org is an ASDSO project that provides individual dam failure case studies and lessons learned as a resource for dam safety engineers, dam operators, owners, regulators, managers, academia and students to help prevent future incidents.

Taum Sauk Pump Storage Plant was constructed by United Electric in Reynolds County, Missouri between 1960 and 1962 to provide a means of hydroelectric power generation during peak demand periods. The plant consisted of an Upper Reservoir situated atop Proffit Mountain contained by a kidney-shaped rockfill dike, a Lower Reservoir and Powerhouse impounded by a concrete gravity dam, and a 7,000-foot-long concrete and steel-lined tunnel that connected the two. On December 14, 2005, the Upper Reservoir of the Taum Sauk Pump Storage Plant failed by overtopping during the final minutes of one of its pumping cycles. As a result, the reservoir’s 4,300 acre-feet volume of stored water was released from a 656-foot-wide breach in 25 minutes, traveling down Proffit Mountain toward the Black River with a peak discharge of 273,000 cfs. Before it reached the river and flowed into the Lower Reservoir where it was entirely contained, the flood destroyed 281 acres of Johnson’s Shut-Ins State Park and ripped the superintendent’s home from its base. By chance alone, loss of life was averted and only four people sustained injuries as a result of the Upper Reservoir failure. However, estimates of the destruction and property damage caused by the failure and ensuing flood have reached $1 billion.