Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

In January 1998, the Archusa Creek Dam in southeast Mississippi failed by breaching through its emergency spillway. At the time of its failure, the dam had a concrete ogee weir for a principal spillway and a vegetated earth emergency spillway. Fortunately, the dam is a low hazard structure, as there is little development downstream, and consequences of failure were mostly limited to the loss of a state-owned, recreational water park. The dam failed as a result of a 5-year storm event, triggered by intense rainfall of nearly 4.25 in. in just a few hours. Runoff generated by the storm caused a rapid rise in lake level to elevation above the flood pool, resulting in flow over the emergency spillway. A breach then formed through the emergency spillway due to progressive erosion and head-cutting caused by excessive water flow velocity, a well-known failure mechanism. This paper examines how the failure happened, including the aspects leading up to the breach. Hydrologic, hydraulic, and geotechnical aspects of the failure are discussed, including the dam’s design and subsequent modifications, its problems leading to failure, the engineering solution used to repair the dam, and how this solution solves the problems that led to failure in the first place.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 4th, 12:00 AM

Earth Dam Failure by Erosion, A Case History

Chicago, Illinois

In January 1998, the Archusa Creek Dam in southeast Mississippi failed by breaching through its emergency spillway. At the time of its failure, the dam had a concrete ogee weir for a principal spillway and a vegetated earth emergency spillway. Fortunately, the dam is a low hazard structure, as there is little development downstream, and consequences of failure were mostly limited to the loss of a state-owned, recreational water park. The dam failed as a result of a 5-year storm event, triggered by intense rainfall of nearly 4.25 in. in just a few hours. Runoff generated by the storm caused a rapid rise in lake level to elevation above the flood pool, resulting in flow over the emergency spillway. A breach then formed through the emergency spillway due to progressive erosion and head-cutting caused by excessive water flow velocity, a well-known failure mechanism. This paper examines how the failure happened, including the aspects leading up to the breach. Hydrologic, hydraulic, and geotechnical aspects of the failure are discussed, including the dam’s design and subsequent modifications, its problems leading to failure, the engineering solution used to repair the dam, and how this solution solves the problems that led to failure in the first place.