Spencer Dam Failure Investigation Provides Lessons to Engineers and
input on the selection of the Panel’s leader or members. The failure investigation focused on identifying what happened (the physical causes of the dam’s failure), why it happened (the human and orga- nizational causes), and the lessons learned from the failure (to keep such failures from happening again). The final investigation report was publicly released on April 21, 2020. Setting Spencer Dam was located on the Niobrara River in northern central Nebraska (NE) about 5 miles southeast of the town of Spencer, NE and about 224 miles northwest of Omaha, NE. The dam was constructed in 1927 to produce hydropower by means of a run-of-river project that had a relatively small reservoir which had become partially filled with sediment. Spencer Dam consisted of a 3,200 foot-long earth embank- ment (herein termed dike) that extended from one side of the river’s floodplain to the other side, was founded primarily on river sediment, and arced northeastward, directing flow along the embankment and
Dam Professionals By Martin Teal, Mark Baker, Robert Ettema, and John Trojanowski
In the early morning of March 14, 2019, the Spencer Dam on the Nio- brara River in northern Nebraska suddenly failed during a major ice run on the river. The embankment portion of the dam failed in two locations: the north breach about 650 feet wide, and the south breach was about 800 feet wide. Flow of ice and water through the breaches inundated areas downstream, washing away structures and leading to a fatality. Following the failure of Spencer Dam, the Chief Engineer of the Nebraska Dam Safety Program (NebDSP) contacted the dam owner, Nebraska Public Power District (NPPD), who agreed that the failure should be investigated by the Association of State Dam Safety Officials (ASDSO), a national non-profit organization serving state dam safety programs and the broader dam safety community. ASDSO convened an oversight group and selected four members for an investigation panel. To ensure independence, neither the NebDSP nor the NPPD had any
Figure 1: Aerial view of Spencer Dam and Vicinity. Photo: Google Earth
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may 2020
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