Spencer Dam Failure Investigation Provides Lessons to Engineers and Dam Professionals

In the early morning of March 14, 2019, the Spencer Dam on the Niobrara 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 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 organizational 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.