Dam Failure Case Study: Spencer Dam (Nebraska, 2019)

Spencer Dam failed during a major early morning ice run on the Niobrara River during a bomb cyclone weather event on March 14, 2019. Large, truck-sized ice rubble caused ice jams along the river. These ice jams failed causing new surges of ice and water. There was no warning to the dam operators. When the ice run reached Spencer Dam, the gates likely jammed with ice restricting flow. The reservoir quickly filled, and the embankment section of the dam overtopped and failed in two locations. One resident in a house 1/3 mile downstream did not evacuate and was later declared dead by drowning. This dam failure case study offers many valuable insights, including (1) river ice run formation, transport, and infrastructure vulnerability (2) the need for Emergency Action Plans and evacuation exercises (3) the need for accurate Downstream Hazard Classification, and (4) the need to research a dam’s history and keep accurate records. The reader is encouraged to read Chapter 7 Lessons Learned of the Spencer Dam Failure Investigation Report.