COLUMBUS, Neb. (AP) – A new report says the owners and state regulators of the Spencer Dam on the Niobrara River in north-central Nebraska underestimated the potential of its failure to cause life-threatening damage.
A man who lived downstream died when it collapsed during an icy flood in March of last year.
The report from the Association of State Dam Safety Officials, released Tuesday, focuses on the physical causes of the failure, the human and organizational causes, and the lessons to be learned from the failure.
It shows the dam had a history of unaddressed ice issues and had no formal emergency plan because regulators from the Nebraska Dpt of Water Resources wrongly assumed that no one would die if it failed.
The report says the state had categorized Spencer Dam as a “significant hazard” – a rating that meant no loss of life was expected if it failed and no formal emergency action plan was required, when it should have been rated as “high hazard,” which could have led to a safety improvement plan.
The report called the classification one of two human factors contributing to the dam’s failure and devastating consequences.
The other was historical records on the dam being lost, unorganized, or unavailable – leaving regulators unaware the dam had failed under ice pressure in 1935 and been damaged by ice in 1960 and 1966.
The result was what appeared to be a well maintained structure that needed no improvements to deal with ice.
The investigation also concluded there was nothing Nebraska Public Power, the dam’s operator, could have done in the early morning of March 14, 2019, to prevent the failure after unusually intense snow and rain created a raging flood on the Niobrara River
Kenny Angel, who lived just beneath the dam, was found dead after the flood washed away his home and business. NPPD workers had warned Angel just minutes before of the impending danger.
The dam safety association is a national non-profit organization serving state dam safety programs and the broader dam safety community. It selected the investigation panel, which included dam engineering experts with decades of specific experience in dam safety and hydrology.
The report is available to the public online DamSafety.org/SpencerDamReport