The Mackay Dam in central Idaho is a mess. The dam is old, poorly maintained, and designed with an inadequate understanding of the geology upon which it sits. This is terrible news as a small town, and a nuclear waste dump are just waiting to be flooded out.
Sadly, funding to fix this dam seems damn hard to come by.
Should the dam fail, Mackay would be wiped out in six minutes, according to the complaint from the Environmental Defense Institute. Including Mackay, an estimated 600 people and their property in Leslie, Darlington, Moore, Arco and Butte City would be affected in the case of a dam failure. "Initially, there can be a wall of water about 80 feet high going down from the dam," McCoy said. "I believe it was those mountains there that created one of the greatest floods on the face of the earth." The dam is classified as a high hazard dam, Falk said, because in the event of failure, it would result in loss of life. However, Falk said the risk of spreading radiation pollution from flooding at the Idaho National Laboratory depends on the amount of water that reaches it. The dam itself is in fair condition, but the primary outlet and spillway are in poor condition, according to a 2021 dam inspection report.
