Dam safety

Thousands Evacuated as Oroville Dam’s Auxiliary Spillway Threatens to Fail

Authorities issued emergency evacuation orders for tens of thousands of people living downstream from Northern California’s Lake Oroville late Sunday, after an auxiliary spillway that was put into service over the weekend appeared in danger of failure due to erosion.

State and local officials said they were racing to plug a hole that opened up in the backup spillway Sunday, while at the same time increasing the amount of water being released from California’s second-largest reservoir after it was filled by rain and snow that have hit the state this winter after a six-year drought.