Oroville Dam is in the foothills of the Sierra Nevada east of the
The dam, which was completed in 1968, has risen rapidly this winter as the Feather River and its tributaries have gushed down swollen after storms that brought heavy rain and snow. The storms, which came after more than five years of severe drought, have led officials to release water from various dams across
A gaping hole appeared in the dam’s main spillway last week, and that prompted state officials to begin releases over the emergency spillway for the first time in the reservoir’s history.
Though the dam itself remains intact, erosion damage to the emergency spillway raises the potential of that spillway failing and unleashing an uncontrolled torrent of floodwaters.
At least 188,000 people living downstream of California's Oroville Dam were ordered to evacuate late Sunday over concern that a damaged emergency spillway could cause severe flooding.