Mass evacuation ordered below California's Oroville Dam
Authorities have ordered nearly 200,000 people in northern California to evacuate an area below a dam spillway that may collapse. A failure of the spillway at Lake Oroville Dam could unleash a massive flood.
Image: Getty Images/M.Ralston
Hole in main spillway
The dam's main spillway was damaged (pictured center), forcing authorities to use the emergency spillway on Saturday for the first time in the dam's 48-year-old history. Officials at first believed the emergency spillway had helped lower water levels in the lake, before they noticed erosion.
Image: Reuters/California Department of Water Resources/William Croyle
Lake overflow
A view of the Lake Oroville Dam (right) from a helicopter. Center-left is the damaged main spillway. The emergency spillway is to the far left.
Image: picture-alliance/AP Photo/Office of Assemblyman Brian Dahle/Josh F.W. Cook
Threat of collapse
The emergency spillway (top half of picture) suffered severe erosion that led authorities to believe it could collapse within hours. They then released more water from the main damaged spillway to "avert more erosion at the top of the auxiliary spillway." Water levels have since receded slightly.
Image: picture-alliance/AP Photo/California Department of Water Resources/A. Madrid
Large-scale evacuations
Evacuation orders were given to about 200,000 people in Oroville, Yuba County, Butte County and Marysville. Oroville was said to be eerily deserted on Sunday. Officials said a 9-meter-high (30-foot) flood wave could hit Oroville if the spillway structure collapsed.
Image: DW
Hillside erosion
A picture released by the California Department of Water Resources shows the the hole in the main damaged spillway and erosion to the hillside. "Once you have damage to a structure like that, it's catastrophic," acting Water Resources director Bill Croyle told
reporters. He emphasized, though, that "the integrity of the dam is not impacted" by the damaged spillway.
Image: Reuters/California Department of Water Resources/William Croyle
Leaving by night
Residents were ordered to leave areas down from the dam due to high water flows and the potential for a failure at a spillway.
Image: picture-alliance/AP Photo/P. Kitagaki Jr.
From droughts to floods
California has experienced years of drought and a water crisis. A picture from May, 2015, shows boats moored in an arm of Lake Oroville when the water level was less than 25-percent capacity.
An emergency spillway at the Lake Oroville Dam has threatened to fail and unleash an wave of flooding on downriver communities.
The National Weather Service said the dam itself remained intact and only the auxillary structure was in danger of collapsing.
A state of emergency has been declared in three counties in northern California and nearly 200,000 people ordered to evacuate.
Officials were forced to use the emergency spillway at Lake Oroville Dam after rainfall in January and February caused water to rise to maximum levels.
