Mass evacuations after hazardous situation at Oroville Dam

Officials have ordered the evacuation of areas near the damaged Oroville Dam in Northern California on Sunday, February 12, 2017, amid concerns the dam's auxiliary spillway might collapse. The spillway is overflowing water since Saturday, February 11 for the first time in its 48-year history. Nearly 200 000 people have been asked to evacuate.

The officials announced they expected a failure of the dam's auxiliary spillway which could send an 'uncontrolled release of flood waters from Lake Oroville' and ordered residents of the low levels of Oroville, as well as areas downstream, to evacuate in a northward direction around midnight UTC (16:00 PST Sunday).

Although Butte County Sherrif said that the erosion of the emergency spillway is not advancing as rapidly as initially thought, the situation remained dangerous and evacuations continued. The mass number of residents moving out of the area has caused major traffic jams on Highway 99 during the evening hours.

The water resources department said crews using helicopters would drop rocks to fill a huge gouge in the spillway. Authorities were also releasing water to lower the lake's level after weeks of heavy rains.

By 08:00 UTC (22:00 PST) state and local officials said those efforts had paid off and, with water no longer flowing over the eroded spillway, the immediate danger had passed. But they cautioned that the situation remained unpredictable.

"Once you have damage to a structure like that it's catastrophic," Bill Croyle, acting director of the Water Resources, told the press conference.

Evacuation orders remain in place for 188 000 people in Oroville, Yuba County, Butte County, Marysville and nearby communities.

Updates

At around 06:30 UTC (22:30 PST Sunday), flows over the auxiliary spillway have ceased, but 100 000 cfs continue down the main spillway, California Water Department said.

The latest update on this story can be found at the following link: Oroville Lake levels dropping, repairs continue before the next storm

Featured image: Water from the Oroville Dam Auxiliary Spillway at Lake Oroville continues to flow toward the diversion pool of the Feather River on Sunday, February 12, 2017. Credit: California Water Department