100,000 people being evacuated right now: Oroville Dam likely will fail tonight

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  Evacuations ordered below Oroville Dam; failure of emergency spillway 'expected'

  Los Angeles Times53 minutes ago
  Video from television helicopters Sunday evening showed water flowing into a parking lot next to the dam, with large flows going down both the damaged main spillway and the emergency ...

 

 

Evacuations ordered below Oroville Dam after a hole is found in its emergency spillway

Millions of gallons of rushing water continued to pound and erode the massive Lake Oroville Dam spillway.

Anna M. Phillips, Matt Hamilton, Paige St. John and Chris MegerianContact Reporters

Residents of Oroville and nearby towns were ordered to immediately evacuate Sunday afternoon after a hole was discovered at the emergency spillway for the Oroville Dam.
Officials said late Sunday that they will attempt to plug the hole using bags of rocks but stressed the situation remains dangerous and urged thousands of residents downstream to evacuate to higher ground.
The National Weather Service initially said the auxiliary spillway at the Oroville Dam was expected to fail at about 5:45 p.m., which could send an “uncontrolled release of flood waters from Lake Oroville.”
Butte County Sheriff Kory L. Honea said that a hole was developing near the lower edge of the emergency spillway and eroding back toward the face of the spillway “at a rather significant rate.”

Live updates: Evacuations ordered below Oroville Dam

“There was significant concern that [the hole] would compromise the integrity of the spillway, resulting in a substantial release of water,” Honea said. “We had to make a very critical and difficult decision to initiate the evacuation of the Oroville area.”
Those in Oroville, a city of about 16,000 people, were asked to flee northward toward Chico. In Yuba County, those in the valley areas were urged to take routes to the east, south or west. In Sutter County, evacuations were ordered for Yuba City, Live Oak, Nicolaus and all communities around the Feather River basin.
“This is not a drill. This is not a drill. Repeat, this is not a drill,” the National Weather Service said. Authorities urged residents to contact neighbors and family members and reach out to the elderly and assist them in evacuating.
By Sunday night, state officials determined the erosion rate had slowed, and experts were devising a plan to dump bags of rocks into the crevice to plug the hole and prevent further erosion, Honea said.

Millions of gallons of rushing water pound and erode the massive Lake Oroville Dam spillway. 

The evacuations marked a dramatic turn of events at the nation’s tallest dam. For several days, officials have been trying to figure out how to get water out of Lake Oroville after the main spillway was damaged.
The emergency spillway had never been used before, and until the last few hours, it seemed to be working well. But water from rain and snow continued to flow into Lake Oroville at a rapid pace, causing water levels to rise to emergency levels.
Lake Oroville is the linchpin of California’s state water movement system, sending water from the Sierra Nevada south to the farms across the San Joaquin Valley and cities in the Southland.
Video from television helicopters Sunday evening showed water flowing into a parking lot next to the dam, with large flows going down both the damaged main spillway and the emergency spillway.
Officials feared a failure of the emergency spillway could cause huge amounts of water to flow into the Feather River, which runs through downtown Oroville, and other waterways. The result could be flooding and levee failures for miles south of the dam, depending on how much water is released.
The videos also showed lines of cars getting out of downtown Oroville. An evacuation center was set up at the Silver Dollar Fairgrounds in Chico.
Diminished by years of drought conditions, the reservoir had become a symbol of the state’s worsening water crisis. But an unusually wet winter took the lake from nearly full to overflowing in less than a week.
At the same time, the nearly mile-long concrete spillway that the dam’s managers rely on to release excess water began to crumble, with erosion worsening as millions of gallons of water poured over it.
Realizing the lake might rise to a level that would trigger the use of an emergency spillway, state workers began clearing the area of trees and brush that could be sent hurtling downstream.
On Saturday morning, water began washing over the dam’s emergency spillway for the first time since it was completed in 1968. Photographs showed a torrent of water rushing downhill to join the Feather River.

On Sunday, officials said that although they expected the uncontrolled spill to end, they plan to continue using the concrete spillway to create more storage in the reservoir in anticipation of rainfall later in the week.
“We’re going to continue to flow water down the spillway and lower the lake,” See said. “You’re going to see the lake dropping over the next several days.”
Officials emphasized that while erosion had carved a massive hole in the emergency spillway, the dam itself is structurally sound.
“Believe me, in the last several days there have been a lot of eyes on it,” said Bill Croyle, acting director of the water department. “Oroville Dam is not in any way a part of the damage that occurred.”
Officials have estimated it could cost $100 million to $200 million to repair the damage to the spillway and other features.
Live updates on the Oroville Dam »