An immediate evacuation from the lower levels of Oroville and other areas have been issued due to a "hazardous situation" developing with the dam's spillway.

The Butte County Sheriff's Department said an eroding hole was found in the auxiliary spillway on Sunday afternoon. The department said after working with the California Department of Water Resources (DWR), evacuations were ordered.

"We had to make a critical and difficult decision to initiate evacuation of the Oroville area," the department said.

The DWR increased the water flowing out of the dam after it reached capacity in early February. To try shore up the water and prevent anymore on-site erosions on the emergency spillway, the DWR plans to drop rocks or boulders.

A California water official says 100,000 cubic feet of water per second continued to flow down the Orville Dam's main spillway.

 

 Department of Water Resources Acting Director Bill Croyle said at a news conference late Sunday that the plan is to continue withdrawing that amount of water for as long as possible.

 

 Croyle says a key goal is to reduce the dam's level ahead of upcoming storms forecast to reach the area Wednesday.

 

 Water levels at Lake Orville rose so high that an emergency spillway was used Saturday for the first time in almost 50 years. Officials noticed erosion on the emergency spillway on Sunday.

 

 Croyle says officials have been unable to access the erosion scar but will be able to analyze the damage better now that water is below its level.

According to the National Weather Service, the areas impacted are Oroville, Palermo, Gridley, Thermalito, South Oroville, Oroville Dam, Oroville East and Wyandotte.

Residents evacuated can shelter at the Silver Dollar Fairgrounds in Chico.

The City of Marysville and Yuba City has also been encouraged to evacuate immediately.

A Northern California sheriff says evacuation orders affecting 188,000 people will stand until there is more information on the condition of the nation's tallest dam's emergency spillway.

For evacuation information, residents in Butte County can call 211 from any landline or cell phone. Yuba or Sutter County residents can call 1-866-916-3566.

With the emergency evacuation orders in place due to the spillways, there are local schools that will be closed on Monday.

This is a developing story. Refresh for more details as they come in.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. </s> (CNN) -- "This is NOT a drill." The Butte County Sheriff's Office repeated the warning three times, telling residents near California's Oroville Dam to evacuate before potential disaster strikes.

The dam's emergency spillway could be on the verge of failing due to erosion, the sheriff's office said in a statement. The structure was expected to give way by 6 p.m. local time (9 p.m. ET).

A spillway controls the flow of water from the lake or river being dammed to the area downstream. It also ensures, during times of high water levels, that the water does not rush over the top of the dam or damage the dam.

"Failure of the auxiliary spillway structure will result in an uncontrolled release of flood waters from Lake Oroville," a statement on Facebook said. "This is an evacuation order. Immediate evacuation from the low levels of Oroville and areas downstream is ordered."

At 770 feet, Oroville Dam is the country's tallest. In addition to flood control, it also serves to provide drinking water and generate hydroelectric power.

In an effort to mitigate the situation, the California Department of Water Resources is increasing water releases from the main spillway to 100,000 cubic feet per second in an effort to lessen the amount of water traveling down the emergency spillway, the sheriff's office said.

The DWR instructed Oroville residents to head north, toward Chico.

The evacuation order also includes "all Yuba County on the valley floor" and the city of Marysville, authorities said.

"Take only routes to the east, south, or west. DO NOT TRAVEL NORTH TOWARD OROVILLE!!!!!" the Yuba County Office of Emergency Services warned residents.

Evacuation shelters have been set up at fairgrounds in Chico and Colusa, CNN affiliate KCRA reported. A California Office of Emergency Services spokesperson told the station that it could be "potentially catastrophic" if the emergency spillway fails.

Marysville is about 40 miles north of Sacramento, Oroville about 70 miles.

The Sacramento Fire Department warned residents that the spillway failure could have effects, including flash flooding, downstream in Sacramento. </s> Roughly 188,000 people living downstream from Northern California’s Lake Oroville were ordered to immediately evacuate on Sunday afternoon after an emergency spillway releasing millions of gallons of water from the lake threatened to fail due to erosion. By late on Sunday night the situation had improved, but the evacuation order has yet to be lifted.

The lake, which is about 150 miles northeast of San Francisco, is held back by the 770-foot-tall Oroville Dam, the tallest in the country. Record storms took Lake Oroville from 80 percent full to overflowing in less than a week, as the L.A. Times explains. While the dam itself is structurally sound, last week a hole caused by erosion was discovered on the main spillway. It spread across the concrete-lined channel, and on Saturday the emergency spillway was used for the first time since the dam was completed in 1968.

Initially the system appeared to be working, but on Sunday engineers spotted a hole in the emergency spillway. At 4:20 p.m local time, an evacuation order was issued for everyone living downstream of Lake Oroville’s dam.

“They have what they expect to be an imminent failure of the axillary spillway,” said Mike Smith, a spokesman for the California Department of Forestry and Fire Protection. “What they’re expecting is as much as 30 vertical feet of the top of the spillway could fail and could fail within one to two hours. We don’t know how much water that means, but we do know that’s potentially 30 feet of depth of Lake Oroville.”

Residents of Butte, Sutter and Yuba rushed out of the area, creating gridlock for miles. An evacuation shelter was set up in Chico, which is north of the lake, at the Silver Dollar fairgrounds. Belen Castaneda, 23, told the Times she was headed there with her family and an elderly neighbor who doesn’t speak English. “We just grabbed everything we could,” she said. “Everyone was freaking out.”

Late on Sunday night the threat decreased when water stopped flowing into the emergency spillway. Officials said they plan to use bags of rocks to plug the hole in the emergency spillway, but the situation is still precarious. Storms are forecast for later this week, and officials said they need to keep draining water from the lake for as long as possible.

California Governor Jerry Brown issued an emergency order on Sunday night. “I’ve been in close contact with emergency personnel managing the situation in Oroville throughout the weekend and it’s clear the circumstances are complex and rapidly changing,” Brown said in a statement. “The state is directing all necessary personnel and resources to deal with this very serious situation.”

Eight California National Guard helicopters will assist with the attempt to reconstruct the emergency spillway. All 23,000 soldiers in the California National Guard have been notified that they should be ready to deploy if needed. According to the AP, the entire California National Guard hasn’t been put on alert since the 1992 L.A. riots. </s> OROVILLE, Calif. – Some 188,000 people were ordered or urged to evacuate in Northern California after authorities warned an emergency spillway in the country’s tallest dam was in danger of failing Sunday and unleashing uncontrolled flood waters on towns below.

Officials warned residents that the spillway could fail within an hour.

But in a late-night news conference, authorities said there was no more water going over the emergency spillway. The concern, they said, was that a 30-foot deep wall of water would be unleased if the emergency spillway failed.

There were still many unknowns, authorities said.

Nonetheless, Butte County Sheriff Kory Honea said the evacuation calls would stand until more information is analyzed.

The California Department of Water Resources said it was releasing 100,000 cubic feet of water per second from the main, heavily damaged spillway in an attempt to drain the lake enough to have it drop 50 feet.

Officials say Oroville Lake levels had decreased by Sunday night.

About 150 miles northeast of San Francisco, Lake Oroville is one of California’s largest man-made lakes, and the 770-foot-tall Oroville Dam is the nation’s tallest.

Over five hours after the evacuations were called for, hundreds of cars carrying panicked and angry people were sitting in bumper-to-bumper traffic.

“The police came and told us to evacuate,” said Kaysi Levias who was with her husband, Greg, at a gas station as they attempted to flee.

“Not giving us more warning,” said Kaysi, finishing his sentence.

“We’ve never been through this before,” said Kaysi Levias. “We have two boys and our dog. All the stuff we could fit in the trunk – clothes and blankets.”

What they couldn’t fit they piled as high as they could in their downstairs Yuba City apartment and joined the line of traffic attempting to leave the city where they had moved just three weeks ago.

The cities of Oroville, Gridley, Live Oak, Marysville, Wheat land, Yuba City, Plumas Lake, and Olivehurst were all under evacuation calls

They went out around 4 p.m. after engineers spotted a hole that was eroding back toward the top of the spillway.

The erosion at the head of the emergency spillway threatened to undermine the concrete weir and enable large, uncontrolled releases of water from Lake Oroville, the California Department of Water Resources said. Those potential flows could overwhelm the Feather River and other downstream waterways, channels and levees.

Sheriff Honea said engineers with the Department of Water Resources informed him shortly after 6 p.m. that the erosion on the emergency spillway at the Oroville Dam was not advancing as fast as they thought.

“Unfortunately, they couldn’t advise me or tell me specifically how much time that would take so we had to make the very difficult and critical decision to initiate the evacuation of the Orville area and all locations south of that,” he said. “We needed to get people moving quickly to save lives if the worst case scenario came into fruition.”

Honea said the plan was to plug the hole by using helicopters to drop rocks into the crevasse.

Water began flowing over the emergency spillway at the Oroville Dam in Northern California on Saturday for the first time in its nearly 50-year history after heavy rainfall. Officials earlier Sunday stressed the dam itself was structurally sound and said there was no threat to the public.

Residents of Oroville, a town of 16,000 people, should head north toward Chico, and other cities should follow orders from their local law enforcement agencies, the Butte County Sheriff’s office said.

The Yuba County Office of Emergency Services asked residents in the valley floor, including Marysville, a city of 12,000 people, to evacuate and take routes to the east, south, or west and avoid traveling north toward Oroville.

Department engineer and spokesman Kevin Dossey told the Sacramento Bee the emergency spillway was rated to handle 250,000 cubic feet per second, but it began to show weakness Sunday at a small fraction of that. Flows through the spillway peaked at 12,600 cubic feet per second at 1 a.m. Sunday and were down to 8,000 cubic feet per second by midday.

Unexpected erosion chewed through the main spillway during heavy rain earlier this week, sending chunks of concrete flying and creating a 200-foot-long, 30-foot-deep hole that continues growing. Engineers don’t know what caused the cave-in, but Chris Orrock, a spokesman for the state Department of Water Resources, said it appears the dam’s main spillway has stopped crumbling even though it’s being used for water releases.

The lake is a central piece of California’s government-run water delivery network, supplying water for agriculture in the Central Valley and residents and businesses in Southern California. </s> This post is up-to-date as of 11:50CT

While the potential of the Oroville Dam collapsing has slightly diminished, if the dam fails as expected it could send an uncontrolled release of flood waters from Lake Oroville to nearby cities. Evacuations began Sunday night as Oroville officials warned of the potential collapse and flooding of the entire city within an hour. Among the counties listed for evacuations are Butte, Sutter and Yuba. Most residents were only given minutes to gather their belongings and evacuate. The area had been in drought for a long time until this year when heavy rain and snow bombarded the state. In Oroville, the average annual rainfall is about 31 inches, but has already seen 25 inches of rain as of Saturday, according to the California Department of Water Resources.

According to California’s Department of Water Resources, the Oroville Dam’s emergency spillway that’s eroding had never been used in the 48 years that the dam has existed. The DWR instructed Oroville residents to head north, toward Chico. Crews have been working tirelessly loading up dozens of bags of rocks for helicopters to drop on dam’s auxiliary spillway. The DWR is hoping to bring the water level down before another expected storm on Wednesday hits. </s> (CNN) At least 188,000 people have evacuated from several Northern California counties after damage to a spillway at the Oroville Dam.

The dam, which is the nation's tallest, remains intact. But the emergency spillway, which guards against the overflow of the dam when water levels are high, was eroding Sunday.

The damage prompted a mandatory evacuation for cities and counties near Lake Oroville. In the worst case scenario, one official said, an uncontrolled release from the dam could send a 30-foot wall of water downstream.

"I'm not going to lift the evacuation order until I have a better idea of what that means and what risk that poses," Butte County Sheriff Kory Honea said in a news conference late Sunday night.

Officials are waiting until daylight Monday to better assess the situation and decide when it's safe for residents to return, Honea said.

California Gov. Jerry Brown issued a state emergency order to help local authorities with the situation and evacuations.

What led up to the emergency

Heavy rainfall in Northern California this winter has filled Lake Oroville to the verge of overflow. The lake also gets water from the northern Sierra Nevada mountain range, which is experiencing one of its wettest seasons. This has triggered concerns over whether the water could overflow the dam and flood nearby communities.

The Oroville Dam provides flood control for the region and is located about 75 miles north of Sacramento.

The dam has two spillways -- the primary and the emergency spillway -- which are channels to leak water out of the lake to prevent overflow. And right now, both have problems.

6:08pm: #OrovilleDam itself is not compromised at current time. Failure would be on auxiliary spillway. See graphic for details. pic.twitter.com/LSxCwsthxC — NWS Sacramento (@NWSSacramento) February 13, 2017

Last week, the primary spillway was damaged by erosion, according to the California Department of Water Resources. Images of the structure showed a massive hole in the lower part of the channel.

spillway at the #orovilledam - erosion was 1st reported 3 days ago, since then it has grown. pic.twitter.com/MNep5CQ9Ni — CANGJOCOPS (@CANGJ3OPS) February 9, 2017

That hole can't be fixed at the moment. It's 250 feet long, 170 feet wide and about 40 to 50 feet deep, said Bill Croyle, acting director of the Department of Water Resources.

"You don't throw a little bit of rock in it," he said.

Of the two, the emergency spillway is a last resort. At Oroville Dam, the emergency spillway is only used if water levels reach 901 feet in elevation. It hasn't needed to be used in its 48-year history -- until this weekend.

Why evacuation order was made

A light flow of water began washing into the emergency spillway Saturday and the volume of water began to increase. Around 3 p.m. (6 p.m. ET) Sunday, authorities learned that the dam's emergency spillway was also eroding, Honea said.

The erosion of the emergency spillway is dangerous because "when you start to erode the ground, the dirt and everything else starts to roll off the hill," said Kevin Lawson, California Fire incident commander.

"It starts to undermine itself. If that is not addressed, if that's not mitigated properly, essentially what we're looking at, is approximately a 30-foot wall of water," he said.

Evacuation orders on Sunday sternly warned residents that the erosion could result in "large, uncontrolled releases of water from Lake Oroville."

Honea's office used the most urgent of language -- "This is NOT a drill" -- in ordering residents to evacuate ahead of an impending disaster. Residents were told that the emergency "spillway is close to failing." The evacuation order included "all Yuba County on the valley floor" and the city of Marysville, authorities said.

An emergency evacuation of the City of Marysville and Yuba County has been issued. — MarysvillePD (@MarysvillePD) February 13, 2017

About 35,000 people from Butte County, 65,000 from Yuba County, 76,000 from Yuba City and 12,000 from Marysville City evacuated, according to California Fire.

Stores closed. Shelters opened. Local gas stations were swarmed with cars as residents tried to leave town. Evacuees waited in traffic trying to get out of low-lying areas.

Sean Dennis, who lives 30 miles south of Oroville, spoke to CNN from his car after spending 4.5 hours in bumper-to-bumper traffic.

"It was pretty scary, just because of how fast everything was developing," he said. "Me and my wife managed to throw as much of stuff as we could into garbage bags, whatever we could find. We got both of our cars loaded down pretty well. We're not taking any chances."

Police said that despite rumors, there were no reports of looting.

Watching the damage

After issuing the evacuation orders, authorities noted significant decreases in the water coming over the emergency spillway.

The flow of water on the emergency spillway eventually stopped Sunday night as the Department of Water Resources withdrew more water from the other spillway.

The main spillway is releasing water at 100,000 cubic feet per second in an effort to reduce the amount of water traveling down the emergency spillway, authorities said. Normal flows down the main spillway are about 55,000 cubic feet per second.

"The goal is to get the lake to drop 50 feet. If we can continue to do that, that brings a little bit of calm to what we're trying to accomplish here," said Cal Fire's Lawson.

So far, there have been no repairs made on the emergency spillway, because teams have been unable to reach the damaged area.

Teams will take a look and assess the situation Monday morning, Croyle said.

Authorities will have to act fast -- more rain is in the forecast for Wednesday. </s> At least 188,000 people living downstream of California's Oroville Dam were ordered to evacuate late Sunday as officials said an emergency spillway was dangerously eroding and a failure could cause uncontrolled floodwaters to pour out of the lake.

Water began flowing over the emergency spillway at the Oroville Dam in Northern California on Saturday for the first time in its nearly 50-year history after heavy rainfall. </s> OROVILLE, Calif. — Officials have ordered residents near one of the nation’s biggest dams to evacuate the area, saying a “hazardous situation is developing” after an emergency spillway severely eroded.

The emergency spillway of the Oroville Dam in Northern California could fail within an hour unleashing uncontrolled flood waters from Lake Oroville, the California Department of Water Resources said on Sunday afternoon.

People in downstream areas need to leave the area immediately, the department said.

Residents of Oroville, a town of 16,000 people, should head north toward Chico, and other cities should follow orders from their local law enforcement agencies, the Butte County Sheriff’s office said.

Water began flowing over the emergency spillway at the dam on Saturday after heavy rainfall damaged the main spillway.

Unexpected erosion chewed through the main spillway earlier this week, sending chunks of concrete flying and creating a 200-foot-long, 30-foot-deep hole that continues growing. Engineers don’t know what caused the cave-in, but Chris Orrock, a spokesman for the state Department of Water Resources, said it appears the dam’s main spillway has stopped crumbling even though it’s being used for water releases.

About 150 miles northeast of San Francisco, Lake Oroville is one of California’s largest man-made lakes, and the 770-foot-tall Oroville Dam is the nation’s tallest. The lake is a central piece of California’s government-run water delivery network, supplying water for agriculture in the Central Valley and residents and businesses in Southern California. </s> OROVILLE, Calif. (AP) — Nearly 200,000 people remained under evacuation orders Monday as California authorities try to fix erosion of the emergency spillway at the nation’s tallest dam that could unleash uncontrolled flood waters if it fails.

About 150 miles northeast of San Francisco, Lake Oroville — one of California’s largest man-made lakes — had water levels so high that an emergency spillway was used Saturday for the first time in almost 50 years.

The evacuation was ordered Sunday afternoon after engineers spotted a hole on the concrete lip of the secondary spillway for the 770-foot-tall Oroville Dam and told authorities that it could fail within the hour.

“I’m just shocked,” said Greg Levias, who was evacuating with his wife, Kaysi.

“We have two boys and our dog,” said Kaysi Levias. “All the stuff we could fit in the trunk — clothes and blankets.”

What they couldn’t fit they piled as high as they could in their downstairs Yuba City apartment and joined the line of traffic attempting to leave the city where they had moved just three weeks ago.

Panicked and angry residents sat in bumper-to-bumper traffic hours after the evacuation order was given.

Raj Gill was managing a Shell station where anxious motorists got gas and snacks while waiting for gridlocked traffic to clear. His boss told him to close the station and flee himself, but he stayed open to feed a steady line of customers.

“You can’t even move,” he said. “I’m trying to get out of here too. I’m worried about the flooding. I’ve seen the pictures — that’s a lot of water.”

State Fire and Rescue Chief Kim Zagaris said at least 250 law enforcement officers from throughout the state are in the area or on their way to help with the evacuation.

A California Highway Patrol spokesman said they would have two planes out Monday to help with traffic control as well as search and rescue.

Late Sunday, officials said the evacuation orders remained in place despite the fact water was no longer spilling over the eroded area.

“There is still a lot of unknowns,” Butte County Sheriff Kory Honea said at a news conference. “We need to continue to lower the lake levels and we need to give the Department of Water Resources time to fully evaluate the situation so we can make the decision to whether or not it is safe to repopulate the area.”

About 188,000 residents of Yuba, Sutter and Butte counties were ordered to evacuate.

Acting Director Department of Water Resources Bill Croyle said officials will be able to assess the damage to the emergency spillway now that the lake levels have been lowered.

The erosion at the head of the emergency spillway threatens to undermine the concrete weir and allow large, uncontrolled releases of water from Lake Oroville. Those potential flows could overwhelm the Feather River and other downstream waterways, channels and levees and flood towns in three counties.

Oroville Lake levels had decreased by Sunday night as they let water flow from its heavily damaged main spillway.

Croyle said the department will continue releasing as much as 100,000 cubic feet per second from the main spillway to try and reduce the dam’s level by 50 feet ahead of storms forecast to reach the area Wednesday.

Department engineer and spokesman Kevin Dossey told the Sacramento Bee the emergency spillway was rated to handle 250,000 cubic feet per second, but it began to show weakness Sunday after flows peaked at 12,600 cubic feet per second.

Honea said there was a plan to plug the hole by using helicopters to drop rocks into the crevasse. But Croyle said at that no repair work was done after officials looked at the flow and available resources.

Gov. Jerry Brown late Sunday issued an emergency order to fortify authorities’ response to the emergency at the dam and help with evacuations.

Adjutant General David S. Baldwin of the California National Guard said at a news conference late Sunday that eight helicopters will be available Monday to assist with emergency spillway reconstruction.

The California National Guard put out a notification to all 23,000 soldiers and airmen to be ready to deploy if needed, he said. Baldwin says an alert for the entire California National Guard hadn’t been issued since the 1992 riots.

Earlier Sunday, officials stressed the Oroville Dam itself was structurally sound.

Unexpected erosion chewed through the main spillway during heavy rain earlier this week, sending chunks of concrete flying and creating a 200-foot-long, 30-foot-deep hole that continues growing. Engineers don’t know what caused the cave-in, but Chris Orrock, a Department of Water Resources spokesman, said it appears the dam’s main spillway has stopped crumbling even though it’s being used for water releases.

The lake is a central piece of California’s government-run water delivery network, supplying water for agriculture in the Central Valley and residents and businesses in Southern California.
The California Department of Water Resources orders residents near Oroville Dam to evacuate, including low-lying levels of Oroville, after an emergency spillway severely eroded.