MEC&F Expert Engineers : 02/13/17

Monday, February 13, 2017

MAJOR BLUNDER CAN CAUSE BILLIONS IN DAMAGES: California water agencies refused to strengthen the earthen spillway in Oroville in 2005

OROVILLE, Calif. (KGO) -- Three environmental groups warned federal and state officials 12 years ago the spillway in Oroville could erode during heavy winter rains and cause a catastrophe.



Our media partner the San Jose Mercury News reports the environmental groups, including the Sierra Club, filed a motion with the federal government in 2005, urging federal officials to require that the dam's emergency spillway be armored with concrete, rather than remain as an earthen hillside.

The Federal Energy Regulatory Commission rejected the request after the state department of water resources and other water agencies said the upgrades were unnecessary.




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Mandatory evacuations in place for residents near Oroville Dam
 



Nearly 200,000 people remained under evacuation orders Monday as authorities try to fix erosion of the emergency spillway. (AP)

Updated 11 mins ago
OROVILLE, Calif. -- Butte County Sheriff Kory Honea says the evacuation below the nation's tallest dam because of the threat of flooding from a damaged spillway will not end right away. Officials said today that they are working on a plan to allow residents to return home when it's safe.

Nearly 200,000 people remain under evacuation orders as authorities try to fix erosion of the emergency spillway at the 770-foot-tall Oroville 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, two boys and a dog.

What they couldn't fit in their trunk 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."

A Red Cross spokeswoman said more than 500 people were at an evacuation center in Chino, California. The shelter had run out of blankets and cots, and a semi-tractor trailer with 1,000 more cots was stuck in the gridlock of traffic fleeing the potential flooding, said Red Cross shelter manager Pam Deditch.

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


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.

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.

ANOTHER BACKOVER DEATH: 1 worker crushed to death after two employees of Graniterock, working as contractors for Caltrans, were run over while they were clearing a mudslide on Highway 17 in Santa Cruz County








A construction worker was killed when he was hit by a dump truck and another was injured while they were clearing a mudslide on Highway 17 in Santa Cruz County Thursday afternoon. (KGO-TV)

By David Louie
Friday, February 10, 2017 12:20AM
SANTA CRUZ, Calif. (KGO) -- A construction worker was killed when he was hit by a truck and another was injured while clearing a mudslide on Highway 17 in Santa Cruz County Thursday afternoon.

The two men were working between Vine Hill and Sugarloaf roads when the incident occurred.

The major storm that has been hammering the Bay area all day may have been a factor in a fatal accident.

The accident happened as a dirt hauling truck was backing up from a cutout along northbound Highway 17 after dumping its load.

Two employees of Graniterock, working as contractors for Caltrans, were run over. The man who was injured got trapped underneath the truck.

CHP Ofc. Trista Drake said the crews were working in bad weather to clear a mudslide blocking the northbound lanes. "It had already been raining for about I'd say 30 minutes...and they were going to work through the rain and we were flagged down by a passerby. Luckily, CHP was right there on scene. A medic got up here quickly. We expedited fire and ambulance to get the gentleman who was trapped extricated quickly and get him over to valley med," Drake said.

The two workers were behind the truck as it was backing up and CHP said both men were wearing bright-colored safety gear to make them visible.

CHP will be investigating whether the truck had a back-up warning beeper or a rear-facing camera.

Graniterock is a well-known Watsonville-based construction company that has been charged with cleaning up an unstable hillside adjacent to Highway 17 northbound lanes since last month when a mudslide slammed into an ABC7 News van, crushing its side and injuring the photographer inside.

Graniterock told ABC7 News they are devastated by the loss of one of its employees and added that the company has not had an accident in many years.

Worker was crushed to death after he was pinned by a forklift at the FDNY parts depot at 30-03 Review Avenue in Long Island City




A worker was killed Saturday in Queens when he became pinned between a forklift and a delivery truck, sources told The Post.

The man was working at the FDNY parts depot at 30-03 Review Avenue in Long Island City, when he put the forklift in neutral and placed it next to his van.

When he left the heavy machinery to retrieve something from the van, the forklift somehow started rolling, crushing him between the van and the forklift, police sources said.

Cops responding to the scene at 12:35 p.m. found the man unconscious and unresponsive, the sources said. EMS brought him to Elmhurst Hospital, where he was pronounced dead, the sources said.