Oroville Dam Evacuations Lifted As Officials Say Structure Can Withstand Next Storm

[Hamartia Antidote]

http://www.npr.org/sections/thetwo-...officials-say-structure-can-withstand-next-st

The Oroville Dam's main spillway as seen on Feb. 14. Crews working round the clock since Sunday have made progress stabilizing this and another spillway damaged by water.

Marcio Jose Sanchez/AP
After two days of round-the-clock work to control water flowing over the Oroville Dam in Northern California, people who live downstream of the structure are allowed to return to their homes, officials announced Tuesday.

Nearly 200,000 people were affected by evacuations after water scoured enormous holes in two of the dam's concrete spillways beginning Sunday, raising concerns that the tallest dam in the country could fail.


THE TWO-WAY
With More Rain Forecast, Crews Work To Reinforce Oroville Dam
Butte County Sheriff Kory Honea announced Tuesday evening he was lifting an evacuation order issued on Sunday, Dan Brekke of member station KQED reported.

"Thousands of lives were protected [from] the looming prospect of a catastrophic failure of the emergency spillway," Honea told reporters, adding that residents should be ready to evacuate again if conditions change.

"There's the prospect that we can issue another evacuation order if circumstances change," he said.

The Red Cross said shelters remained open on Tuesday evening.

The Federal Emergency Management Agency also announced that federal disaster relief for Butte, Sutter and Yuba counties had been approved by the White House on Tuesday.

On Monday and Tuesday, crews dumped enormous rocks into damaged sections of the dam's damaged emergency spillway, hoping to prevent further erosion. The spillway is supposed to carry water from Lake Oroville around the main wall of the dam when the lake level is too high.

With the lake level still high and more rain forecast for later this week, officials rushed to prevent a catastrophe, as The Los Angeles Times reported:

"A swarm of trucks and helicopters dumped 1,200 tons of material per hour onto the eroded hillside that formed the dam's emergency spillway. One quarry worked around the clock to mine boulders as heavy as 6 tons. An army of workers mixed concrete slurry to help seal the rocks in place.

" 'This is an aggressive, proactive attack to address the erosion,' said Bill Croyle, acting director of the state Department of Water Resources. 'There's a lot of people, a lot of equipment, a lot of materials moving around, from the ground and from the air.'

"At the main spillway, a different and riskier operation was underway: Despite a large hole in the concrete chute, officials have been sending a massive amount of the swollen reservoir's water down the chute to the Feather River in a desperate attempt to reduce the lake's level.

"The structure continued to hold Tuesday without sustaining more significant damage, officials said."

drought in California, the National Weather Service said Tuesday that much of the state is on track for the wettest winter ever recorded, filling reservoirs and replenishing alpine snowpack that will continue to feed rivers for months.

View image on Twitter

 

[Hamartia Antidote]

Picture of drought conditions at the dam in 2014

2 years later...video of water level so high its coming over the walls

now the water has stopped and they can repair the area the water was gushing over the wall.

 

[oprih]

This dam will collapse soon, infrastructures in america are comparable to that in third world countries.

 

[AZADPAKISTAN2009]

I think I watched a documentary on US infrastructure they stated most of the major cities in USA are running on stuff made almost 100 years ago

 

[LA se Karachi]

Thankfully, we're finally coming out of this long drought. Quite a turnaround from a year ago:

 

[Hamartia Antidote]

I think I watched a documentary on US infrastructure they stated most of the major cities in USA are running on stuff made almost 100 years ago

That's probably true. While many countries have only recently started coming out of the third world we already achieved it over 100 years ago. So we already went through the entire process of building skyscrapers, subways, dams holding clean drinking water, piped in water to all houses, sewers, natural gas lines, electrical power grids, bridges, etc a very very very long time ago. There is simply a huge amount of stuff already built.

For instance the Brooklyn Bridge in NYC where you see pictures of cars going across in lots of movies opened in 1883.

Still in use today. 134 years later.

Met Life tower (50 stories 213 meters)...still standing. Built over 100 years ago!! I think there is only 1 building in Pakistan taller than it.

The Woolworth building is even taller (57 floors 241 meters) and is also over 100 years old.

Picture of a subway tunnel from the 1890's.

In the 1840's piped in water in cities occurred. In the 1850's they added water purification and piped sewer systems. That's 150 to 175 years ago. Cities were wired for electricity in the 1880's...130 years ago!

Elevators in the 1850's allowed buildings to be taller than ~8 stories (which was about the max tolerable to walk up a staircase several times a day).

So by the end of the 1880's you could be sitting in a nice warm bath in a skyscraper with piped in clean hot and cold water, electrical lighting, and a toilet. Yes, that makes our infrastructure well over 100 years old.

Many countries are now doing things in the 21st Century that we had already accomplished in the 19th Century. Actually many are STILL failing the drinkable water part...they have to boil it.

This is incomprehensible to most Americans as we have had purified drinkable hot and cold water straight out of the tap for about 150 years.

 

[Hamartia Antidote]

Amazingly even with all the crazy rain and the water overtopping the walls the dam has held!!

Oroville Dam crisis: Officials nearing lake level goal

The California Department of Water Resources on Saturday morning was just more than 5 feet away from reaching its goal to drop lake Oroville to 850 feet.

As of 8 a.m. the lake sat just above 855 feet. That's more than 45 feet below the dam's emergency spillway. [which was being topped over a few days ago!!]

Water is flowing out of the dam at about 70,000 cubic feet per second, about nearly 524,000 gallons per second, according to DWR data.

Evacuation warnings remain in effect Oroville and areas of Butte County near the Feather River.

This dam will collapse soon, infrastructures in america are comparable to that in third world countries.

You are correct about third world countries. While we have had dam failures and deaths; they never were of the collossal failure scale as China had in 1975 when 35,000+ people were killed immediately (and up to 100,00 -200,000 people died from injuries/famine months afterwards) when a 25 year old dam burst due to crappy construction as it too was overtopped by heavy rains. 10+ Million left homeless. https://en.wikipedia.org/wiki/Banqiao_Dam

 

[Hamartia Antidote]

http://www.mercurynews.com/2017/02/...-inching-down-us-sen-kamala-harris-tours-dam/

Water levels at Lake Oroville inching down; US Sen. Kamala Harris tours dam

U.S. Sen. Kamala Harris on Thursday toured the damaged spillways at Oroville Dam and was briefed by local, state and federal officials on the ongoing crisis at the lake.

Harris, in an exchange with reporters at Oroville Airport where she arrived by helicopter, expressed gratitude for the work done at the dam, adding she wanted to see firsthand what has happened there so she could advocate for the resources California needs.

“We need to make sure that we’re putting enough resources into maintenance of the infrastructure writ large,” she said. “So it’s about the dams. It’s about what we’re doing in terms of response to floods. It’s about what needs to happen in terms of giving local folks — responders, law enforcement — the tools they need and the resources they need when it comes to evacuating large numbers of people.”

Further, the senator said officials must take a “critical look at the bureaucracy that might be a part of this process and do what we can to eliminate that bureaucracy.”

She said the emergency at the dam affects not only the region but also the state and the country.

“This region produces the fruits and vegetables consumed by the entire country,” Harris said. “This is about the economy of this region, about the state and the country. This is about protecting our environment.”

Asked whether the crisis at the dam was caused by a failure of state governance, Harris said the crisis “was caused by a few things, including Mother Nature.”

“And you know, thank God it’s been raining, right?” she said.

“We’ve been wanting rain and we got it. But it highlighted an issue that had been an issue for a while. And that emphasizes the need that we have to make sure that we’re putting adequate resources into inspections and maintenance of all these facilities around the state.”

Timothy Scranton, a coordinating officer for the Federal Emergency Management Agency, said the agency has provided logistical support and stands ready to support local and state officials with any additional emergency at the dam.

“We’re also developing plans — catastrophic plans — in case there is something that takes place, and we’re keeping a close eye on the levee system,” Scranton said.

He added: “The water is here. We have stored energy in the snowpack that’s going to come down into the lakes and to the rivers, and we have to be prepared for any future events that might happen.”

Butte County Sheriff Kory Honea said the meeting Thursday with Harris, as well as representatives for U.S. Sen. Dianne Feinstein and state and federal agencies, was “productive.”

Honea said officials discussed the “importance” of the dam both economically and in terms of local and national security. He said the meeting also touched on the recovery process going forward.

“Not only in terms of repairing the damage that was done to the system, but also how do we keep that from occurring again,” Honea said. “What does it look like in terms of ensuring this is a stable system and that it continues to provide the important elements of infrastructure that it does.”

The sheriff said the meeting also broached the subject of the “historical concerns” the local community has had with the state Department of Water Resources over the dam.

“There was a very good discussion about moving forward and trying to get a better understanding of each other’s roles,” Honea said, adding, “There is often opportunity in crisis, and I think now we turn towards looking for that opportunity.”

Paul Hahn, Butte County’s chief administrative officer, said as work at the dam shifts toward a “recovery mode,” county officials intend to build upon relationships with state and federal officials established by the sheriff.

“This is a long haul,” Hahn said. “And we want to rebuild the economy. We want to rebuild the trust in the community and the dam.”

THE CURRENT SITUATION

The water level at Lake Oroville continued to inch down Thursday, and DWR scaled back releases through the damaged main spillway at noon.

Releases were cut back to 50,000 cubic feet per second from 60,000 cfs. Even that lower rate was higher than the flow of water into the lake. Inflow at 4 p.m. Thursday was about 39,000 cfs.

As of 4 p.m. Thursday, the water level was at the 850.58-foot elevation, more than 50 feet below the problematic emergency spillway’s lip.

DWR began drawing the lake down after the Feb. 12 crisis at the emergency spillway, when erosion in the hillside below the concrete weir threatened to collapse the structure and flood areas downstream. The water level then was about 902 feet.

The level was reduced to below 849 feet by Monday. Inflow from the most recent set of storms bumped the lake up 4 feet to 853 feet by 4 a.m. Wednesday, but the water has been dropping steadily since then.

A new storm is scheduled to arrive Saturday night, but the National Weather Service has scaled back its estimate of how strong it will be. It is now expected to bring as much as a quarter-inch of rain on the valley floor and a half-inch in the foothills.

For comparison, according to DWR the Feb. 16-21 storm system dumped 10 inches at Brush Creek, in the foothills above Lake Oroville.

The new storm will be cold, with snow levels from 2,500 to 3,500 feet. Less than a foot of new snow is expected.

Work is continuing to protect the area below the emergency spillway, with rock being piled into ravines dug by the runoff over the weir, and a concrete slurry being poured over that.

DWR is also making preparations to dig out debris at the base of the main spillway in the Diversion Pool, so the water level there can be reduced enough to bring the Hyatt Powerplant under the dam back on line. Another 13,000 cfs can be taken out of the lake through the powerhouse when it is operating.

The reduction in releases from the spillway are intended to allow progress to be made on Diversion Pool debris removal.