Losing battle at Oroville Dam While Flood Water Swamp Towns Near Dam. Officials were warned about the main spillway’s fragility 12 years ago but ignored concerns.

Losing battle at Oroville Dam While Flood Water Swamp Towns Near Dam. Officials were warned about the main spillway’s fragility 12 years ago but ignored concerns.

Engineers are LOSING the battle to lower water behind California’s crumbling dam by 50ft before new storm hits on Wednesday – after admitting the waters have only dropped 11ft in 24 hours

  • Water level at Lake Oroville has only been reduced by 11ft since it reached its capacity on Saturday afternoon
  • Department of Water Resources had hoped to lower it by 50ft before storms hit as soon as Wednesday night 
  • Water is being drained from the lake down by the damaged main spillway at a rate of 750, 000 gallons per second
  • It still may not be enough to lower the water levels sufficiently before rain hits which will cause it to rise again 
  • 200,000 residents in California may be displaced for weeks as emergency services race to repair spillways
  • They left in ‘pure chaos’ when a sudden evacuation order was issued on Sunday after days of assurances from officials that the situation was safe  
  • Environmental groups predicted the exact chain of events in 2003 but had their fears ignored by officials  
  • Now officials are working to patch up the erosion hole on the main spillway so it can return to normal function 

DailyMail

The brimming lake threatening to topple California’s crumbling Oroville Dam has been drained by just 11 feet since it overflowed on Saturday, a worrying fraction of the 50ft it needs to be reduced by before more rain hits the region this week.

The current water level of Lake Oroville is 889ft, 11ft less than its 900ft capacity which was reached on Saturday, pushing water over an emergency spillway which began to collapse under the pressure.

Engineers are draining the lake at a rate of 750,000 gallons per second which lowers the level by about a foot every three hours but they are not moving fast enough to bring it down to their target of 850ft by Wednesday.

The dam’s main spillway, which would normally offset rising water levels in the lake, has been compromised by a gaping hole caused by erosion which engineers are trying to fix while still allowing water to pass down it.

The continuing flow of water will worsen the erosion but they have been left no choice given the weakness of the emergency spillway.

If the lake exceeds its capacity before the hole is repaired, it could destroy the emergency spillway and send a 30ft wall of water cascading into Butte, Sutter and Yuba counties.

Some 200,000 residents were evacuated in anticipation of such an event on Sunday and have taken refuge in make-shift shelters where they could remain for weeks before it is safe to return.

They fled when authorities were finally forced to issue an emergency evacuation order after days of claiming the situation was safe.

The evacuees have since told of their hurried escape, describing the scene of entire communities fleeing in their packed up cars as ‘pure chaos’.

Race against time: Water is being sent down the damaged main spillway at Oroville Dam (above) as engineers desperately try to reduce water levels in the lake (top) before it rains again on Wednesday 
Race against time: Water is being sent down the damaged main spillway at Oroville Dam (above) as engineers desperately try to reduce water levels in the lake (top) before it rains again on Wednesday

‘Everyone was running around. It was pure chaos. All of the streets were immediately packed with cars, people in my neighborhood grabbing what they could and running out the door and leaving,’ Maggie Cabral told KFSN.

The emergency situation has been in developing for a week and began last Tuesday when officials were forced to acknowledge a gaping hole in the main spillway.

They halted water flow on the spillway to investigate the damage but said at the time there was no immediate threat to the public.

The emergency spillway, which had never before been used, was then put to work but soon buckled under the pressure. Because it was backed only by land and soil, authorities were forced to admit that it would likely fail and evacuated the area suddenly on Sunday afternoon.

The sudden order after days of of public assurances that the situation was safe created pandemonium in the town of Oroville and others surrounding the dam.

Some already had their bags packed and hit the road immediately but others were left to scramble after being told for days that they were in no danger.



Workers are trying to plug the erosion in the main spillway with rocks which are being brought in by lorries and choppers and then dropped onto the hole 
Workers are trying to plug the erosion in the main spillway with rocks which are being brought in by lorries and choppers and then dropped onto the hole

The problem: The crisis was sparked when authorities stopped allowing water down the main spillway to investigate a large hole caused by erosion (left), sending all of the surplus lake water to an emergency spillway which wasn't equipped to handle it. Now, water gushing down the eroded spillway again before storms bring more rain to the reservoir The problem: The crisis was sparked when authorities stopped allowing water down the main spillway to investigate a large hole caused by erosion (left), sending all of the surplus lake water to an emergency spillway which wasn't equipped to handle it. Now, water gushing down the eroded spillway again before storms bring more rain to the reservoir

The problem: The crisis was sparked when authorities stopped allowing water down the main spillway to investigate a large hole caused by erosion (left), sending all of the surplus lake water to an emergency spillway which wasn’t equipped to handle it. Now, water gushing down the eroded spillway again before storms bring more rain to the reservoir.

Evacuation: Almost 200,000 people were ordered to leave the towns downhill of the Oroville Dam on Sunday as heavy rainfall left it at risk of bursting. On Monday it emerged that authorities had ignored warnings about a possible collapse 12 years ago
Evacuation: Almost 200,000 people were ordered to leave the towns downhill of the Oroville Dam on Sunday as heavy rainfall left it at risk of bursting. On Monday it emerged that authorities had ignored warnings about a possible collapse 12 years ago
Water continued to swamp towns at the foot of the dam including Oroville (above) which thousands of residents fled on Sunday
Public toilets at Riverbend Park in Oroville were swamped on Tuesday as the situation grew even more severe 
Public toilets at Riverbend Park in Oroville were swamped on Tuesday as the situation grew even more severe
Swamped: The town of Marysville, 50ft away from the dam, was submerged on Tuesday as rivers continued to swell 
Swamped: The town of Marysville, 50ft away from the dam, was submerged on Tuesday as rivers continued to swell

The chaos was described as a ‘textbook example’ of why the country needs to invest in infrastructure by White House Press Secretary Sean Spicer on Tuesday as he said President Trump was keeping a ‘close eye’ on the situation.

He has not yet released  $162.3 million in disaster assistance that California has requested.

Evacuation centers have been set up at a fairgrounds in Chico, California, about 20 miles northwest of Oroville, but major highways leading south out of the area were jammed as residents fled the flood zone.

Javier Santiago, 42, fled with his wife, two children and several friends to the Oroville Dam Visitors Center in a public park above the dam and the danger zone.

With blankets, pillows and a little food, Santiago said: ‘We’re going to sleep in the car.’

The sudden evacuation panicked residents, who scrambled to get their belongings into cars and then grew angry as they sat in bumper-to-bumper traffic hours after the evacuation order was given.

Raj Gill, managing a Shell station where anxious motorists got gas and snacks, said 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 showed up at an evacuation center in Chico, California.

The shelter ran out of blankets and cots, and a tractor-trailer with 1,000 more cots was stuck in the gridlock of traffic fleeing the potential flooding Sunday night, Red Cross shelter manager Pam Deditch said.

On Monday it was revealed officials were warned about the main spillway’s fragility 12 years ago but ignored concerns.

Environmental groups predicted that the main spillway could erode under heavy rainfall and flagged their fears to the Federal Energy Regulatory Commission in 2003, requesting updates and improvements to the dam spillways.

The improvements were never made because water agencies which would have had to pay for them deemed them unnecessary.  Infrastructure improvements earmarked across the state in January this year didn’t include the Oroville Dam either.

The $100billion list was made by the governor’s office and included plans for the Folsom Dam but made no mention of Oriville.

On October 17, 2006, three environmental groups – the Friends of the River, the Sierra Club and the South Yuba Citizens League – filed a motion with the Federal Energy Regulatory Commission (FERC) urging the government to fully reinforce the dam’s emergency spillways with concrete, according to The Mercury News. 

In the face of heavy rainfall, the groups said, the earthen spillways might begin to collapse and erode, leading to the river downhill being inundated with water – as happened over the weekend.

Worse, they said, there was a serious risk of ‘loss of crest control’ – that is, the lip of the dam might fail, resulting in a massive and dangerous surge that would ’cause damages and threaten lives in the protected floodplain downstream’.

But the Department of Water Resources, and the agencies in the line to foot the bill – told the FERC that the spillways could handle 350,000 cubic feet of water per second and there was no danger.

‘The emergency spillway meets FERC’s engineering guidelines for an emergency spillway,’ wrote John Onderdonk, a senior civil engineer with FERC, in 2006. ‘The guidelines specify that during a rare flood event, it is acceptable for the emergency spillway to sustain significant damage.’

Despite that, the weekend saw the earthen spillways being eroded with flows of just 6,000-12,000 cubic feet per second – less than five percent of FERC’s supposed safe rate.

State officials said in 2008 no ‘significant concerns’ about the spillway’s integrity had been raised in any government or independent review.

Also on Monday, it emerged that California Governor Jerry Brown had overlooked the Oroville Dam in the $100 billion list of ‘key’ infrastructure projects filed this month.

The list, generated at the request of the National Governor’s Association after Donald Trump called for $1 trillion of infrastructure investment, is a ‘wish list’ of projects for Brown, CNBC reported.

But while the list mentions the Folsom Dam, some 60 miles south of Oroville, as well as flood control in Sacramento, 66 miles away, there is no mention of Oroville Dam itself.

Instead, most of the suggested upgrades in the three-page document are related to transportation, such as highways, bridges and railroads.

Projects to reduce flooding risk in Marysville, 30 miles south of Orosville and 50 miles from the dam, are mentioned, as are other levee and dam plans.

All are placed below a proposed high-speed rail track between Los Angeles and San Francisco on the list – although the governor’s office says that the order of the list does not represent how important the projects are.

It added that the list was ‘an initial list of projects. By no means does it represent all of the state’s priorities.’

Brown later said that he was not aware of the 2006 report or the concerns raised about the dam.



 

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