Cannons, laser, radars planned to keep birds from toxic pit
After thousands of snow geese died in the toxic water of a former open-pit mine in Montana last fall, the companies responsible for the pit are bringing out the big guns. Literally.Montana Resources and BP-owned Atlantic Richfield Co. are proposing to use four propane cannons on tripods that would be triggered by long-range motion sensors as one additional measure to scare birds away from the Berkeley Pit during the spring migration.Also in the plan are radars, air and water drones and strategically positioned lasers that would create a "net" across the pit and deter the birds from landing in the metal-laden water.
The massive snowpack in the mountains above Oroville Dam is beginning to melt as temperatures rise and could soon test the troubled reservoir with its biggest inflows since last month’s crisis.
The snow is so deep here that scientists can't measure it
One sure sign the Sierra Nevada is experiencing a historic winter is the snowpack is getting too deep for devices scientists use to measure it. It’s a problem that cropped up Wednesday when researchers sought to confirm snow depth at a data site on Slide Mountain at Mount Rose Ski Tahoe near Reno. @ByBenSpillmanRENO, Nev. — One sure sign the Sierra Nevada is experiencing a historic winter is the snowpack is getting too deep for devices scientists use to measure it.
Managers of the state-run dam say they’ll be forced to rely on the lake’s damaged main spillway to discharge water down the Feather River as soon as next Friday. The concrete chute, which partially collapsed last month amid heavy outflows, has been offline for repairs for nearly two weeks while reservoir levels have been down.
Officials with the state Department of Water Resources are confident the mangled spillway and the eroded hillside below it can handle the releases as they wait for drier months to make permanent fixes.
But the wild card remains the weather — how much water pours into the lake and how quickly.
“It’s going to start to get a lot of snowmelt coming in,” said Roger Bales, a professor of engineering at UC Merced and director of the Sierra Nevada Research Institute. “Depending on the flow rate that you put through there, there’s the potential for more damage and more deterioration.”
Late Wintry Wallop Targets 39M From Ohio to Cape Cod
About 39 million people on Friday were under a winter weather alert.About 39 million people on Friday were under a winter weather alert in a narrow swath stretching from eastern Ohio to Cape Cod, Massachusetts.
“Yes, I’m concerned,” he said. “Everyone has concerns.”
The California Department of Water Resources and host of collaborating agencies continue to monitor the Lake Oroville spillway flows late Thursday afternoon as 35,000 cubic feet per second (cfs) of water was released over the damaged spillway. More erosion is expected, but the releases will help operators absorb the inflow of the storm waters expected Thursday evening and Friday. DWR first noticed erosion on the spillway Tuesday morning and shut off flows to investigate. There is no imminent or expected threat to public safety or the integrity of Oroville Dam in Butte County. Photo taken 3:10 p.m. PST February 9, 2017. Kelly M. Grow/ California Department of Water Resources
A small flow of water goes down Oroville Dam's crippled spillway Tuesday, Feb. 28, 2017, in Oroville, Calif. California water authorities stopped the flow of water down the spillway, Monday, allowing workers to begin clearing out massive debris that's blocking a hydroelectric plant from operating.
Geologists from the U.S. Army Corps of Engineers and California Department of Water Resources survey the bottom of the damaged Oroville Dam spillway and the huge energy dissipator blocks at the base of the spillway. The outflow from the spillway has been zero since Monday afternoon, which has given workers the opportunity to start the debris removal from the diversion pool. Photo taken February 28, 2017. Brian Baer/ California Department of Water Resources, FOR EDITORIAL USE ONLY
An aerial view of the damaged Oroville Dam spillway after the California Department of Water Resources gradually reduced the outflow from the spillway from 50,000 cubic feet per second (cfs) to zero on February 27, 2017. The reduction allows work to begin to remove debris at the spillways base and reduce water surface elevation in the diversion pool at the Butte County site. Photo taken February 27, 2017. Dale Kolke / California Department of Water Resources
Oroville Dam's crippled spillway is inspected via helicopter after it was shut off Monday, Feb. 27, 2017, in Oroville, Calif. California water authorities stopped the flow of water down the dam's spillway allowing workers to start clearing out massive debris that's blocking a hydroelectric plant from working. (Paul Kitagaki Jr./The Sacramento Bee via AP)
The main spillway of the Oroville Dam on Monday, Feb. 13, 2017 in Oroville, Calif. Nearly 200,000 people downriver from Lake Oroville were ordered to evacuate Sunday night, after an emergency spillway next to the reservoir�s dam appeared in danger of collapse.
In this Saturday, Feb. 11, 2017, water flows down Oroville Dam's main spillway, near Oroville, Calif. Officials have ordered residents near the Oroville Dam in Northern California to evacuate the area Sunday, Feb. 12, saying a "hazardous situation is developing" after an emergency spillway severely eroded. (AP Photo/Rich Pedroncelli)
Water flows through break in the wall of the Oroville Dam spillway, Thursday, Feb. 9, 2017, in Oroville, Calif. The torrent chewed up trees and soil alongside the concrete spillway before rejoining the main channel below. Engineers don't know what caused what state Department of Water Resources spokesman Eric See called a "massive" cave-in that is expected to keep growing until it reaches bedrock.
A member of Cal Fire, right, talks to workers on the Oroville Dam project in front of the main spillway in Oroville, Calif., Monday, Feb. 20, 2017. Forecasters issued flash flood warnings Monday throughout the San Francisco Bay Area and elsewhere in Northern California as downpours swelled creeks and rivers in the already soggy region. (Hector Amezcua/The Sacramento Bee via AP)
An aerial view of the damaged Oroville Dam spillway as the California Department of Water Resources gradually reduced the outflow from the spillway from 50,000 cubic feet per second (cfs) to zero on February 27, 2017. The reduction allows work to begin to remove debris at the spillways base and reduce water surface elevation in the diversion pool. Photo taken February 27, 2017. Dale Kolke / California Department of Water Resources
Officials walk past the Oroville Dam after investigating it for damage on Monday, Feb. 13, 2017 in Oroville, Calif. Nearly 200,000 people downriver from Lake Oroville were ordered to evacuate Sunday night, after an emergency spillway next to the reservoir�s dam appeared in danger of collapse.
An excavator moves dirt and rocks to level off an area along the banks of the Feather River to creat a road for other heave equipment that will be used to clear debris from the river as thousands of gallons of water rush over the auxiliary spillway at Oroville Dam in Oroville, Calif., on Sunday, February 12, 2017. The California Department of Water Resources is now working to remove debris from the river so water flow down the Feather River doesn't impede the hydroelectric generation at the dam.
The California Department of Water Resources has suspended flows from the Oroville Dam spillway after a concrete section eroded on the middle section of the spillway. There is no anticipated threat to the dam or the public. DWR engineers are assessing the options to repair the spillway and control the reservoir water level. The Butte County facility is the tallest dam in the United States at 770 feet and is a key part of the State Water Project. Photo taken February 7, 2017. Kelly M. Grow/ California Department of Water Resources, FOR EDITORIAL USE ONLY
Water flows over the emergency spillway at Oroville Dam Saturday, Feb. 11, 2017, in Oroville, Calif. Water started flowing over the emergency spillway at the nation's tallest dam for the first time Saturday after erosion damaged the Northern California dam's main spillway.
Water gushes down the Oroville Dam's main spillway Wednesday, Feb. 15, 2017, in Oroville, Calif. The Oroville Reservoir is continuing to drain Wednesday as state water officials scrambled to reduce the lake's level ahead of impending storms.
A helicopter kicks up dust as it lands at a staging area near the Oroville Dam on Monday, Feb. 13, 2017, in Oroville, Calif. State officials have discussed using helicopters to drop loads of rock on the damaged emergency spillway of the dam.
California Department of Water Resources crews inspect and evaluate the erosion just below the Lake Oroville Auxiliary Spillway after lake levels receded on Monday morning. The outflow from the primary Oroville Spillway remains at 100,000 cubic feet per second (cfs) to decrease the lake level by 50 feet to handle the next round of storms this week. Photo taken February 13, 2017. Kelly M. Grow/ California Department of Water Resources, FOR EDITORIAL USE ONLY
Oroville Dam Spillway: The story of a catastrophe in photos Left: 2014, the spillway never kicked into use when the lake level was low due to little rain. Right: 2017, after several weeks of heavy rain, the spillway was used heavily and eroded.
The Oroville Dam spillway releases 100,000 cubic feet of water per second down the main spillway in Oroville, California on February 13, 2017. Almost 200,000 people were under evacuation orders in northern California Monday after a threat of catastrophic failure at the United States' tallest dam. Officials said the threat had subsided for the moment as water levels at the Oroville Dam, 75 miles (120 kilometers) north of Sacramento, have eased. But people were still being told to stay out of the area.
A home is seen marooned as the surrounding property is submerged in flood water in Oroville, California on February 13, 2017. Almost 200,000 people were under evacuation orders in northern California Monday after a threat of catastrophic failure at the United States' tallest dam. Officials said the threat had subsided for the moment as water levels at the Oroville Dam, 75 miles (120 kilometers) north of San Francisco, have eased. But people were still being told to stay out of the area. / AFP PHOTO / Josh EdelsonJOSH EDELSON/AFP/Getty Images
Water and debris rush down the side of the hill as thousands of gallons of water rush over the auxiliary spillway at Oroville Dam in Oroville, Calif., on Sunday, February 12, 2017. The California Department of Water Resources is now working to remove debris from the river so water flow down the Feather River doesn't impede the hydroelectric generation at the dam.
Damage to the spillway at the Oroville Dam is depicted in a photo released by the California Department of Water Resources on Feb. 28, 2017.
Problems at the nation’s tallest dam began Feb. 7 when a gaping hole emerged on the main spillway. Without the chute fully functional, lake water rose and days later poured over an emergency spillway, eroding the hillside beneath it. Fear that the hill would give way, sending water uncontrollably downstream, prompted the temporary evacuation of nearly 200,000 people.
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A mega March snowstorm is just hours away. You've got your flashlight, your charger, extra batteries and extra beer.You are all good, right?
The worst never came, but questions about why and how both spillways failed remain unresolved.
About 170 state employees alongside as many as 500 contractors have been working 24 hours a day to strengthen the lake’s crippled water outlets. Crews have reinforced the concrete main spillway and bolted it to the ground to prevent further collapse, while pouring concrete and laying heavy boulders beneath the emergency spillway to stabilize the scarred hillside.
Repairs have so far cost $100 million, through February, or about $4.7 million a day, according to the state. A long-term fix could be twice as much.
“Public safety is paramount, and we’ll be managing the reservoir through the spring runoff season to ensure public safety while we work towards (permanent) repairs,” said Department of Water Resources spokeswoman Lauren Bisnett in an email to The Chronicle.
Since the main spillway was taken offline Feb. 27, a move made possible when cool and dry weather limited runoff to the lake, workers have cleared out much of the broken-off concrete that washed from the main chute into the Feather River below — about 803,000 cubic yards of it, officials said.
Avalanche in Austria kills three Swiss men, fourth missing
Three Swiss men were killed when their ski touring group was swept away by an avalanche in western Austria, and a fourth was missing in 12-metre-deep snow, police in the Tyrol region said on Wednesday. Rescuers were using snow drilling machines to try to rescue the missing person in the remote area near the Jochgrubenkopf, a roughly 2,450m-high peak.The group of eight people was using touring skis, with which one can climb and descend, making remote areas accessible."Four of them were able to free themselves (from the snow)," a spokeswoman for Tyrol police said.
Removing the concrete allowed operations to resume at the dam’s hydroelectric plant, which not only produces power but offers another outlet for water releases. The power station was shut down after the debris caused water to pool near the plant and threaten its turbines.
As lake levels begin to rise next week, state officials said, the powerhouse will release as much as 13,500 cubic feet of water per second, while the main spillway will release as much as 40,000 cubic feet of water per second.
While the reservoir can discharge as much as 150,000 cubic feet per second when everything’s working properly, the state anticipates that the lower outflow will be sufficient to accommodate the inflow from the mountains — at least in the short-term.
The lake level is expected to rise to 865 feet above sea level by late next week, but no higher. State officials are trying to keep the lake below 901 feet, the point at which water would begin pouring over the emergency spillway again.
Managing the lake level would be tricky this year even without the hobbled spillways. The mountains that feed the Feather River have the most snow they’ve accumulated in years, if not decades, promising near-record runoff in coming months.
In fact, Mount Lassen, to the north, has the state’s biggest snowpack in terms of water content, records show. The snow, which was 238.5 inches deep in the latest snow survey, contains about 118.5 inches of water.
“Everybody’s hope is that they’ll be able to keep up with the snowmelt without putting high flows over the (main) spillway,” said Bales, at UC Merced. “The big concern would be getting more rain during the snowmelt, because then you would have both coming in.”
Kurtis Alexander is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: @kurtisalexander
What happened at Lake Oroville?
View The Chronicle’s step-by-step, multimedia look at the crisis at projects.sfchronicle.com/2017/oroville-explainer.
Police search for autistic man who went missing after L.A. Marathon .
Police in Santa Monica are asking the public to help find a man with autism who went missing after running in the L.A. Marathon. Romario Snow, 21, was last seen just before 2 p.m. Sunday near Ocean Avenue and Santa Monica Boulevard, near the marathon finish line, according to the Santa Monica Police Department.