Update 1:29 p.m.: Officials say the volume of water flowing down the main spillway at Lake Oroville will remain at 55,000 cubic feet per second Sunday, down from 100,000 cfs at the height of concern over an emergency spillway failure.
Work continues 24 hours a day strengthening the base of the emergency spillway, where erosion caused officials to fear that the spillway could fail, sending a 30-foot wall of water downstream. Crews have been adding concrete and rock to strengthen the 1700-foot wide, 30-foot tall spillway and prevent further erosion.
Lake elevation had fallen to 852 feet by 4 a.m. Sunday, and the California Department of Water Resources has said the aim is to reach 850 feet to make space for inflows during upcoming storms. Water flows over the emergency spillway when the lake reaches 901 feet.
Crews built a barge Saturday to carry excavation equipment to the base of the main spillway, where erosion has caused debris and sediment to accumulate, threatening pooling of water around the dam’s currently inactive Hyatt Power Plant. Bringing the power plant back online is another priority.
A storm arriving Sunday night is expected to bring heavy rain throughout northern California and will likely increase inflows to the lake. Evacuation warnings are still in place for downstream communities in Butte and Yuba counties.
-Capital Public Radio Staff
The nearly $1 billion auxiliary spillway at Folsom Dam is scheduled to be completed later this year. It stands in contrast to the troubles 75 miles away at the state-run Oroville Dam, where thousands of people fled last week after an eroded spillway threatened to collapse.
The failure could have sent a 30-foot wall of floodwater gushing into three counties.
The two dams illustrate widely diverging conditions at dams across California and underscore the challenge of maintaining older dams with outdated designs.
Butte County Sheriff's Office said Saturday that 27-year-old Cody Bowles and 31-year-old Lucia Ripley were arrested Friday in the town of Biggs.
The office says the man was loading his vehicle with the engine running when Bowles and Ripley armed with a shotgun jumped in, running him over as he attempted to stop them. He was flown to a hospital with serious injuries.
It says Bowles was booked for carjacking, vehicle theft, mayhem, hit and run and assault with a deadly weapon. Ripley was booked for vehicle theft.
Officials say at least six people have been detained for burglaries and robberies committed during the evacuation.