Oroville Dam Update: Water Levels Lower Despite Additional Rainfall

Pam Wright and Ada Carr
Published: February 19, 2017

The California Department of Water Resources says the level of Lake Oroville continues to fall despite the stormy weather, and the amount of water flowing down the spillway continues to be cut.
As of Sunday morning, Lake Oroville was at 81 percent capacity as which is still 114 percent of the historical average for the date. This is a major decrease from last Sunday, when the lake was at 100% capacity, or 148 percent of the historical average for that day.
The next round of stormy weather through early Tuesday will unleash more heavy rain on the region and flood warnings have been issued by the National Weather Service, according to weather.com meteorologist Chris Dolce.
In a statement, the department stated that "as runoff flows into the reservoir, water levels will likely fluctuate but will remain within acceptable and typical depths during times of storm activity."
It also says the amount of water flowing down the spillway has been reduced to 55,000 cubic feet per second. Earlier this week, outflows were at nearly 100,000 cubic feet per second. Work continues around the clock to shore up areas eroded below the spillway despite the weather.
Damage to spillways of the Lake Oroville dam forced the evacuation of 188,000 people last weekend. The evacuation order was eventually reduced to a warning and residents were allowed to return home, yet some remained uneasy. 

Matthew Prumm, 34, lives just blocks away from the levee and told the AP he had to leave after spending a restless night worrying about what could happen to him if the dam fails.

"I tried to sleep here last night, and I just couldn't sleep," Prumm says, adding that friends kept pressuring him to "get the hell out."

California Department of Water Resources Chief Bill Croyle said water was draining at about four times the rate that it was flowing in and the repairs should hold at the nation's tallest dam. 

The order was reduced after state water officials said they had drained enough of the lake behind the dam so that its earthen emergency spillway will not be needed to handle runoff from an approaching storm.
However, Butte County Sheriff Kory Honea warned that residents returning home "have to be vigilant," and "there is the prospect that we will issue another evacuation order ... if the situation changes."
While the news that residents could return to their homes was welcomed by many residents, others chose to stay away out of fear, reports the Associated Press.
"My plan is to stay here," said Donald Azevedo, who evacuated from Marysville with his wife, Tasha, their four Chihuahuas and more than 30 relatives. They spent two nights at the Nevada County Fairgrounds in Grass Valley, California.
Azevedo told the AP that he and his family will stay away from their home until the incoming storms pass.  
Others, including evacuees staying at Neighborhood Church of Chico, began packing immediately once they heard the news that the order was lifted.
"You don't appreciate home until it's taken away from you," Oroville resident Margaret Johnston told the Associated Press. She spent two nights at the church with her two sons.

At the height of the storms, Lake Oroville water levels reached a level so high that an emergency spillway was used for the first time in its 48-year history.

Workers hoisted huge white bags filled with rocks, and at least two helicopters will fly them to where they will be released in the spillway's erosion, reports the AP. Dump trucks full of boulders also are dumping their cargo into the gaping hole on the damaged spillway.

Report Indicates Officials Were Warned Dam's Weakness

Environmental activists and local government officials warned more than a decade ago of the risk of catastrophic flooding below the Oroville Dam, according to a recently released report.

At the time, state and federal regulators dismissed those fears, saying it was unnecessary to reinforce the dam with concrete.

Recent events at Oroville Dam have brought that 2005 decision under scrutiny.

According to the Associated Press, during a relicensing process for the dam in 2005, environmental groups demanded that the dam be reinforced with concrete or boulders. They feared catastrophic erosion from water escaping when the reservoir was cresting over full capacity.

A final environmental impact report dated June 2008 said there were no "significant concerns" about the hillside's stability.

"I think that the warning that was given should have been taken with the utmost seriousness," said Bob Wright, an attorney at Friends of the River, an environmental group that joined forces with the Sierra Club and South Yuba River Citizens League.

Both Bill Croyle, acting head of the Department of Water Resources, and Gov. Jerry Brown said they were unaware of the warnings, noting that decisions are based on the recommendations of state engineers.

"They tell us what we need and we do it," Brown said."But we live in a world of risk. Stuff happens and we respond."

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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