The California Department of Water Resources says it will need to begin opening gates on the Sacramento Weir as early as midday Monday, to manage downstream flows in the Sacramento River.
Managing the water in California during a series of significant storms involves local, state, and federal teamwork.
The California Department of Water Resources Flood Operations Center is open, which means it's the center of all things water during a series of strong storms like we've had.
"There's the Bureau of Reclamation that operates Shasta and Folsom," says Jon Ericson, chief of the department's Hydrology and Flood Operations office. "We have the state Department of Water Resources operates Oroville. We have many local partners: Yuba County and many in the San Joaquin System as well. What we try to do is coordinate here."
There are flood control measures all across northern California that impact the Sacramento San Joaquin Valley. They include several dams called weirs that divert water into flood plains.
"The system starts up north near Redding," says Ericson. "There's a series of weirs. There's Tisdale Weir, Colusa Weir, Moulton Weir. Those all flow through gravity at certain stages in the main stem of the Sacramento River. A lot of those will flow to the Butte Basin and eventually to the Sutter Bypass. One of the key relief structures for the city of Sacramento is the Yolo Bypass."
The Sacramento Weir is opened by hand to let water run into the bypass, if the river is running more than 90,000 cubic feet per second, or if the river reaches 30 feet high.
"We actually have our Sacramento maintenance yard go out there and they actually have to what we call, 'pull the gates,' says Ericson. "So, there's about 48 operable gates on the Sacramento Weir and we start to open those depending on what the stages of the Sacramento River are."
The Sacramento River carries about a third, or 31 percent, of the state's runoff and is the primary drain for the 27,000 square mile Sacramento River Basin.
The weir was last opened in January 2006.