OROVILLE, Calif. – The Latest on problems with an emergency spillway at the nation's tallest dam (all times local):
At least 130,000 people have been asked to evacuate over concerns California's Oroville Dam's emergency spillway could fail.
Officials say Oroville Lake levels are decreasing as they let water flow from its heavily damage, main spillway but point out water is still spilling over the dam.
California officials say the cities of Oroville, Gridley, Live Oak, Marysville, Wheat land, Yuba City, Plumas Lake, and Olivehurst are all under evacuation orders.
Butte County Sheriff Koney Honea says engineers with the California Department of Water Resources informed him shortly after 6 p.m. that the erosion on the emergency spillway at the Oroville Dam is not advancing as fast as they thought.
Honea says two inches of water is still coming over the dam, but that is significantly down from earlier flows.
Honea says there is a plan to plug the hole by using helicopters to drop rocks into the crevasse.
He says the evacuation order went out after engineers spotted a hole that was eroding back toward the top of the spillway.
Honea adds authorities wanted to get people moving quickly to save lives in case "the worst-case scenario came into fruition."
California officials say the cities of Gridley, Live Oak, Nicolaus, Yuba City and communities near Feathers River have been added to the evacuation order.
Hundreds of cars in wall-to-wall traffic can be seen on Highway 99 as people stream out of Oroville away from the dam.
Authorities in Yuba County are asking people living in the valley floor to evacuate.
The Yuba County Office of Emergency Services says people should take routes to the east, south, or west and avoid traveling north toward Oroville.
The California Department of Water Resources says it is releasing as much as 100,000 cubic feet per second from the main, heavily damaged spillway to try to drain the lake.
Department of Water Resources spokesman Kevin Dossey tells the Sacramento Bee the emergency spillway was rated to handle 250,000 cubic feet per second, but it began to show weakness Sunday at a small fraction of that. Flows through the spillway peaked at 12,600 cubic feet per second at 1 a.m. Sunday and were down to 8,000 cubic feet per second by midday.
Officials have ordered residents near the Oroville Dam in Northern California to evacuate the area, saying a "hazardous situation is developing" after an emergency spillway severely eroded.
The Butte County Sheriff's Office says the emergency spillway could fail within an hour unleashing uncontrolled flood waters from Lake Oroville.
The department says people in downstream areas need to leave the area immediately.
It says residents of Oroville, a town of 16,000 people, should head north toward Chico and that other cities should follow orders from their local law enforcement agencies.
Water began flowing over the emergency spillway at the dam on Saturday after for the first time in its nearly 50-year history after heavy rainfall.
Officials say water will continue to flow over an emergency spillway at the nation's tallest dam for another day or so.
Water began flowing over the emergency spillway at the Oroville Dam in Northern California on Saturday for the first time in its nearly 50-year history after heavy rainfall.
California Department of Water Resources spokesman Eric See said at a Sunday press conference that skies are clear and the overflow is steadily slowing. It's expected to stop by midday Monday.
In addition to the emergency spillway, water also flowed through the main spillway that was significantly damaged from erosion. Officials said they'll assess the damage starting Monday.
See stressed the dam is structurally sound and there was no threat to the public.
About 150 miles northeast of San Francisco, Lake Oroville is one of California's largest man-made lakes.