The sheriff said he had received assurances from state and federal experts that the situation was now deemed safe.
Honea could not estimate when people will be able to return home, but said he's working on a "repopulation plan" that would let residents return to areas least at risk of flooding. "We know we're going to have erosion going on but it's in the best interest of the lake right now to be able to keep using the spillway to evacuate water", department spokesman Eric See told the Associated Press.
Workers used helicopters and backhoes to dump large boulders and sandbags in place on Monday as the main concrete spillway was used to drain water from the lake at about three times the rate it was filling up. Almost 200,000 residents in the areas downstream from the Oroville Dam were asked to evacuate.
All schools in Sutter and Yuba counties have been closed.
Another series of storms is headed for Northern California starting on Wednesday.
The lake level was at 889 feet as of 9 a.m. ET, and officials are reportedly aiming for it to decline to 860 feet or below before new rain and melted snow starts running into the reservoir on Thursday.
Sunday evening officials issued mandatory evacuation orders for 200,000 people around Oroville Dam after a hole developed in an auxiliary spillway threatening massive and widespread floods. There were hints the evacuation would be lifted when people spotted road blocks being removed just after noon Tuesday. Some at the Silver Dollar Fairgrounds in Chico were upset to be away from their homes, while others tried to stay positive.
On Monday, Brown sent a letter to U.S. President Donald Trump asking him to issue an emergency declaration, which would open up federal assistance for the affected communities, after an emergency overflow channel appeared on the brink of collapse. The groups warned of a complete failure of the dam itself, threatening lives and property.
One would think routine inspections were conducted on the tallest dam in North America to protect hundreds of thousands of people living below but apparently officials believed it would last forever. Some comments suggested also that the first hole in the main spillway developed above an altered zone of rock, as a more brownish coloration of the rock would suggest. S. and now remains intact, but the emergency spillway is compromised and at risk of failure.
Stork said it is not unusual for dams to be constructed with one primary, concrete-lined spillway and another unlined emergency spillway.
Speaking late Monday, Gov.
Authorities have lowered the Butte County evacuation orders due to the Oroville Dam spillway incident to an Evacuation Warning.
Spicer did not say whether the president had responded to the request, but the administration is working with the Federal Emergency Management Agency.
Press Secretary Sean Spicer nonetheless finally addressed the crisis with reporters during his Tuesday briefing, saying, as KRON 4 reports, "The President's been keeping a close eye on the Oroville Dam situation in California", and using this as an excuse to bring up Trump's previously promised "major infrastructure package", since this is a flawless example of the nations "crumbling" infrastructure.