SAN FRANCISCO (AP) — For six days, amid rising waters and heavy rain, officials assured Northern California residents living downstream from a damaged dam that they were safe. Then on Sunday afternoon, a few hours after once again being told they were safe, the alarm was sounded: evacuate immediately. A portion of the dam never tested before was on the brink of failing, sending a 30-foot wall of water rushing down the Feather River and imperiling about 200,000 residents ordered to flee to higher ground.
Here's a timeline of what officials told the public, and how quickly their statements went from "no threat" to "evacuate...this is not a drill."
TUESDAY: The department announces it halted flows from the Oroville dam spillway around noon after engineers notice damage to a spillway. "There is no anticipated threat to the dam or the public."
WEDNESDAY: The department says it plans to release water through the damaged spillway for two hours to determine how much flow it can handle. "The dam is sound," the Department of Water Resources states, "and no imminent threat to the public exists."
THURSDAY: The department says the test release of water further damaged the spillway. Nonetheless, officials say they plan a bigger release of water to make room in the reservoir for coming rains. "There is no imminent or expected threat to public safety or the integrity of Oroville Dam," the agency states.
THURSDAY, 9:34 p.m.: The department says rising water will likely start flowing over an "emergency spillway" as early as Saturday.
FRIDAY: The department says it's increasing the flow rate of water from the "nearly full" reservoir to handle runoff from heavier-than-expected rains and in hopes of avoiding use of the emergency spillway. "Oroville Dam itself is sound and there is no imminent threat to the public," the department says.
SATURDAY, 6:45 a.m.: The department says it expects water to flow over the emergency spillway by noon, as water pours into the reservoir faster than it leaves. It repeats that the Feather River is not expected to flood and there is no danger to public safety.
SUNDAY, noon: At a news conference, department spokesman Eric See characterizes "overall conditions as stable." He says the emergency spillway appeared to be holding up with no visible erosion.
SUNDAY, 4:45 p.m.: The department tweets an evacuation warning: "Auxiliary spillway at Oroville Dam predicted to fail within the next hour. Oroville residents evacuate northward." Butte County Sheriff Kory Honea shortly afterward orders downstream communities evacuated. "This is not a drill," he posts on the sheriff's Facebook page.
MONDAY, 12:30 p.m.: Officials at a news conference in Oroville offer no timeline for evacuated residents to return home. The acting head of California's water agency says he's "not sure anything went wrong."