Spillway timeline

Day-to-day look at events surrounding the Oroville Dam spillway incident.

This article was published on 02.16.17

Feb. 7: “Concrete erosion” discovered on Oroville Dam spillway.

Feb. 8: Spillway releases resume to assess capability.

Feb. 9: With determination of “no imminent or expected threat to public safety,” spillway flow increases to offset inflow. Rising lake level increase brings never-before-used emergency spillway into conversation.

Feb. 10: Main spillway releases curbed due to increased erosion. Butte County superintendent closes Oroville schools.

Feb. 11: At 8 a.m., water starts flowing over emergency spillway for first time in reservoir’s 48-year history.

Feb. 12: Erosion detected on emergency spillway. At 4:20 p.m., under threat of potential structure failure, sheriff orders evacuation of Oroville, Thermalito and areas south. Yuba and Sutter counties follows suit. Main spillway flows increased dramatically.

Feb. 13: California Department of Water Resources works to repair damage on both spillways.

Feb. 14: Yuba and Sutter county schools close.

Feb. 15: After confirming integrity of emergency spillway, mandatory evacuation lifted.