by AUBREY REBELO
On Sunday, February 11,2017, officials in Northern California ordered residents near the Oroville Dam to evacuate the area after an emergency spillway severely eroded. The California Department of Water Resources said that the emergency spillway could fail within an hour, unleashing uncontrollable amounts of waters from Lake Oroville into the surrounding cities and counties. People in downstream areas needed to leave the area immediately, the department said. Residents of Oroville, California, a town of about 16,000 people, headed north toward Chico, and other cities should follow orders from their local law enforcement, if need be, the local sheriff’s department stated.
The Yuba County Office of Emergency Services asked residents in the valley floor, including Marysville, a city of 12,000 people, to evacuate and take routes to the east, south, or west to avoid traveling north toward Oroville. The California Department of Water Resources said the leak was releasing as much as 100,000 cubic feet per second from the heavily damaged spillway.
The DWR spokesman, Kevin Dossey said the 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. on Sunday and were down to 8,000 cubic feet per second by noon the same day. Water began flowing over the emergency spillway at the dam on Saturday after record breaking heavy rainfall damaged the main spillway.
Unexpected erosion cracked through the main spillway, sending huge chunks of concrete flying everywhere and creating a 200-foot-long, 30-foot-deep hole that continues growing. Engineers say that they still do not know what caused the concrete to cave in. As of now, the state officials are working to get the dam fixed up before the next big storm is said to hit.