Mass Evacuation in California as Dam Weakened by Rain

Almost 200,000 people were under evacuation orders Monday after damage to the auxiliary spillway of a dam in northern California raised fears the structure could fail and unleash torrential waters.

The reservoir of the Oroville Dam, located 75 miles (120 kilometers) north of the state capital Sacramento, had been completely full after several weeks of heavy rain.

The 770-foot dam itself was not in danger of collapse, according to officials, but the emergency spillway was causing major concern due to erosion damage on its concrete top, the Sacramento Bee newspaper said.

Authorities were releasing 100,000 cubic feet (2,830 cubic meters) of water per second from the main spillway, which dropped the reservoir Sunday to a level where there was no more flow into the auxiliary spillway, the Bee cited Department of Water Resources spokesman Doug Carlson as saying.

About 188,000 people in downstream communities had been ordered to flee on Sunday afternoon.

"Yes, an evacuation has been ordered," the Yuba County Office of Emergency Services said in a Facebook post. 

"All Yuba County on the valley floor. The auxiliary spillway is close to failing... Take only routes to the east, south, or west. DO NOT TRAVEL NORTH TOWARD OROVILLE!!!!!"

Governor Jerry Brown issued an emergency order to deploy resources to the affected area.

"I've been in close contact with emergency personnel managing the situation in Oroville throughout the weekend. It's clear the circumstances are complex and rapidly changing," he said in a statement. 

"The state is directing all necessary personnel and resources to deal with this very serious situation."