The combined population of the areas under evacuation would appear to reach nearly 100,000 people. The California Department of Water Resources is ordering residents to evacuate northward.
— CA — DWR (@CA_DWR) February 13, 2017
Social media accounts report traffic jams as people try to get out of harm's way. A flash flood warning has been issued and will remain in effect through Monday afternoon, local television stations report.
A government official reported that helicopters will drop off containers filled with rocks to strengthen the emergency spillway.
On Tuesday, a huge hole formed in the spillway of the dam, which officials fear will grow until it hits bedrock. The dam's emergency spillway was then put into use, but severe erosion meant that officials are not sure it will be able to hold. Though officials described the situation as stable as recently as this morning, they are now urging residents in low-lying areas to leave, BNO News reports.
The dam is the nation's tallest, and California's second largest reservoir.
— Jamey Singleton (@jameysingleton) February 13, 2017
Officials had been expecting a problem for days, but had hoped to avoid using the emergency spillway, the Chicago Tribune reported yesterday. This is the first time in the dam's nearly 50-year history that the emergency spillway has been used.
Water began flowing over the emergency spillway — basically a route quickly cleared of brush to allow water to be released in a somewhat controlled fashion — for the first time in the dam's history on Saturday. The fear is that erosion in the emergency spillway could cause an uncontrolled flow of water.