Oroville Dam-area mandatory evacuations lifted

State and federal officials ignored calls in 2005 from environmental groups to armour the earthen spillway in concrete to prevent erosion.

About 150 miles northeast of San Francisco, Lake Oroville - one of California's largest man-made lakes - had water levels so high that an emergency spillway was used Saturday for the first time in nearly 50 years. They're also trying to dump as much water out of the lake.

"You don't appreciate home until it's taken away from you", said Johnston, who spent the last two nights sheltering at a church in Chico, California.

Crews, meanwhile, worked on Tuesday night to Wednesday morning to fortify the dam's spillway at Lake Oroville, the Sacramento Bee reported.

"The emergency spillway meets FERC's engineering guidelines for an emergency spillway", he added.

The damaged main spillway has been stable for four days.

KQED describes the emergency spillway as "essentially an ungated 1,700-foot-wide notch in the rim of the reservoir".

The Feather River raged near the hatchery in Oroville.

"The situation is a textbook example of why we need to pursue a major infrastructure package in Congress", Spicer said at a daily briefing on February 14.

Wet weather later this week could spell more trouble for the dam, though officials said storms shouldn't be as strong as the recent systems that have pushed lake levels to their highest. Heavy storms pushed its water levels to record highs, threatening to release uncontrolled flooding over a number of communities south of the dam.

Oroville Dam-area mandatory evacuations lifted

Helicopters pass each other as they work on the Oroville Dam. Water levels at the 770-foot-tall structure were less than seven feet from the top on Friday.

While the Oroville Dam is not now compromised, both its primary spillway and the emergency spillway have problems due to severe erosion, authorities warned. Concrete gave way, opening a massive hole the size of a football field.

Water is no longer flowing through the damaged spillway, but the situation remains "unpredictable".

She said when she first heard about the dam's problems, she didn't believe it.

A spokesperson for the State Department of Water Resources said lake levels are also dropping at a rate of eight feet per day.

Is the situation still risky?

"This is not a drill".

The sudden evacuation panicked residents, who scrambled to get their belongings into cars and then grew angry as they sat in bumper-to-bumper traffic hours after the order was given.

Officials warned that a 30 foot wall of water could come crashing down on Oroville and the surrounding areas if the spillway burst.

Residents of Oroville were ordered to evacuate the area on Sunday afternoon. However, he stressed that "the integrity of the dam is not impacted" by the damaged spillway. Jerry Brown said Monday that he sent a letter to the White House requesting direct federal assistance in the emergency, though some federal agencies have been helping already.

  • Joanne Flowers