California Towns Flee as Oroville Dam Threatens to Release 'wall of water'

CNN/ Newswire | 2/13/2017, 11:08 a.m.
A massive crevasse that formed in a spillway at Northern California's Oroville Dam has spurred mass evacuations, with nearby residents ...
Damage to a spillway on California's Oroville Dam prompted an urgent call for residents downstream to evacuate to higher ground Sunday.

By Eliott C. McLaughlin and Paul Vercammen


OROVILLE, California (CNN) -- A massive crevasse that formed in a spillway at Northern California's Oroville Dam has spurred mass evacuations, with nearby residents fleeing the worst-case specter of a three-story wall of water rushing downstream.

In all, about 188,000 people, mostly in Butte, Sutter and Yuba counties, evacuated from the area, some being given only minutes to gather their things.

"Everyone was running around; it was pure chaos," Oroville resident Maggie Cabral told CNN affiliate KFSN on Sunday. "All of the streets were immediately packed with cars, people in my neighborhood grabbing what they could and running out the door and leaving. I mean, even here in Chico, there's just traffic everywhere."

The area had long been in drought until this year when heavy rain and snow bombarded the state. In Oroville, the average annual rainfall is about 31 inches, but since October, the Feather River, which begins at Lake Oroville, had already seen 25 inches of rain as of Saturday, according to the California Department of Water Resources.

The lake also gets water from the northern Sierra Nevada mountain range, which is experiencing one of its wettest seasons.

This week's weather report supplied a sliver of good news, as no rain is predicted until Wednesday.

As of early Monday, water was not flowing over the spillway, and while officials were cautiously optimistic, those hopes could "be dashed at first light when engineers get a better look at the backup spillway. We know (the floodwater pressure) is tearing up the bottom of the spillway," DWR spokesman Doug Carlson told CNN.

2 spillways, 2 problems

Oroville Dam is the country's tallest, and the emergency spillway that's eroding had never been used in the 48 years that the dam has existed, the DWR says. The closest Lake Oroville came to topping the emergency spillway was in January 1997, when the lake level rose to within a foot of flowing over it.

The Oroville Dam provides flood control for the region. The dam has two spillways to release water out of the lake to prevent overflow. Both have problems.

In the main spillway, which is lined, or paved, erosion has caused a hole almost the side of a football field and at least 40-feet deep to form in the lower part of the channel. It can't be fixed immediately.

"You don't throw a little bit of rock in it," said DWR acting director Bill Croyle.

The emergency spillway, which is an embankment covered with trees, is a last resort and was used for the first time in history on Saturday when the lake topped 901 feet, its capacity, and a light flow of water washed into the spillway.

Around 3 p.m. (6 p.m. ET) Sunday, authorities learned that the emergency spillway was also eroding, Butte County Sheriff Kony Honea said.

DWR and CAL FIRE crews quickly began clearing the brush, trees and rocks to limit the amount of debris washing into the lake's diversion pool and the Feather River. The California Department of Fish and Wildlife began evacuating young salmon and steelhead from the Feather River Hatchery downstream.