(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. Crews are working around the clock to drain some of the lake before the next rain storm hits Wednesday.
Environmental groups warned state and federal officials 12 years ago that the nation’s tallest dam in California was an imminent disaster. Their warnings, that heavy rain and fast-rising waters could overwhelm spillways and flood communities downstream, were ignored. Lake Oroville topped capacity for the first time in history Saturday night, forcing water into those spillways.
Spillways that are now eroding after years of not being used due to long periods of drought.
Kevin Lawson, a California Fire Incident Commander said, “When we had water coming over the top of the emergency spillway, it was beginning to erode the ground, right? And when you start to erode the ground the dirt and everything else starts to roll off the hill.”
Almost 200,000 panicked residents were told to evacuate Sunday from areas surrounding the lake.
Julie Swift, an Oroville Resident said, “I just got a text message and then an alert saying ‘get out as fast as you can.’ So we packed up our dogs and lifted up our couches and just got ready.”
As emergency crews work fast to plug the hole in the emergency spillway, they have increased the amount of water flowing into the main one. The goal is to drop the lake’s water level 50 feet before the next rain hits Wednesday.
Authorities are happy with the progress so far, but reiterated that the threat isn’t over for the towns downstream.
Kory L. Honea, Butte County Sheriff said, “We need to have time to make sure that before we allow people back to those areas, it is safe to do so. So I want to make it clear. Evacuation is still in effect.”