Transcript for Nearly 200K evacuated near Calif. dam amid flood warning
In northern California a state of emergency as water gushes from the nation's tallest dam. Forcing more than a 100000 people from their homes. We got through clothing our hands and do but not all necessities. We've. There was pretty chaotic. The oral build dams it's north of Sacramento. And hold water back from lake or a bill now at record levels and in danger of spilling over into towns after a series of storms and snow. We need to give the department water resources time to thoroughly about a week the situation so that we can make some decisions as to whether Ortiz. Whether or not it is safe to. Re populated areas. Last week chunks of concrete flew off the nearly mile long main spillway creating a 200 foot long thirty foot deep hole. This ever happened before it forced Dan manages to hold off on releasing water even as a dam reached its limits. Officials then trying a never before used emergency spillway. The efforts by DWR to lower the lake level by utilizing the spillway to reduce the water has been effective in. Now there is no more water going over the emergency spillway engineers don't know what caused the cave in that is expected to keep growing until it reaches. You could see that really could have fooled power in California has been made available. Officials say that dam itself is safe but this is an all hands on deck situation. Helicopters planes hundreds of police officers and army personnel all being brought it to assist in patrolling evacuated city. To help in search and rescue operations. Stephanie promise BC news Washington.
This transcript has been automatically generated and may not be 100% accurate.