RACHEL MARTIN, HOST:
Let's go to Northern California now, where the potential failure of an emergency spillway in the nation's tallest dam prompted a massive evacuation. That would send uncontrolled torrents of water to communities downstream from the dam, 180,000 residents have been ordered to leave the area near the Oroville Dam. It's about 70 miles north of Sacramento. Reporter Dan Brekke of member station KQED is covering this story. Dan, thanks so much for being with us.
DAN BREKKE, BYLINE: Good morning, Rachel.
MARTIN: Can you just explain how is it that water was pouring into this emergency spillway?
BREKKE: Well, the story of how the water was in the emergency spillway is sort of a tale of falling dominoes. Starting with a very, very wet winter, a very, very wet series of storms last week that caused a rapid, just sort of torrent of runoff coming into this giant reservoir at Lake Oroville. That's behind this giant dam you mentioned, Oroville Dam. And right in the middle of that, the main spillway, which is a - it's a relief mechanism. When they see water coming up, they have to maintain enough space in the reservoir to catch floodwater. So they let water out.
And while they were doing that, there is a big hole in the middle of the main spillway. So they had to shut it down. And they could not use it the way they normally would. So the lake rose 50 feet in just a few days and got up to this emergency spillway, which had never been used since the dam went into service in 1968. And on Saturday morning, it began pouring over there.
MARTIN: What is happening at this very moment? And we've talked about these evacuations, but what's the scene?
BREKKE: Well, the scene in the evacuation center that I was in last night in Chico, Calif. - which is about 20 or 30 miles from Oroville - was a lot of confused, scared people not knowing how long they're going to be out of their homes and not being certain what's going to happen to their homes. And then for the water, the Department of Water Resources, which is really in charge of taking care of the dam, they're waiting for daylight to see what the conditions are there.
They began an emergency release of water last night down the damaged spillway that I mentioned. And that did have the effect of lowering the lake low enough so that the emergency spillway apparently is no longer in immediate danger of failing.
MARTIN: You talked to some of these people, I understand?
BREKKE: I did. And like I said, there were a lot of confused and scared people. One of the people I talked to was Marilyn McKinney (ph). She was there with a family group. Her son said leaving town looked like a zombie apocalypse with everybody running around. But, you know, it was very anxious for them because they had to leave somebody behind, and that's what she told me about.
MARILYN MCKINNEY: My daughter-in-law is still there with her sister who is bed ridden, but we've got her in a wheelchair. They were supposed to be sending an ambulance or someone to help transport her out, and nobody has shown up for her yet. She called 911, and 911 said that they weren't sending anybody else out there.
MARTIN: So just briefly, Dan, what's the biggest concern going forward?
BREKKE: Biggest concern is that we have another series of storms coming in later this week. And they have to clear enough space in this reservoir that they don't run continued risk of failure of the emergency spillway and a massive flood downstream.
MARTIN: Dan Brekke is a reporter with member station KQED. Thank you so much, Dan.
BREKKE: You're welcome.
(SOUNDBITE OF CHASING DREAMS' "EVERYTHING IS MOVING, BUT NOT THE SKY") Transcript provided by NPR, Copyright NPR.