A report from the San Jose Mercury News says federal and state officials ignored warnings as far back as 2005 about problems with Oroville Dam's emergency spillway.
The revelation is important as heavy winter rains caused Lake Oroville to overflow, damaging a main spillway and forcing operators to utilize an emergency spillway for the first time in Oroville Dam's history. This caused heavy erosion and fears that the uncontrolled flow would bring down a 30-foot wall of water to communities in low-lying areas. On Sunday, approximately 200,000 people were told to evacuate from their homes.
Journalist Paul Rogers talked on Insight with Beth Ruyak about the concerns from environmental groups.
- San Jose Mercury News: Oroville Dam Feds And State Officials Ignored Warnings 12 Years Ago
- MORE: The Sacramento Bee also republished a report from 2005 on the same issue
Below is a transcript of parts of the interview with Rogers. Listen to the full interview by clicking on the audio player above.
On who raised the concerns and why:
Rogers: In 2005 and 2006, the concerns were coming from three environmental groups: the Sierra Club, the Friends of the River and the South Yuba Citizens League. The groups filed formal motions with the federal government's Federal Energy Regulatory Commission (FERC), arguing that as part of the relicensing of Oroville by the federal government, it should require the state of California to put in an armored concrete emergency spillway.
Right now, the emergency spillway just has a concrete lip that's about 1,700 feet long. When water goes over the top, it just runs down the hillside. It's just an earthen hillside. And basically the dam was designed for that. And so officials at FERC, along with the state and many other water agencies around the state, said, "Oh we don't need to do that." It's well within its design capacity. Also, it had never been used before and so they didn't require the state to do that.
But when a small amount of water flowed over the top this weekend, the erosion was so severe that they had to evacuate 200,000 people because they worried about that whole side of the reservoir collapsing.
On the language and what was in the legal motions:
Rogers: These motions are public documents, they're part of FERC's process. There are motions that were filed by the Metropolitan Water District of Southern California and the state water contractors, who very likely would have had to pay for these upgrades, and their motions at the time said 'we don't think any of this is necessary.' So the environmental groups, as it turned out, were quite prescient in what they were worried about.
I think there were also other concerns by the neighboring counties there about erosion. They were worried that the hillside could erode down and put a bunch of trees, sediment and other things into the river, which might break levees and flood the towns lower down. But it was the environmental groups that really pushed this idea that we need to cover the whole thing with concrete because it might actually result in what they call a 'loss of crest control.' In other words, uncontrolled release of billions of gallons of water.
Rogers gives his opinion on the response from the state Department of Water Resources: When asked about the 2005 legal motions, officials said they weren't aware of the documents, but that they would look at them.
Rogers: In defense of the Acting Director of the California Department of Water Resources Bill Croyle, he has got a lot on his plate. He's up there trying to stop what could be one of the largest dam disasters in U.S. history. So he hasn't had time to go back filtering through documents from 12 years ago, I don't think.
But FERC is involved in this. The agency has offices in San Francisco. They have engineers who pay very close attention to these dams because they have to license the hydroelectric dams in California and FERC is on the site right now. In fact, FERC sent an order to the state Department of Water Resources ordering them, within five days, to convene an independent panel of experts to look into what happened, to make recommendations on how to fix it quickly and what recommendations permanently need to be made going forward.
On the implications of FERC's order:
Rogers: I think what it means is that somebody has got to fix the main concrete spillway which is all broken up; that's going to cost probably $200 million or more. And then the question is, will FERC force the state of California to go back and put concrete down that emergency spillway so this doesn't happen again. Now who knows how much that would cost. That's a bigger job than repairing the existing spillway thing. So you're probably talking about half a billion dollars or more by the time we're done (with both the main and emergency spillway).
And then the question is who will pay. It's a flood control dam so do the people downstream who get the flood control...do their taxes go up, do we take money from California's water bond Prop. 1 that was passed a couple of years ago to build new reservoirs and spend it on this kind of project, or do all the water contractors who buy the water - Metropolitan Water District, Santa Clara Valley Water District, Kern County water agency, do they raise the rates of their customers to pay for it? If you made me guess, it might be some combination of all three, but in the end probably the contractors and the people who buy this water in L.A. and Silicon Valley and in the Central Valley are going to end up paying most of the bill.
Rogers talks about how he is following up on his report and whether he's gotten a response with the State Department of Water Sources:
Rogers: I'm actually following up more with the people at the time at FERC and the Metropolitan Water District and other agencies, who were arguing most vociferously that we not upgrade the emergency spillway.
I wouldn't expect any time in the next few days to get a straight answer out of the Department of Water Resources because they're on a five-alarm emergency right now trying to make sure that whole towns aren't wiped out. So they need to be focused on that. But obviously there are going to be investigations on this that lasts for a year or two.
This is going to be going on for a long time and every bit of paper is going to come out. It's going to be similar to the PG&E explosion with the natural gas line in San Bruno or other significant infrastructure failures. We're going to see a lot of questions answered and I think a lot of documents that go all the way back to the 1950s. Why did they build a bad spillway in the first place? That's a pretty good question and that's one that engineers who used to work for Jerry Brown's father know the answers to. I don't think any of them are alive anymore.
Currently, 100,000 cubic feet per second of water is being pushed down the main spillway. In past reports, officials said the capacity for the entire spillway system is 350,000 cubic feet per second. Rogers talks about that figure and how to relate it to the current situation:
Rogers: It just shows you how well a lot of dams are engineered. The consequences of failure are so catastrophic that they build in lots of safety to these dams. And 350,000 cubic feet per second is twice the rate of the Mississippi River at St. Louis. Water in that area is flowing at about 170,000 cubic feet per second. So imagine this river, which is like a mile wide, and double that. And that's what this spillway could handle, at least according to the engineering specifics that it was designed for. That kind of a flow would be water that's 20 feet deep over the top of that spillway. And they said, "No problem, it will go right down the hillside into the Feather River."
The problem, as we saw, was when water less than five percent of that volume went over on Sunday, it carved away the hillside and DWR said the whole thing could collapse. So there's a lot that we still have to learn about why the engineers who built the tallest dam in the United States got it so wrong on the emergency outlet.
This article has been edited for clarity.