OROVILLE — In the confusion and chaos of the emergency at Oroville Dam, as thousands of residents were being evacuated, public safety officials and others involved in managing the crisis found themselves clashing with the people operating the nation’s tallest dam.

Butte County Sheriff Kory Honea questioned an assertion by the director of the state Department of Water Resources that the situation was stabilizing. He demanded to know whether the technical experts advising dam operators were properly credentialed. Honea and Cal Fire incident commander Kevin Lawson shot down suggestions that water could be allowed to flow once again down the dam’s emergency spillway – the structure whose near-failure prompted the evacuation in the first place.

The frustrations and friction flared up in a series of meetings and conference calls between top officials in Gov. Jerry Brown’s administration, local officials and others during the worst of the dam crisis on Feb. 12 and 13. Handwritten notes taken during the conversations, the contents of which were first reported Thursday by the Associated Press, shine a fresh light on the tense discussions between dam managers, public safety officials and others as they wrestled with enormous uncertainties and sometimes conflicting strategies for dealing with one of the gravest crises in California water history.

Much of the ire was directed at DWR, which manages the dam. At one point, an unidentified official suggested that the agency wasn’t grasping the severity of the situation, which threatened to unleash a torrent of water from the state’s second largest reservoir on Oroville and other downstream communities.

“DWR brains work differently,” the official said on a call the morning after the evacuation. “(They) don’t weigh worst case (scenarios) as heavily.”

DWR has come under criticism from some elected officials, Oroville community leaders and others for its handling of the near disaster at Oroville Dam. But while the notes suggest friction arose between leaders of DWR and other agencies, current and former officials who attended the meetings said this week they were mostly in sync with each other as they kicked around multiple ideas for dealing with an emergency that threatened the lives of nearly 200,000 people.

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“There was lots of back and forth. Lots of discussions,” said Bill Croyle, who was DWR’s acting director at the time. “Lots of scenarios being run – lots of Plan A, Plan B, Plan C.”

Last week, an independent team of experts investigating the disaster released a report that concluded that bad design and construction, along with inadequate state oversight, led to the collapse of Oroville’s main spillway.

The team said that water entering through cracks or repair seams in the main spillway may have triggered crumbling of the spillway. Its report cited a series of problems with the original construction of the spillway in the 1960s, including thin concrete, poorly placed drains and inadequate foundations.

In an interview with the Sacramento Bee this past week, Honea said that DWR officials never once dismissed his concerns about public safety. He said the notes miss some of the nuance of the back and forth discussions.

“It was just a matter of us trying to manage a complex problem,” Honea said. “In that process, you’ve got to talk about things. You’ve got to weigh pros and cons. You’ve got to talk about what the worse-case scenarios might be and how that all plays out.”

But the notes reveal that some officials were second-guessing DWR’s decisions, including its management of the dam after the crater formed in the main spillway on Feb. 7. Dam operators dialed back water releases the next four days to try to minimize the damage to the concrete spillway, even though it was raining heavily and water levels on Lake Oroville were quickly rising.

According to an unidentified participant on one of the calls, the chief of DWR’s Oroville field division, Pat Whitlock, wanted to increase the water releases down the main spillway but was overruled. “We lost time because of it,” the person said.

The decision proved critical. The reservoir filled to the point that water crested over the adjacent emergency spillway – a concrete lip resting stop an unlined hillside – for the first time in the dam’s 48-year history.

Croyle assured the community the emergency spillway could handle the flows. But the next day, on Feb. 12, the hillside below the structure started eroding. In his interview with the Bee, Honea said he wasn’t aware the erosion was so severe until that evening, when a concerned geologist arrived with a picture of the erosion and showed it to Whitlock.

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“I walked up to the table where Pat (Whitlock) was sitting because I was going to tell him good night and let him know that I was leaving … and I heard him say, ‘This isn’t good.’ I heard him say, ‘Does the sheriff know about this?’”

Honea said that a short time later, DWR estimated that the erosion would chew through the hillside in around an hour. Honea said there were close to 40 officials in a room discussing what to do.

“It sounded to me that thousands of lives of lives are at risk, so in a loud and a rather authoritative tone, I yelled for everybody to be quiet and listen to me. … I said, ‘It sounds to me that I need to order the evacuation of the southern part of Butte County. If there is anybody in this room who thinks that’s the wrong move or has a better idea then you need to speak up now. Tell me now.’ The room fell quiet, and everybody stayed quiet. So I said, ‘I’ve got to do this.’”

In the notes, he’s described as calling the decision to evacuate pulling “the big red handle.”

“If it wasn’t for one geologist … (Whitlock) is afraid we wouldn’t have even caught the problem,” the notes say.

The crisis eased a few hours later that evening, after DWR officials finally ramped up water releases from the main spillway, blasting apart the lower half. That lowered lake levels, relieved pressure on the emergency spillway and halted the erosion on the hillside below.

The notes from the conference calls show DWR’s top official struggling to balance competing concerns. Croyle wanted to minimize damage to the main spillway because he’d need to keep it functional enough to handle heavy spring runoff that was looming in the weeks ahead. And because of peculiarities in how the dam complex is set up, massive water releases from the fractured main spillway posed a threat to the adjacent power plant. The facility is the dam’s primary outlet outside of flood season.

“We have been working hard to protect the plant,” Croyle said the night of the evacuation. “It’s important for us.”

At the same time, he recognized the importance of reducing lake levels as quickly as possible to tamp down the immediate threat to towns and cities along the Feather River.

“Risk to public more important,” he said that night, according to the notes.

One additional problem loomed that evening: It was dark, and officials were having trouble verifying that the lake levels were falling and the spillways weren’t dangerously eroding away.

“Can’t confirm. Dark,” one meeting participant was quoted in the notes as saying.

Six years earlier, the Federal Energy Regulatory Commission had urged DWR to install lighting and cameras around the dam and other measures to improve response times in case of a major problem, according to a memo obtained by the Associated Press.

Croyle, however, said in the interview this month that officials were able to get a good read on the situation, thanks in part to a law enforcement helicopter that was able to conduct visual inspections.

“We lit up the area with a helicopter,” he said.

The notes reveal that some officials – it isn’t clear who – were discussing that evening whether the evacuation order should be rescinded. The idea was dropped because Honea was insisting it needed to stay in place until the state could assure him the public wasn’t in jeopardy. Residents were allowed to return home on Feb. 14, two days after the order.

On a conference call the morning of Feb. 13, just hours after the hillside erosion had been stalled, one of the officials mused about the possibility of resuming the use of the emergency spillway. Honea and Lawson, the Cal Fire incident commander, forcefully shot down the suggestion.

“Use of emergency spillway is off the table,” Honea is quoted as saying.

“Stay away from spillway water over emerg spill,” Lawson adds, according to the notes.

“Yesterday was scary,” Honea says later that morning. “1,000s of people could have died. Let’s not let that happen again.”

During one discussion that morning, Honea asked Croyle why the public should trust the DWR’s insistence that the main spillway was holding up, considering how wrong the state’s assertions were about the stability of the emergency spillway.

“Don’t know,” Croyle is quoted as saying. “Doing best we can (with) current monitoring. There could be an issue later, it appears stable now.”

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Honea also questioned whether the experts DWR had on site were “competent” and “credentialed.”

He said that he wasn’t necessarily second-guessing the DWR. Rather, he said, he was trying to get officials to speak clearly so that he could understand. He said he defaulted to a law enforcement officer’s “interrogation mode.”

“Engineers and geologists and hydrologists, they speak their own language,” Honea said. “It was a stressful situation. I went to my default comfort zone which was getting people to tell me the information I needed in terms that made sense to me so that I could make the decisions I needed to make.”

The Associated Press contributed to this report.