A member of Cal Fire, right, talks to workers on the Oroville Dam project in front of the main spillway in Oroville, Calif., on Monday. (Hector Amezcua/AP)

— Larry Bowen ducked beneath the large white portico to escape the freshly falling rain, the first droplets of a thick storm that would pour down over Northern California later that night. He and his wife, Robin, came to this hillside outpost to look out at the Oroville Dam, like hundreds of others in recent days who were suddenly all too aware of infrastructure, spillways and reservoir levels.

One week before, they were among the 180,000 people ordered to evacuate their homes amid fears that erosion had compromised the dam’s spillway system, which is used to regulate the water in the dam’s reservoir.

The situation has improved and the immediate threat of catastrophic floods has passed, according to state officials. But many here in California’s Central Valley remain on high alert for potential evacuations because of the heavy rain that continues.

Storms in recent days have overwhelmed Northern California’s levees, flooded its rural towns and closed highways. That the Oroville Dam, the nation’s tallest, reached such a grave condition has raised questions about whether California’s infrastructure is up to the task.

The Bowens came to see it with their own eyes: “It’s going to be all right, there’s nothing to worry about now,” said Larry Bowen, 71.

Could, and should, the government have done more to protect the infrastructure? How long has the community been sitting beneath a powder keg masked by years of drought?

“You never know. They’ll lie about it anyway,” Larry Bowen said. “You know politicians, they’re all a bunch of damn liars. We don’t know, and you don’t know, and nobody knows because it’s all politics.”

That sentiment is common among members of this small community of 15,000 about 70 miles north of Sacramento. They are relieved and optimistic that the dam is no longer compromised — if it were to fail, officials have said, it could unleash a 30-foot wall of water — but they do not know who to blame for the infrastructure problems, if anyone at all. The government cannot control the weather, after all. And it is unclear what days of additional rain could do to change the positive outlook.

Ben Sparks, who has lived in Oroville since 1975, said that the state bears some responsibility for what has happened. Environmental groups wrote in a 2005 report that the dam’s emergency spillway could fail, but authorities did not heed the warning.

“They could have prevented some of it. And I think part of it is money; the Department of Water Resources, they didn’t want to fix it because it would cost too much. So they just let it go,” he said. “And since we had an emergency, then the federal government gets in, and then it gets federal money.”

Looking out at the dam from a hillside neighborhood, Sparks said he feels safe today but expects extensive work to come.

“What they’re doing is an emergency thing, and as far as I’m concerned, it’s temporary. Obviously they can’t just let it keep eroding,” he said. “With the circumstances, with all the water, there’s no way they can get into a permanent fix at this point.”

(Jayne Orenstein/The Washington Post)

Oroville’s residents have become accustomed to the sounds of crews working day and night to reinforce the dam’s spillways. (Signs pepper the roadway leading to the dam, intended for truck drivers carrying in loads of rock to reinforce the spillway, with phrases such as, “You’re our dam heroes.”)

Bill Croyle, acting director of the Department of Water Resources, told the Mercury News on Friday that the state’s main priority is securing the dam — and that investigations into what caused the failure are “going to be a while.” He estimated that fixing the dam could cost as much as $200 million.

Going forward, there will be intense scrutiny about how state officials have approached the Oroville dam’s design and safety features, from its inception to recent work on the dam a few years ago. Chris Souder, a professor in construction management at California State University at Chico, said the spillway’s relative thinness — 15 inches — could be to blame for a recent hole that appeared there.

“Back to the primary spillway, in the ’60s they didn’t understand what they understand today,” Souder said. “And over the years of them not doing anything about it, even though they did do some work on it years ago, it doesn’t take much before that thing gets exponentially worse and worse and worse.”

The emergency evacuation order last week caught many area residents off guard. Some waited too long to make contingency plans and some waited too long to leave, having been previously reassured by officials that the dam was in good shape.

Jeff Ballard, a local pastor, began to make several phone calls before leaving town last week to let people know about the evacuation — but many of the people he called did not believe him at first.

“For sure people were not ready. They weren’t thinking catastrophic failure. Because the spillway had been broken for quite some time and we had seen the water shooting out,” he said. “So it seemed like no big deal, and we have trust and faith in our levee system.”

Ballard’s family returned to Oroville on Friday because the lake level dropped and they felt comfortable at home. But record rainfall continues to pound California and, when the rainy season ends in March, snow melt from the nearby Sierra Nevada looms.

A thick rain poured down on Oroville again Monday, so heavy that it nearly obscured the Feather River’s muddy banks. With another storm barreling toward the area Tuesday, local officials warned people to be ready to evacuate “at a moment’s notice.”

And many in these communities have their cars packed and ready. Susan Sullins and her family were staying at her mother’s home on the other, elevated side of town, though she said she is mostly confident the dam is safe.

“We don’t want to have to evacuate in the middle of the night or randomly when we could just stay here,” she said. “They say it could be a 30-foot-tall wall of water. That’s pretty frightening, that it could just wipe out everything.”