Winemaker Paul Hobbs has been ordered to stop work on his controversial orchard-to-vineyard conversion near Sebastopol after inspectors found that hundreds of yards of blackberry bushes and bay laurel had been cleared illegally from a protected zone above a creek.

"It's a very serious violation of their permit," said Sonoma County Agricultural Commissioner Tony Linegar, whose office issued the stop work order to the Paul Hobbs Winery.

Rules prohibiting the removal of riparian growth from within 50 feet of a waterway are a "cornerstone of our erosion control plan," he said.

Hobbs has had several high-profile run-ins in recent years with county officials and neighbors over his land-clearing practices. On Friday said he had been in Asia when the clearing took place.

"I've got to say, I'm baffled and I'm very sad to see this situation. I feel bad for putting the county through this," he said. "I'm taking full responsibility for this and I'm going to make the changes I need to make to fix it."

The order, issued on Tuesday, also cited a failure to install proper erosion control measures, which allowed sediment to flow into the creek during recent rains.

"Hobbs let everyone down here," Linegar said.

The Watertrough Road project has been fiercely opposed by people who say it will disturb pesticides once used at the orchard and cause them to drift to nearby schools, endangering children in particular.

On Friday, some of those parents said that their doubts had grown now about whether Hobbs could comply with measures he has promised to undertake to minimize the impact on the schools.

"If they're doing this, how about all those other steps? They're far more complicated," said Christine Dzilvelis, whose daughter attends Orchard View School. "Mitigating the dust when they remove the trees is far more complicated than complying with regulations in a riparian zone."

Told of those concerns, Hobbs said: "That's why I'm going to have a change of leadership. I'm going to have someone new take over. I'm confident we can do it.

"I'm painfully aware of the scrutiny and this is the last thing I wanted or needed. I really thought we had it buttoned down. We didn't."

Agricultural Commissioner inspectors and Regional Water Quality Control Board staff discovered the violations after responding to a complaint.

"This sort of activity is not condoned by our winegrape growing community. We're all really disappointed," said Linegar, who had previously strongly defended Hobbs' project against its critics.

Hobbs, whom Forbes magazine dubbed "the Steve Jobs of wine," has been caught up in a repeated conflicts locally over environmental practices.

The latest came just weeks after he started the conversion of the 48-acre former orchard next to Apple Blossom School.

"It's utterly shocking, to say the least," said 5th District Supervisor Efren Carrillo, who has harshly criticized Hobbs in previous cases.

Those included one 2011 instance in which he was also ordered to stop work after clear-cutting trees from a former Christmas tree farm near Sebastopol. That year, Hobbs also cleared trees on a 10-acre site east of Guerneville without needed permits.

Asked whether he should have learned from those missteps, Hobbs said: "That's what the whole community will be asking.

"The fact is, some of these things, it sounds like an old broken record: 'I must be stupid; I must not care about anything; I'm just the bad apple that Efren Carrillo said I was,'" he said.

"I don't believe that," Hobbs said, "but how believable is that when they see this kind of thing?"

Carrillo vowed Friday that the issue would not be ignored. "I will tell you that the full force of the law is going to be applied in this matter," he said.

Officials with the Twin Hill School District had worked with Hobbs to gain assurances that he would take steps to protect schoolchildren, including erecting a dust fence and limiting chemical spraying in the vineyard.

School board president Maben Rainwater said Friday that "up to this point I had been satisfied."

Now, he said, "Wow, maybe we were getting a little too hopeful that they were going to be good stewards. It seems like that's not the case. But it's not for me to be the judge."

The Sonoma County District Attorney's environmental crimes unit is to examine the case, said Carrillo. Also, said Linegar, state Fish and Wildlife authorities and the National Marine Fisheries Service may become involved.

"The stop-work order is going to stay in place until all the agencies involved decide what the appropriate remediation and penalty will be. It's hard to say how long that could take," Linegar said.