Supervisors Decide to Sue Over Ahmanson Project : Development: The move protects the county’s options. The suit may challenge an environmental study.

Los Angeles County supervisors on Tuesday became the second agency to declare a legal challenge against the massive Ahmanson Ranch housing project, prompting the developer to say that a flurry of lawsuits could scotch the whole plan.

The 3,050-home development that would be built on a former sheep ranch in the Simi Hills above Calabasas was approved Dec. 15 by the Ventura County Board of Supervisors. Although it lies entirely within Ventura County, the project has stirred considerable opposition in western Los Angeles County because the only access is along Los Angeles County roads.

The Los Angeles County supervisors’ decision Tuesday is intended to protect the county’s options because state law requires any objections to be filed within 30 days of the project’s approval.

Since mid-December, local officials have been negotiating with Ahmanson Land Co. executives for concessions such as road improvements.

“What we have here is a need to protect the county’s interest and we have to file a lawsuit to do that,” Supervisor Ed Edelman, who represents the area, said before the unanimous decision to sue. “We have to be protected.”

The suit is expected to be filed against the Ventura County Board of Supervisors and the Ahmanson Land Co. It probably will challenge the adequacy of the report detailing the project’s environmental impact.

Ventura County Supervisor Maria VanderKolk, the project’s biggest supporter, called Tuesday’s action “incredibly irritating,” saying Los Angeles County has developed as it pleases without regard to the effects on Ventura County communities.

“I think that if Los Angeles County had developed the way we are looking at development in this county, we wouldn’t be faced with the kinds of problems we are,” she said. “It really boggles my mind.”

Calabasas decided last week to sue and the Los Angeles City Council is expected to vote on the matter today. By suing, all the municipalities run the risk of winning fewer concessions in court than Ahmanson already has offered.

Both Calabasas and Los Angeles County officials have said that they want to continue negotiating with Ahmanson.

But Ahmanson President Donald Brackenbush hinted Tuesday that the developer might not be as willing if lawsuits are filed.

“Once the lawyers get involved, things get escalated,” Brackenbush said. “I don’t know if there is such a thing as a friendly lawsuit.”

Brackenbush added that after the suits are filed Friday, they will be evaluated by Ahmanson attorneys. If they contain points that could pose a serious threat to the project, Brackenbush said, Ahmanson is prepared to drop its plans--jeopardizing a complicated deal in which more than 10,000 acres of parkland would be sold to the Santa Monica Mountains Conservancy for a below-market $29.5 million.

Opponents of the project dismissed Brackenbush’s comment as brinkmanship, and Brackenbush acknowledged later that the odds of Ahmanson pulling out of the project are extremely small.

“Do I think there is a possibility?” he said. “I do not think there is a 1% chance of that. I have not heard anything so far that there is anything working out there that we have not anticipated or covered. It’s certainly not very probable.”

Times staff writer Daryl Kelley contributed to this story.