Conservancy Aided in Drive for Mission Canyon Land : Zoning: A judge removes approvals on 500 high-priced homes in nearby Mandeville Canyon, and a major developer pulls out of the project.

The Santa Monica Mountains Conservancy’s hopes of obtaining Mission Canyon in West Los Angeles to augment a vast natural park within the city could be greatly improved by two recent events involving a controversial Westside property, the conservancy’s director said this week.

In one development, a federal judge on Friday stripped a 1,500-acre site in the Mandeville Canyon area of zoning approvals for 500 high-priced homes. The ruling means that whoever tries to develop the property must start from scratch, contending with strict hillside-construction laws and litigious homeowners’ groups that did not exist when the now-defunct approvals were granted more than a decade ago.

In the other event, real estate developer Ray A. Watt, one of California’s largest and most politically influential builders, said he is no longer involved with the project. Watt also said a proposed land swap with Los Angeles County--in which land he owns near the proposed Elsmere Canyon Landfill would be exchanged for Mission Canyon property--had been abandoned.

Joseph T. Edmiston, executive director of the conservancy, said Watt’s withdrawal from the Mandeville Canyon project and the Elsmere landfill negotiations, coupled with Friday’s court ruling, could enhance efforts to shield Mission Canyon from development.

Edmiston said the conservancy would renew its efforts to obtain Mission Canyon--a former county landfill just west of the San Diego Freeway and south of Mulholland Drive--with the goal of preserving thousands of acres of open land within city limits for a “grand park that would rival anything in the world.”

“I don’t want to falsely raise people’s hopes, but that would bring within our ability the purchase of that property,” said Edmiston. He added that Mission Canyon--if combined with the nearby Rustic and Sullivan canyons, and Topanga State Park to the west--could create a contiguous, nearly 15,000-acre park within the city of Los Angeles.

Last fall, as county, city and private interests negotiated over the creation of a regional landfill, the conservancy worked behind the scenes to preserve the Westside’s Mission, Rustic and Sullivan canyons and extract guarantees they would not be used for garbage dumps.

Watt’s involvement in the Mandeville property had threatened preservation of nearby Mission Canyon because he had proposed acquiring a part of Mission for an access road to the luxury housing project, and building some of the proposed, 500 single-family homes there.

A Watt company offered $69 million last summer for the Mandeville property, whose current owner, Eastport Associates, is attempting to reorganize under Chapter 11 of the federal bankruptcy laws.

But Watt allowed his option on the Eastport site to expire weeks ago, even before Friday’s detrimental court ruling, according to Los Angeles County Administrator Richard Dixon. And the developer told The Times this week, “As far as we’re concerned at this time, why, we’re no longer involved with the project.”

Attorneys for Eastport said they would appeal the court ruling and attempt to restore rights to build on the land.

U.S. District Court Judge Terry J. Hatter Jr. ruled that Eastport’s zoning approvals, granted in 1979, had expired in 1987 after being extended several times by the city. Hatter also held that special-interest legislation written to benefit the Eastport project could not revive building rights that had already expired.

Watt said it was unlikely he would try again to obtain the Eastport site, even if an appeal is successful.

“At this time, I would say no,” Watt said in a phone interview Tuesday. He declined to explain. Edmiston and city and county officials said they had heard in recent weeks that Watt wanted to assume a “lower profile” in the Eastport project.

Eastport Associates’ general partner Donald H. Albrecht did not return phone calls.

Also defunct, said Watt, is his proposal that his company obtain Mission Canyon from Los Angeles County in exchange for property he controls next to Elsmere Canyon in the Santa Clarita Valley, where the city and county are working on an agreement to jointly operate a regional landfill. Watt’s 630 acres would increase the capacity of the 190-million-ton garbage dump.

When Watt’s land swap was proposed last summer--as part of a larger series of trades involving the federal, state and local governments--city and county officials said it was a factor in their negotiations over the creation of the landfill. But Watt said this week of the proposed land exchange, “We’ve abandoned that,” while Dixon and other officials said it had not been a factor in landfill discussions for some time.

Dixon said, however, that Watt’s property might still be added to the landfill in the future but in a cash purchase, not as part of an exchange.

It could not be determined Wednesday whether Watt might still try to build in Mission Canyon, apart from the Eastport site. County Supervisor Deane Dana said through a spokesman Wednesday that when he last spoke to Watt, about two weeks ago, the builder was still interested in developing Mission Canyon even though he was no longer interested in the Eastport site.

Watt could not be reached for clarification.

Under a proposed joint-powers agreement between the city and county for operation of a regional landfill, none of the three Westside canyons--Rustic, Sullivan or Mission--would be used as dumping sites. But the county retains the right to sell or lease Mission Canyon to a third party, leaving open the possibility of its development.

Edmiston said he assumed the provision was written with Watt in mind.

Dixon said the county has long considered developing a golf course in a portion of Mission Canyon and still believed it could attract bidders for such a project, even with the future of the Eastport site in question.