Suit Filed in Effort to Block San Joaquin Hills Tollway : Growth: Four environmental groups seek to overturn Coastal Commission approval of $1-billion, 17.5-mile road. They cite fears of pollution, loss of wildlife habitat.

Four local environmental groups this week filed a lawsuit against the California Coastal Commission and the county’s Transportation Corridor Agencies in an attempt to stop construction of the controversial San Joaquin Hills toll road.

The long-expected lawsuit, filed in San Francisco Superior Court on Tuesday, is considered one of the last chances that environmentalists have to stop the $1-billion, 17.5-mile tollway from being built.

Environmentalists, who were outraged when the commission voted to allow construction of the road last November, are suing to overturn the commission’s decision. They are also seeking an injunction to halt any grading or construction on the project until the decision, which they say was in violation of the state’s Coastal Act, is reconsidered.

“We feel certain that we will stop the project,” said Joel Reynolds, a senior attorney with the Los Angeles office of the Natural Resources Defense Council, which is representing Friends of Laguna Coast, Laguna Greenbelt Inc., Laguna Canyon Conservancy and Stop Polluting Our Newport in the lawsuit.

“It’s an environmental and financial white elephant,” Reynolds added. “It’s a bad project, and it should be terminated.”

Mike Stockstill, spokesman for the county’s Transportation Corridor Agencies, blasted the lawsuit in a brief statement released Thursday.

“This project will provide 1,500 desperately needed jobs and traffic relief for thousands of local commuters,” Stockstill said.

The coastal commissioners, citing a need to stimulate the economy and create jobs, voted to allow construction of the project after a hearing in Santa Monica on Nov. 18. Their approval was one of the last roadblocks to construction of the tollway, which would extend the Corona del Mar Freeway from MacArthur Boulevard in Newport Beach to Interstate 5 near San Juan Capistrano.

If built, the tollway will bisect Laguna Canyon, which is being turned into a huge regional park. The rugged canyon is beloved by many Laguna Beach residents, who resent the proposed road’s intrusion in an area that serves as their buffer from development.

The proposed road would cut through land that is considered prime habitat of the California gnatcatcher, a small gray songbird that has been proposed by the federal government for listing as an endangered species. A decision on listing the bird is expected to come in mid-March.

The tollway would also cross 15 streams, damaging 14.5 acres of rare wetlands that are home to birds and other creatures. To compensate for the damage, the tollway agency has agreed to try to build about 25 acres of new wetlands.

Environmentalists also worry that the road will increase air pollution and spur more South County growth.

Laguna Greenbelt president Elizabeth Brown is among local activists who consider their battle against the tollway the most important ecological fight in Orange County.

“We know that this is the wrong project at the wrong time,” Brown said Thursday. “The purported short-term benefits will be vastly outweighed by the long-term damage to the environment.”

The road, planned for about 20 years, is mainly designed to relieve traffic congestion for residents of Laguna Beach, Aliso Viejo, Lake Forest and Newport Coast.

Last week, the county’s Transportation Corridor Agencies received final federal approval from the U.S. Army Corps of Engineers to build the road through wetlands. It was the last environmental permit the road builders needed before construction could begin. The agency, however, still must arrange financing for the project.

Times staff writer Marla Cone contributed to this story.