Fairfax County officials, seeking to dispel criticism that a proposed road in the southeastern section of the county would damage Huntley Meadows Park, announced plans yesterday to build the road in a way that they said would actually benefit the 1,262-acre nature preserve.

The proposed Lockheed-Van Dorn Connector could be built with an elaborate system of pipes, bridges and ponds to expand rather than destroy wetland areas, according to a county environmental plan released yesterday.

"The wetland areas we create will be very important for keeping clear water flowing into the park," said Fairfax Supervisor Joseph Alexander (D-Lee), who presented the plan with County Board Chairman John F. Herrity at a morning news conference.

"The construction of the roadway is going to minimize the intrusion of sediment," he said. "It's going to create additional wetlands."

The $13 million road, which was conceived in 1968, would provide a direct link between Rte. 1 and the Springfield Mall area of Fairfax, diverting thousands of motorists a day from a network of inadequate neighborhood streets.

But the 2.2-mile road would traverse the northern section of Huntley Meadows, one of the region's largest park and wetland areas and home to more than 200 species of birds, including the bald eagle. A coalition of environmentalists and citizens groups has fought the road project for nearly a decade.

Last fall, the federal government ordered the county to prepare a new environmental assessment of the project, rescinding a finding by the U.S. Department of the Interior that the four-lane road would not harm the park. That new study was released yesterday.

Opponents of the road project remain skeptical. "The county's work in the past has been inadequate," said Norma Hoffman, president of the Citizens Alliance to Save Huntley.

"We have examples of similar structures that have been unsuccessful."

Environmentalists had raised concerns that the road would act as a dam, cutting off the water supply to wetlands in low areas of the park. Wetlands are considered a vital natural resource because they filter out water pollution and help prevent flooding by absorbing excess runoff.

The new plan calls for creating a kind of sieve beneath the road, with 18-inch diameter pipes at 200-foot intervals and bridges over streams and drainage channels. In addition, the county plans to create ponds on the downstream side to collect and filter the runoff from development projects on the north side of the park.

The environmental plan must be approved by the Interior Department before the county can proceed with the project, but county officials said yesterday that they expect to begin construction in 1989.