Fairfax County's ambitious plan to limit growth in its sparsely developed west is being challenged in court by developers even before the County Board of Supervisors officially has adopted it.

The early challenge opens what may be another major battle between the fast-growing county and its powerful developer community, raising doubts about the county's hopes to move from confrontation to consensus as it plans what some have called its "last frontier."

A suit filed by the law firm of developer-attorney John T. (Til) Hazel Jr. on behalf of five local landowners asks the Circuit Court to forbid the board to downzone 97 acres of property on Little Rocky Run in a rural area near Centreville. The property is part of a 38,500-acre expanse where the county is proposing to limit home building in order to keep pollution out of the Occoquan Reservoir, which provides drinking water to 600,000 Northern Virginians.

The lawsuit by the Compton Road Property Partnership threatens a delicate political and ecological balance most county board members hoped to achieve in approving two far-reaching land use plans on July 26. One plan would permit high-density office and town house construction in a small area of the Occoquan basin, which would please many developers, while the other would limit growth in the rest of the valley.

The board linked the two plans after considerable debate in April, promising not to give the developers the increased density at Rte. 50 and Interstate 66 before acting on the larger downzoning. "That was done in order to assure that we safeguard the water quality and this fragile watershed before going into higher intensity land uses," Supervisor Martha V. Pennino said then.

The lawsuit filed July 1 by Hazel's partner, Francis A. McDermott -- a dissenting member of the task force that recommended the Occoquan downzoning -- challenges the county's right to rezone the land, saying "no factual basis exists to support the proposed downzoning."

Under the current zoning, the owners of the $791,000 property on Compton Road, led by Nebraska resident Donald A. Tollefson, could build 90 houses on a 97-acre parcel that lies south of the road. The county, however, has refused to allow them to tie into a nearby sewer needed for development and is now proposing to allow only 18 homes on the land, according to the lawsuit. Zoning lawyers have said that the downzoning will sharply reduce the value of land that could otherwise be intensely developed.

The suit asks the Circuit Court, which has overturned county land use plans before, to force Fairfax to allow the landowners to tie into the nearby sewer -- currently under construction by Hazel and several partners -- and to keep the current zoning. The owners filed the suit before the county's planned July 26 vote on the downzoning to stake a legal claim to the present zoning, their lawyers said.

The Compton Road lawsuit has led some ecologists to say the county may end up with intense development in one area but without limits in the rest of the valley. Supervisor Audrey Moore, who strongly supports limiting growth, said the lawsuit is an early sign that developers such as Hazel will fight the Occoquan plan in court once the board approves development in the Rte. 50/I-66 area west of Fairfax City.

"The same people who want the upzoning want to have their cake and eat it, too," Moore said. "I just don't like the smell of it or the feeling of it."

Moore said she believes the supervisors should not give final approval to the Rte. 50/I-66 plan unless the Occoquan plan survives in court, an idea quickly rejected by Board Chairman John F. Herrity. "There are certain obvious political ties and there are certain relationships because they're in the same general area," Herrity said. "But I don't think you can tie them in one land-use package."

Hazel, who with a partner owns 600 acres slated for a major highway interchange and office park in the Rte. 50/I-66 area, declined to discuss Moore's comments. He has said in the past that the Occoquan downzoning will accomplish little, and he called the citizens task force that recommended the plan a "play group," according to a transcript of an April 1 meeting of another committee on which Hazel sits.

In that same meeting of citizens and developers planning the Rte. 50/I-66 area Hazel also said, "Why don't they have an upzoning on 50/66 and a downzoning on the other end and make it balance out . . . ," according to the transcript.

Supervisor Marie Travesky, whose district includes the land, criticized its owners for jeopardizing the entire downzoning for the sake of 90 acres, especially when Fairfax is permitting the owners to develop their land north of Compton Road. "Talk about squeezing every last dime out of something, that's just incredible," she said.