News that Sequoia Building Corp. of Fairfax City wants to build a 1,200-acre recreational community called Cascades on the banks of the Potomac River is fanning the flames in the border war between Fairfax and Loudoun counties.

Great Falls residents are pitted against each other in their battle to keep traffic from the rapidly growing eastern Loudoun subdivisions out of their neighborhoods. Meanwhile, the two counties cannot agree on the long-range transportation plan for the area.

"It's probably the biggest cat fight we've seen here in 20 years," said Ruth Carver, chairwoman of the Great Falls Citizens Association Planning and Zoning Committee.

Although it took three rezoning applications, six years of battles with Loudoun supervisors and a lawsuit in the 1970s to open the tract to residential development, Warren K. Montouri, a trustee for a group of Middle Eastern investors who own the land, sat on the land for five years. Sequoia has a contract to purchase the tract from the group.

With its wooded ravines, terraced flood plains that housed hundreds of migrating Canadian geese in spring and fall, and two miles of waterfronts where the Potomac River, backed up by a dam, widens into a calm lake, the property offers a rare opportunity to a developer.

But first a developer must settle how residents will get to and from the property.

If Sequoia builds the maximum of 2,052 homes for which the property now is zoned, it could dump as many as 16,211 cars daily through Great Falls neighborhoods, according to figures in a Loudoun County planning staff report.

Rather than allow commuters to clog up the winding country lanes in Great Falls, current plans call for a new road from Cascades to Route 7.

Loudoun County's master plan shows this road as the southerly leg of the Algonkian Parkway, a road that would swing through subdivisions alongside the Potomac River, collecting traffic heading for Routes 7 and 28.

Developers already have purchased land and offered to build a two-lane segment of the Algonkian Parkway with room to widen it to four lanes from the southern edge of the Cascades property southward through subdivisions in western Fairfax County to meet Leesburg Pike at today's Holly Knoll Drive.

But mentioning the Algonkian Parkway to Great Falls residents is like putting a match to timber. Citizens in subdivisions through which the new highway would travel are considering filing suit to block its construction, said Darrel Dochow, whose home on Holly Crest Court would back onto the road. Holly Knoll, a subdivision of homes on quarter-acre lots selling in the $150,000 range, would be split by the proposed roadway.

People who live along the back roads of Great Falls fear that lawsuits could block construction of the Algonkian Parkway, forcing Cascades traffic to wend its way down bumpy Brockman Lane and Seneca Road, which have hairpin bends and are scarcely wide enough for two cars to pass, Carver said.

Residents along these roads already are growing restless about transportation plans for the area as commuters from the Great Falls Forest subdivision now under construction just inside the Loudoun border are using these back laneswhile they await construction of the Algonkian Parkway.

Left to mediate between these two constituencies is Dranesville Supervisor Nancy Falck. Dochow and other Holly Knoll residents accused Falck of acquiescing to the politically influential residents of Seneca Road. Meanwhile, the Seneca Road residents are keeping Falck's feet to the fire to ensure that the Holly Knoll route is built and that cul de sacs are placed on their roads to block commuters from Loudoun County.

Resigned to a no-win situation, Falck said: "I just wish when Loudoun County does its land-use planning, it does appropriate transportation planning without dumping its commuters into our subdivisions."

Falck might have lost round one in the Algonkian Parkway dispute, but she has not laid down her sword. Her next battle is to prevent construction of a bridge over Sugarland Run that would link the Cascades leg of the Algonkian Parkway to developments further west. She fears this would funnel more traffic through Holly Knoll.

"To build that bridge now would simply worsen Route 7 just when we have made a major effort to give it some relief," Falck said. She wants the traffic instead to head for the Dulles Toll Road via Route 28.

Falck could be fighting without allies. Although Fairfax County is refusing to include the Algonkian Parkway on its master plan, the roadway has the backing of the Virginia Department of Highways and Transportation and the National Capital Transportation Planning Board. In February, the latter refused Falck's request to delete the Sugarland Run Bridge from its regional transportation plans.

"We need to have the Algonkian Parkway, there's no question about it. It's a major loop for that construction along the river," said Eastern Loudoun Supervisor Steve W. Stockman. Moreover, Stockman is trying to have the Algonkian Parkway at Holly Knoll Drive intersect with the Springfield Bypass, a move that would make the parkway a major transportation route in Northern Virginia. The bypass is a four-lane highway being designed to link Springfield in southern Fairfax to Fair Oaks to the west and Route 7 west of Tysons Corner to the north.

It would be understandable for Holly Knoll residents to fear these plans: Conservative estimates by Loudoun County planners show 23,900 cars daily in the year 2010 traveling the Algonkian Parkway, only about one-third less than the traffic that now sputters along Route 7 at the Fairfax County line. These figures would dictate a four-lane highway through Holly Knoll, according to VDH&T calculations.

With the cards stacked against Holly Knoll residents, all Falck can do right now is to ensure that the design for the Cascades access road includes berms and landscaping sufficient to mask the rumble of traffic.

Confident that the disputes can be resolved, Sequoia Building Corp. has contracted to purchase the property and is proceeding with plans for it.

"We see this as the nicest residential community in the whole Washington area," said Ray Smith, Sequoia's president.

He envisions homes backing onto a golf course, with horseback riding trails winding between, another golf course on the flood plain, and a restaurant on the waterfront where sailors, canoers and motorboat users can moor. Golf champion Jack Nicklaus' company already has inquired about developing the golf courses, Smith said.

The property currently is zoned for a planned residential community of four to eight homes per acre, with a provision to build the higher density if a four-lane access road is constructed. Smith has not yet decided how large a community he favors but is weighing as many as 4,000 units because Loudoun County's development policies call for dense development on its eastern border.

That sits ill with neighboring Fairfax County, which has zoned Great Falls for low-density development.

But as Loudoun County planner Richard D. Calderon puts it: "History repeats itself. In the '50s and '60s, as Fairfax County developed, Arlington was screaming at Fairfax for shoving all its commuters through Arlington's residential communities. Now Fairfax County is turning around and screaming at Loudoun."