Kelly Edens has been a dog owner her entire life. But when the Arlington resident learned that part of her children's playground might be taken over by a dog park, she and other neighborhood moms decided that Fido should have to play second fiddle.

"That's when the 'Mommy Mafia' said, 'Hold on a second, this has become a much bigger issue,' " Edens said. "It clearly boils down to children versus dogs, and you better bet I'm going to choose children."

Those are the stakes, to the mothers anyway, in the latest skirmish in a long-running battle over the Fort Ethan Allen Community Canine Area in Arlington, one of several disputes in Northern Virginia in recent years caused by the growing popularity of dog parks.

Fort Ethan Allen, one of seven dog parks in the county, was established in the 1980s to provide a fenced-in area for dogs, and their owners, to exercise and socialize.

But in 2000, the county discovered that the park had inadvertently been located on the site of a historic Civil War fort in Fort Ethan Allen Park in North Arlington. Complaints had been mounting from neighbors about the poor drainage, which resulted, among other things, in standing puddles of dog urine. But the county couldn't fix the drainage problem, because the site is in a historic district.

The county approached the problem in the typical Arlington way: It appointed a community working group to find a new site for the park. The panel's recommendation was not approved. A new task force, appointed in January, worked for months holding field tours of possible sites, considering 35 in all.

The task force ended up recommending the same location that had been rejected earlier: an open field along Stafford Street east of the Madison Community Center, about 200 yards south of the existing dog park. In June, the County Board approved the construction of a $400,000 dog park there, complete with landscaping and an underground drainage system.

All that effort, however, may be going to the dogs.

Dog owners were not happy about having to move their park. Parents were not happy at locating the new dog park next to a playground used frequently by neighborhood children. But the battle escalated when parents recently learned that some dog owners now want to expand the park beyond the initial three designs offered by the county, which envisions a park of 20,000 to 22,000 square feet.

That, the parents say, would inevitably take space from the playground, either from an oval-shaped blacktop area next to the jungle gyms and swings or an adjacent grassy, tree-shaded area.

"I recognize the importance of having space for dogs, but when it comes to taking space from kids I just don't understand it," said Alexandra Beall, one of a group of neighborhood mothers who call themselves Parents Advocating Children's Turf. "There aren't many places for kids to safely run and play, and this is one place where they can just run their little legs off."

Dog owners point out that the existing park is between 26,000 and 27,000 square feet, so they would be losing thousands of square feet under the initial designs.

"I don't think it's unreasonable to ask for at least comparable space," said Judith Green, founder and co-chair of Arlington Dogs, which advocates for dog owners. "We're all compromising. Why is it such an issue for the moms to sacrifice a little of the land?"

Green rejected the characterization of the battle as being about dogs vs. kids. "That's where they are wrong," she said. "It's about resistance to change and unwillingness to compromise."

Other dog owners said that although they would love a larger park, they have reluctantly accepted that the space for them and their dogs will have to shrink.

"We knew from the get-go it would be smaller," said Maureen Farrell, the liaison for Madison Dogs, a group that helps the county look after the park. "It wasn't our desire to move. We're satisfied where we are now. The space is good, and people are familiar with it. But as good citizens, we agreed to move."

Dog parks, Farrell added, offer a variety of benefits to both canines and their owners. "For many people, this is their primary means of exercising their dogs and it's wonderful for the socialization of their dogs," she said. "A lot of the people use it for socialization, too. Most of us know each other and have become friends."

Since the initial designs were revealed to the public at a series of community meetings this fall, numerous dog owners have told the county "that they firmly believe they should have comparable space to the existing park," said Michelle Ferguson, an assistant county manager. "Some were very upset about the new park being smaller."

In response, she said, members of the task force, which is helping to design the new park, instructed county staff to "go find more space."

Ferguson said the county's intent, based in part on feedback gained during the task-force process, is "to construct a community canine area that is generally the same size as the existing one."

It remains unclear where the additional space for the park will come from. "Whether it will come from the playground depends on you how define the playground," Ferguson said. "Would we take the actual fenced-in play area? No, that's certainly not our intent. But it would potentially take some open space in the area where kids can now run around and play in."

County officials will present a new design at a community meeting tonight, and the County Board is expected to take up the issue next month. It is unclear when construction of the new park, expected to be completed in 2006, will begin.

"We have a lot of interested groups who have issues or concerns," Ferguson said. "Our challenge is how do we balance it all."

Peter Fallon, chairman of the Fort Ethan Allan Community Canine Area Task Force, said there will have to be compromise on all sides. "We're not going to succeed if everyone is keeping score and trying to defend their little mini-turf," he said. "People need to remember that all of these uses for this space have coexisted in the past and they will again."

Arlington is looking to relocate the Fort Ethan Allen dog park, above, to land near the Madison Community Center.The dog park at Fort Ethan Allen Park has poor drainage and will be relocated.