Everybody thinks an alcohol-free pool party for some graduating seniors of W.T. Woodson High School is a great idea: The parents who would throw it, the students who would attend it and the police who would condone it.

Even Fairfax County zoning officials who have refused to allow it say it sounds like it would have been fun.

"I understand, my son's graduating, too," Claude Kennedy, the county's chief zoning enforcer, said yesterday. "But there's nothing I can do for them. Those were the guidelines given to me."

Fairfax zoning officials have informed neighbors of the Sommerset-Olde Creek community that they cannot throw a pool party for their graduating seniors, originally scheduled for 9 p.m. to midnight Thursday, because it would violate county regulations.

A Board of Zoning Appeals policy stipulates that community swim clubs are limited to six late parties a season, and they must be held on Friday, Saturday and preholiday evenings. Next Thursday -- Graduation Day for all but one county high school -- is out of the question, officials say.

"Most people were very disappointed," said party organizer Barbara Kersten, whose son is graduating next week from Woodson. "They couldn't understand why the county was not able to make an exception for something that we felt was beneficial for the students."

According to Kersten, there were 24 families in the neighborhood interested in participating. There were also plans for a disc jockey and a buffet, she said.

"Sounds wonderful," Fairfax Supervisor Audrey Moore (D-Annandale) said of the pool party. But when told about the problem in her district, she sighed: "I know, the law's the law's the law, but there're always exceptions . . . . It's just a darned shame."

Moore is not the only one who thinks the pool party prohibition is all wet.

"It's a great idea because the kids aren't on the street, and there's not alcohol," said Officer Judy Dailey, a police spokeswoman.

Robert E. Campbell, vice president of the organization, said club members learned about the zoning requirement recently by accident, in the course of dealing with inspectors when the pool house was undergoing renovations.

Afterward, Campbell notified the county's Zoning Enforcement Branch of Somerset's schedule of social functions. But zoning officials threw water on the pool party.

Sandy Hicks, a senior zoning inspector, said there are sound reasons behind the zoning requirement, well-known to people who live near community recreation facilities. "We used to have a lot of problems with early-morning swim meets," she said.

Bill Shoup, assistant to the zoning administrator, said yesterday that the only way the zoning requirement could be modified would be for the swim club to go before the BZA and ask for an amendment. With high school graduation only five days away, however, that's not viable because it would take about 90 days to get a hearing before the board, he said.Staff writer D'Vera Cohn contributed to this report.