Creating boundaries for elementary schools at the Moneys Corner and Hiddenbrook sites in western Fairfax County may be some of the most difficult boundary adjustments the county will face as it opens seven new schools this year, according to Roger Webb, head of the school system's Facilities Planning Department.

Webb said Tuesday that these two schools will be difficult because the area's population is growing rapidly. At a series of meetings Saturday on the new schools, some parents said they feared their children would be shifted once, only to be moved again.

"We're concerned we're going to be one of those pick-up-and-put-down communities," said Anna Nickels, a member of the PTA at Floris Elementary School, near Moneys Corner. "As further development occurs, we don't want to go to a new school."

"We're anticipating {other} new schools . . . knowing we can't solve the problem for five years," Webb said. A bond referendum next year may include funds for schools near Moneys Corner and Hiddenbrook to open in 1990 or 1991, he said.

The Moneys Corner proposals also drew comment from some parents in the Hunters Woods Elementary School area, where the Fox Mill Woods development could be allocated to the new school. "I would like to see the Hunters Woods boundaries remain unchanged," said local PTA president Ann Ruebelmann.

School Superintendent Robert Spillane will submit a formal recommendation to the board Dec. 17 on all new school boundaries. After more community meetings and public hearings, the board is scheduled to vote March 10.