The Montgomery County Council gave preliminary approval last week to a plan to open two new high schools in the Gaithersburg area in 1988 and 1989. Construction of the two facilities, part of the school system's proposed six-year building program, will cost $44 million.

The plan will be included in the county budget that will be voted on May 15.

The school board will decide which school, Watkins Mill High School in the Montgomery Village area or Quince Orchard High School west of I-270, will open first. The board had recommended in its request that Watkins Mill open in 1987, and Quince Orchard open the following year.

Watkins Mill is nearing the construction bidding stage and Quince Orchard is in the planning stage, said Ann Briggs, coordinator of facilities planning with the schools.

County Executive Charles W. Gilchrist had said he favored opening one of the high schools during the six-year period (1986-1991) and starting construction on the second school by 1991.

When introducing the county's six-year building program in January, Gilchrist said the opening of both schools during the same time period was not supported by student enrollment projections and would strain the capital budget needlessly.

The new high schools, serving grades 9 through 12, will ease crowding at Seneca Valley and Gaithersburg high schools and at three local feeder junior high schools. When the new high schools open, Seneca Valley and Gaithersburg will serve ninth grade students in addition to grades 10 through 12.

The council also approved a $540,000 purchase of 12 portable classrooms to accommodate 900 students who will be transferred from Northwood High School to Kennedy, Einstein and Wheaton high schools. The school board voted March 4 to close Northwood at the end of this school year.

A planned upcounty vocational center will receive $80,000 for curriculum development, but construction funding was delayed for later years. Funding of a new up-county administration office was also deferred.

Final council action on the two new high schools, along with the proposed county six-year building program and next year's operating budget, will be taken May 15.