Hickory Elementary, Licata continued, may be over capacity because of new subdivisions in the development envelope around Bel Air, but that doesn't correlate with the limited building permits being issued, he said. County records, however, show two major housing subdivisions were approved in the Hickory attendance area in the past 30 months.

Board member James Thornton asked what the school system's plan is to deal with the underuse of high schools.

Redistricting might be a possible strategy, Licata said, but one has to look at the surrounding schools first and how much housing might be built in the future.

For example, he said, if Bel Air High School continues to increase in enrollment, the school system would look at C. Milton Wright and Fallston high schools and see if those facilities could handle some BAHS students.

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The numbers

Enrollment exceeds capacity at only two secondary schools, Harford Technical High School, a magnet school which enrolls students from all over the county, and Patterson Mill High in Bel Air. Harford Tech had 1,010 students on Sept. 30, 2012, 90 more than its capacity of 920. Patterson Mill had 941 students, 17 more than its capacity of 924.

Enrollment was less than capacity at the other nine high schools and at all nine middle schools. Projections through 2019 show Harford Tech's enrollment remaining at about the same level, between 108 and 110 percent of the school's capacity, and Patterson Mill's enrollment remaining in the 101 to 102 percent range.

Among the 33 elementary schools, enrollment at six is either at or greater than capacity, but none are above 105 percent. Only one, Hickory Elementary north of Bel Air, is projected to exceed 110 percent by 2015, the level that could trigger a home building moratorium in the school's attendance area, under the county's Adequate Public Facilities Ordinance. Only Hickory, at 104 percent, and Churchville Elementary, at 102 percent, are projected to be above 110 percent in 2019, both at 113 percent.

More significantly, perhaps, there are a number of schools in the county where enrollment is below 80 percent of their capacity.

Five elementary schools have enrollment below 80 percent of capacity: Norrisville, 74 percent; Havre de Grace, 74 percent; North Bend, 76 percent; Roye-Williams, 69 percent; and Darlington, 60 percent.

Nine secondary schools, half the 18 in the system, where enrollment is less than 80 percent of capacity are Fallston High, 70 percent; Edgewood High, 71 percent; Joppatowne High, 75 percent; Havre de Grace High, 79 percent; Magnolia Middle, 64 percent; Havre de Grace Middle, 69 percent; Aberdeen Middle, 72 percent; Edgewood Middle, 76 percent; and North Harford Middle, 78 percent.

Some other highlights of the report include:

Youth's Benefit Elementary School has the largest enrollment of any elementary school, 958, with William Paca/Old Post Road close behind at 954. Both schools have aging facilities that are in need of replacement, school officials have agreed.

Darlington Elementary has the fewest students, at 192. The next lowest is Norrisville Elementary with 252 students.

• Darlington's 60 percent enrollment to capacity is a red flag, because the state requires local systems to look closely at schools where enrollment falls under than level, the Harford School official in charge of facilities and their use told school board members.

Elementary schools at or above 100 percent capacity are Abingdon, Churchville, Dublin, Hickory, Ring Factory and Youth's Benefit.

Southampton Middle School in Bel Air has the largest enrollment of any middle school, 1,540 students.

Patterson Mill is at 98 percent capacity, the highest out of all the middle schools, and Magnolia Middle has the lowest use, at 64 percent capacity.

Edgewood High School has the most students enrolled, 1,743, but is at just 71 percent of capacity. Edgewood's current building, a replacement for the original built in the early 1950s, opened in 2010.