ELGIN — More students are filling the classrooms of Elgin School District U46, according to the latest official enrollment figures for the state's second-largest school district.

U46's overall enrollment jumped by about 150 students to 41,453 compared to last year, according to the district's Sept. 30 enrollment figures released Monday night.

Two of the five high schools in U46 — Elgin High School and South Elgin High School — had the largest enrollment increases in the district, with 182 students and 186 students, respectively. That put Elgin High's population at 2,373 students and SEHS's enrollment at 2,569 students.

The district added a bilingual education program at Elgin High last school year. Tony Sanders, the district spokesman, said that likely accounts for the growth there. As the population of the area that South Elgin High's boundaries encompass has grown, so has the student body.

U46's middle schools saw a drop in enrollment of 135 students and its elementary schools saw an increase in enrollment of 141 students.

Sanders said district officials are unsure of what accounts for the enrollment drop at the middle school level or the growth in the elementary schools.

In any case, Sanders said the enrollment is not growing as rapidly as it had in the early 1990s. Some schools are overenrolled, like Nature Ridge Elementary School in Bartlett, which is about 9 percent over its capacity of 708 students. Other schools are underenrolled, such as Glenbrook Elementary School in Streamwood, which is about 33 percent below its capacity of 634 students.

However, with the district facing a $53.5 million deficit, it can't afford to cover the $35 million-plus tab to construct new buildings or tack on additions to existing buildings to meet current enrollment constraints at all of its schools.

Instead, the district, along with its Citizens' Advisory Council, will review attendance zones over the course of the next year. It anticipates making recommendations for boundary changes to the board of education that, if approved, will go into effect for the 2011-2012 school year.

Sanders said boundary changes would "help us in balancing the enrollments across the district so that schools are neither over- or underenrolled."