Students filed into class for the first day of school Tuesday and — if district projections are correct — there are more of them than ever.

With greater development and more families moving into Issaquah, Sammamish and the Renton Highlands, Issaquah School District administrators anticipate more than 18,760 students to enroll in the 2015-2016 school year. That translates to a 4 percent increase, more than double that seen between the 2013-2014 and 2014-2015 school years.

The most significant increases are expected to occur in middle school and Running Start enrollment at a rate of 6.1 percent and 9.9 percent, respectively, according to general fund comparisons in the district’s budget analysis. Alternative Learning Enrollment saw the greatest percentage increase of all at 39.3 percent, though the category only sees single-digit student enrollment year-over-year.

With those increases come greater amounts of money flowing both in and out of district coffers.

On August 26, the Issaquah School District Board of Directors authorized a 2015-2016 budget with revenues and expenses of $217.3 million and $220.2 million, respectively — both figures 12.6 percent greater than what was budgeted the prior year. The difference will be taken out of district reserves, expected to sit at just under $19.6 million by the end of this school year.

The projected revenues and expenses tie directly into a larger student population, reflecting a larger state contribution to Issaquah schools met by increased classroom and program expenses. The district receives $9,599 in public funding for each of its full-time students — an amount that administrative documents note is nearly $1,000 less than the statewide average.

Projections through the end of the current decade show slower district growth over the next four school years. But the school population is expected to sit at nearly 19,600 students by the 2019-2020 school year.

The district is currently looking at putting a bond measure on the spring 2016 ballot to fund two new elementary schools, a middle school and high school, while expanding several existing campuses. A bond committee recommended a $518.5 million bond measure to the superintendent in May. Superintendent Ron Thiele will bring his recommendation to the school board for approval at a future date.