Katy ISD officials already knew the school district's enrollment was growing, and they now have an even better idea on how much the student body could expand—possibly exceeding 105,000 students in 10 years.

At the Oct. 27 school board meeting, officials with Population and Survey Analysts gave its annual demographic report to trustees. Using data that included job growth, home and apartment construction, transportation improvements and birth rate, PASA President Pat Guseman said her firm predicts, in a moderate growth model, KISD enrollment will increase by about 2,400 to 3,100 students each year for the next 10 years.

According to the model, the school district, which now has a student body of just more than 70,000, will hit the 84,000 mark in five years and reach an enrollment of more than 98,000 in 10 years.

In PASA's high-growth scenario, there could be more than 86,000 students in 2019 and more than 105,000 students in 2024.

In the state, KISD's growth rate of 4.3 percent a year ranks second to Frisco ISD at 7.4 percent.

The PASA report singled out an increase in kindergarten enrollment as one of the prevailing factors as to why the student body is expected to rapidly grow. Kindergarten enrollment increased 8.4 percent in 2014, the highest jump at that grade level since a 10.43 percent boost in 2005.

"Kindergarten growth determines the next 12 years of student growth, so we're very interested in following it," Guseman said.

Another factor, that signaled growth for the school district is that 3,252 apartments are expected to be added inside Katy ISD boundaries during the next year, the report said.

"We've never worked with a school district that added almost 3,300 apartments, and that's what we anticipate between this October and next October," Guseman said. "We are expecting a really high growth of students in those apartments because parents want to move to this district, and that's one way they're able to do that."