Katy ISD enrollment could top 105,000 in 10 years

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

"It's really an exciting district, and because is large geographically, it has many years to continue to grow," Guseman said.

The report by PASA singled out the growth of Katy ISD's kindergarten enrollment as one of the prevailing factors as to why the student body is expected to rapidly grow in the next 10 years. Kindergarten enrollment increased 8.4 percent in 2014, the highest jump at that grade level since a 10.43 percent boost in 2005. In 2013 [about 5 percent] and 2012 [about 7 percent], kindergarten enrollment also increased compared previous years.

"Kindergarten growth determines the next 12 years of student growth, so we're very interested in following it," Guseman said. "We know that those kindergarten numbers are up quite a bit and have been now for three years. We're watching that closely because that means an acceleration of growth for the district."

One surprising factor, the report says, that also signaled growth for the school district in an increase of apartments in the area. PASA expects 3,252 apartments will be added inside Katy ISD boundaries during the next year, and that will bring more students.

"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."