Lake Washington School District officials are re-evaluating enrollment projections after a larger-than-expected jump in student population for the 2016-17 school year.

The bump of 1,178 students pushed LWSD’s total student population to 29,008 — now the third-largest district in the state behind Seattle and Spokane.

“Our business services department is diving into the numbers to determine where the extra growth came from,” Kathryn Reith, LWSD communications director, said.

The unexpected bump may be attributed to the district’s switch to all-day kindergarten, Reith said. In the past, some parents who wanted all-day kindergarten would chose private school options and enroll their students in public first grade.

With all-day kindergarten now fully-funded by the state, more parents could be choosing to skip the private school step.

The switch to all-day kindergarten has been a smooth one, district-wide. Most elementary schools already had all-day kindergarten classes, with a half-day option offered.

Monica Garcia, principal at Peter Kirk Elementary, said though parents can still opt-out of the all-day kindergarten program, few parents have chosen to do so.

“It’s right about where I expected,” Garcia said, adding that the switch has been easy for the students as well. “We give them wiggle breaks, and the more-challenging material is handled in the morning. After lunch there’s a long recess, and then quiet time — it’s different in every room.”

Heidi Paul, principal at Alexander Graham Bell Elementary, said parents seem to appreciate the opportunity for all-day instruction.

“We haven’t had parents express frustration or challenges,” Paul said. “They had the option, if they were concerned about all-day, to elect a half-day option. We didn’t have any families take that option.”

Regardless of the all-day program’s impact, the district may need to adjust projections used when planning for bond measures, similar to the measure passed earlier this year. Reith said the district looks at numbers every year and tinkers with the long-term plan.

LWSD was the sixth-largest district two years ago, surpassing Tacoma, Kent and Evergreen. Lake Washington is also among the fastest-growing districts in the state. Seattle added around 900 students for a total of 53,102 in 2016, while Spokane added around 550 students for a total of 30,771 students in 2016.