By the time today's kindergartners head off to college, two of Des Moines' fastest growing suburbs could each have three high schools and together serve nearly as many students as Des Moines Public Schools.

Ankeny, which became the first Iowa district to add a second high school in 40 years when Ankeny Centennial opened in 2013, is preparing for a third high school to open sometime between 2030 and 2034.

Waukee, where a second high school will open 2021, is already thinking about a third to keep pace with the district's rapid enrollment growth.

“We’re in a growing time and the challenge is there,” Waukee schools spokeswoman Amy Varcoe said. “(But) it’s exciting to be a part of Waukee and the culture and the growth.”

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Together, the new schools would give Ankeny and Waukee one more high school than Des Moines Public Schools, the state's largest district.

The new high schools are part of aggressive growth plans that include adding as many as five elementary buildings, new middle schools and early childhood centers in the suburban districts over the next five years.

Ankeny officials began updating the district's long-term facilities plan last month. It's the first time the topic of a third high school has been raised and there are still a lot of details that need to be worked out, Ankeny Superintendent Bruce Kimpston said.

It could be a traditional school like Ankeny High and Ankeny Centennial, or one focused on career training with some regular classes, he said.

► More:Waukee's second high school will have a rooftop terrace, two-story media center

"There will be three buildings that will house high school students," Kimpston said, but "beyond that, there are many discussions that need to be had."

In the meantime, officials are moving ahead with plans to add three new elementary schools and two new middle school buildings in the next dozen years. That includes an $18.9 million elementary school set to open next fall in the Prairie Trail neighborhood. It's Ankeny's 11th elementary building.

Waukee's plans for the next five years include two new elementary schools and more space for preschool programs. The district also must find additional space for students in sixth through ninth grades.

Waukee officials said a third high school will be needed if the district continues to grow, but they do not yet have a timeline in place.

Surging enrollment

Waukee is the fastest-growing school district in the state, adding 2,311 students between 2013 and fall 2018. Ankeny is close behind with 1,646 new students in that time.

Enrollment has increased rapidly as families with children pour into both communities. Officials don't expect the growth to curtail anytime soon.

Ankeny has made the U.S. Census Bureau's list of the nation's fastest-growing cities with populations greater than 50,000 for three consecutive years. It's now the state's ninth largest city with a population of 62,416 people, according to the latest census figures.

City leaders expect Ankeny will reach nearly 130,000 residents by 2040, which would make it Iowa's third largest city.

Waukee grew from 13,790 people in 2010 to more than 20,600 as of mid-2017, according to the census bureau. But the school district also includes growing portions of Clive, Urbandale and West Des Moines.

School enrollment has more than quadrupled to 10,321 students since 2001.

"One of our unique challenges as compared to some districts … is that we work with multiple municipalities," said Waukee Associate Superintendent Terry Hurlburt. "Waukee’s growing, but we also receive the growing parts of West Des Moines, Urbandale and Clive."

With 11,353 students, Ankeny is now the sixth largest school district in the state behind Des Moines, Cedar Rapids, Davenport, Sioux City and Iowa City.

Kimpston said he expects Ankeny's current trend of growing approximately 2,000 students every five years to continue.

The district works with demographers to forecast growth. Many of the young families now moving into the district have children younger than school age. That means the school system needs to prepare for the influx, he said.

Ankeny plans to convert Terrace Elementary into a centralized early childhood center in fall 2020.

Waukee, which works with the same demographers, is seeing a similar increase in the number of young families. This year's kindergarten class has more than 970 students, while the Waukee High School senior class numbers near 600 students, Hurlburt said.

The district's facilities plan currently runs through 2022, Waukee Superintendent Cindi McDonald said. Officials update the plan annually and discuss more long-range growth plans.

Conversations about the district's second high school began around 2009, she said.

When it opens in 2021, Waukee will be the first district to go from one to two high schools since Ankeny did it in 2013. (Iowa City grew from two to three high schools when it opened Liberty High in 2017.)

If the Des Moines metro continues to grow as it has since 2001, Ankeny will be nearing 16,000 students by 2031 and Waukee will have close to 17,000 students. Combined, that would put the two suburbs about 600 students short of Des Moines Public Schools' enrollment.

Des Moines, which has around 32,320 students, will have added 1,300 students if it continues to grow at the rate it has since 2001.

Staying ahead of growth

School districts must think ahead when preparing for a new school.

Ankeny already has land purchased for its 12th elementary building, which won't open until at least 2023, and it's in the process of securing land for a 13th elementary.

"I’m actually looking at land for the 14th (elementary)," Kimpston said. "You don’t want to fall behind."

As Ankeny plans future projects, district officials have spoken to legislators about extending the state's 1-cent sales tax for education. The "Secure an Advanced Vision for Education" (SAVE) tax is set to expire in 2029.

Keeping the sales tax in place is the top legislative priority for both Ankeny and Waukee school districts.

School districts use SAVE revenue to pay off long-term bonds used to fund infrastructure projects and technology needs. During last year's legislative session, the House approved the tax extension through 2050, but it was never debated on the Senate floor.

"People might ask the question, why are you concerned about a penny beyond 2030?" Kimpston said. "If we don't have SAVE, then we would have to resort to having bond issues often."

Waukee will open its ninth elementary school next fall. In February, voters passed a $117 million bond referendum to build the district's second high school. McDonald said the district has reached its bonding capacity through 2029.

"If (SAVE) is extended, then we can continue to count on those dollars to work on construction projects," she said.

Upcoming projects

Ankeny and Waukee school districts plan to open four new elementary schools, a new high school and complete additions and upgrades at several more buildings within the next five years.

Fall 2019

Fall 2020

Fall 2021

Waukee opens its second yet-to-be-named high school.

Ankeny completes additions to its two high schools, building them out to accommodate approximately 1,900 students apiece.

Fall 2022

Waukee opens its 10th elementary school.

Fall 2023