Denver Water’s Hillcrest project reached another milestone Feb. 18, as construction crews poured the foundation for the second of three new water storage tanks.

Crews placed 1,500 cubic yards of concrete on the 310-foot-diameter slab that will support a 15-million gallon tank. The three new structures will replace Hillcrest’s original two tanks that were built in the 1960s.

The site in south Denver looked like a busy beehive with 125 workers on hand to complete the job. Watch this time-lapse video to see the work in action.

“Hillcrest is a $100 million project that provides a double benefit for the metro area,” said Doug Raitt, engineering manager. “We need the new tanks to store water for our customers and building them supports jobs in Denver’s construction industry.”

The Hillcrest renovation is one example of the many water infrastructure projects on tap at Denver Water and across the country. Many of the nation's water systems were built after World War II and are now reaching the point where it’s more cost effective to rebuild than repair.

A 2015 study by the American Water Works Association found that restoring existing water systems across the country will cost at least $1 trillion through 2040. Read “Will water get too expensive for some Americans?" to learn what this means for Denver.

Denver Water’s complex network of dams, treatment plants and pipes spans 12 counties and was built as far back as the late 1800s. That’s why the organization plans to spend $1.3 billion over the next five years on capital improvements like replacing the Hillcrest tanks.

“Denver Water has 1,100 workers, but with big projects like Hillcrest, we rely on outside contractors to help us get the job done,” Raitt said.

Around 60 people work on the Hillcrest site every day, according to Michael Haarmann from MWH Constructors.

“Over the course of this project’s four years, we’ll have about 1,000 people working on this facility,” Haarmann said. “Those jobs include project managers, engineers, carpenters, architects, pipefitters, electricians and laborers.”

Other Denver Water projects include a $600 million state-of-the-art water treatment plant north of Golden, upgrades to the dam at Ralston Reservoir and replacement of a major water delivery pipeline in Jefferson County.

About 1,050 people have worked on Denver Water’s new Operations Complex since the spring of 2016, according to Mortenson Construction, the general contractor on the project. The number of workers is expected to climb to nearly 2,000 by the end of 2017.

“These infrastructure investments by Denver Water are just as important to our community as the Convention Center, transit projects, DIA and our major sports stadiums,” said Tom Clark, CEO of the Metro Denver Economic Development Corporation. “A city can’t be successful in the economy without building infrastructure.”