Replacing Grass Can Help Save Water, but Just How Much?

Way before spring, when the trees are leafless skeletons and the grass is dry and beige, the people in charge of helping plants blossom at the University of Northern Colorado were hard at work. Chris Bowers, the school’s energy and sustainability manager walked through the churned-up dirt of a construction site near the campus commons building. Sparse and brown on a chilly January day, he laid out a vision for the space’s future in warmer months.

“There will be people hanging out and studying and eating lunch and using a space that was not used at all before,” Bowers said.

This site is an experiment in reshaping the unused grassy expanses that sprawl across campus. For decades, the area was a patch of green grass that fell into the category of “nonfunctional turf”—a term water experts use to describe grass that serves no purpose besides aesthetics.

Now, as part of a statewide effort to save water, Colorado’s government is trying to convince people and institutions to rip out their thirsty grass lawns and replace them with native plants and more functional space. It comes amid an urgent need to cut down on water use, but there are limits to the amount of water that can be saved.

With the help of a state grant and money from the nonprofit Western Resource Advocates, UNC’s patch of grass—which long served no purpose besides looking pretty—will be replaced with a patio, spots for hammocks and native prairie grasses.

“This is the first step in what we hope is a push forward in this becoming more of a standard across campus,” Bowers said.

While UNC is only replacing grass in a relatively small area for now, the water savings are fairly substantial. That area will see its water use go down from about three million gallons each year to about one million. UNC officials said the native plants in that area may actually demand more water than is currently used during their first three years of growth but will need less in the long term. Some years, they said, those plants might require no irrigation water and grow using only water that falls from the sky.

The project is part of a program from the Colorado Water Conservation Board, the state’s top water management agency. It gave grants to fifty different water-saving projects, the majority of which are on the Front Range.

As Colorado—and more broadly, the arid Southwest—struggles with drought and long-term drying due to climate change, policymakers are under pressure to cut back on water use. Colorado’s turf replacement program is borne out of that reality, but it may only be able to make a minuscule dent in the state’s overall water use.

The overwhelming majority of the state’s water—between 80-90 percent—is used for agriculture. Only 7 percent of the state’s water is used by cities and towns, and only 2.7 percent of the state’s water is used outdoors in cities and towns. So any efforts to cut down on lawn watering will only be working within that tiny slice of the state’s overall water portfolio.

A 2024 report from the CWCB estimated how much water could reasonably be saved through turf replacement programs. After taking out water used for trees and shrubs, and functional turf like sports fields or city parks—which experts say are worth watering—state officials think they can save .004 percent of the state’s total water use.

The CWCB requested $1.4 million in its 2025 budget to run a more complete analysis of land cover across Colorado and get a more accurate appraisal of how much nonfunctional turf there is across the state.

Jenna Battson, the agency’s outdoor water conservation coordinator, said programs to replace nonfunctional turf are still worthwhile, especially as a way to give people a visible reminder of ways to cut back on water use.

“They think, ‘Oh, I can do this and save water,’ and then it might cascade and allow them to start thinking about other ways that they can reduce their water use,” she said. “Which I think will have a broader impact than just the water savings on its face.”

Battson said a turf replacement project like UNC’s, on a college campus near a busy road, might have an added impact because of what she called “the neighbor effect.”

“If you’re doing more really public spaces that are highly visible,” Battson said.” That impact can also spread because people are seeing it.”

Larger projects like the one on UNC’s campus will certainly deliver water savings, but what actually happens to that saved water is another question entirely. In cities across the arid West, conserving municipal water rarely means more water is left in the rivers that supply them.

Around Colorado and the Southwest, some cities have instituted conservation measures to help facilitate further growth. In Colorado Springs, for example, a regime of grass replacement and lawn watering restrictions has allowed the city to grow by about 40 percent while bringing average per capita water use down by nearly 40 percent, and total water deliveries down by about 25 percent.

Those kinds of savings are especially important in Greeley, where population growth has exploded in recent years. Between 2022 and 2023, Greeley grew by 3.1 percent, far and away the largest rate of growth among Colorado’s 15 largest cities.

Lindsay Rogers, policy manager for municipal conservation at Western Resource Advocates, says those water savings are still valuable.

“It’s very possible that the savings from the UNC project are not going to end up back in the Poudre River,” she said. “But there’s still a huge benefit to using those savings to support new growth, as opposed to relying on new supplies.”

Western Resource Advocates helped pay for the UNC project. The group also receives funding from the Walton Family Foundation, which supports KUNC’s Colorado River coverage.

Turf replacement programs have been switched into hyperspeed in the cities that need it most. While the practice is still gaining traction in Colorado, fast-growing cities elsewhere in the Colorado River basin have leaned hard into it.

In Las Vegas, which has a relatively small allocation of water from the Colorado River, the city has grown by about 750,000 people since 2002 and managed to bring down its use of Colorado River water by 26 percent. Those kinds of savings are partially thanks to a turf removal program going back more than two decades, but also a uniquely aggressive enforcement strategy in which a team of investigators drives around issuing fines for water waste.

While similar efforts are unlikely in Colorado anytime soon, policymakers are pushing ahead to cut back on nonfunctional grass to save more water in cities.

The Colorado Water Conservation Board is still taking proposals for more water conservation projects like the one at UNC. It recently picked seven projects that are close to getting approved. Battson said there’s already high demand for the next round of funding, which is about $470,000.

Starting January 1, 2026, a new statewide law will go into effect prohibiting local governments from allowing new nonfunctional turf to be planted.

This story is part of ongoing coverage of water in the West, produced by KUNC in Colorado and supported by the Walton Family Foundation. KUNC is solely responsible for its editorial coverage.