The City of Phoenix recently announced its Water Services Department received a grant to pilot a program testing innovative water conservation technology in partnership with Arizona State University.
The funds will be used to inject water-absorbing polymers, also known as hydrogels, under the turf of 12 acres of soccer fields on the ASU West campus.
“This is technology that is currently being used in California,” said Kathryn Sorensen, Phoenix Water director. “The City of Phoenix applied for a grant with the U.S. Bureau of Reclamation, in partnership with Arizona State University, and received a $100,000 grant to pilot this same technology here in our desert soils to see how well it works out for us.”
The hydrogels are injected beneath the roots of grass turf, creating a barrier that can absorb water while slowly releasing it over time, similar to a sponge, Sorensen said.
“The idea is that it will reduce the amount of water that is necessary to keep the turf healthy,” she said.
According to the City of Phoenix, testing in California showed that hydrogels can reduce lawn water usage by 40 to 45 percent.
“We’re always looking for ways to innovate when it comes to water conservation,” Sorensen said. “As we look to a future that’s hotter and drier, it’s really, really important that we continue to do everything we can and really push the boundaries on water conservation as an adaptation measure.”
The pilot program will look to see if hydrogels can retain enough water to keep the soccer fields at ASU West healthy while using less irrigation.
“The soccer fields currently use about 11 million gallons of water [per year], and we’re hoping through the pilot to demonstrate about a 40 percent reduction in the amount of water used,” Sorensen said.
A 40 percent reduction in water usage on the 12 acres being tested would mean using 4.4 million fewer gallons of water per year, saving ASU and the city approximately $25,400 per year, according to the City of Phoenix.
About 60 percent of water consumed in the Southwest goes to exterior landscaping. The hydrogels can absorb up to 400 percent of their weight in water and release up to 96 percent of the water into the turf, retaining the ability to absorb and release water over a period of 5 to 7 years, according to the City of Phoenix.
“We are eager to see if this project produces similar or better conservation results in our climate and soil as compared to California,” said JoEllen Alberhasky, program manager for sustainability practices at ASU. “If so, it will become another valuable tool in addressing the ongoing drought in Arizona.”
If the program is successful, Sorensen said the City of Phoenix will likely expand the use of hydrogels to more of its turf facilities, including city parks and municipal golf courses. The city would also try to make the technology available to private golf courses, sports facilities and, eventually, even homeowners.
“Whether we would just encourage other, private individuals to use it or offer an incentive is, at this point, unknown,” she said. “It’s just too early to know yet.”
But one thing is certain: If hydrogels lead to healthy, green grass while using less water, they are a win for Arizona.
“We know that the flows of the Colorado River are going to diminish over time and that the river is already over-allocated,” Sorensen said.
Looking to the future, she said, Arizonans need to continue to innovate and create new ways to save water.
“[We must] use our water wisely so that we can continue to provide the quality of life that we have here in the Valley of the Sun,” she said.