For decades, the University of Utah irrigated its manicured Kentucky bluegrass lawns using culinary water from Salt Lake City. Excess rain and snowmelt runoff was channeled away through storm drains, sometimes adding to erosion or pollution problems downstream. But in recent years, the U’s Plant Operations realized that the campus could save money while keeping the lawns green by capturing the runoff water.
“We asked, ‘What would it take for campus to run all of its operations without using any more water than what naturally falls on campus all year?’ ” says Cory Higgins, director of Plant Operations. The idea grew into a goal of achieving “water neutrality” by 2020: The campus aims to harvest and retain for irrigation the annual average 18 inches of rain and snow that falls on its 600 acres of land.
But there are challenges to becoming water neutral. “For one thing, our water doesn’t come evenly throughout the year,” says Higgins. Winter snowpack and fall and spring rains bring pools of water to campus, but the grounds crews need the water most in the summer and early fall. So Plant Operations staff members explored how big of a storage tank they would need to retain the water for use when the landscape plantings needed it. Historically, the campus had accessed all of its water from onsite wells near Rice-Eccles Stadium that drew from a natural aquifer below campus, says Higgins, so his office decided to tap into that aquifer for irrigation water. “We realized nature provides us with a storage tank in our aquifer,” Higgins says.
Since 2010, the University has installed two of six planned sections of a secondary water system for moving ground water around campus. The U also plans to construct bio swales along the new HPER mall and USTAR interdisciplinary malls to capture the water flowing down from the Health Sciences and Fort Douglas areas, as well as the adjacent buildings and parking lots. Bio swales are gently sloped drainage courses in the landscape that help remove silt and pollutants from surface runoff water. Although the proposed HPER bio swales are currently in need of funding, if completed they would capture about a third of the campus’ water needs.
With the new policy changes, the U will continue to purchase drinking water from Salt Lake City. Non-potable water was used during summer 2011 for irrigating the lower-campus lawns around Presidents Circle. This summer, the non-potable water will be used for most of the grounds westward from Orson Spencer Hall. “The summer after that, we’ll do even more, working our way up, with a plan to get all the way up to the hospitals,” says Higgins. And all new building projects will be designed to help detain water, or slow it down in order to avoid erosion problems downstream.
Eventually, the campus hopes to retain the amount of water that historically fell during 10-year major storm events. Still, as the campus becomes more water wise, Higgins says, his office will monitor how much water the University can legally store. State laws regarding water harvesting allow for directing or storing water as long as it is eventually released back into the drainage system. “Legally, we have to let a certain amount of water run across campus, because historically it did,” says Higgins. “As we push that, at some point, we might be retaining more than our legal limits. But we’ve got a long ways to go.”
Meanwhile, the University is also working to reduce overall water consumption, by installing low-flow toilets and high-efficiency showerheads, and using secondary water to flush toilets in some cases. The campus will also see more xeriscaping around new developments and renovations, with drought-tolerant, native plants.