Simple Change to Irrigation Patterns at IRM Save 700,000 Gallons of Water Per Year
Cutting back on the irrigation for the terraced grass roofs at the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research (IRM Building) will save the university an estimated 700,000 gallons of water this year.
Jamie Hand, an energy analyst in Facilities Services, worked with Landscape Manager Julie Sutton to reduce the irrigation about two months ago.
“It was sort of a pilot project to see if the plants could get by with less water,” Hand said.
The grass roofs at the Parnassus building function as open space for the researchers working on treatment strategies for conditions such as heart disease, diabetes, epilepsy, multiple sclerosis, Parkinson’s disease, Lou Gehrig’s disease, spinal cord injury and cancer. The green roofs also provide additional insulation and act like a water filter.
Hand began reviewing irrigation patterns at different spaces around campus several months ago. “I started looking at irrigation practices because of the drought and the university’s water reduction goals. This is the first building Julie and I looked at together. I’m hoping to roll out similar reviews to other campus locations that use a lot of irrigation over the next year.”
Steaven Campbell is responsible for UCSF’s Water Action Plan, which describes the university’s water reduction efforts. The plan’s central goal is a 20 percent per capita reduction by 2020, compared to a 2007-2010 benchmark period. UCSF has made significant strides towards that goal but the university still needs to reduce its annual consumption by roughly 20 million gallons. “Our irrigation improvements will play a small but important role in achieving that 2020 goal,” Hand said.
When he began reviewing irrigation patterns, Hand noticed that the grass roofs at the IRM Building were being watered daily for about 12 minutes. “At the time the building opened, it was important for the plants to become established,” he said.
Hand worked with Sutton to assess the plants and she agreed they looked healthy and established and she made programming changes to begin watering the roofs three times a week for about eight minutes per day. “We have a Calsense ‘smart’ controller system on the roof and slope of the IRM building as well as in other areas at Parnassus and the Mission Bay campus,” Sutton said. “One of the unique features is that the system calibrates the watering schedule based on evaporation rates, local weather data and precipitation collected in localized rain buckets. Based on those factors, the irrigation controllers will adjust to reduce watering times accordingly. The system also monitors flow to alert when there is an irrigation break and can be controlled by a central desktop computer in addition to in the field use.”
For the next month, Sutton and Hand assessed the new watering cycle and the plants. “We expected the plants to remain healthy. With the new watering cycle we saw no significant changes in the health of the plants,” Hand said.
“Now that the green roof is established, we can modify the irrigation with the intention that the landscape can sustain with occasional supplemental watering,” Sutton said.