Look around the Harvey Mudd College (HMC) campus and you’ll see them almost everywhere—lush, green plants native to California. Hidden right below under the soil is the drip irrigation system that keeps them thriving.
Together, the drought-resistant plants and the watering system, which were introduced to HMC in 2005 as part of one of many “green” efforts to make the campus more sustainable and Earth-friendly, simultaneously beautify the grounds while saving the college a whopping eight million gallons of water per year.
“When I started working here 16 years ago, there was water everywhere,” says Mike Barber, grounds services manager who has designed the layout of HMC’s native landscaping and helped implement it with his grounds crew of five men. “Much of the campus grounds were covered with ivy, which requires lots of watering and attracts spiders, rats and snakes. The switch from the spray-head irrigation system to the current drip system and the native plants has dramatically reduced the amount of water we need and use. The native plants also produce berries and fruit, and attract a variety of birds and butterflies.”
To get an idea of how much water is currently being saved, Barber provides this comparison: “We water the native plants a couple of hours each week with the drip irrigation system, which designates water to the root systems and uses about 10 gallons of water each hour. In contrast, the old spray-head system would use about 100 gallons of water per minute for each area of the campus that required watering. [There are about 600 areas at HMC that require watering].”
The idea to switch from a fixed spray-head system to a centrally controlled drip system originated from a project HMC students took part in which evaluated the college’s water use and its impact, both financial and environmental.
The new system, a product of Rain Bird, is controlled by a computer system that communicates with HMC’s weather station.
Here’s how it all works:
The irrigation system calls the weather station through a modem. In turn, the station provides information regarding current humidity, wind and rain, allowing the irrigation system to calculate how much water is required to meet the needs of the greenery around campus. The system then signals the timers in each campus area require watering, and the drip system goes to work.
“Imagine the past fixed schedule of, let’s say, 40 minutes of daily watering in each area for 365 days per year, compared to only about two hours per week in each area using dramatically less water,” says Barber.
Since introducing the drip irrigation system and the native plants, which Barber travels as far as San Juan Capistrano to purchase, even HMC’s oak trees have become healthier.
“The native oaks prefer drier soil and get root fungus with too much moisture,” Barber explains. “As soon as we made the changes, the trees became greener and lost fewer leaves,” both signs of tree health.
Putting other “green” practices to work, HMC’s grounds crew also recently replaced 125 sprinklers with drip irrigation in the flower beds surrounding the Norman F. Sprague Memorial Library. In addition, they recycle all of the green waste and use fallen leaves as ground cover to nourish the oak trees.
But much more work remains.
Barber and his crew plan to change out more ivy patches around campus to native landscaping, as well as putting in moisture sensors to help save even more water.
“There’s always more that can be done,” says Barber. “You drive around outside [of your home or workplace] and see people wasting so much water. It’s upsetting. I see it everyday, and now I send letters, make calls and report it whenever I can.”