UT’s irrigation system saves millions of gallons since last year

Christine Ayala

UT’s irrigation system is conserving millions of gallons of water and helping increase efficiency after an upgrade last year.

The system has helped reduce the University’s water use for irrigation by 66 percent, although it was only projected to save 57 percent, according to Markus Hogue, irrigation and water conservation coordinator.           

Last year the irrigation system updated 18,000 sprinkler nozzles and 108 controllers monitoring the campus water use, to keep track of usage and collect data from areas on campus to make modifications to the system which measures evapotranspiration. Evapotranspiration is the amount of moisture in the soil lost to wind, sunlight and temperature changes. This allows the system to calculate the amount of time needed for water to run to replenish the water lost.

“We don’t over water. We don’t under water. We put back what has been pulled out,” Hogue said.

The system also accounts for rainfall. When the campus received two inches of rainfall this past week, the system measured how much water was replaced and reduced the amount of water added back through irrigation. 

Hogue said last year the campus saved 10 million gallons because the system can detect unusually high-pressure flow, typically caused by broken sprinkler heads. On average, 125 sprinkler heads break monthly.

“Before, on the old system, these things could continue to happen for a month or two until one of our irrigators that was going through that system saw, flagged it and repaired it,” Hogue said. “Now, within a minute or two we know about it and we’re able to shut it off.”

Hogue said the time saved by the system allows the irrigation team to modify the system and handle other issues affecting plant growth such as worms and making water available for squirrels that may otherwise damage the system.

Jacob Johnson, the City of Austin’s water conservation specialist, said the University is part of a four-year pilot program to conserve water by allowing commercial properties a water budget instead of restricted hours for watering. The budget is affected by drought conditions, and will be reduced if the drought worsens.

Johnson said although the University is not required to follow city water restrictions as a state-owned property, it has abided by the program’s budget and provided the city with useful data on how the efficient system helps save water.

“Over the last year, they have been very successful,” Johnson said.  “UT is one of our largest customers in water use. If a large customer with a lot of outdoor water use like UT can make significant reductions, that’s a pretty big impact on our system.”

Facilities Service manager John Burns said the program allowed the University to water throughout the week, while abiding with the water restricted hours mid-day. Normally the city only allows watering on specific days.

“We’re watering more days a week but putting less water out on those days. If we had to water all in one day it would be really impossible,” Burns said.

Hogue said the system is expected to continue to reduce water usage as they continue making modifications.