NewsUtah Drought


How much Utahns need to water is likely less than expected

Posted at 8:35 PM, May 31, 2022
and last updated 2022-06-01 00:23:20-04

PROVO, Utah — As the summer approaches, many Utahns are starting to ask how much they need to water and what it will cost them.

A new study from Brigham Young University has some answers, and it might be surprising to some.

The project was headed up by Rob Sowby, a BYU professor and civil engineer.

They started by looking at two cities in Utah.

“We looked at irrigation bills from thousands of customers in these two cities and paired that information with aerial images,” Sowby said.

The aerial images broke color into red, blue and green. They also looked at infrared imagery.

What they found was that “healthy landscapes are greener and cooler than other things in the images.”

While that makes a lot of sense, they made a new discovery when they paired that with water bills showing how much someone watered their lawn.

“We found that watering will increase the landscape health — but only up to a certain point,” Sowby said. “After that, as you add more water, the quality of the landscape does not improve.”

The main point is there is an optimum point beyond which watering doesn't offer any benefit.

That point is lower than many might think and is the key question that comes next.

To start, Sowby recommended that Utahns look at the Utah Division of Water Resources' Weekly Lawn Watering Guide, which tells the best times and amount of water.

Sowby also recommends technology as a solution.

"Smart irrigation controllers, timers that look ahead at the weather and help us optimize the timing of our irrigation," he listed as examples.

So this summer, the science shows water restrictions don’t have to ruin your landscaping.

"Their landscapes will look healthier. They're not going to use as much water. They'll save money on their water bill. It’s a win-win-win,” Sowby said. “Water conservation does not have to be a sacrifice.”