BYU study: Half of Utah households overwater, damage landscapes

PROVO, Utah — The latest drought-focused research out of Brigham Young University showed that as many as half of Utah’s households are still watering their landscapes too much.

That not only wastes water, but overwatering does not even produce the healthiest lawns. This research shows that too much water is bad for lawns. There’s an optimum amount that will produce healthy plants without wasting so much.

“Just the low-hanging fruit suggests that we can do a lot better with the landscapes that we already have,” said Rob Sowby, a water resources engineer at BYU.

His team focused on two cities in Utah County in their latest research. They examined secondary water bills of anonymous customers over thousands of parcels and paired that data with aerial images over an entire month.

“We used what we call four-band imagery that takes pictures of not just color, but also heat from the cities, and tells us how healthy those landscapes are,” Sowby said.

Healthy landscapes are cooler and greener, and the data showed that many of the unhealthy landscapes were being overwatered.

“As these customers are applying more water, the landscapes get healthier. But, only up to a point. There’s this optimum point, beyond which further irrigation does not make the landscape look any better or be any healthier,” the water resources engineer said.

In the imagery, those parcels looked yellow or brown. Researchers could also tell from the heat signature that those parcels were not doing as well as their neighbors.

That’s why the Utah Division of Water Resources puts out its weekly watering guide with recommendations for every county. Last week, it recommended one watering for northern Utah, but none this week because of the storm. Smart meters also gauge your water needs based on your specific conditions.

”Water conservation does not have to be a sacrifice,” Sowby said. “The data that we have suggest that we can still have healthy and good looking landscapes with a lot less water use.”

Their research also showed that tiered-billing systems help reduce water waste. Those who had to pay more incrementally when they used more water, saved more water than those who paid a flat rate.

“Those customers who were subjected to those rates used water more efficiently, even after we controlled for some of the other things, like precipitation, and plot size,” Sowby said.