Researchers used tree rings to look at Utah's climate record as far back as 1429; they found the worst drought this century doesn't even make the top 10 most devastating.

A research team used sandpaper and microscopes to look at the rings of "drought-sensitive tree species," a Brigham Young University news release reported.

The researchers found that the year 1703 was the first of 16 in a row that would have "below-average" stream flow. The Weber River was believed to have flowed at only 13 percent of the normal in 1580 due to intense droughts.

The most severe drought recorded was in 1492; all four of the worst-known droughts were believed to have occurred during Christopher Columbus' lifetime, the news release reported.

"We're conservatively estimating the severity of these droughts that hit before the modern record, and we still see some that are kind of scary if they were to happen again," Brigham Young University professor Matthew Bekker, said in the news release. "We would really have to change the way we do things here."

Today's climate and stream flow records only go back about a decade in Utah, but tree rings can help researchers recover this missing data.

The team looked at  Douglas fir and pinyon pine trees, which have rings that are especially susceptible to water availability. The team used samples from both live and dead trees. They used modern stream flow to gauge how the trees would have reacted to water in the past.

The researchers believe the western climate tends to fluctuate more than it did in the 1900s. The prior centuries had significantly more frequent sever wet and dry periods.  

We're trying to work with water managers to show the different flavors of droughts this region has had," Bekker said. "These are scenarios you need to build into your models to know how to plan for the future."