NEWS

South Dakota drought enters hibernation mode. Here's why recent snowfall won't make a difference.

Dominik Dausch
Farm Forum
Map showing drought intensity levels in South Dakota as of Thursday, Dec. 22, 2022.

It might seem strange to think about South Dakota's years-long drought during the winter months - and in the wake of last week's deadly storm that dumped snow across the state - but that dryness plaguing the state's soils continues to have an impact even now, experts say.

According to the latest U.S. Drought Monitor report, more than 60% of the state is experiencing some form of dryness, with the southeast corner of the state suffering the same extreme drought conditions since August.

One would think the holiday season precipitation would bring some much needed moisture to South Dakota, but National Weather Service meteorologist Jeff Chapman told Farm Forum "very little" moisture has since entered the soil.

"Typically, you don't get significant changes in drought status this time of year, because you can't change things … Our soils were frozen at the top levels," Chapman said. "What we have done is build a base of snow with a higher moisture content."

More:More snow is headed to Sioux Falls, but this will be a 'more mild' round, NWS officials say

What this means, elaborates Anthony Bly, a soils field specialist with South Dakota State University Extension, is that this winter's frost will tend to penetrate the state's dry dirt deeper and quicker than its wet soils. This is because water radiates heat in the ground, which can delay the freezing process.

The effects of drought in the spring, summer and fall can have an impact on underground infrastructure in the winter, Bly added. He said pipes, which are normally buried below the "frost line," or the depth at which groundwater will freeze, are at greater risk of shifting or bursting in frozen but arid earth.

In the winter, frost becomes a surface-level issue

Dennis Todey, director of the USDA Midwest Climate Hub at Iowa State University, told Farm Forum the drought is serious enough that "any moisture is helpful," but he added the snow wouldn't provide any immediate moisture benefits until it starts to melt in the spring.

The NWS seven-day forecast suggests temperatures are unlikely to shift above freezing, diminishing the threat of flooding during the winter. But once it does, however, the still-frozen soil can become rather dense and impermeable, which prevents it from absorbing most of the moisture.

"It's more water on the land, which can lead to more runoff," Todey said. "When it does run-off, there is a benefit. It goes into the Missouri River system, which is also low, but there is … no immediate moisture benefit."

Bly said last week's storm also brought some strong winds, which could have blown topsoil around and caused some potential soil erosion in drought areas.

"In the areas [south] of Interstate 90, they're really dry and have really poor crops. As you go north, the situation improves," Bly said, adding he's personally seen topsoil loss on land around Beresford and Centerville, South Dakota.

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If there's a silver lining to the storms (and the drought), the soil experts agree it can be found in the idea that any precipitation is better than nothing.

"We're going to need some moisture, and this is a good sign," Bly said. "For me, what this shows me is that it can snow, it can rain, it's not completely shut out. Where it goes from here, nobody knows."

Dominik Dausch is the agriculture and environment reporter for the Argus Leader and editor of Farm Forum. Follow him on Twitter and Facebook @DomDNP and send news tips to ddausch@gannett.com.