Water shortage small concern for Mid-Atlantic region
By BRUCE HOTCHKISS
Water shortage in the Mid-Atlantic? Delmarva? Maryland?
Oh, it’s possible. But don’t hold your breath.
Think 25, 30, 40, maybe 50 years, say the experts.
A lot of factors have to come together.
But in the Midwest and the West, it’s another story.
Many parts of the country are in what weather forecasters are calling a “snow drought.”
Reservoirs are bone dry. Ski slopes are brown, not white.
Measurements of snow depths in the Rockies are in inches, not feet.
And that’s of concern to farmers out there, and could be to farmers here.
Snow melt from the mountains in the spring is counted on to fill the ditches, and the streams and the rivers and provide irrigation for the crops and water for the livestock.
A water shortage there, sufficient to impact crops, could in turn impact commodity markets for farmers everywhere.
In this part of the country, however, according to Dr. Karen Prestegaard, associate professor in the University of Maryland Department of Geology, the farmers — indeed everyone — is blessed with huge underground aquifers.
Although they are declining, it is a slow process.
The flow, of course, declines in the summer but the water volume is bolstered again in the winter.
The summer problem is evapotranspiration, a term used to describe the sum of evaporation and plant transpiration from the earth’s land surface to atmosphere.
Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and water bodies.
Transpiration accounts for the movement of water within a plant and the subsequent loss of water as vapor through stomata in its leaves.
Eighty percent of the water available to a plant can be subject to evapotranspiration, according to Prestegaard, which is why only a portion of the water coming from an irrigation system is returned to its source.
How much water flows underneath the Mid-Atlantic?
The town of Easton, Md. offers a hint.
The town has 12 wells, all active. It needs to use only four at a time to meet the needs of its population of 16,000-plus.
So, Prestegaard says, deep down, in the sand layers, where the big aquifers flow, and depending on many factors including climate change, “there might be a problem some day.” But it is not right around the corner.
That’s not the case elsewhere in the nation.
As of Jan. 4, only 22 percent of the nation was covered with snow.
And and the lack of snowcover across portions of the Midwest might spell “big trouble” for winter wheat yield later this year.
“If there is an arctic cold outbreak with below-zero temperatures, that could cause big problems for winter wheat, which is planted in the fall and goes dormant in the winter.
“Subzero cold could cause stunted growth and reduce the production for this year’s wheat crop,” according to Expert Senior Agricultural Meteorologist Dale Mohler.
AccuWeather.com meteorologists believe that a change in the winter pattern is on the horizon, and more cold waves might penetrate the United States.
Snowcover actually acts to insulate winter wheat from arctic cold snaps, keeping the soil temperature closer to freezing rather than subzero.
Mohler said the lack of storms and mild weather are the factors that have left winter wheat vulnerable.
Most of the other crops of the Midwest should not be damaged by the lack of snowcover.
However, many crops in this region rely on moisture from melting snow during the spring.
If there is a snow deficit in the winter followed by a dry spring, that would be bad news for other crops as well, the meteorologists say.