This actually sounds like a plot line for a B-grade horror movie…a towering wall of dust about a mile and a half high barreled through northwest Texas in early October, enveloping the town of Lubbock in a cloud so thick that for a good half hour on Monday evening, people couldn’t see more than a few feet. The only thing though is that this isn’t a movie…it is happening right now in the U.S. Southwest.
Huge dust storms have also blanketed Phoenix this summer and fall, and scientists warn that the Southwest faces more mammoth storms in coming months, as the extreme drought that has gripped the region shows no sign of easing. And the impact won’t be limited to towns in a dust storm’s path. The loose soil in the air affects mountain snowpacks and river levels in a much broader region, and even river-based tourism.
Dust storms aren’t unknown in the Southwest, which suffered through the Dust Bowl in 1930s. But storms have increased in frequency and ferocity in some areas in recent years. For example, a monitoring station in the San Juan Mountains in southwest Colorado has recorded a big jump in dust storms. The total concentration of dust that settled on the ground after the storm season was 24 times as great in 2010 as it was in 2005. One likely culprit: The persistent drought has killed plants that once held down loose soil.
Residents of the Southwest have seen the effects of these dust storms firsthand this year. Three huge walls of dust slammed into greater Phoenix in a six-week period this summer and a fourth raked the desert south of the city in early October, causing three separate pileups on Interstate 10, including one fatality.
Think of a blizzard…only it is sand.
The storms create immediate problems on the ground, including traffic jams that can last hours. The high winds often knock down power lines and cause other property damage. Scientists are also beginning to understand the broader impact. Dust kicked up in Texas or Arizona often drifts on the jet stream north to the Rocky Mountains. The dark particles blanket the snowpack, absorbing sunlight much as a black shirt would. That can accelerate the melting process by weeks.
And that, in turn, has profound effects all along the Colorado River Basin, which provides drinking water to 27 million people in seven Western states and Mexico. Water managers say they don’t have enough reservoir capacity to capture all the water they need for the rest of the year when so much comes rushing down the river in a short period of time in early spring. Lower river levels later in the season are tough on farmers trying to irrigate late-summer crops like hay. The low flows also make it less appealing to raft during peak summer tourism months.
What can be done? Scientists say there are practical solutions. Planting abandoned cropland in native, drought-tolerant plants would hold down soil. In addition, restrictions on grazing, bulldozing and taking off-road jaunts on vulnerable lands would help as well.