A welcome surge of melting snow is pouring out of the Rocky Mountains. It’s filling drought-stricken rivers of the southwestern United States and fending off a water shortage. But at the same time, the great volume of snowmelt is threatening to push rivers over their banks.
Last winter brought above-average snowfall to much of Colorado, Utah, and Wyoming. As summer approaches and temperatures climb, an abundance of melting snow is rushing into the Colorado River, the Rio Grande, and other waterways after a desperately dry 2018.
“It couldn’t have come at a better time,” says Greg Smith. He is a hydrologist (scientist who studies water) with Colorado Basin River Forecast Center. “There’s this big sense of relief this year that we’ve kind of rebounded.”
Colorado was blanketed by 134% of its normal snowfall last winter. Utah had even more, at 138%. Wyoming peaked at 116%.
That will put so much water into the Colorado River that Lake Powell, a giant reservoir downstream in Utah and Arizona, is expected to rise 50 feet this year, says Marlon Duke, spokesman for the U.S. Bureau of Reclamation. The bureau manages Powell and dozens of other reservoirs.
The reservoir is rising fast—six to 15 inches per day. The National Park Service warned people to keep cars and boats at least 200 yards from the shoreline to keep them from being submerged overnight.
The influx into Powell will allow the Bureau of Reclamation to send enough water downstream into Lake Mead in Arizona and Nevada to avoid a possible water shortage there. Arizona, California. and Nevada rely heavily on the reservoir.
Last year, the bureau predicted a better than 50% chance that Mead would fall so low that Arizona — which has the lowest-priority rights to the reservoir — would have to take a cut in its share in 2020. The shortage now might be put off until after 2021, Duke says.
Besides replenishing reservoirs—a boon to cities and farms that depend on them—the surging rivers mean good rafting conditions. But some sections are so wild that guides are avoiding them for safety concerns.
To help prevent flooding, Colorado authorities spent weeks clearing debris from streams. Predicting the great flow from the snowmelt, they moved ahead of it to make sure waterways were ready to direct the rush when it came. Only a few reports of localized flooding have been made so far, according to the National Weather Service.
Weather and climate experts say it’s too early to declare the Southwest’s two-decade-long drought over. But at least for the present, the region can drink deeply and give thanks for the refreshing reprieve.
Behold, I am doing a new thing; now it springs forth, do you not perceive it? I will make a way in the wilderness and rivers in the desert. — Isaiah 43:19
(Big Cottonwood Creek near Salt Lake City, Utah, is running high, fast, and icy cold. The state’s snowpack this winter was almost double the previous year, which was the driest on record. AP Photo)
