Even a “best case scenario” El Niño won't fix the West’s drought

Lake Mead and Lake Powell, both critical water reservoirs for the Colorado River, which provides water to seven different states, have hit multiple record lows throughout August. While the projected El Niño could bring additional rainfall to the region, experts warn it won’t be enough. 

For the lakes to refill, the upper basin states — Colorado, Utah, New Mexico, and Wyoming – must see increased snow, so their snowmelt can replenish Lake Mead and Lake Powell. Though El Niños broadly lead to wetter weather patterns, that precipitation increase doesn’t always apply to the upper basin states. In fact, the correlation is moderate at best, Molly Taft writes for WIRED.

Even if the upper basin states do see increased precipitation, they may also see a warmer winter, with precipitation evaporating immediately, or fall as rain instead of snow, to the lake's detriment. The lower basin states will almost certainly see increased precipitation, but as they are downstream from Lake Powell and Lake Mead, more water in these areas won’t do much for them.  

“All of the experts agreed that the best-case scenario—in which the mountains that feed the Colorado get a record snowpack year, and Lake Powell and Lake Mead get pulled back from the brink—won’t be nearly enough to make a serious dent in the problem,” Taft writes. “Some projections show that the river’s flow could shrink as much as 30 percent by 2050 thanks to climate change.”

Read the full story, below.