Due to the exceptionally dry winter across much of the western United States ,Lake Powell is expected to receive about 47 percent of its average inflow in the spring and summer months of 2018.
The Colorado River Drainage Area has only a ten percent chance of getting enough snow throughout the rest of winter and spring to bring Lake Powell’s water inflows up to average, said Greg Smith, a hydrologist with the Colorado Basin River Forecast Center, part of the National Oceanic and Atmospheric Administration.
If this precipitation trend continues Lake Powell water inflow will be the seventh worst in 54 years.
"Things are looking pretty grim" along some of the tributaries that feed the Colorado River, Smith said during an online conference on the spring outlook for Lake Powell.
Powell, along with Lake Mead on the Nevada-Arizona border, helps ensure the Colorado River system has enough water to get through dry years.
Approximately 40 million people in seven states – Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming – get their water from the Colorado River, and approximately 25 percent of America’s agriculture is grown with water from the Colorado River.
Lake Mead is currently at 41 percent of capacity and Lake Powell is currently at 56 percent capacity.
The western U.S. has been in a prolonged drought for the last 15 years. The Colorado River has received less than a hundred percent of its average inflow for 12 of the last 15 years.
A study published in 2017 by researchers from the University of Arizona and Colorado State University predicts that climate change could cut the Colorado's flow by one-third by the end of the century.
Each of the seven states that depend on the Colorado River for their water are allotted a certain percentage of it each year. This year’s dismal runoff isn’t expected to impact water allotments this year, but if dry winters continue some municipalities may not get their normal allotment in future years.