Grim forecast for Colorado River levels

DENVER — The outlook for the most important river in the Southwest remains grim this summer after April storms failed to produce much snow in the mountains that feed the waterway, forecasters said Monday.

The National Oceanic and Atmospheric Administration said the Colorado River is expected to carry only 43 percent of the average amount of water into Lake Powell, one of two reservoirs that store and distribute water from the river.

It’s the fifth-lowest forecast in 54 years.

“It’s pretty dramatic. It’s a very low runoff season,” said Greg Smith, a hydrologist with the agency.

But officials have said that Lake Powell and its companion, Lake Mead, will be high enough to avoid mandatory cutbacks for water users this year.

Arizona, California, Colorado, Nevada, New Mexico, Wyoming and Utah use the river or its tributaries, along with 20 native American reservations.

The river is under increasing stress because of rising demand and declining flows. The region has been in a drought for 18 years — long enough that some researchers say it may represent a permanent shift.

Global warming is also contributing to the reduced river flows, scientists said.

Last year’s snowfall was uneven but mostly below average across the mountains that feed the Colorado.

The western Wyoming mountains that give rise to the Green River, the Colorado’s largest tributary, received 116 percent of their average snow at the peak of the winter, Smith said.

But river valleys in southwestern Colorado ranged from 44 to 56 percent of average at their best.

“Southwest Colorado had their lowest precipitation on record,” Smith said.

Water levels in some mountain rivers will peak in the next week or so, Smith said.