An extraordinarily wet and snowy winter has improved the outlook for the Colorado River, which is Southern California’s primary source of drinking water.

Data supplied by the U.S. Bureau of Reclamation shows snow water equivalent in the Colorado Rockies has reached 158% of average after surging about 8% in just one week.

(U.S. Bureau of Reclamation)

Experts say the snowmelt should comfortably provide water to roughly 40 million people for another year.

This season’s snowpack in the Rockies surpasses record levels four years ago, followed by three consecutive below-average years, including last year’s dismal 83.9% on this date according to information from

The map above shows snow water equivalent above average in every region of the Upper Colorado River Basin, including 134% in the critical Colorado Headwaters region and an astounding 477% in the mountains in the Four Corners area:

  • 477% — Lower San Juan (Four Corners area)
  • 106% — Delores (southern Colorado Rockies)
  • 206% — Dirty Devil (southern Utah plateau)
  • 202% — Lower Green (northeast Utah)
  • 187% — Upper San Juan (northwest New Mexico)
  • 165% — Gunnison (south-central Colorado)
  • 149% — White-Yampa (north-central Colorado)
  • 134% — Colorado Headwaters (central Colorado)
  • 117% — Upper Green (southwest Wyoming)

If you think the deep snow will directly translate to more water in Lake Mead, temper your expectations. Water managers have already set the course for the next few months, planning to fill up reservoirs upstream from Lake Mead in an effort — some say a desperate effort — to preserve “normal” in the times of climate change.

Climate experts who have monitored the Upper Colorado River Basin through the “megadrought” that began 23 years ago are saying that water flow has decreased by 20% over the past two decades. That’s a result of a 2.5-degree increase in average temperatures along the river’s path.