Heather Sackett did a good story this week on new data Brad Udall has been sharing that geographically parses the declines in streamflow across the Colorado River Basin. For folks like us down here in New Mexico, dependent on the San Juan as a critical source of supply, the news is not good:

This month, Brad Udall, senior water and climate research scientist at Colorado State University, presented data that shows when comparing records from the past 20 years to those from most of the 20th century, rivers in the southern half of the upper Colorado River basin have lost a larger percentage of flows than rivers in the northern part of the basin.

For example, flows on the San Juan River near Bluff, Utah, have declined by 30% and flows on the Dolores River near Cisco, Utah, have declined by 21%. Flows on the Yampa River near Maybell and the Colorado River near Glenwood Springs have each lost just 6% of flows.

“We do think it’s going to dry more in the south and less in the north and we should at some point see a gradient, and sure enough, that has popped up at some of these gauges,” Udall said.