Drivers of Drought in the Upper Colorado River Basin

Science Center Objects

The purpose of this project is to investigate Colorado River basin droughts, and the climatic factors that influence those droughts. The project uses paleoclimatic data to extend instrumental climate and flow records, along with climate change projections to assess the range of possible conditions that may be expected to occur and to determine how warming temperatures may influence river flow and water supply in the future.

Colorado River Basin map

Research Questions

This collaborative project, between researchers and water resource practitioners, has three main sets of stakeholder-driven questions:

  • Given instrumental records for the 20th and 21st centuries, how have the contributions of antecedent soil moisture, winter/spring temperatures, and total cool season precipitation varied during the major periods of low flow in the upper Colorado River Basin (UCRB) and its major sub-basins?
  • Using tree-ring reconstructions of past soil moisture, temperature, and precipitation, are contributions of these three factors to low flows over past centuries similar to those of the 20th and 21st centuries? Are there differences in these contributions between cooler and warmer time periods? Have contributions changed over time?
  • What is the sensitivity of UCRB low flows to different scenarios of changes in soil moisture, winter precipitation, and winter/spring temperatures projected by the latest global climate models (CMIP5)? How do results relate to conditions during significant low flow events captured in the instrumental and paleo record?


Project Resources


Colorado River Streamflow - A Paleo Perspective




Woodhouse, C.A., G.T. Pederson, K. Morino, S.A. McAfee, G.J. McCabe. 2016. Increasing Influence of Air Temperature on Upper Colorado River Streamflow. Geophysical Research Letters 43.

Contact Greg Pederson,, or Connie Woodhouse,, for a copy of the paper.





Southwest Climate Science Center Project: Disentangling the Influence of Antecedent Temperature and Soil Moisture on Colorado River Water Resources

Final Workshop at Salt River Project


CO River Basin Data

Data and Tools



Project Personnel (Principle Investigators and Key Collaborators)

Connie Woodhouse – University of Arizona, Tucson AZ (
Gregory Pederson – U.S. Geological Survey, Bozeman MT (
Adam Csank – Desert Research Institute
Stephanie McAffee – University of Nevada, Reno
Gregory McCabe – U.S. Geological Survey, Denver CO
Stephen Gray – U.S. Geological Survey, Anchorage AK
Jay Alder – U.S. Geological Survey, Corvallis OR

Water Management Partners

Dave Kanzer – Colorado River District, CO
Eric Kuhn – Colorado River District, CO
Don Meyer - Colorado River District, CO
Charlie Ester – Salt River Project, AZ
Jon Skindlov – Salt River Project, AZ
James Walter - Salt River Project, AZ
Laurna Kaatz – Denver Water, CO
Steve Schmitzer – Denver Water, CO
Mark Waage – Denver Water, CO
Jim Prairie – Bureau of Reclamation, Lower Colorado District
Carly Jerla – Bureau of Reclamation, Lower Colorado District
Ken Nowak - Bureau of Reclamation, Lower Colorado District
Paul Miller – NOAA Colorado Basin River Forecast Center
Kevin Werner – NOAA Regional Climate Services, Western Region
Michelle Stokes – NOAA Colorado Basin River Forecast Center
Michelle Garrison - Colorado Water Conservation Board


This project is funded by the DOI Southwest Climate Science Center (grant no. G14AP00152), and the NOAA Climate Assessment for the Southwest.