Examining the Influence of Temperature and Precipitation on Colorado River Water Resources: Reconstructing the Past to Understand the Future Completed

Streamflow in the Colorado River is heavily influenced by high-elevation snowpack. Warming temperatures in spring can reduce snow-fed flows, with serious implications for the water supplies that support communities and wildlife. While it is already well-known that precipitation has a significant influence on river flow, recent observations suggest that temperature and the amount of water in soil may also influence streamflow. In the face of a changing climate, it is important that resource managers understand how factors such as changing temperatures and precipitation will affect this vital water source.

To address this need, researchers are examining records of streamflow, temperature, soil moisture, and precipitation in the upper Colorado River basin going back more than 100 years, to see how these variables have changed during periods of low flow and drought. Next, researchers will analyze tree rings to reconstruct climatic conditions over the past 1,000 years to see if more recent droughts differ from historical climate patterns. This information will help researchers determine if droughts are lasting longer or are more severe than historical droughts, improving our understanding of the impacts of climate change in the region.
 
So far, researchers have found that warming temperatures have played an increasingly important role over the past decades, both exacerbating droughts and dampening the effects of wet winters on high flows. The results of this study will help water managers assess the range of possible conditions that may be expected to occur in the future in the Colorado River basin, and help determine how warming temperatures may influence the river’s flow and the region’s water supply.

Additional information and products from this work can be found on the USGS Northern Rocky Mountain Science Center's website here.