Recent streamflow declines and snow drought in the Upper Rio Grande tributary basins

TitleRecent streamflow declines and snow drought in the Upper Rio Grande tributary basins
Publication TypeConference Paper
Year of Publication2019
AuthorsSteele C, Elias EH, Reyes J.T.
Conference NameUniversities Council on Water Resources
Date Published06/2019
Conference LocationSnowbird, UT
ARIS Log Number364363

To understand how future climate change will impact agricultural communities in the southwest, it is essential that we know how water availability has varied in the past. Over the last half century, there has been a trend of declining streamflow across the southwestern United States. For rivers such as the Rio Grande, with more than 65% of the native flow originating as snowpack in mountainous headwaters, this trend has been driven by changes in winter precipitation, decreasing snow water equivalent (SWE), rising temperatures and earlier spring snowmelt. Researchers have already documented how lower SWE contributes to reduced streamflow volume from the entire Upper Rio Grande (URG) headwaters to the state line between Colorado and New Mexico. In this paper, we analyze the relationship between SWE and streamflow volume over the last 30 - 40 years at a finer spatial scale, looking at individual high elevation watersheds in New Mexico that contain tributaries of the Rio Grande. In addition, we use longer term datasets to identify years of snow drought that resulted from significantly lower winter precipitation. Two years of critically low snowpack (2002 and 2018) provide insights into potential future snow drought scenarios. We intend to use these findings to summarize potential impacts from climate change on the rural, acequia communities who live in and cultivate the narrow valleys situated just below the high elevation watersheds.