Research team monitors snow melt that feeds Colorado streams and rivers

When it snows in Fort Collins, Alyssa Anenberg heads west to Lory State Park, but not to snowshoe or ski. Instead, the Colorado State University graduate student gathers information about how nutrients move through the soil after snow falls and eventually melts.

Anenberg, who is pursuing a master’s degree in Watershed Science, is part of a team monitoring snowpack, soil moisture and streamflow at different elevations across the state. Their goal is to determine how melting snow affects the flow of rivers and streams, which has an impact on agriculture, recreation and Coloradans’ everyday lives.

John Hammond, who is working on a doctorate in Earth Sciences through the Warner College of Natural Resources, said the team is monitoring conditions at 11 watersheds across the state. In addition to on-the-ground tracking, researchers use satellite information from NASA and snow monitoring information from the Natural Resources Conservation Service’s SNOTEL network.

“It’s surprising how few people realize so much of their water supply depends on mountain snowpack,” said Hammond. “Snow isn’t just about recreation. It’s about everybody’s livelihood and it’s a very important resource for water used at home and in agriculture.”

Over the long haul, states like Colorado have measured high-elevation snowpack and used the measurements to forecast water supply. The CSU team is studying snowpack at middle and low elevations, where the snow does not last as long.

“These areas sometimes contribute large amounts of water to streamflow, but they aren’t measured by SNOTEL or other organizations,” said Stephanie Kampf, associate professor in the Department of Ecosystem Science and Sustainability, who oversees this research in the Natural Resource Ecology Lab at CSU. “Predicting water supply is not just about high-elevation snow. Low elevations with mixtures of snow and rain also matter, and we need a better understanding of how much water they produce.”

To date, researchers have identified a few trends, including one that may not sound too surprising.

“Overall, we see that low snow years give us less streamflow,” said Hammond. “In Colorado, it’s typically drier. If you have a small input from a small snow event or rainfall, it might only partially wet the soils.”

What’s the solution? Hammond said one option is to change the way reservoirs, dams and ditches are managed. At the same time, reservoir management is complex.

“Reservoirs are only so large, and they’re managed for multiple objectives, including municipal water supply, recreation, irrigation and flood control,” he said. “If snow melt occurs earlier, by a few weeks or months, you’d have to store that water for a longer period. Management objectives can be in competition with each other.”