Snow hydrology in Minnesota headwater catchments

Snow is essential to life in Minnesota. During the cold winter months, snowpack insulates overwintering forest seedlings against harsh temperatures and provides recreation opportunities that represent a way of life for Minnesotans. In the springtime, the melting snowpack becomes the spring “freshet”, which produces large stream flows, fills wetlands and ponds unique to our northern landscapes, and recharges critical groundwater stores.

However, a reliable winter snowpack in Minnesota is threatened by climate change. While predictions of future winter precipitation amounts are uncertain, steadily increasing winter temperatures likely mean a shorter winter snowpack season, with periodic melt during the winter months. The lack of a reliable winter snowpack will negatively impact tourism, recreation, and supply throughout the state.

These changes to climate and forests are also likely to have dramatic impacts on Minnesota’s water resources. However, we do not know enough about how shifts in snowmelt and forest composition will alter groundwater and surface water storage in the headwater catchments that supply our regional water resources.

We expect that increased air temperature will contribute to:

  • Less precipitation falling as snow and thus a smaller snowpack
  • Earlier snowmelt and spring runoff
  • A shift to earlier forest water uses in the spring, leading to less runoff and groundwater recharge.

However, most studies of snow accumulation and snowmelt processes have been conducted in mountainous regions in the western US. Therefore, understanding snow dynamics in headwater catchments in the U.S. Midwest, which is governed by entirely distinct climate, soil, and topographic controls, represents a critical knowledge gap.