DRI’s Rosemary Carroll, Research Professor of Hydrology, co-authored a new study that found spring runoff in mountains across the Western U.S. is much older than previously known. Using advanced dating techniques, the research discovered that melting mountain snowpacks first replenish groundwater reserves before filling springs several years later. This means that the water relied on by communities across the West takes over five years from snowflake to streamflow. The research has implications for water management and our understanding of the changing dynamics of water availability.