When snow melts or rain falls, some of the water runs off into streams or rivers. Most of the water, however, goes down into the soil. The water that stays close to the soil’s surface flows laterally and down hillsides. Scientists in this study wanted to know how much this soil water, compared to other sources of water, contribute to stream flow in certain areas. They also wanted to know how levels of snowfall affect groundwater’s contribution to stream flow. Topics: Water, Aquifers, Chemistry, Ground Water, Infiltration, Rainfall, Snowfall, Streamflow.