Snow water storage in mountainous regions of the western United States affects how much water ends up in streams versus being used by plants or evaporating. By studying the timing of snowmelt and rainfall, researchers found that more snow water storage leads to more water flowing in streams, especially in certain mountain areas. This stored snow water released in summer increases the amount of water in streams. If snow water storage decreases due to warming, less water will flow in streams, impacting ecosystems and water supplies.