The USGS Water Science School
Mountain snow fields and glaciers act as natural reservoirs for water in some areas, such as the western United States and Canada. They store precipitation from the cool season, when most precipitation falls and forms snowpacks, until the warm season when most or all snowpacks melt and release water into rivers. In certain parts of the world, snowmelt is essential for the summer irrigation season and to supply people and cities with water.
As much as 75 percent of water supplies in some western states are derived from snowmelt. As this picture of Bow River Falls, downstream from the Bow Glacier in Banff, Canada shows, spring meltwater can provide for some dramatic viewing for visiting tourists.
Back to: Water cycle: Snowmelt runoff to rivers
Credit: http://www.rocky-peak.com/