Overview
General Water Resources Information
Sources of surface water and groundwater originate from precipitation in the form of rain and snow. Much of the precipitation runs off the landscape into streams and rivers or is retained by lakes and artificial retention dams. Some precipitation moves into the soil to recharge groundwater aquifers. A small amount of water stored deeper has originated from older precipitation. In the past, artesian wells tapped into the water from these deep sources and supplied water to many cities and towns as South Dakota was developing.
The geology of the landscape often controls the disposition of precipitation. In the eastern part of the state, much water can be stored in aquifers and in glacier lakes. Since precipitation is greatest in the eastern part of the state, most of the water resources of the state are located there. In the central and western part of the state, most of the stored water resources are in surface sources such as rivers and reservoirs.