While many rock layers appear to be perfectly horizontal, most have a slight incline, or dip. Ground water moves downdip, along the contact of the permeable and less permeable rock, until it reaches a location where erosion exposes the rocks to the atmosphere, such as a stream valley or hillside, creating an outlet for the water to move onto the land. Gravity moves infiltrating water downward and then laterally in the downdip direction on top of the less permeable rock layer. The contact spring model works well in consolidated rocks such as limestone, sandstone, and shale that are common in Kansas. The layering that is typical of these rocks makes it easier to understand the mechanisms that create the springs.
Contact springs can also occur in unconsolidated material, such as sand and gravel.
Most Kansas springs are gravity springs, where water flows to the surface by the action of gravity, as at contact springs. However, in a few of the state's springs, water is forced to the surface by artesian pressure. Under artesian conditions, the pressure in an artesian aquifer is greater than the pressure at the land surface. Artesian springs were more common in the state before heavy pumping lowered the water table and lessened the pressure that might have created artesian conditions. Water under artesian pressure rises to the land surface.