Hydrologic 4

Salem Plateau Summary (Imes and Emmett. 1993)- The Ozark Aquifer System consists of 9-21 layers of water bearing sandstone, dolomites and limestones. The Salem plateau aquifer is unconfined and under the Springfield Plateau it is confined. All of these layers rest on the St. François confining layer. What is ordinarily termed the Ozark Aquifer is also termed lower, middle, and upper to avoid confusion with the Springfield Plateau layers. Recharge can be direct by infiltration of rain to the water table. But this is also Karst country and in many places rain infiltrates through thin soil into karst along with surface runoff. The amount of porosity distributed as springs in the Salem Aquifer where karst is common is amazing. Contrary to popular belief, spring discharge (or some large fraction of it) is recent runoff or recent rain, and spring systems are sensitive to surface pollution. Missouri has few natural lakes with the exception oxbow lakes (which not all purists view as lakes). Losing streams have subsurface flow to other streams (and vice versa). The landscape has evolved through karst, spring, and stream interaction contemporaneously with other patches of landscape that are less karst and perhaps more of the classical soil infiltration, evapotranspiration, infiltration to the water table and gaining/losing streams watershed model. Both are illustrated in Figure 10. Figure 11 illustrates the occurrence of gaining and losing streams within the area of the Ozark Aquifer.