The proportionate amount of surface area that can be paved in Floridan aquifer recharge areas in east-central Florida without reducing the net recharge to the Floridan aquifer is a function of many variables that include rainfall, depth to water table, depth to potentiometric surface of the Floridan, evaporation from paved areas, evapotranspiration from unpaved areas, runoff, pattern of paving, and leakance coefficient of the confining beds. Equations that incorporate those variables, except pattern of paving, are developed and coupled to produce a conceptual model that estimates relative amounts of water available for recharge and percentage of unpaved area below which Floridan aquifer recharge rates must increase. The model is not intended to be used as a basis for engineering design. Rather, its purpose is to show approximate mathematical interrelations of rainfall, runoff, evapotranspiration, percentage of paving, and Floridan aquifer recharge, and to make quantitative estimates of amounts of water available for Floridan aquifer recharge before and after paving. The allowable percentage of paving calculated in four examples ranges from 86.8 percent to 3.6 percent. (Woodard-USGS)
