The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by a middle confining unit. The middle confining unit and the Lower Floridan aquifer generally contain highly mineralized water. In most reports on the hydrology of southwest Florida, the term "Floridan aquifer" has been applied to the water-bearing rocks, herin referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is a productive aquifer and supplies more than 10 times the amount of water pumped from either the surfical aquifer system of the intermediate aquifer system in most of the study area (Duerr and other, 1988). 

This map report depicts the potentiometric surface of the Upper Floridan aquifer in May 1995. The potentipmetric surface represents to the level to which water will rise in tightly cased wells that tap a confined aquifer system. The surface is mapped by determining the altitude of water levels in a network of wells and is represented on maps by contours that connect point of equal altitude. This map represents water-level conditions near the end of the dry season when ground-water withdrawals for agricultural use are usually high. The cumulative rainfall for the study area was 2.98 inches above average for the period from June 1994 through May 1995 (Southwest Florida Water Management District, 1995)