Hydrologic sections through Lee County and adjacent areas of Hendry and Collier counties, Florida

Most of the freshwater underlying Lee, western Hendry, and northern Collier Counties (fig. 1) occurs within the uppermost 400 feet of sediments which comprise the marine terrace sands, Fort Thompson Formation, Caloosahatchee Formation, Tamiami Formation, and part of the Hawthorn Formation. Although all these sediments contain water, they may be divided into those which yield water to wells (aquifers) and those which yield little to no water to wells (confining beds.) The aquifers are composed of permeable materials including sand, sandstone, limestone, or combinations of these sediments. The confining beds of of low permeability and usually consists of fine-grained materials, such as clay or marl or mixtures of these sediments with sand, sandstone, or limestone. Thus, limestone usually yields water to wells, whereas marly limestone does not.