Florida is underlain by sedimentaryÊrock layers. Most sediments were deposited in the ocean and contain seawater trapped in the spaces between grains of sediment. Over the years, this salt water interacted chemically with some of the minerals present, so that pore water is now typically two to six times as salty as seawater. This highly saline water is called connate water. Connate water is encountered, typically, at depths of tens of meters to a few hundred meters.
Rainwater, falling on the ground surface, soaks in, in part, providing a thin layer of fresh water in the upper part of the stack of sedimentary rocks. This thin layer is called meteoric water. It overlies connate water. Water wells are drilled into meteoric water but not into connate water. On beaches and near-shore islands, a very thin layer of meteoric water overlies ocean water, which in turn overlies connate water.
Drainage depends on slope as well as rock type; if the surface is flat, water cannot run off very well, and if the rock has very few pores, water cannot soak in very well.
