Generalized Configuration of the Base of the Biscayne Aquifer in Broward County, USGS WRIR 87-4034, figure 37

The base of the Biscayne aquifer are shown in this map. The base is drawn on the bottom of highly permeable limestone or sandstone in the Tamiami Formation that is virtually contiguous with overlying rocks of very high permeability in the Fort Thompson Formation, Anastasia Formation, or Tamiami Formation. In general, the Biscayne aquifer is shallow, and the base deepens gradually in west and central Broward county. However, the aquifer thickens, and the base deepens very rapidly in the coastal area to more than 300 feet below sea level.