1. Potentiometric surface of the upper Floridan aquifer, west-central Florida, May 1995 Yale Public content 1995. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; Copies can be purchased from Open-File Reports Section. English. Public. Florida and Floridan Aquifer.