1. Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, May 1986 [cartographic material] Yale Public content 1986. 2002-06-01T04:00:00Z. 2023-10-31T03:01:37Z. Geological Survey (U.S.). The Survey ; Open-File Services Section [distributor]. English. cartographic image. Public. Florida.