BULLETIN NO. 68


 HYDROGEOLOGIC FRAMEWORK OF THE SOUTHWEST
 FLORIDA WATER MANAGEMENT DISTRICT


 By Jonathan D. Arthur, (P.G. #1149), Cindy Fischler (P.G. #2512), Clint Kromhout (P.G. #2522),
 James M. Clayton, (P.G. #381), G. Michael Kelley (P.G. #249), Richard A. Lee (P.G. #956), Li Li,
Mike O'Sullivan (P.G. #2468), Richard C. Green (P.G. #1776), and Christopher L. Werner (P.G. #2366)


 INTRODUCTION

 Background

 Groundwater comprises approximately 85
percent of the total water-resource supply in the
Southwest Florida Water Management District
(SWFWMD), where existing water demands are
on the order of 435 billion gallons per year
(Southwest Florida Water Management District,
2006a). By 2025, the population of the region is
expected to increase more than 30 percent,
placing further demands on water resources.
Development of alternative water supplies and
continued water-resource management and
conservation are critically important toward the
sustainability of groundwater resources within
the aquifer systems of southwest Florida. These
practices, however, require the accumulation,
management and interpretation of
hydrogeological data.

 In the mid-1990's, the SWFWMD and the
Florida Department of Environmental Protection
- Florida Geological Survey (FDEP-FGS)
entered into a cooperative project to develop a
series of geologic and hydrogeologic cross
sections throughout the 16-county SWFWMD
region. The project was designed to characterize
the relation and extent of lithostratigraphic1 and


hydrostratigraphic2 units within the region with
an emphasis on use of hydrogeologic data
collected by the District's Regional Observation
and Monitor-well Program (ROMP). This project
was later expanded to include production of
surface and thickness maps of the units
represented in the cross sections.

 To accomplish the goal of the regional cross
section project, the District was divided into four
study areas (three project phases): Phase IA
includes Pinellas and Hillsborough Counties;
Phase IB includes Manatee, Sarasota, Hardee,
DeSoto and Charlotte Counties; Phase II includes
the northern part of the District, from Levy,
Marion and Lake to Pasco Counties; and Phase
III includes the southeastern part of the District,
encompassing all areas not covered in Phases IA,
IB and II. Interim reports were published for
Phase IA and II (Green et al., 1995 and Arthur et
al., 2001a, respectively). Rather than separately
publishing reports for the remaining phases, the
cross sections are incorporated in this report.

Purpose and Scope

 The purpose of this study is to refine the
hydrogeological framework of the region to
facilitate science-based decision making with
regard to the protection, conservation and
management of southwest Florida's water


1 Lithostratigraphic units are laterally extensive
sequences of rocks and sediments reflecting unique
lithologic characteristics; each unit was deposited
within a generally similar paleo-environment during
a given period of time in Earth's history.


2 Hydrostratigraphic units include laterally extensive
sequences of rocks and sediments that are related by
hydrogeologic characteristics. Hydrostratigraphic
units may or may not correlate with lithostratigraphic
units.