GEOHYDROLOGY OF THE CROSS- FLORIDA BARGE CANAL AREA WITH SPECIAL REFERENCE TO THE OCALA VICINITY By Glen L. Faulkner U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report I-73 Prepared in cooperation with: U.S. DEPARTMENT OF THE ARMY CORPS OF ENGINEERS Tallahassee, FL 1973 U.S. DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary U.S. GEOLOGICAL SURVEY Vincent E. McKelvey, Director The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. For additional information Copies of this report can be write to: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Branch of Information Services Suite 3015 Box 25286 227 N. Bronough Street Denver, CO 80225-0286 Tallahassee, FL 32301 800-ASK-USGS Additional information about water resources in Florida is available on the World Wide Web at http://fl.water.usgs.gov CONTENTS Preface............................................................................................................. ix Conclusions...................................................................................................... 1 Abstract ............................................................................................................ 4 Introduction....................................................................................................... 7 Purpose and scope..................................................................................... 7 Acknowledgments....................................................................................... 10 Previous investigations............................................................................... 11 The hydrologic monitoring program............................................................ 12 Description of area........................................................................................... 15 Location and extent..................................................................................... 15 Topography................................................................................................. 15 Climate........................................................................................................ 19 Rainfall................................................................................................... 19 Temperature.......................................................................................... 21 Winds..................................................................................................... 21 Humidity................................................................................................. 21 Sunshine................................................................................................ 21 Drainage ..................................................................................................... 21 Geology............................................................................................................ 24 General....................................................................................................... 29 Stratigraphy................................................................................................. 29 Pre-Cenozoic......................................................................................... 29 Early Tertiary ......................................................................................... 29 Late Tertiary .......................................................................................... 34 Contents iii Geology - Continued Quaternary............................................................................................. 38 Structure...................................................................................................... 39 Folding ................................................................................................... 39 Fracturing and faulting ...........................................................................40 Geomorphology........................................................................................... 48 Hydrology.......................................................................................................... 52 General........................................................................................................ 52 Surface water .............................................................................................. 53 Occurrence and movement ................................................................... 53 Quality of surface water ......................................................................... 54 Ground water............................................................................................... 55 General .................................................................................................. 55 The shallow aquifer................................................................................ 56 Distribution and extent...........................................................................56 Quality of water in the aquifer ................................................................ 57 The Floridan aquifer .................................................................................... 57 Character and distribution...................................................................... 57 Potentiometric surface of the aquifer ..................................................... 58 Characteristics of recharge to the aquifer .............................................. 61 Characteristics of water movement through the aquifer ........................69 Quality of water in the aquifer ................................................................ 78 iv Contents Hydrology - Continued Ground water - Continued Qualitative relationships of the Cross-Florida Barge Canal to the ground-water regime.............................................................................. 83 General............................................................................................. 83 Rodman Pool.................................................................................... 83 Eureka Pool ..................................................................................... 84 Inglis Pool......................................................................................... 87 Summit Pool..................................................................................... 90 Quantitative flow relationships between Summit Pool and Silver Springs drainage area .......................................................................... 92 General............................................................................................. 92 Flow-net analysis.............................................................................. 93 Static water level in Summit Pool..................................................... 98 Ground-water flow rate, Summit Pool to Silver Springs ................... 102 Effect of lockage on Summit Pool ....................................................105 Pollution in the Summit Pool. ...........................................................107 Special Survey of City of Ocala drainage well system........................... 110 Additional studies needed or considered ....................................................111 Geology.................................................................................................. 111 Hydrology............................................................................................... 111 References.................................................................................................. 113 Contents IV ILLUSTRATIONS 1. Index map of North Florida showing route of Cross-Florida Barge Canal, outlines of geohydrologic investigation areas, and monitoring network area 8 2. Profile along Cross-Florida Barge Canal from St. Johns River at Palatka to the Gulf of Mexico............................................................................................. 9 3. Index map to ground-water monitoring network stations, In Cross-Florida Barge Canal area ....................................................................................... 13 4. Physiographic divisions of Florida ................................................................ 16 5. Physiographic subdivisions of north Peninsular Florida ...............................18 6. Climatic divisions of Florida .......................................................................... 20 7. Drainage basins in north Peninsular Florida................................................. 23 8. Index map to major structural features of Florida which affect the area of the Cross-Florida Barge Canal......................................................................... 25 9. Geologic map of north Peninsular Florida showing rocks present at or near the surface of the ground..................................................................................27 10. Geologic section (X-X’) of north Peninsular Florida through area of Cross- Florida Barge Canal.................................................................................... 28 11. Description of stratigraphic section in area of Cross-Florida Barge Canal. 30 12. Isopach map of Cenozoic sediments in north Peninsular Florida .............. 31 13. Geologic map showing stratigraphic units at or near land surface, Cross-Flor- ida Barge Canal area..................................................................................33