Water Resources of Duval County, Florida By G.G. Phelps U.S. Geological Survey Water-Resources Investigations Report 93-4130 Prepared in cooperation with the City of Jacksonville, Florida Tallahassee, Florida 1994 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 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 Earth Science Information Center Suite 3015 Open-File Reports Section 227 N. Bronough Street Box 25286, MS 517 Tallahassee, FL 32301 Denver Federal Center Denver, CO 80225 II CONTENTS Contents Introduction ...............................................................................................................................................1 Purpose and Scope.....................................................................................................................................1 Study Area and Population........................................................................................................................2 Water Use in Duval County ......................................................................................................................4 The Hydrologic Cycle ...............................................................................................................................6 Climate ......................................................................................................................................................8 Temperature and Evaporation ...........................................................................................................8 Rainfall............................................................................................................................................10 Geology ...................................................................................................................................................12 Geologic History .............................................................................................................................12 Physiography...................................................................................................................................14 Terraces ...........................................................................................................................................16 Ground-Water Resources ........................................................................................................................18 General Concepts ............................................................................................................................18 Hydrogeologic Setting ............................................................................................................18 Ground-Water Occurrence......................................................................................................20 The Surficial Aquifer System and Intermediate Confining Unit ....................................................22 Lithology and Thickness.........................................................................................................22 Water-Table Unit and Wetlands .............................................................................................24 Limestone Unit........................................................................................................................26 Water Levels and Well Yields ................................................................................................28 Quality of Water .....................................................................................................................32 The Floridan Aquifer System..........................................................................................................34 Lithology and Thickness.........................................................................................................34 Recharge and Discharge .........................................................................................................36 Transmissivity and Well Yields..............................................................................................38 Potentiometric Surface............................................................................................................40 Quality of Water .....................................................................................................................44 Surface-Water Resources ........................................................................................................................48 Drainage Basins...............................................................................................................................48 Gaging Station Network..................................................................................................................50 Streamflow ......................................................................................................................................52 Duration of Flow.....................................................................................................................54 Flood Frequency .....................................................................................................................56 Flood-Prone Areas...........................................................................................................................58 St. Johns River.................................................................................................................................60 Quality of Surface Water.................................................................................................................62 Specific Conductance..............................................................................................................66 Chloride...................................................................................................................................68 Nutrients..................................................................................................................................70 Availability of Additional Information ...................................................................................................72 References ...............................................................................................................................................74 Contents III FIGURES Water Resources of Duval County, Florida 1. Map showing location of Duval County, Florida......................................................................... 3 2. Graph showing total freshwater use in Duval County, 1965-90 .................................................. 5 3. The hydrologic cycle in Duval County......................................................................................... 7 4-8. Graphs showing: 4. Average minimum, average maximum, and average monthly temperatures in Jacksonville, 1951-80 ............................................................................................................ 9 5. Monthly pan evaporation in Gainesville, 1988...................................................................... 9 6. Minimum, average, and maximum monthly rainfall in Jacksonville, 1951-80................... 11 7. Rainfall above and below the average annual rainfall in Jacksonville, 1852-1989............. 11 8. Cumulative departure from average rainfall in Jacksonville, 1867-1981............................ 11 9-11. Maps showing: 9. The Florida Platform and its relation to the Appalachian Mountains ................................. 13 10. Physiographic subdivisions of Duval County ..................................................................... 15 11. Terraces of Duval County.................................................................................................... 17 12. Section showing relation of geologic and hydrologic units in Duval County............................ 19 13. Generalized section of an aquifer ............................................................................................... 21 14-16. Maps showing: 14. Thickness of sediments overlying the Floridan aquifer system in Duval County............... 23 15. Wetlands of Duval County .................................................................................................. 25 16. Altitude of the top of the limestone unit of the surficial aquifer system ............................. 27 17. Graphs showing water level in a well completed in the limestone unit, and daily rainfall at the Naval Air Station, Jacksonville, 1968............................................................................... 29 18-21. Maps showing: 18. Aquifer test sites of the surficial aquifer system in Duval County...................................... 31 19. Generalized distribution of chloride concentration in water from the surficial aquifer system .................................................................................................................................. 33 20. Altitude of the top of the Floridan aquifer system............................................................... 35 21. Approximate extent of natural recharge and discharge areas of the Floridan aquifer system in Duval