Simulation of Runoff and Water Quality for 1990 and 2008 Land-Use Conditions in the Reedy Creek Watershed, East-Central Florida U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 02-4018 Prepared in cooperation with the Reedy Creek Improvement District Cover photographs by Eddie Snell, Reedy Creek Improvement District, Florida. Simulation of Runoff and Water Quality for 1990 and 2008 Land-Use Conditions in the Reedy Creek Watershed, East-Central Florida By Shaun M. Wicklein and Donna M. Schiffer U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 02–4018 Prepared in cooperation with the Reedy Creek Improvement District Tallahassee, Florida 2002 U.S. DEPARTMENT OF THE INTERIOR GALE A. NORTON, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, 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 write to: Copies of this report can be purchased from: District Chief U.S. Geological Survey, WRD U.S. Geological Survey Suite 3015 Branch of Information Services 227 North Bronough Street Box 25286 Tallahassee, FL 32301 Denver, CO 80225-0286 Additional information about water resources in Florida is available on the Internet at http://fl.water.usgs.gov CONTENTS Abstract.................................................................................................................................................................................. 1 Introduction ........................................................................................................................................................................... 2 Purpose and Scope....................................................................................................................................................... 2 Previous Investigations................................................................................................................................................ 4 Acknowledgements ..................................................................................................................................................... 4 Description of Study Area ........................................................................................................................................... 4 Study Approach ........................................................................................................................................................... 7 Simulation of Hydrology and Water Quality......................................................................................................................... 8 Data Collection and Compilation ................................................................................................................................ 11 Spatial Data........................................................................................................................................................ 11 Time Series Data................................................................................................................................................ 11 Model Development .................................................................................................................................................... 17 Hydrologic Model Calibration..................................................................................................................................... 22 Hydrologic Model Confirmation................................................................................................................................. 26 Water-Quality Model Calibration ................................................................................................................................ 31 Future Land-Use Scenario Simulation .................................................................................................................................. 47 Scenario Development................................................................................................................................................. 47 Hydrology.................................................................................................................................................................... 49 Water Quality............................................................................................................................................................... 51 Water-Quality Loads.................................................................................................................................................... 54 Summary................................................................................................................................................................................ 57 Selected References............................................................................................................................................................... 59 FIGURES 1. Map showing location of study area........................................................................................................................ 3 2. Map showing sub-watersheds and data collection sites in the Reedy Creek watershed, Florida............................ 5 3. Diagram showing Hydrological Simulation Program-Fortran flowchart for (a) impervious and (b) pervious land segments...................................................................................................................................... 9 4. Map showing meteorologic and atmospheric deposition sites, and rainfall sites and Thiessen polygons used for the Hydrological Simulation Program-Fortran model of the Reedy Creek watershed, Florida................ 13 5. Graph showing relations between (a) discharge and stage and (b) regression residuals and stage for Bonnet Creek near Kissimmee, Florida............................................................................................................. 16 6-8. Maps showing: 6. Land use in the Reedy Creek watershed, Florida, used in the 1990-95 hydrologic and water- quality simulations........................................................................................................................................... 18 7. Distribution of land segments in the Reedy Creek watershed, Florida ........................................................... 20 8. Surface-water reach network used in the Reedy Creek watershed, Florida .................................................... 21 9-39. Graphs showing: 9. Observed and simulated monthly mean discharge values at Whittenhorse Creek near Vineland, Florida ..... 25 10. Discharge duration curves for observed and simulated daily mean values at Whittenhorse Creek near Vineland, Florida ............................................................................................................................................. 25 11. Observed and simulated monthly mean discharge values at Davenport Creek near Loughman, Florida ....... 27 12. Discharge duration curves for observed and simulated daily mean values at Davenport Creek near Loughman, Florida........................................................................................................................................... 27 13. Observed and simulated monthly mean discharge values at Reedy Creek near Vineland, Florida................. 29 14. Discharge duration curves for observed and simulated daily mean values at Reedy Creek near Vineland, Florida ............................................................................................................................................. 29 Contents III 15. Observed and simulated monthly mean discharge values at Bonnet Creek near Vineland, Florida............... 30 16. Discharge duration curves for observed and simulated daily mean values at Bonnet Creek near Vineland, Florida............................................................................................................................................. 30 17. Observed and simulated monthly mean discharge values at Reedy Creek near Loughman, Florida ............. 32 18. Discharge duration curves for observed and simulated daily mean values at Reedy Creek near Loughman, Florida.......................................................................................................................................... 32 19. Simulated and observed daily mean dissolved oxygen concentration at Reedy Creek near Vineland, Florida ............................................................................................................................................................. 34 20. Simulated daily mean and observed periodic total phosphorus concentration values for Whittenhorse Creek near Vineland, Florida .......................................................................................................................... 36 21. Simulated daily mean and observed periodic phosphate concentration values for Whittenhorse Creek near Vineland, Florida .......................................................................................................................... 36 22. Simulated daily mean and observed periodic ammonia nitrogen concentration values for Whittenhorse Creek near Vineland, Florida.................................................................................................... 37 23. Simulated daily mean and observed