1. Model Status Update July 01, 2015

2. Agenda Purpose Model Development Update Model Calibration Status Next Steps Schedule Public Input

3. Purpose Inform stakeholders on status of model development Provide more detailed information on some of the model components Discuss next steps and timeline

4. Core Team Members Lead Groundwater Modelers Fatih Gordu, PE and Douglas Durden, PE (SJRWMD) Trey Grubbs (SRWMD) Lead Surface Water Modeler Tim Cera, PE (SJRWMD) PEST Calibration Expert John Doherty, PhD (Developer of PEST - Watermark Numerical Computing Pty. Ltd.)

5. Model Overview About 60,000 square miles (Probably largest gw model in the US) 5 times larger than NEF 6 times larger than ECFT 11 times larger than NCF MODFLOW-NWT 2500x2500 ft grid 7 layers HSPF models Steady-state calibration (2001 and 2009)

6. Model Layers

7. Lateral Boundary Conditions

8. Springs and Rivers GHB and River Package SRWMD HEC-RAS model St. Johns River SW Model

9. ET Extinction Depth (Modified from Shah et al., 2007) Extinction Depths (ft) under Forest Land Cover Soil TypeHydricPartly hydricNon-hydric sand4.99.814.8 loamy sand5.610.515.4 sandy loam7.512.517.4 sandy clay loam9.814.819.7 sandy clay10.215.120.0 loam12.016.921.8 silty clay14.319.224.1 clay loam16.621.526.4 silt loam16.921.826.9 silt17.422.327.2 silty clay loam18.023.027.9 clay23.628.533.5 Extinction Depths (ft) under Grass Land Cover Soil TypeHydricPartly hydricNon-hydric sand4.96.68.2 loamy sand5.67.28.9 sandy loam7.59.210.8 sandy clay loam9.811.513.1 sandy clay10.211.813.5 loam12.013.615.3 silty clay14.315.917.6 clay loam16.618.219.8 silt loam16.918.520.3 silt17.419.020.7 silty clay loam18.019.721.3 clay23.625.326.9

10. Calibration Target Wells Data Filling Types (2001, 2009, 2010) (1) Original data > 6 months (2) Filled data > 6 months (3) Filled second data > 6 months (4) PCA data > 6 months (5) Any data < 6 months

11. Model Development Update Water Use Data Updates Ag water use updates Technical team comments SWFWMD Comments Recharge Package HSPF/MODFLOW Interaction

12. Water Use Data RegionPS/CII/RecDSSAG FL Water Use SJRWMD/SRWMD/SWFWMD Permit Database Estimated by SJRWMD using parcel data and well construction database and SWFWMD Database SJRWMD/SRWMD/SWFWMD Permit Database Estimated by Balmoral Group using AFSIRS, USGS estimates and Metered/Reported water use GA Water Use Provided by USGS Estimated by GIS Associates using Census blocks and USGS estimates Estimated by Balmoral Group using AFSIRS and USGS estimates SC Water Use Estimated by GIS Associates using Census blocks and USGS estimates Estimated by Balmoral Group using AFSIRS and USGS estimates

13. Water Use Summary (MGD) (Draft – subject to change) YearRegionPS/CII/RecDSSAGTotal 2001 FL60486213902 GA/SC362418681272 Total96612710812174 2009 FL55486212853 GA/SC2984410761418 Total85213112882270 2010 FL55685202843 GA/SC302448101156 Total85812910111999

14. Well Package AE wells (Permitted Wells) Well coordinates are known Source aquifer is only one aquifer MNW package (Permitted Wells) Well coordinates are known Source aquifer is more than one aquifer and/or not identified in the database BC wells (Estimated water use) Well coordinates are unknown Water use estimated

15. Recharge Package – HSPF Models 54 USGS HUC 8 watersheds More than 1800 subbasins Rainfall and PET NLDAS (North American Land Data Assimilation System)

16. MODFLOW -HSPF Interaction Max ET rate for MODFLOW ET Package ( Remaining ET for Active groundwater) Recharge (AGWI + IGWI) Baseflow Sinks and Drainage Wells

17. HSPF Closed Basins Closed No other outlet Confined or semi-confined High recharge rate Closed with Sink or Drainage Wells Known sink or drainage wells in basin Closed with Transfer Down Gradient Unconfined All water expected to be active groundwater

18. HSPF MODIFICATIONS (Inactive Groundwater Storage Implementation to account for Groundwatershed )

19. ModelCalibration Status Model Initialization/Testing PEST (Parameter Estimation Tool) Calibration Process Observation Groups Parameters Groups

20. Model Initialization/Testing Testing Model Conceptualization Addressing model convergence issues Testing range of parameters Gaining more insight on groundwater flow system Developing information for PEST calibration Getting input from SWFWMD

21. PEST CALIBRATION

22. How does PEST work? STARTFINISH If Reached Min SSR: Sum of squared residuals

23. Observation Groups Observed Water Levels Vertical Head Differences (SAS/UFA and UFA/LFA) Horizontal Head Differences Temporal Head Differences (2009 – 2001) Springflows Baseflows (By segment and total) Wetting penalty Lake Leakages APT Transmissivities

24. Parameter Groups Hydraulic Conductivities (Pilot Points) Spring Conductances River/Lake Conductances Recharge Multipliers

25. Calibration Target Statistics (From Model Conceptualization Report)

26. Next Steps Complete Initial PEST Calibration (2001 and 2009) Initiate transient calibration process