Model Status Update July 01, 2015

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

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

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.)

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)

Model Layers

Lateral Boundary Conditions

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

ET Extinction Depth (Modified from Shah et al., 2007) Extinction Depths (ft) under Forest Land Cover Soil TypeHydricPartly hydricNon-hydric sand loamy sand sandy loam sandy clay loam sandy clay loam silty clay clay loam silt loam silt silty clay loam clay Extinction Depths (ft) under Grass Land Cover Soil TypeHydricPartly hydricNon-hydric sand loamy sand sandy loam sandy clay loam sandy clay loam silty clay clay loam silt loam silt silty clay loam clay

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

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

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

Water Use Summary (MGD) (Draft – subject to change) YearRegionPS/CII/RecDSSAGTotal 2001 FL GA/SC Total FL GA/SC Total FL GA/SC Total

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

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

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

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

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

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

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

PEST CALIBRATION

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

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

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

Calibration Target Statistics (From Model Conceptualization Report)

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