Model Status Update February 03, 2016 Agenda Land Surface - PowerPoint PPT Presentation

Model Status Update February 03, 2016

Agenda  Land Surface Elevation Updates  Baseflows  Latest Model Results  Model Calibration Status  Water Supply Plan Model Scenarios  Next Steps  Public Input

Progress-to-Date  Model construction and Initial calibration  Water use geodatabase and withdrawals  Return flow methodology and quantities  Hydrologic boundary condition  Land surface elevation update  Baseflow Reviews

Major Reasons for Delay  Land Surface Elevation Update  Baseflow Improvements  More Quality Assurance Checks

Land Surface Elevation Updates  Three sets of data available for the entire model domain  USGS National Elevation Dataset (NED)  Used for initial model development  NASA Shuttle Radar Topography Mission (SRTM)  Considered but not used  USGS 3D elevation Program (3DEP)  Used for updating the model

USGS 3D Elevation Program  Bare earth ground readings  Supersedes NED  derived from the highest quality DEMs available

Before Land Surface Elevation Update • Errors in elevation dataset led to erroneous simulated flooding in some areas

After Land Surface Elevation Update

River Package/Baseflows  Estimated baseflows exceeding total flows  Estimated stages vs Observed stages

Est 2001 Baseflow = 1124 cfs 2001 Total Obs flow = 750 cfs Dashed Green: Simulated Total Flow Solid Blue: Observed Total Flow 2001

Est 2001 Baseflow = 216 cfs 2001 Total Obs flow = 106 cfs Dashed Green: Simulated Total Flow Solid Blue: Observed Total Flow 2001

Est 2001 Baseflow = 149 cfs 2001 Total Obs flow = 70 cfs Dashed Green: Simulated Total Flow Solid Blue: Observed Total Flow 2001

River Package/Baseflow Updates  Baseflow Update  Post-processing  Ratio approach  Hydrograph Separation  Update with observed river stages  Mostly Georgia rivers

Latest Model Results

SAS Water Levels

UFA Water Levels

LFA Water Levels

Vertical WL Differences

Springs

Baseflows

Calibration Statistics Statistical Criterion Proposed Target Percent 2001 2009 Both -5 feet < Mean Residual < 5 feet 80% 76% 78% 80% -2.5 feet < Mean Residual < 2.5 feet 50% 46% 52% 54% Mean Absolute Residual < 5 feet 80% 80% Mean Absolute Residual < 2.5 feet 50% 50% Root Mean Square of Errors < 5 feet 80% 79%

Water Supply Plan Scenarios  2009 reference year  Projected water use  Pumps-off

Model Status  HSPF Models  Calibration of models with ag and non-ag irrigation, RIBS, spray fields, golf courses, and septic field seepage completed  Groundwater Model  Updates and Refinement in progress

Next Steps  PEST Calibration (2001 and 2009)  Technical Team Review  Model Scenarios

Upcoming Meetings  Technical Team Meetings  March, 2016  Steering Team Meeting  February, 2016

Public Input