EAA Groundwater Modeling Initiatives

Presented to: National Academy of Sciences National Research Council Committee Presented by: Geary M. Schindel Chief Technical Officer Aquifer Sciences – Program Manager Edwards Aquifer Authority

Groundwater Modeling Initiatives (1999) • < 1999 Edwards Aquifer models produced by US Geological Survey (USGS), Edwards Aquifer Research Data Center (EARDC), and Texas Water Development Board (TWBD) (GWSIM IV) • Optimization Technical Studies Report (May 1999) – Model development one of 17 research initiatives

Groundwater Modeling Initiatives (1999) • USGS and TBEG selected as contractor • EAA, Department of Defense (DOD), San Antonio Water Systems (SAWS), and USGS were funding partners • Formed Groundwater Modeling Advisory Panel (GMAP) to provide oversight to contractors • MODFLOW groundwater modeling software selected

Groundwater Modeling Initiatives (1999 – 2004) • GMAP composed of representatives from EAA, SAWS, TWDB, Southwest Research Institute (SWRI), DOD, two outside karst scientists and four consultants • Oversight and guidance to USGS and Texas Bureau Economic Geology (BEG) – How to model convergent/turbulent flow system using a laminar flow model – No good numerical models for karst – Recharge, dry cells, springs, faults, etc.

Groundwater Modeling Initiatives (1999 – 2004) • Model to be used for: – Demand Management/Critical Period Management Issues – Enhanced recharge evaluations – Evaluation of aquifer cap issues • HCP • ASR • Spring Augmentation • Recharge and Recirculation

Groundwater Modeling Initiatives (2004) • USGS MODFLOW model completed in 2004. – Management modules

Groundwater Modeling Initiatives (2011) • 2011 Groundwater Model Initiative – Improve confidence in modeling efforts – Provide additional research tool – Improve model resolutions • MODFLOW – Verification and post audit process • Finite Element initiative

Groundwater Modeling Initiatives (2012) • Finite Element initiative – March 2012 • SWRI Contractor Selected • Groundwater Model Review Panel formed – Martin Saar – Neven Kresic – Bill Hutchison – James Beach (appointed by SAWS)

Groundwater Modeling Initiatives (2011 – 2014) • MODFLOW model updates initiated – Data Set updates (2001 – 2009) – Model Verification process – Post Audit

Groundwater Modeling Initiatives (2014) • Two current EAA modeling initiatives – MODFLOW Post Audit Updates – Finite Element Model – Both to be completed by December 2014 • EAA Modeling efforts are a “continuous improvement process”