IN 2014 THE CALIFORNIA LEGISLATURE PASSED THE SUSTAINABLE GROUNDWATER MANAGEMENT ACT (SGMA). LOCAL AGENCIES REFERRED TO AS GROUNDWATER SUSTAINABILITY AGENCIES (GSAS) ARE RESPONSIBLE FOR ACHIEVING SUSTAINABILITY WITH PLANS DUE IN 2020 OR 2022. DECIDING ON THE ACTIONS THAT ARE OPTIMAL FOR ACHIEVING SUSTAINABLE GROUNDWATER MANAGEMENT IS A CHALLENGE. THE DECISION-MAKING ACTIVITY TO BE ENHANCED THROUGH THIS PROJECT IS THE DEVELOPMENT OF THE GROUNDWATER MODEL. THIS IS A KEY DECISION-MAKING ACTIVITY AS IT PROVIDES THE MODELING TOOLS REQUIRED TO PREDICT AND ASSESS CHANGING CONDITIONS AND THE OUTCOMES OF POSSIBLE ALTERNATE WATER MANAGEMENT ACTIONS; SO IS THUS THE FOUNDATION ON WHICH TO BUILD EFFECTIVE GROUNDWATER MANAGEMENT. ENHANCING THIS DECISION-MAKING ACTIVITY DIRECTLY SUPPORTS DECISION-MAKING WITHIN THE GSAS AND THE GOALS OF THE CALIFORNIA DEPARTMENT OF WATER RESOURCES (DWR) AND THE STATE WATER RESOURCES CONTROL BOARD RELATED TO GROUNDWATER MANAGEMENT. THE GENERAL GEOGRAPHIC AREA OF INTEREST IS THE CENTRAL VALLEY OF CALIFORNIA. THIS IS AN IDEAL AREA FOR OUR STUDY GIVEN THE ENORMOUS GROUNDWATER MANAGEMENT CHALLENGES AND ALLOWS US TO LEVERAGE ONGOING WORK AND ESTABLISHED RELATIONSHIPS AT THE STATE AND LOCAL LEVELS. WE ARE PARTNERING AT THE STATE LEVEL WITH DWR AND THE STATE WATER BOARD AND AT THE LOCAL LEVEL WITH THE GSA OF BUTTE COUNTY AND THREE GSAS IN THE KAWEAH BASIN. WE WILL TAKE AS OUR STARTING MODELS THE CENTRAL VALLEY HYDROLOGIC MODEL (CVHM) DEVELOPED BY THE U.S. GEOLOGICAL SURVEY AND THE UPDATED VERSION SPECIFIC TO THE KAWEAH BASIN REFERRED TO AS THE KAWEAH MODEL. THE CVHM IS A NUMERICAL MODEL THAT ACCOUNTS FOR INTEGRATED VARIABLE WATER SUPPLY AND DEMAND AND SIMULATES SURFACE-WATER AND GROUNDWATER FLOW AND SUBSIDENCE ACROSS THE CENTRAL VALLEY AQUIFER SYSTEM ON A MONTHLY BASIS. WE WILL WORK WITH THE CVHM AND THE KAWEAH MODEL TO SIGNIFICANTLY IMPROVE THE SPATIAL RESOLUTION OF THE MODELS AND THE QUALITY OF THE DATA IN THE DEPTH RANGE OF 100 TO 500 M THUS IMPROVING THE USEFULNESS AND ACCURACY OF MODEL PREDICTIONS FOR GROUNDWATER MANAGEMENT AT THE SCALE OF THE GSAS. WE WILL TAKE AN INNOVATIVE APPROACH TO ACQUIRING THE INPUT DATA NEEDED FOR THE IMPROVED MODELS INTEGRATING INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR) DATA AND AIRBORNE ELECTROMAGNETIC (AEM) DATA TWO DATA TYPES WHICH CONTAIN COMPLEMENTARY INFORMATION ABOUT THE COMPOSITION AND HYDROLOGIC AND GEO-MECHANICAL PROPERTIES OF THE SUBSURFACE. THE INVERSION FRAMEWORK THAT WE WILL ADOPT TAKES AS INPUT THE INSAR DEFORMATION TIME SERIES AND THE HYDRO-STRATIGRAPHIC MODEL DERIVED FROM THE AEM DATA. IT WILL PROVIDE US WITH ESTIMATES OF VERTICAL AND HORIZONTAL HYDRAULIC CONDUCTIVITY POROSITY SPECIFIC YIELD AND SPECIFIC STORAGE UNDER ELASTIC AND INELASTIC CONDITIONS AT THE SCALE OF THE AEM DATA. THESE PARAMETERS WILL BE INCORPORATED INTO THE GROUNDWATER MODELS ALLOWING WATER MANAGERS TO ASSESS THE IMPACT OF CHANGING CONDITIONS AND ALTERNATE MANAGEMENT ACTIONS ON BOTH HEAD LEVELS AND LAND SUBSIDENCE. AN ESSENTIAL COMPONENT OF THIS PROJECT IS ENSURING THE ADOPTION OF THE DEVELOPED MODELS AND THE APPROACH TO MODEL DEVELOPMENT. WE WILL WORK CLOSELY WITH THE GSAS TO ENSURE THAT THE PRODUCTS OF OUR RESEARCH MEET THE LOCAL WATER MANAGEMENT NEEDS. IN BOTH STUDY AREAS THERE IS A COMMITMENT TO PROVIDING THE STAFF TIME REQUIRED TO FACILITATE THE ADOPTION OF THE MODELS AND MODELING APPROACH AND A FINANCIAL COMMITMENT TO ASSIST WITH THE COSTS OF ACQUIRING THE AEM DATA. WHILE WE ARE DEVELOPING TESTING AND DEMONSTRATING THIS NOVEL APPROACH TO GROUNDWATER MODEL DEVELOPMENT WITH FOUR GSAS THERE IS STRONG SUPPORT FOR THIS WORK AT THE STATE LEVEL IN THE AGENCIES ULTIMATELY RESPONSIBLE FOR SGMA OVERSIGHT AND TECHNICAL ASSISTANCE. OUR APPROACH WILL COMBINE INSAR DATA WITH AIRBORNE GEOPHYSICAL DATA TO DEVELOP GROUNDWATER MODELS WITH THE QUALITY OF DATA (RESOLUTION AND DEPTH) NEEDED TO MEET THE CHALLENGE OF SUSTAINABLE GROUNDWATER MANAGEMENT. .