Texas A&M University-Corpus Christi (TAMU-CC) will conduct a study to advance understanding of groundwater inflows and nutrient transport to bay systems in South Texas for improved Environmental Flow recommendations and nutrient criteria. TAMU-CC will accomplish this by explicitly incorporating groundwater discharge into the freshwater inflow needs and nutrient budgets. The objectives are to: map groundwater discharge and groundwater-surface water interaction zones; quantify the spatial-temporal distribution of groundwater and surface water contaminant (nutrients, organic matter) transport and discharge; evaluate nitrogen sources (i.e. anthropogenic vs. natural; agricultural vs. alternative); and evaluate the role of groundwater nutrients in system-wide nutrient budgets (i.e., inputs-outputs). To fulfill these objectives, TAMU-CC will quantify groundwater discharge on a seasonal basis to Aransas Mission Estuary and will quantify contaminants within the groundwater that may contribute to water quality degradation.