Model calibration and sensitivity analysis will be conducted using automated parameter-estimation methods. Preliminary modeling using existing data and model parameters developed by Frenzel (1991, 1992) will be used to begin to understand the hydrologic system from a modeling perspective. Numerical Groundwater-Flow Model - A steady-state numerical groundwater-flow model (MODFLOW-NWT Niswonger and others, 2011) will be constructed and calibrated to represent hydrologic processes in the Rio San Jose Basin. Daily streamflow values of Rio San Jose, as measured at USGS streamflow-gaging station 08343500 (1936 to 2015), will be used for calibration. Water-Budget Estimates - A daily water-budget model, Precipitation-Runoff Modeling System (PRMS Leavesley and others, 1983), will be used to generate water-budget component estimates. USGS staff will estimate current and historical domestic water use using census records, average per capita water use, and aerial photo analysis to assist in identifying exempt (unregulated) uses including lawn or non-commercial garden watering and small-scale industrial uses.

Water Use - Water-right and current/historical water-use information will be obtained from the New Mexico Office of the State Engineer and water purveyors located within the study area.

The map will provide insights about generalized groundwater-flow directions, horizontal and vertical water-level gradients, and the gaining/losing stream reaches. Potentiometric-Surface Map - A potentiometric-surface map will be constructed in the Rio San Jose Basin based on data collected during this study. Hydrogeologic Framework - The interpretation of the hydrogeologic framework of the Rio San Jose Basin will be based primarily on existing maps of surficial geology and the lithologic information from drillers’ logs. Hydrochemical data will be collected to define groundwater-flow paths and provide estimates of ages of water. Synoptic sets of streamflow measurements will be made during low-flow and high-flow conditions to delineate gaining/losing stream reaches, which will be used to calibrate the groundwater flow model. Hydrologic Data Collection – Groundwater-level and streamflow data will be collected, and a monthly groundwater-level monitoring network will be established. Rio San Jose, NM, NMWSC(Credit: Andrew Robertson, USGS New Mexico Water Science Center. Develop coupled groundwater/surface-water flow model (GSFLOW) to investigate aquifer-stream interactions, provide water budgets, and simulate effects of current and potential groundwater and surface-water management and changing climatic conditions.Construct hydrogeologic framework, potentiometric-surface maps, sources of recharge, groundwater flow paths, and groundwater/surface water exchange.Collect and compile hydrologic information, including groundwater-level measurements, streamflow data, well log information, and aqueous geochemical analysis.Upon completion of the study, the model will be transferred to the Pueblos of Acoma and Laguna and other stakeholders for continued assessment of management alternatives in the basin. During Phase 2, an integrated hydrologic flow model will be constructed and calibrated as a tool to simulate the flow system and potential effects of water-use and climate scenarios on groundwater and surface-water resources in the Rio San Jose Basin. During Phase 1, existing and new geologic, groundwater, surface-water, and hydrochemical data will be compiled and evaluated to characterize the flow system. The objectives will be met by conducting the study in two phases. The proposed work will provide a better understanding of the nation’s water-resources, assist the stakeholders in the Rio San Jose Basin in evaluating various water-management options, and support the USGS mission of disseminating water-resources information to the public.

This project will provide the Pueblos of Acoma and Laguna with quantified estimates of water availability and use in the Rio San Jose Basin and the ability to simulate the hydrologic effects of water-rights settlement options. Water Level Measurement, Rio San Jose, NMWSC(Credit: Andrew Robertson, USGS New Mexico Water Science Center.

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