MODFLOW-NWT model used to assess historical and future trends in groundwater availability in the Trinity River alluvium aquifer, Texas

The U.S. Geological Survey, in cooperation with the Trinity River Authority, the Tarrant Regional Water District, the City of Dallas, and the North Texas Municipal Water District, constructed a finite-difference numerical groundwater-flow model of the Trinity River alluvium aquifer using MODFLOW with the Newton formulation solver (MODFLOW-NWT). This model, along with a surface water model and an analysis of long-term trends in water availability, was developed as a component of the Trinity River Basin Integrated Water Availability Assessment to evaluate future conditions under different global climate models. Thirty-three simulations are included in this data release, including one for the calibrated model, one forward run of the historical climate data, thirty scenario simulations to evaluate the global climate model, and one scenario simulation to evaluate local trends. The historical numerical model was temporally discretized into one initial steady-state stress period to equilibrate in 1949 and 69 annual transient stress periods representing the period 1950-2018. Conversely, the future model projections were temporally discretized into one initial steady-state stress period to equilibrate in 2018 and 69 annual transient stress periods representing the period 2019-2087. Soil-Water-Balance was also used during the modeling process to generate input data for the MODFLOW model. This U.S. Geological Survey data release contains all of the input and output files for the simulations described in the associated model documentation publication (https://doi.org/10.21423/twj.v14i1.7146).