A three-dimensional MODFLOW-NWT groundwater flow model was developed to evaluate the impacts of alternative water management scenarios on the groundwater resources of Eagle, Dayton, and Churchill Valleys, Nevada. In addition, the resulting impact on flows in the Carson River and Lahontan Reservoir are also evaluated. During the economic boom that occurred from 2004-2006 in northwestern Nevada, municipal and housing growth increased stress on the limited water resources of this semi-arid region. In 2008, when the economy slowed, new housing development stopped, and immediate pressure on finite groundwater resources abated. In anticipation of economic recovery and resumed growth, however, the U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation, began a hydrogeologic study of the middle Carson River Basin. The three-dimensional, transient numerical model of groundwater and surface-water flow for the middle Carson River Basin extending from Eagle Valley to Churchill Valley was developed as part of this project. This model was used to evaluate the potential effects of three alternative water-management scenarios, and variations of the scenarios, on groundwater storage within the aquifer system and impact on river flows. Information from the model can provide a basis for basin-wide investigations seeking to quantitatively evaluate the effects of climate change or yet-to-be-determined alternative management strategies. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20235008).