MODFLOW-2000 model used to evaluate potential effects of existing and proposed groundwater withdrawals on water levels and natural groundwater discharge in Snake Valley and surrounding areas, Utah and Nevada

A previously developed three-dimensional steady-state numerical groundwater-flow model was modified to transient conditions with respect to well withdrawals, and used to simulate drawdown and capture of natural discharge from existing and proposed groundwater withdrawals in Snake Valley and adjacent areas in western Utah and eastern Nevada. The original steady-state model simulates and was calibrated to 2009 conditions and was used as the first stress period in this transient model. Six transient stress periods, spanning 2010-2114, were added to the model to assess timing of the potential withdrawal effects. A seventh steady-state stress period was also added to determine the ultimate long-term effects of the well withdrawals. To investigate the potential effects of existing and proposed future groundwater withdrawals, 10 withdrawal scenarios were run. All scenarios were run at 5, 10, 15, 30, 55, and 105 years from the start of 2010; additionally, all scenarios were run to a new steady state to determine the ultimate long-term effects of the withdrawals. Capture maps run to the new steady state were also constructed as part of this analysis. 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/ofr20171026).