The supplemental data presented here contains raster data in .tif format of the empirically estimated mean annual (1987-2015) net evapotranspiration (ETnet) for the Harney Basin Groundwater Evapotranspiration Area. The final mean annual ETnet estimate for the Harney Basin was determined using both empirical and physics-based methods. The final ETnet estimate was combined with additional data to estimate groundwater discharge through evapotranspiration (ET) in the Harney Basin. See Garcia and others (2022) for a detailed description of how these data were estimated and evaluated.