The southeastern United States was modeled to produce historical and potential future simulations of streamflow statistics using the Precipitation Runoff Modeling System (PRMS) as part of the study documented in LaFontaine and others (2019). Hydrologic simulations using one observation-based historical climate dataset (Maurer and others, 2002), 13 used historical climate simulations using statistically downscaled general circulation model (GCM) output from the Coupled Model Intercomparison Project (CMIP5), and 45 used potential future climate simulations using statistically downscaled CMIP5 GCMs for four representative concentration pathways were used for the computation of 52 hydrologic statistics of streamflow using output data files from each simulation. Output files for the simulations include: 1) historical annual values of each statistic for each HRU and stream segment for the period 1952-2010 for the observation-based simulation, 1952-2005 for the 13 GCM-based historical simulations, and 2045-2075 for the 45 GCM-based future simulations, 2) PRMS summary output files with daily time step basin-averaged output variables for the period 1950-2010 for the observation-based simulation, 1950-2005 for the 13 GCM-based historical simulations, and 2006-2099 for the 45 GCM-based future simulations. The first year of the PRMS summary output files should be ignored due to model initiation. LaFontaine, J.H., Hart, R.M., Hay, L.E., Farmer, W.H., Bock, A.R., Viger, R.J., Markstrom, S.L., Regan, R.S., and Driscoll, J.M., 2019, Simulation of Water Availability in the Southeastern United States for Historical and Potential Future Climate and Land-Cover Conditions: U.S. Geological Survey Scientific Investigations Report, 2019-5039, 83 p., https://doi.org/10.3133/sir20195039. Maurer, E.P., Wood, A.W., Adam, J.C., Lettenmaier, D.P., and Nijssen, B., 2002, A long-term hydrologically based dataset of land surface fluxes and states for the conterminous United States: Journal of Climate, v. 15, no. 22, p. 3237–3251, accessed September 24, 2017, at https://doi.org/10.1175/1520-0442(2002)015<3237:ALTHBD>2.0.CO;2.