This dataset provides compiled and computed data from 1900 through 2017 associated with Streamflow statistics used to perform regional analyses for the Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity river basins. These seven river basins are mostly within Texas, but parts of some of the basins extend into New Mexico and Louisiana. Because changes in precipitation, temperature and groundwater levels can appreciably affect streamflow, understanding changes in streamflow requires taking these forcing variables into account. Long-term streamflow statistics for these seven river basins were derived by analyzing streamflow data and other observed climatological variables. Data include tables of accumulated surface-water storage data modified from the National Inventory of Dams (NID), (Table 1), delineation of State counties or parishes by study basin (Table 2), National Oceanic and Atmospheric Administration (NOAA) precipitation stations by study basin (Table 3), and daily mean precipitation data (Table 4). In addition to data collected in 188 counties in Texas, this data release includes data collected in 4 counties in New Mexico, and 1 parish in Louisiana. Data not included in this dataset include temperature and groundwater-level elevation data, which are referenced in the associated larger work citation.