This data release contains eight datasets and metadata related to streamwater constituent load estimation and E. coli bacteria concentration predictions at 15 watersheds in DeKalb County, Georgia for 2012 to 2016 (the water-quality model calibration data goes through 9/22/2017 and the water-quality assurance samples goes through 11/7/2017). Loads were estimated for 15 constituents: biochemical oxygen demand, chemical oxygen demand, total suspended solids, suspended sediment concentration, total nitrogen, total nitrate plus nitrite, total phosphorus, dissolved phosphorus, total organic carbon, total calcium, total magnesium, total copper, total lead, total zinc, and total dissolved solids. The data release includes the following eight datasets: (1) daily base-flow separation results that were used as explanatory variables in the load estimation models; (2) water-quality assurance sample concentrations; (3) laboratory standard reference sample concentrations; (4) water-quality outliers that were excluded from the calibration datasets used in regression models for estimating streamwater constituent loads and E. coli bacteria concentrations; (5) calibration datasets containing explanatory variables for modeling constituent loads; (6) model coefficients and model diagnostic statistics used to estimate streamwater constituent loads, including portable document format files (pdf) with reports and plots for evaluating model fits; (7) time-step data used for estimating loads from the model coefficients; and (8) annual and period of record streamwater constituent load and yield estimates, including the 95-percent confidence intervals of the estimates.