Evaluation of baseflow separation methods with real and synthetic streamflow data from a watershed

•Performance of graphical & digital filter baseflow separation methods are compared.•Methods are compared using real data with a subjective concept of hydrologic plausibility.•Synthetic data from an integrated hydrologic model used for more rigorous assessments.•Estimated baseflow hydrographs reveal seasonal variability.•Filtered UKIH approach works best for most study locations but depends spatially.