Stream sampling was conducted in the Whitemans Creek watershed in February 2012 to assess water quality during winter baseflow conditions. A total of 30 stream sites were sampled where streams in the watershed intersected roadways. In addition to conventional water quality parameters (e.g., major anions, major cations, ammonium, soluble reactive phosphorus, alkalinity, dissolved organic carbon), stable isotopes of nitrate and sulfate were analyzed to provide insights into the sources of these compounds in the streams. Select artificial sweeteners (acesulfame, cyclamate, saccharin, sucralose) and anionic herbicides (glyphosate, AMPA, 2,4-D, glufosinate, fosamine, MCPA, picloram) were also measured as novel tracers of certain anthropogenic activities that potentially impact water quality. These data, as well as information on the sampling and analytical methods used, and interpretation of the data, are presented in the report, Water quality snapshot of Whitemans Creek during winter baseflow conditions (https://open-science.canada.ca/items/a9626ada-8a8c-4647-9e02-7efc19c9779a).