Surface water and hyporheic porewater samples were collected at high frequency during the 2017-18 (01/20/2018-01/21/2018) and 2018-19 (01/10/2019-01/12/2019) flow seasons, and opportunistically throughout the 2019-20 flow season (12/17/2019-1/25/2020) from the lower reaches of Von Guerard Stream, Taylor Valley, McMurdo Dry Valleys, Antarctica. Porewater samples were collected using plastic tubing inserted to depths of 15 or 30 cm and drawn out by syringe. This data package includes sampling locations and water chemistry data (including concentrations for dissolved organic nitrogen species, dissolved organic carbon, silica, as well as water isotopes). A laboratory nitrification potential assay was performed on sediments collected from Von Guerard stream during the 2017-18 flow season to assess the functional microbial potential of the hyporheic microbial community to perform nitrification.