This portion of the data release presents water column dissolved nutrient concentration data and water quality parameters from samples collected in the Elwha River estuary, Washington, in 2006, 2007, 2013, and 2014 (USGS Field Activities L-15-13-PS, L-24-13-PS, T-R5-13-PS, T-R6-13-PS, T-RA-14-PS, 2014-614-FA, 2014-628-FA, 2014-633-FA, 2014-666-FA). Water column samples were collected by hand in acid-washed opaque bottles from multiple locations. Water quality was measured using a handheld Hydolab Data Sonde 4a. The locations of water sample collections were determined with a hand-held global positioning system (GPS). The water samples were filtered through GF/F filters immediately after collection. The filtrate was collected in scintillation vials and frozen until analysis at either the University of Washington marine chemistry lab (2006 and 2007 samples) or the University of California Santa Barbara Marine Science Institute analytical lab (2013 and 2014 samples). Nutrient concentration and water quality data are provided in a comma-delimited spreadsheet (.csv).