Steps to Reproduce: We compiled a combination of hydrological and biogeochemical data from 12 streams of the KCS regular monitoring program for the period of 2008-2019 available at https://data.krycklan.se/. Stream water levels were continuously measured using automatic stage loggers at all sites and discharge was estimated using site-specific rating curves. Rating curves were created from salt dilution velocity-area, and time-volume flow measurements covering most of the observed flow range (Karlsen, Grabs, et al. 2016). For nutrient analysis, all samples were collected in acid-washed high-density polyethylene (HDPE) bottles, stored in cold conditions and filtered (0.45 µm) in the lab within 24-72 hours. Filtered subsamples were frozen (-20°C) immediately after subsampling and stored for later analysis of NO3-N, NH4-N, and PO4-P, samples for DOC and TDN were refrigerated (+4°C) and analyzed within 10 days after field collection. The analytical methods for DOC, TDN, NO3- and NH4+ have been described in detail by Blackburn, et.al., (2017). Dissolved inorganic nitrogen (DIN) was calculated as the sum of NO3 (including nitrite) and NH4, while dissolved organic nitrogen (DON) was calculated as the difference between TDN and DIN. Dissolved inorganic phosphorus (DIP) was analyzed as PO4 on a Seal Analytical Autoanalyzer 3 HR using method G-297-03.

This dataset DB.KCS.Q&Nut comprises all data for discharge (l/s) and nutrient concentration: DOC (ppm), TDN (ppm), DIN (ppb), NO3 (ppb), NH4 (ppb) and PO4 (ppb) for 12 streams of the Kryclan Catchment Study for the period of 2008-2019 used in the manuscript: "Concentration-discharge patterns reveal catchment controls over the stoichiometry of carbon and nutrient supply to boreal streams", to be submitted to a scientific journal shortly after the publication date of this dataset.