These data include volume-weighted, average, monthly concentrations of cations, anions, and pH measured in Watershed 1. HBWatER is a long-term record of stream and precipitation chemistry and volume. Currently this record is supported by NSF LTREB funding (for sample collection and processing), USDA Forest Service (USFS) funding (for maintenance of stream gauges, analytical chemistry and sample archiving), and LTER (for disposable supplies). The HBWatER supervisory team currently includes Emma Rosi (Cary Institute of Ecosystem Studies), Emily Bernhardt (Duke University), John Campbell (USFS), Charley Driscoll (Syracuse University.), Mark Green (Case Western Reserve University), Bill McDowell (University of NH ), and Lindsey Rustad (USFS). The long-term hydrologic record and calculation of fluxes are currently supervised by John Campbell (USFS). The collection and management of the long-term chemistry record is currently supervised by Emma Rosi (Cary Institute of Ecosystem Studies) and Emily Bernhardt (Duke University). At present field samples are collected by Tammy Wooster (Cary Institute of Ecosystem Studies), Chemical analyses are performed by Jeff Merriam (USFS). Data management and archiving is performed by Mary Martin (University of NH) HBWatER was initiated in 1963 by G.E. Likens, F. H. Bormann, R. Pierce, and N. Johnson. The record has been funded over its lifetime by the Mary Flagler Cary Charitable Trust, The Andrew W. Mellon Foundation, HBR LTER grants (#8702331, #9211768, #9810221, #0423259, #1114804, #1637685) and NSF LTREB (# 1256696). A full list of contributors to the HBWatER over its lifetime is provided at: Bernhardt E., G. Likens, E. Rosi. 2019. Continuous precipitation and stream chemistry data, Hubbard Brook Ecosystem Study, 1963 – present.. Environmental Data Initiative. https://doi.org/10.6073/pasta/4022d829f3a1fa4057b63b5db8b1a172. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.