Stream water chemistry and benthic macroinvertebrate data collected in the North Fork of Clear Creek and Clear Creek, CO, USA before and after the diversion and treatment of acid mine drainage by a high-density sludge lime process water treatment plant. Stream water chemistry and benthic macroinvertebrate samples were collected from November 2011 through October 2019 at 6 sites located above and below the North Clear Creek Water Treatment Plant (NCCWTP). The NCCWTP became fully operational in September 2017. Measured water chemistry included pH, conductivity, alkalinity, ferrous iron, total and dissolved concentrations of metals and major geochemical cations, and dissolved organic carbon. Replicate (n=5) benthic macroinvertebrate samples were collected using a 0.1 square meter Hess sampler at targeted riffle habitats among sites. Benthic samples were processed from detrital material in the laboratory using a subsampling technique to reach 300+ invertebrates, and identified to the lowest taxonomic resolution possible, typically to genus (except for chironomids that were identified to subfamily).