DWCZ - CO - Coal Creek - Stream and Spring Chemistry, Radon, and Stable Water Isotopes - 2021 - Johnson (DWCZ-CC-RadonArray-KJohnson)

Spring and stream sampling was conducted across the Coal Creek watershed during summer 2021 (June–October) to evaluate groundwater chemistry and identify locations of groundwater discharge to stream channels. Sites were sampled approximately weekly for synoptic assessment of Coal Creek and associated springs to study surface water and groundwater interactions. Data include intermittent spring (IS) and surface water (SW) chemistry used to evaluate groundwater contributions to streamflow. Associated isotope datasets include δ2H, δ18O, and 222Rn values from 8 stream locations along Coal Creek, 7 groundwater springs within the watershed, and precipitation isotope samples collected by the Next Generation Water Observing System (NGWOS) between November 2020 and September 2021. These data were collected to evaluate how groundwater contributions from fractured hillslopes and alluvial fans respond to summer monsoon rainfall and seasonal drying. Understanding groundwater–surface water interactions in montane systems is critical for future water availability in the western United States, where groundwater contributions are expected to become increasingly important for sustaining summer streamflow. Related isotope data are archived through ESS-DIVE.