Time series of dissolved methane and carbon dioxide concentrations for Falling Creek Reservoir, Beaverdam Reservoir and Carvins Cove Reservoir in southwestern Virginia, USA during 2015-2025

Surface samples and depth profiles of carbon dioxide and methane concentrations were sampled from 2015 to 2025 in three drinking water reservoirs in southwestern Virginia, USA: Beaverdam Reservoir (Vinton, Virginia), Carvins Cove Reservoir (Roanoke, Virginia), and Falling Creek Reservoir (Vinton, Virginia). All three reservoirs are owned and operated by the Western Virginia Water Authority as primary or secondary drinking water sources for Roanoke, Virginia. The dataset consists of depth profiles of dissolved greenhouse gas (carbon dioxide, methane) samples measured at the deepest site of each reservoir adjacent to the dam. Additional surface samples were collected at a gauged weir on Falling Creek Reservoir's primary inflow tributary, from a wetland adjacent to Falling Creek Reservoir, and from the reservoir outflow. At Beaverdam Reservoir, additional samples were collected at three outflow sites below the dam and at the mid-reservoir outflow. Samples were collected approximately fortnightly from March-April, weekly from May-October, and monthly in November-February at Falling Creek Reservoir and Beaverdam Reservoir. Samples were collected twice in 2025 at Carvins Cove Reservoir. Additionally, upstream surface samples were taken at multiple tributaries in Carvins Cove Reservoir. In 2019, surface samples along the stream and reservoir continuum in both Falling Creek Reservoir and Beaverdam Reservoir were collected monthly during the summer stratified period. In 2025, littoral samples were collected from Falling Creek Reservoir monthly from June to October (see site descriptions file for geographic coordinates of sampling sites). A maintenance log and quality assurance/quality control analysis scripts accompany the data package.