Time series of high-frequency sensor data measuring water temperature, dissolved oxygen, conductivity, specific conductance, total dissolved solids, chlorophyll a, phycocyanin, fluorescent dissolved organic matter, and turbidity at discrete depths in Beaverdam Reservoir, Virginia, USA in 2020-2021

We monitored water quality in Beaverdam Reservoir (Vinton, Virginia, USA) with high-frequency (10-minute) sensors in 2020-2021. Beaverdam Reservoir is owned and managed by the Western Virginia Water Authority as a secondary drinking water source for Roanoke, Virginia. This reservoir experiences substantial water level changes over the years due to its position at the headwaters of its catchment as well as management, and ranged from 10.2 to 12.48m (mean=11.31m, median=11.38m) during the monitoring period. Depth profiles of water temperature were measured by thermistors on ~1-meter intervals above the surface of the reservoir to 0.5 m above the sediments, complemented by dissolved oxygen and pressure sensors deployed at depth. These sensors (thermistor temperature, dissolved oxygen, and pressure) were held stationary as the water depth fluctuated from 10.2-12.48m. A YSI EXO2 sonde measuring temperature, conductivity, specific conductance, chlorophyll a, phycocyanin, total dissolved solids, dissolved oxygen, fluorescent dissolved organic matter, and turbidity was attached to a buoy that moved with the changing water level and thus was kept at a constant ~1.5 m depth. Dissolved oxygen was monitored at three different positions: 1.5 m from the EXO2, in the mid-water column at 2.37-4.65 m depth, and bottom waters at 9.70-11.92 m depth. All variables were measured at the deepest site of the reservoir adjacent to the dam.