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Metal and nutrient loads were calculated from 2019-2024 from the inflow stream to Falling Creek Reservoir (FCR), a drinking water reservoir located in Vinton, Virginia, USA. The reservoir is owned and operated by the Western Virginia Water Authority and is managed as a secondary drinking-water source for the city of Roanoke, VA. Only Fe, Mn, and nutrients (TN and TP) were analyzed and calculated in 2019. The full suite of metals (Li, Na, Mg, Al, K, Ca, Fe, Mn, Cu, Sr, Ba) and nutrients were analyzed from 2020-2024. The loads that were collected using an ISCO automated sampler located at the main inflow tributary to FCR. Sampling frequency was approximately fortnightly from spring to fall (March - November). Load calculations were performed using the calculated cumulative flow over the sampling period from the ISCO and the analyzed total metal and nutrient concentrations. Please note we are publishing this data package before the nutrient samples have been analyzed, but will be included in later versions. 

Depth profiles of total and soluble metals were sampled from 2014-2024 in three drinking-water reservoirs: Falling Creek Reservoir (FCR), Beaverdam Reservoir (BVR), and Carvins Cove Reservoir (CCR). FCR and BVR are located in Vinton, Virginia, USA and CCR is located in Roanoke, Virginia, USA. Only Fe and Mn were analyzed from 2014-2019. The full suite of metals (Li, Na, Mg, Al, Si, K, Ca, Fe, Mn, Cu, Sr, Ba) were analyzed from 2020-2024. All reservoirs are owned and operated by the Western Virginia Water Authority and are managed as drinking-water sources for the city of Roanoke, VA. The dataset includes metal samples that were collected along a depth profile taken at the deepest site of each reservoir near the dam. Additional samples were collected at a gauged weir located on the primary inflow tributary, as well as at a secondary tributary to FCR. A 2024 sampling campaign at FCR included outflow spillway surface water sampling. A 2022 sampling campaign at CCR included inflows and a partial depth profile at the deepest site. Sampling frequency in FCR and BVR in 2024 was approximately weekly during the summer and fall (May - October), approximately fortnightly during the spring (March - April), and approximately monthly during the winter (November - March). In 2022, sampling frequency at CCR was approximately fortnightly during summer and fall (May - October). 

Sediment traps were deployed to assess the mass and composition (lithium, sodium, magnesium, aluminum, potassium, calcium, iron, manganese, copper, strontium, barium, total organic carbon, and total nitrogen) of settling particulates in the water column of two drinking water reservoirs—Beaverdam Reservoir and Falling Creek Reservoir, both located in Vinton, Virginia, USA. Sediment traps were deployed at two depths in each reservoir to capture both epilimnetic and hypolimnetic (total) sediment flux. The particulates were collected from the traps approximately fortnightly from April to December from 2018 to 2023, then filtered, dried, and analyzed for lithium, sodium, magnesium, aluminum, potassium, calcium, iron, manganese, copper, strontium, and barium (2018 to 2023) and total organic carbon and total nitrogen (2018 to 2022, due to instrument repairs). Beaverdam and Falling Creek are owned and operated by the Western Virginia Water Authority as primary or secondary drinking water sources for Roanoke, Virginia. The sediment trap dataset consists of logs detailing the sample filtering process, the mass of dried particulates from each filter, and the raw concentration data for lithium (Li), sodium (Na), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), iron (Fe), manganese (Mn), copper (Cu), strontium (Sr), barium (Ba), total organic carbon (TOC) and total nitrogen (TN). The final products are the calculated downward fluxes of solid Li, Na, Mg, Al, K, Ca, Fe, Mn, Cu, Sr, Ba, TOC, and TN during the aforementioned deployment periods. 

Depth profiles of total and soluble metals were sampled from 2014-2023 in three drinking-water reservoirs, Falling Creek Reservoir (FCR) Beaverdam Reservoir (BVR), and Carvins Cove Reservoir (CCR). FCR and BVR are located in Vinton, Virginia, USA and CCR is located in Roanoke, Virginia, USA. Only Fe and Mn were analyzed from 2014-2019. The full suite of metals (Li, Na, Mg, Al, Si, K, Ca, Fe, Mn, Cu, Sr, Ba) were analyzed from 2020-2023. All reservoirs are owned and operated by the Western Virginia Water Authority and are managed as drinking-water sources for the city of Roanoke, VA. The dataset includes metals samples that were collected along a depth profile taken at the deepest site of each reservoir near the dam. Additional samples were collected at a gauged weir located on the primary inflow tributary, as well as at a secondary tributary, to FCR. A 2022 sampling campaign at CCR included inflows and a depth profile at the deepest site. Sampling frequency in FCR and BVR in 2023 was approximately weekly during the summer and fall (May - October), approximately fortnightly during the spring (March - April), and approximately monthly during the winter (November - March). For previous sampling campaign frequencies, please see past revisions of this data product. 

Sediment traps were deployed to assess the mass and composition (iron, manganese, total organic carbon, and total nitrogen) of settling particulates in the water column of two drinking water reservoirs—Beaverdam Reservoir and Falling Creek Reservoir, both located in Vinton, Virginia, USA. Sediment traps were deployed at two depths in each reservoir to capture both epilimnetic and hypolimnetic (total) sediment flux. The particulates were collected from the traps approximately fortnightly from April to December from 2018 to 2022, then filtered, dried, and analyzed for either iron and manganese or total organic carbon and total nitrogen. Beaverdam and Falling Creek are owned and operated by the Western Virginia Water Authority as primary or secondary drinking water sources for Roanoke, Virginia. The sediment trap dataset consists of logs detailing the sample filtering process, the mass of dried particulates from each filter, and the raw concentration data for iron (Fe) and manganese (Mn), total organic carbon (TOC) and total nitrogen (TN). The final products are the calculated downward fluxes of solid Fe, Mn, TOC and TN during the deployment periods. 

Abstract Water level drawdowns are increasingly common in lakes and reservoirs worldwide as a result of both climate change and water management. Drawdowns can have direct effects on physical properties of a waterbody (e.g., by altering stratification and light dynamics), which can interact to modify the waterbody's biology and chemistry. However, the ecosystem‐level effects of drawdown remain poorly characterized in small, thermally stratified reservoirs, which are common in many regions of the world. Here, we intensively monitored a small eutrophic reservoir for 2 years, including before, during, and after a month‐long drawdown that reduced total reservoir volume by 36%. During drawdown, stratification strength (maximum buoyancy frequency) and surface phosphate concentrations both increased, contributing to a substantial surface phytoplankton bloom. The peak in phytoplankton biomass was followed by cascading changes in surface water chemistry associated with bloom degradation, with sequential peaks in dissolved organic carbon, dissolved carbon dioxide, and ammonium concentrations that were up to an order of magnitude higher than the previous year. Dissolved oxygen concentrations substantially decreased in surface waters during drawdown (to 41% saturation), which was associated with increased total iron and manganese concentrations. Combined, our results illustrate how changes in water level can have cascading effects on coupled physical, chemical, and biological processes. As climate change and water management continue to increase the frequency of drawdowns in lakes worldwide, our results highlight the importance of characterizing how water level variability can alter complex in‐lake ecosystem processes, thereby affecting water quality.