The continuous exchange of water between surface water and groundwater is a key environmental process controlling the transport and the fate of nutrients, solutes and pollutants in river networks. The dynamics of the near-stream groundwater has a non-negligeable role on controlling flow direction and solutes exchange between the stream water with the adjacent groundwater, however it is rarely considered in solute transport experiments. Despite the amount of individual studies, we are still uncertain about how the physical processes controlling in-stream solutes transport change with different hydrologic conditions and how these processes can be inferred by modelling outcomes. In this project we investigated groundwater and stream interactions in order to characterize the physical processes that control the water and solute exchange in the river corridor and their variability over time. To do so, we drilled 36 wells in the near-stream domain, and 7 piezometers in the stream channel. We observed the water level and electrical conductivity every 15 min at 22 of the 36 wells with a water level sensor (Orpheus Mini, OTT, Kempten, Germany, resolution of 1 mm and accuracy of ��0.05% FS) over a period of 32 months (July 2018 - March 2021). The dataset includes the following files: > "Raw groundwater measurements.xlsx" This file includes groundwater table elevation measured as depth from the upper limit of the well (time step of 15 minutes, Orpheus Mini, OTT, Kempten, Germany, resolution of 1 mm and accuracy of ��0.05% FS). Every excel file includes also Electrical Conductivity measurements (��S/cm) and Voltage (V) of the instruments. Every sheet in this .xlsx file reports measurement for one sensor in the specific observation-well where it was placed. > "Groundwater elevation data - wells metadata and fixed groundwater table elevation.xlsx" This file includes the raw groundwater table measurements measured via the OTT, information on the well network, elevation and location of the observation wells, location of subsurface layers, and suggested correction of the groundwater table measurements for short periods with missing data. > "Hand-measurements and metadata.xlsx" This file includes the list of in-situ inspections and hand-measurements of the groundwater table conducted over the entire observation period in every well and piezometer of the groundwater-monitoring well network. Every sheet includes details on the instruments measuring the groundwater table, their offset with hand-measured data, information on their re-calibration, and calculation of the groundwater elevation above the reference plane after each hand-measurement.

{"references": ["Bonanno, E., Bl\u00f6schl, G., & Klaus, J. (2021). Flow directions of stream-groundwater exchange in a headwater catchment during the hydrologic year. HydrologicalProcesses,35(8), e14310.https://doi.org/10.1002/hyp.1431018"]}

The authors acknowledge funding from the Luxembourg National Research Fund (FNR) through the project: HYDRO-CSI (PRIDE15/10623093).