Files:

• SG_head_daily_2017.txt: Daily averaged head data for surface water in the main channel of Second Creek. Measured using Schlumberger Diver pressure transducer in a manually installed fully screened PVC pipe.

• PZChannel_head_daily_2017.txt: Daily averaged head data for shallow groundwater in the main channel of Second Creek ("PZCC"). Measured using Schlumberger Baro pressure transducer in a manually installed PVC pipe that was screened at 73.6 to 111.1 cm depth in the sediment bed.

• PZWWetland_head_daily_2017.txt: Daily averaged head data for shallow groundwater in the west wetland flanking the Second Creek main channel ("PZI2"), along east-west transect across Second Creek. Measured using Schlumberger Baro pressure transducer in a manually installed PVC pipe that was screened at 94.5 to 114.8 cm depth in the sediment bed.

• PZEWetland_head_daily_2017.txt: Daily averaged head data for shallow groundwater in the east wetland flanking the Second Creek main channel ("PZE2"), along west-east transect across Second Creek. Measured using Schlumberger Baro pressure transducer in a manually installed PVC pipe that was screened at 117.9 to 129.6 cm depth in the sediment bed.

Datum / Time zone:

Elevation datum used for all head data are meters above mean sea level (masl). All time stamps are at the start of the day in Central Time. Data are averaged over measurements over the day.

Calibration:

Raw pressure transducer data were compensated using air pressure records from Eveleth, MN (U.S. Local Climatological Data (LCD) from the National Centers for Environmental Information, https://www.ncei.noaa.gov/) (i.e., air pressure was subtracted from the raw pressure data). The compensated data were then calibrated to manual water level measurements and surveyed top-of-casing elevations taken at the start and end of the monitoring period. Note that there were no on-site air pressure data available, but periods when the pressure transducers were out of the water (and were thus measuring air pressure) were checked against the Eveleth air pressure records to ensure that Eleveth air pressure records adequately captured conditions at Second Creek (distance of about 35km over low-relief terrain). Head measurements were ultimately used to determine head gradients between the surface water and shallow groundwater, and so any errors in air pressure data would cancel out when differencing the concurrent head values.