Upland ground water tables are currently measured at 12 sites on the experimental forest; 11 were measured monthly and one (well 305) was recorded daily and monthly values were extracted. As many as 25 wells have been measured over the years, some for only short periods. There is one well in research watersheds S2, S4, S5, and S6; three in research watershed S3, and 5 in research watershed S1.
Upland wells used for monthly monitoring are 3.2 cm (2 inch) galvanized metal pipes. Wells were drilled using a mobile drill rig. The wells penetrate through confining till layers (where present) to measure water level in the regional aquifer. All wells, except the 305 well, are only screened along the bottom 1.2 m or 1.8 m of a well, which is a sand point. The 305 well is screened below ground and cased (not screened) aboveground. Rudimentary well drilling-logs list the drill-hole lithology (available upon request) and well depths (available in well_depths.csv). These wells were visited during the first week of every month and a chalked steel tape was used to obtain a depth to water (data resolution 0.3 cm) from the top of the pipe. The steel tape was retracted, and the depth to water table was determined by subtracting the water line depth from the depth of tape inserted in the well. Since 2006, Waterra WS-2 Water level meters (WS2-00267) have been used to measure depths to the water. The depth is read directly from the tape at the point at which the sensor first sounds (resolution = 0.3 cm /0.01 ft). Elevations have been measured relative to known benchmarks (the pipe tops). The water table elevations are recorded in feet above mean sea level and converted to meters above mean sea level. Elevations were recorded on tally sheets until the mid-1990s, after which values were added to spreadsheets.
Data from wells 101, 102, 202 and 303 are complete from 1962 to the present. Data from wells 103, 304, 401 and 501 are complete from 1963 to the present. Data from wells 105 and 106 are complete from 1964 to the present. Data from well 305 are complete from 1967 – 2016. Well 601 data start during 1982. All water table elevation data are reported in meters above sea level.
The sites and methods are described in further detail in the publication:
Sebestyen, S.D., C. Dorrance, D.M. Olson, E.S. Verry, R.K. Kolka, A.E. Elling, and R. Kyllander (2011). Chapter 2: Long-Term Monitoring Sites and Trends at the Marcell Experimental Forest. In Randall K. Kolka, Stephen D. Sebestyen, Elon S. Verry, and Kenneth N. Brooks (Ed.). Peatland Biogeochemistry and Watershed Hydrology at the Marcell Experimental Forest (pp 15-71). CRC Press, Boca Raton, FL. https://www.fs.usda.gov/treesearch/pubs/37979.
Daily data from well 305 can be found at:
Verry, Elon S.; Elling, Arthur E.; Sebestyen, Stephen D.; Kolka, Randall K.; Kyllander, Richard. 2018. Marcell Experimental Forest peatland and upland water table elevations. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2018-0002
