A transect of wells is established on the marsh platform, perpendicular to the marsh edge.  A total of 5 wells are dug to the depth of the water table under the marsh platform.  Wells 1-4 are spaced approximately evenly within the first 5m of marsh edge with well 5 approximately 20m upland from the marsh edge.   A water level logger, referred to as the tide gauge, (Onset HOBO U20 series) is placed at the river bottom directly in front of the transect . Individual water level loggers (Onset HOBO U20 series) are used in each well and they measure water height in terms of absolute pressure.  Barometric pressure is measured above ground with an additional Onset HOBO U20 series water level logger to tease out the atmospheric pressure from water column pressure.  Prior to deployment, each water level logger is sealed in protective plastic whirl-pak bags filled with freshwater, and calibrated to known water depths.  Once in the field, water height measurements, in terms of absolute pressure, are recorded every 10 minutes.    Pressure readings are uploaded from the HOBO water level loggers using HOBOware software which compensates for temperature, fluid density, and barometric pressure, then are converted to absolute water height above the river bottom.  Data is QA/QC'd to ensure that the loggers report the same flood water elevation on the marsh surface. The surface elevation of the marsh as measured by the marsh water level loggers must match that of the gps'd surface elevation.  Any corrections made to a particular logger data field (logger # Dc (m)) are reported in the Offset corr field (Offset corr logger # (m)).

Well Location Information:

Logger                Well              Height of Marsh Surface Above Creek Bottom (m)           Horizontal Distance Upland of Creek Edge (m)

1 (tide gauge)                                                    0.00                                                                          -10.36                                                                                     

2                           1                                           2.676                                                                           0.00        

3                           2                                           2.827                                                                           2.47          

4                           3                                           2.884                                                                           5.00  

5                           4                                           2.880                                                                           7.56 

6                           5                                           2.903                                                                         20.28    

Logger 1 tide gauge located on river bottom.

Marsh wells 1-5, numbered consecutively moving upland.

NOTES AND COMMENTS: Due to occasional equipment malfunction, readings are not continuous throughout the field season.  Times in EST.

All loggers were refurbished and new batteries  added at the beginning of the year.  Several loggers didn't pass QA/QC stds and were removed from the field.  Temporary loggers from the Valiela Panama project were used during several deployments.  Although the logger number was different during several deployments, the same well and same depth was used so data should be comparible.  The final well was abandoned during most of 2016 due to the lack of a replacement logger.