The PVC mat penetration device, Well B3, is located at Station B3 beyond Sta. B2 in an area dominated by neke fern in 2001, but increasingly encroached upon by cattail and para grass.

The following legend applies to the graph above:

Vertical lines "I" and "II" mark changes in the water level measurement device: before I - ; I - tape device (see photo at right) used; II - tape device weight modified.

The following are all derived from measurements made with the weighted drop line. The heavy blue line is height of water above a "solid" bottom. The wide green line represents "top of mat" calculated as tape reading from solid bottom to pipe lip, less pipe extension above mat, plus a correction (+0.02) for the effect of the observer depressing the mat. The wide brown line represents "bottom of mat" calculated as "top of mat" minus mat thickness. The small blue points show the depth of solid bottom measured with the weighted line. These are at the same elevation because all measurements derived with the weighted line assume this bottom is a fixed point (although it may not be). Vertical lines representing the well are shown at selected points in time, plotted from the measurement to pipe lip from solid bottom and pipe length.

The following plots are from measurements made at the the water level staff gage or by stadial survey from the staff gage. The fine dashed line is the water level recorded at Na Pohaku o Hauwahine, corrected to a USGS gage located elsewhere in the marsh. All other well measurements are corrected by the same factor as appropriate, although a method of matching the water level at the well and the "marsh" water level is still being developed. The maroon points represent actual elevation measurements of the solid bottom from standard leveling survey techniques using the elevation of the WL gage as the "back sight."