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GFLOW supports "horizontal flow barriers" that may be open poly-lines, as shown near the well in the figure, or closed slurry walls. The latter may be used to simulate aquifer remediation whereby a scavenger well pumps contaminated groundwater that is contained by a low permeable slurry wall. In the figure the Instant Inspector feature is used to display all model data at a point inside the slurry wall (the point in question is at the upper left corner of the data panel). This Instant Inspector is invoked by a Shift-Left-Click on the mouse. The ragged contours around the slurry wall show the jump in the head from a little over 400 feet on the outside to about 373.5 feet on the inside of the wall.
The horizontal barrier near the well, see upper right of figure, is a no-flow boundary, forcing all water that flows toward the well to pass around it. Again, the no-flow boundary exhibits ragged contours indicating a jump in the head across the barrier.