The value of a constant pressure head boundary condition at a particular node, n, is given by the initial value of the pressure head. Examples of constant pressure head boundary condition are: a constant groundwater level, the water level in an infiltration ring during ponded infiltration experiments, a constant water level in a furrow, and the surface boundary when a Guelph permeameter is used.
See also the "How to Edit Boundary Conditions" topic.
See available Water Flow Boundary Conditions.