• How to define constant hydraulic head of free water above topography

    I'm a beginner with FEFlow, and this is probably a very easy problem I'm having, but unfortunately I'm the only one around here working flow modelling, so I have to ask you for help.

    I'm trying to simulate flow in an analog experiment, where I have a fully saturated sand body, with an outflow at the bottom (constant hydraulic head). The sand body has a topography and is covered by a water-body with a constant hydraulic head that is larger than the bottom hydraulic head. So I basically induce a flux from top to bottom.  through the sand.

    The problem I have is that I don't understand how to assign either (1) cells with conductivity values for open water (is that possible?) or (2) assign the hydraulic head of a constant water level above the topographically uneven sand body.

    Can anybody help me out here?