I want to model a transient boundary condition at one side of my 3D model. I have the measured seawater levels and wish to include salt water intrusion. In v5.3 the option to change the head in a saltwater head is not available for a time varying function ID. Does this mean I have to enter several time varying function IDs for every layer in my model (different depths), at each node corrected for the depth? How do I prepare this efficiently: depths vary per node... also at the boundary.