[uml]

I am new to Paraview so this is probably very lame question. So far I am using legacy VTK format to visualize my data in Paraview. I have model with unstructured grid - polygon cells, more dense in areas of interest, less dense further away. For every cell water level changing in time. Is there a way how to display changing elevation / water level in Z dimension for otherwise static cells in time and define the geometry (the significantly most of data) only once?

So far I am able to achieve it only as having vtk and all XYZ geometry off all cells for every time step which is horrendously data space consuming.