Pumping a confined aquifer doesn't just lower a water table — it can permanently sink the ground above it. This simulator models the real mechanism: as hydraulic head drops, Terzaghi's effective-stress principle transfers the lost pore pressure onto the aquitard's clay skeleton, which compacts under a bilinear elastic/inelastic storage law exactly like the aquitard-drainage models hydrogeologists use to explain subsidence in the San Joaquin Valley, Mexico City and Houston. Watch a cutaway aquifer system compact in 3D, drive drawdown with a pumping-rate slider, tune how much more compressible the clay becomes once stressed beyond its history, and stop pumping to see the aquifer rebound — while a fixed borehole extensometer keeps a hard record of how much of that subsidence never comes back.