This paper deals with the groundwater flow in a semi-confined aquifer causing the phenomena of consolidation and free surface lowering. Since the main effect of consolidation has taken place before noticeable lowering of the free surface, one may solve each phenomenon on its own. The real solution may be obtained by the principle of superposition. However, the solution for lowering the free surface is delayed due to the cosolidation by a certain timelapse, depending on the placecoordinates.