I have a question regarding the water table level and the how hard a pump has to work, or pump size, based upon that.

It is my understanding that as the water table goes down the subersible pump must work harder, even though it is in a fixed position. With my pump, as the water table goes down in a drought it takes longer to cycle off.

What I don't understand is why the amount of water above the pump makes a difference, since the pump is always pumping from the same position/depth, unless more pressure means less work for the pump.

Any clarification would be appreciated.