What is the Static Head of Water in the Well?
The static head inside a water well tells us how much water is available to the pump after the well has rested, water has risen to its maximum height inside the well, and the pump is about to turn on. This sketch, courtesy of Carson Dunlop offers a graphic explanation of well static head. The static head in a well is is not the total amount of water than can be pumped out of the well, it’s just where we start. After all, we will also have to include the rate at which water runs in to the well while we’re pumping water out. Looking at our rough well sketch below and repeated at Components of a Drilled Well with a Submersible Water Pump and just considering the vertical arrows at the left side, we see that we have a total well depth (d), which in more detail is comprised of the air gap at the top of the well (a), the pump clearance at the bottom of the well (c), and the static head (h) which is the height of the column of water inside the casing which can be pumped out by the water pump
