Water and Well Depth
“What is well depth?”
Well depth is defined as the full depth from ground level to the solid rock at the bottom of your well shaft.
“What is the difference between the water table and static water level?”
Static water level or (simply) water level are synonymous phrases and define the depth or distance from ground level to the level of water within the well — at RESTING STATE.
“Resting state” means you are not pumping and haven’t pumped recently, and the well has filled back up to it’s maximum level. If you have pumped, then the water level, of course, is changing as the well fills back up to the static level. (The speed at which it refills – e.g. three gallons per minute – is called your “Recovery Rate”.)
Water Table is the level below which the pores in the soil and rock and saturated with water. The static water level in an individual well can be quite a lot higher or lower than the water table, depending on the shape of rock strata and their relative permeability.
“How do I determine the static water level?”
You can approximate the depth to groundwater from the well driller’s drilling log when the well was initially drilled. If you don’t have this information, you can contact a local well driller to have the water depth confirmed by sounding or other measurement technique.
NOTE: If you want to determine your static water level yourself, you’ll need: a small steel weight, a 1 1/4″ to 1 1/2″ diameter bobber, 200 feet of a lightweight fishing line or kite string.
- Attach the weight to the end of the line or string. Affix the bobber 1 inch above the weight.
- Remove the well cap and lower the weighted end with bobber into the well casing.
- When the bobber reaches the water level, the line will go limp. You’ll feel a slack in the line.
- At the point where you feel the slack, mark the line at the top edge of the casing (you can tie a small knot in the line, use tape or a marker)
- Pull the line back up from the casing. Measure the length of the line from the bobber to the marked line. This is your static water level.