Well Hydraulics: Drawdown, Specific Capacity and Pump Testing
This is the diagnostic heart of well system operation. Three simple measurements, taken
consistently, will tell you more about the condition of your source than anything else you can
do.
The three measurements
- Static water level - the level in the well when it has been at rest long enough to
recover. It reflects the aquifer, not the pump.
- Pumping water level - the level while pumping at a stated rate, once it has stabilised.
- Pumping rate - the discharge, measured, not assumed from the nameplate.
Levels are measured from a fixed, marked reference point on the casing, and the reference
point is recorded so that every later reading is comparable. An electric sounder or an air line
is used; a steel tape works. What matters far more than the method is using the same method
from the same point ev