What do you call the difference between the pumping level and the static level?

The difference between the pumping level and the static level is referred to as drawdown. Drawdown is a critical concept in water supply and management, as it indicates how much the water level in a well drops when water is being extracted. The static water level is the height of the water in the well when no water is being pumped, while the pumping level is the height of the water during active extraction.

Understanding drawdown is essential for determining the sustainability of a water source, as excessive drawdown can lead to issues such as decreased well efficiency, ecological impacts, and potential depletion of the aquifer. Monitoring drawdown allows operators to make informed decisions about water extraction rates, ensuring that long-term water supply is maintained without causing harm to the surrounding environment or water source.