What does Specific Capacity measure?

Specific Capacity is a vital measure in hydrogeology and well performance, specifically indicating how much water a well can produce in a given time relative to the amount of water level decline (drawdown) experienced in the well. By calculating the specific capacity, one can determine a well’s efficiency in yielding water. It is defined as the ratio of the discharge (the amount of water produced) to the drawdown (the difference in water level before and during pumping).

Understanding this concept allows operators to assess the productivity of the well under specific conditions, making it critical for water supply management, system design, and operational decisions. When water is pumped from a well, drawdown occurs due to the removal of water from the surrounding aquifer, and the specific capacity provides insight into how effectively the well can be sustained over time with minimal impact on water levels. This metric is crucial for ensuring that a water supply remains reliable and sustainable.