Which term describes the amount of water a well will produce for each foot of drawdown?

• A. Specific yield
• B. Specific capacity
• C. Specific discharge
• D. Flow rate

Answer: (B)

Specific capacity describes how much water a well will produce for each foot of drawdown. It is the pumping discharge (in gallons per minute) divided by the drawdown (in feet), usually expressed as gpm per ft. This metric shows how efficiently a well can deliver water under pumping conditions and allows meaningful comparisons between wells. For example, pumping 120 gpm with a 6 ft drawdown yields a specific capacity of 20 gpm per ft. The other terms describe different concepts: specific yield relates to how much water an aquifer can release from storage, not well performance during pumping; specific discharge is the velocity of flow through the formation per unit area and isn’t tied to a well’s drawdown; flow rate is simply the total discharge without considering drawdown.