Specific Capacity
Hydrology
A well's yield in gallons per minute per foot of drawdown — a measure of well efficiency.
Specific capacity (GPM divided by drawdown in feet) is the cleanest single number for comparing well performance over time or between wells. A drop in specific capacity is the earliest reliable indicator that a well needs rehabilitation. New wells in Utah commonly test at 0.5 to 5 GPM/ft depending on aquifer and screen design.