A pumping‐test method for the determination of specific yield

The specific yield of a water‐table aquifer is one measure of the amount of water within the aquifer that is available for recovery (development). It is expressed as a percentage or decimal fraction of the total volume of material of which the aquifer is composed. The specific yield may be determined during the course of an equilibrium pumping test by comparing the volume of dewatered material in the cone of depression with the total volume of discharge water. An equation is developed theoretically that expresses the volume of dewatered material in terms of test data. A related equation indicates the magnitude of losses at the pumped well. These equations were tested by applying them to test data tabulated in ground‐water literature.