The relationship between specific capacity and aquifer transmissibility in the Houston Area, Texas

Water well drillers gather information essential to recovery tests as part of normal procedure. Added effort could yield additional valuable information. More care in measurement of water levels both before and after a period of pumping can be used with ground‐water formulae to determine approximate well efficiency. A relationship exists between the ability of an aquifer to perform (transmissibility) and the specific capacity of a well. By means of pumping tests, both transmissibility and specific capacity may be measured. The theoretical specific capacity can be obtained based on the measured transmissibility. Well efficiency may be estimated from a comparison between measured specific capacity and theoretical specific capacity. Tests of wells owned by the City of Houston, Texas, were selected for analysis. Test results were compared with curves showing theoretical relationships. From the comparison, wells in the Houston area are not completely developed. It may not be economical to develop a well to 100 percent efficiency, but theoretical relationships should be used in well development.