Unsteady Drawdown in Well Groups

The unsteady drawdown response has been studied for a variety of well groups which are arranged in a two-line or rectangular array. The individual wells are assumed to fully penetrate a homogeneous, isotropic, artesian aquifer with constant hydraulic properties, and the principle of superposition has been used to develop a relationship for calculating the drawdown at any given point within the well system. An equivalent radius concept is introduced and quantified, and several graphical presentations have been given to illustrate the relationship between different combinations of variables, which include well capacity, number of wells, well spacing, line spacing, and pumping time. Finally, a representative dewatering problem has been included to demonstrate an application of the procedures developed. In general, these analytical and graphical procedures provide useful tools for the engineer who is charged with the responsibility of designing or analyzing the transient response of typical water supply or dewatering well systems.