Abstract.A method of analyzing the pumping and recovery phases of large diameter wells based on a Kernel function method is presented. Consideration is given to the effect of the seepage face, which is the difference between the well‐water level and the aquifer level on the well face. A computer program for the Kernel function method written in BASIC, is provided. In the analysis of a representative field test, the importance of including the seepage face is demonstrated; if the seepage face is ignored, both the transmissivity and storage coefficient are underestimate