The effects of a falling water table on the gravity drainage of a one-dimensional soil profile and associated delayed yield phenomena are investigated by theory and experiment. The theoretical considerations result in a new type of numerical model which incorporates the falling water table as a time-varying boundary condition. Drainage experiments were conducted in a standard sand column which was fitted with an adjustable valve at the base allowing various drawdown rates to occur. The results of this study showed good agreement between the experimental and numerical prediction of delayed yield such as that which might be encountered in pumping-test data in a phreatic aquifer. (Author)