The aim of this work is to show out some properties of Guyon's method for drain spacing determination in unsteady state of flow. The analysis has been carried out in the marshy gley soil of the experimental field with drain spacing of 10 m, 20 m and 30 m. The method assumed modeled dynamics of water recharge, which hasn't been observed during the experimental trial. Therefore, its application is limited.

The aim of this work is to show some properties of the application of Kraijenhoff Van de Leur-Maasland’s method for drain spacing determination in unsteady state of flow. The analysis of the method is based on data obtained from drainage field with 10 m of drain spacing which dries out eugley soil. The results of analysis show the range of method applicability as well as certain limitations in the case of non-modelled dynamics of ground water recharges.