Use of horizontal drains to avoid the effects of groundwater rise has been examined by many researchers both for slope stability and to safeguard building foundations.
Formulations have therefore been stated linking hydrogeological parameters and the area involved in the piezometric depression related to drainage.
This paper deals with the efficacy of horizontal drainage on the attenuation of a continuous series of rising and lowering of the groundwater head of the rivers. The repetition of these events can indeed produce underground erosion and subsidence of the soil. The horizontal drains arrangement is parallel to river, and the effectiveness of the drainage depends over all by their distance and by their depth respect to watercourse.