The article is devoted to the design substantiation of a new type of drainage structures based on fibrous materials for ground dams. To assess the effectiveness of the application, two-dimensional modeling of hydraulic processes using the software environment Plaxis 2D AE 2013 finite-element method of a ground dam was carried out. Experimental research has become the basis study the effect of the rock mass on the filtration flow of water passing through the drainage from fibrous polymeric materials. Method of valuation suggested in article of the height of the layer and the slope of drainage from fibrous materials take into account the experimental data obtained for ground dams.