Drainage facilities that are used for gravitational drawdown of underground water incorporate a perforated tubular header, enclosed within a shell that protects the ground from degradation by the infiltration flow entering the drainage from the outside; by design, the header operates on the principle of a reciprocal filter and normally is composed of granular or fibrous geosynthetic materials. Over the drainage path, inspection pits and silt basins are arranged for on-line control of the drainage system [1]. The header of such a gravity-flowing facility, laid with a low gradient toward the drainage basin, allows a uniform discharge of the filtration flow and further transfer of the accumulated drainage water. The main inadequacy of a single-header drainage system is its rather short service life, to which the many-years experience of these systems has attested, for example, those in service at the Nizhegorodskaya hydroelectric power plant (HPP), Botkinskaya HPP, Tsimlyanskaya HPP, or protective structures of the city of Kazan [2, 3]. Because of accidental faults, most commonly a change in granular composition of the filtering shell, silting or even complete plugging of the drainage header may take place, with far-reaching adverse effects, especially if the change in infiltration flow rate causes a loss of stability of the structure. Even at low gradients (on the order of several pro mille), the header diameter must be sufficiently large to allow passage of a transient flow. This requires a larger supply of costly (and frequently not always readily available) filtering material — high-grade crushed stone, sorted sand-gravel mix, and geosynthetic materials. In doing repairs of a single-header drainage, it is necessary to make a by-pass channel, excavate a significant amount of soil, and replace the filtering material We have developed a header drainage system that is devoid of those shortcomings owing to its using two (or more tubular headers). One header, in an elevated position (Fig. 1), is an inlet header into which the infiltration flow is discharged at a specific rate q, whereas the other header is intended for transient passage of the drained water at a discretely incremental flow rate Qt. Thus designed, the drainage system provides a way toward higher operating reliability, higher economy, and cost-effectiveness. The inlet tubular header (with a diameter corresponding to the drainage flow rate) is placed in a position elevated with respect to one (or more) plain dead headers for transient passage of drained water over the drainage path. Thus, the inlet header (communicating with one or more neighboring wells) and the dead headers are functionally separated. These are essential features of our innovative design. In the drainage facility thus configured, fouling or silting of the inlet tubular header with