To prevent a water-barrier sheet laid on a slope face from forming sagging wrinkles and being broken by being pulled downward with weight of covering soil at the time of reclaming a waste disposal site, etc.

A protective material 1 made of felt, etc., to which hooks of a Hook-and-Loop fastener can be combined, is brought into contact with a created slope face A. Then, the water-barrier sheet 2 to which the face fastener 3 having hooks constituting one side of the Hook-and-Loop fastener is adhered by a double coated adhesive tape is combined to a surface of the protective material 1 via the face fastener 3. A part of the protective material 1 and the water-barrier sheet 2 combined by this combining are inserted and held between grooves 5, 5, 5 at flat parts B1, B2, B3 formed on the slope face A, are pressed by U-shaped grooves 6, 6, 6 and required parts of the surface are covered with soil 7 to create reclamation.