System for draining and/or retaining rain water in e.g. building roof, has intake pipe discharging into cavity or into bed and provided for supplying rain water, where bed is made from water-permeable material e.g. sand or gravel

摘要

The system has a cover (10) opened downwardly in its entire cross-section and immersed partially into a ground (12). The cover defines a receiving cavity (22) for rainwater, where the cavity stays in connection with the ground over a lower opening (20) of the cover. An intake pipe (14) discharging into the cavity or into a bed (16) is provided for supplying the rain water, where the bed is made from water-permeable material e.g. gravel. The cover is arranged on the bed and is designed as a single-piece, precast concrete part, where the cover has a cylindrical-shape.