The combination of a flexible pipe, e.g. plastic, and a reinforcing member mounted around the pipe to strengthen the pipe and to enhance its ability to resist deformation under load. In one embodiment the reinforcing member includes a flexible perforated plastic netting containing an aggregation of lightweight elements such as expanded polystyrene beads capable of wrapping around the pipe, preferably in helical fashion along the length of the pipe. In another embodiment, a number of members are mounted on the pipe in longitudinally extending fashion.In all embodiments, the beads provide drainage around the pipe when it is placed in a trench and obviate the need for gravel normally used in conventional systems.