It is used during the infiltration of water into the ground. Tunnel absorbs water, and then successively infiltration it in the ground. Rainwater drained from the roof with drainage pipes into the tunnel, where it is freely infiltration in the ground. The tunnels are used during infiltration of treated wastewater in domestic wastewater treatment plants. The device can be placed through the green, the pedestrian traffic. When using the drainage tunnels must remember that it can only be used in permeable soils and poorly permeable, where the groundwater level is correspondingly low. The tunnel is made of polyethylene.