Option No. 3. In recent years, the often used option.
This option of arranging drainage in appearance is excellent. Closer to the bottom of the trench, the pipe is laid and sprinkled on all sides by gravel, in all calculations this type of drainage trench will work at best for seven to ten years not whiter. Just as in the first version there will be a siltation of the working area, and then the pipe catfish. What prevents the water output of water. The most reliable and long -term way is the following option.