PURPOSE: To surely remove moisture in soil by joining an upper pipe and a lower pipe with a connector arranged in buried pipes and forming the upper pipe with a protrusion at the middle and a slant and providing an opening at the upper part of the lower pipe and a bottom slant at the lower part and further forming a slender retaining chamber in the inside and forming a dish-like part at the opening side.

CONSTITUTION: An upper pipe 2 and a lower pipe 3 divided into two from an SJ pipe 1 are joined with a connector 4 discontinuously arranged along the longitudinal direction. Next, the lateral section of the upper pipe 2 is formed by a protrusion 5 at the middle and a slant 6 extending downward from the lower end thereof to expand toward the edge. Next, the lateral section of the lower pipe 3 is formed to be a slender chamber 11 having an opening 9 at the top, an acutely projected bottom slant 10, and a retaining space in the inside and further, a dish-like part 12 is formed at the opening side. Rain water and others in the ground is effectively guarded from the upper pipe 2 to the lower pipe 3 side to temporarily retain the water in the lower pipe. Moreover, rain water is made to flow downward at a high speed and also longitudinally conducted to gradually discharge it.