a central slotted generally tubular feature 30 also extending along the length of the drainage rod 20 the drainage rods 20 are about one inch across the diagonal the slots 29 and 31 extend lengthwise and allow water to enter into each generally tubular features 28 30 all along their length which then collects and flows downwardly through the features 28 30 to enhance percolation of water into the soil the pressure of the water in the rods 20 and the entrance of air at the top allows rapid percolation into the soil the slots 29 are formed by a wall defining each tubular feature 28 curving back towards a central region of said rod 20 with a gap forming the longitudinal slot 29 the center tubular feature 30 also has a gap forming the slot 31 the tubular features 28 30 tend to be compressed radially when the soil is saturated by moisture by the effects of hydrostatic pressure to narrow the slots 29 31 this effect tends to prevent silting in of the tubular features 28 30 over time allowing free continued flow of water downwardly preferably to the level of the watertable as indicated in fig2 thus the drainage rods 20 will intercept moisture migrating towards the house and cause it to percolate rapidly downwardly below the footings instead of reaching the foundation walls the smooth plastic construction also tends to defeat any tendency for roots to grip the drainage rods 20 enabling them to be pulled up for inspection if desired as seen in fig3 b the ends of the drainage rods 20 can be fused at 19 to create a rounded blocked upper end to facilitate driving and penetration.