Abstract: A drainage method is provided for the construction or renovation of stabilized or grass-covered grounds, particularly sports grounds, and a machine for implementing same. It consists in forming a network of first and second surface drainage trenches which intersect each other, the second trenches being oriented in the direction of the slope and appreciably deeper than the first trenches so as to be provided with drains which are situated below the level of the bottom of the first trenches, the drains communicating with a collector at the side of the ground and the assembly of trenches being filled with filtering material.