French drains are used to remove excess water from an area. These drains can be made from either gravel-filled trenches or PVC piping with holes drilled in the pipe. A true French drain is made with gravel, but with gravel driveways, PVC piping is recommended. The PVC piping only needs to be 10 to 15 cm (4 to 6 inches) in diameter for draining purposes. It must also be rugged enough to withstand the weight of vehicles driving over it.
Locate the best area for the French drain. The optimum location will have the best drainage capabilities, and a place where water can drain without damaging your property. There must also be a slight grade so that the water can drain correctly.
Place 60 cm (2 foot) stakes at both ends of the French drain installation. For trenches that are longer than 15 m (50 feet), place a stake every 15 m (50 feet). Where the grade of the French drain is highest, make a mark on the stake at around 30 to 40 cm (12 to 16 inches). For every 15 m (50 feet), the grade of the trench should fall at least 15 cm (6 inches).
Mark the other stake 15 cm (6 inches) lower than the first stake measurement. Tie a dry line from one stake to the other to help measure the depth. To grade the trench, place the butt of the tape in the trench and measure to the line. The measurement should be the same from the start of the trench to the end.
Dig the trench with a shovel and pick axe. The trench needs to be deep and wide enough to allow the pipe to sit level with the driveway's surface.
Attach sections of the PVC piping together with glue at the joints. The holes along the drain should line up the whole length. Lay pipe in the trench with the holes facing up to allow the water to flow into the pipe drain without obstruction.
Cover the PVC-manufactured piping with gravel, leaving only the very top portion visible.