A soggy lawn that never seems to drain is a threat to your house, plants and trees. The French drain is an effective yet low-cost solution to lawn-drainage problems. Widely used since the 1800s, the traditional French drain is a simple trench filled with gravel and sand but has evolved to include a perforated drainage pipe that helps to drain and divert water. Installing a French drain isn't as complicated as it seems and can be completed in as little as a half day's work.
Dig a trench where you plan to install the French drain. Dig a trench that is approximately eight to 12 inches deep and 5 to 6 inches wide.
Check the slope of your trench. Make sure there is enough downward slope in the direction you need the water to flow. Dig to create a continuous slope if needed, ensuring that there are no long, flat areas along the length of the ditch. Use a level to help determine how your trench is sloping.
Add two inches of gravel to the bottom of your trench.
Wrap your perforated drain pipe in a filter fabric. Lay your drain pipe on top of the gravel. Run the upper end of the drain pipe to the surface of your lawn. Cap the upper end. This will allow you to access the drain pipe to unclog it if needed.
Fill in around the pipe with gravel. Make sure that at least one inch of gravel surrounds all sides of the pipe.