Underground drainage pipes are a simple way to drain areas that are prone to remaining wet long after any significant rainfall. Drainage pipes are typically placed around the perimeter of foundation to collect excess water, which is then connected to one or more drainage pipes that lead away from the home or lawn on a downward slope.
Drainage Ditch Depth
A typical drainage ditch is 12 to 18 inches deep and 6 inches wide.
Drain Pipe Placement
Drainage ditches can simply be filled with gravel, which allows water to flow more easily than normal soil. It is most effective to place a drainage pipe in the ditch at a depth of 12 to 18 inches and then fill the ditch with gravel.
Drain Pipe Slope
Maintaining a depth of 12 to 18 inches is best for drain pipes, but the depth of the pipe may vary in order to maintain a downward slope, which is critical for proper drain functioning.