Remove soil from the proposed drain area. For basement walls and retaining walls, remove the soil down to where the wall meets the foundation footer. This will be the lowest point where the water is most likely to cause problems. Make sure the soil is removed fot at least 36 inches from the wall. Remember that the soil will need to be removed along the entire length of the problem area.
Install 6- or 8-inch perforated drain pipe at the base of your foundation basement wall or retaining wall and extend it past the wall 4 feet. Cover the pipe with 2 feet of gravel, but do not compact the gravel. Next, cover the gravel with landscaping fabric to prevent soil from clogging the perforated drain holes on the drain tile pipe, and re-cover the area with the soil removed prior to installation. The drain pipe will collect any excess water from the surrounding soil and drain it away from the area.
Dig a trench 36 inches wide and 36 inches deep for low-lying areas with poor drainage. The trench should run at least 4 feet past the problem area and into a 4-by-4-foot gravel pit that is 5 feet deep. The pit must be filled with gravel and the perforated drain pipe extended into the pit to allow proper drainage away from the problem area and into the gravel pit.