Drain swales are by far the most efficient form of drainage. Swales are small ditches that start in the middle of the backyard and move down the side yards to the front in an A pattern. Water is moved by grading away from the structure to the drain swales, which then move the moisture to the front of the home. As part of regular maintenance, you should inspect around the yard to insure that the grade is moving all moisture away from the structure and your yard walls. Drain swales are sometimes compromised by the addition of hard surfaces and landscaping. If you have created areas near the home that will hold moisture, then be sure to use proper grading to move the moisture as far away from the home as possible.
Hard surfaces, area drains, and soil percolation are not ideal. Drains tend to become clogged, hard surfaces and soil percolation may tend to cause the ground to settle. You should regularly monitor the area drains and insure that they stay clear of leaves and other debris. Grading should move moisture to the area drains where it is then moved out of the yard. If hard surfaces begin to settle, they may direct moisture toward the structure. Unfortunately, there’s not much you can do for this condition other than replacing or removing the concrete. Any areas near the structure where water cannot drain, such as planters or areas sealed by walkways, prevent moisture from draining and create soil percolation. It’s very important to limit the amount of moisture in these areas as the soil can expand like a sponge. The expansion of the soil near the foundation can generate enough pressure to move the entire home, therefore damaging the foundation.
For more information, contact Scott at www.scottsauer.com.