Inadequate drainage of surface water, either from rain or irrigation, away from the home often contributes to subgrade soil saturation. This is the number one cause for foundation problems in Southern California.” Inadequate drainage occurs when the topography is flat, topography slopes toward the house, irrigation volume is unnecessarily high, torrential rains create ponding conditions, water has no escape route (bathtub scenario), or drains are blocked. The adjacent yards/planter areas are flat or drains towards the house. For many houses, water may have saturated the soil adjacent to this foundation due to inadequate surface drainage during irrigation, past torrential rains, or an excessive use of the hose along the backyard wall. One of the most prevalent scenarios we see, is rain gutters draining directly adjacent to the foundation, and often into a planter that creates pooling. Proper drainage is important to keep water away from perimeter foundations to prevent foundation movement. Water percolates through the topsoil to saturate the subgrade soil under the foundation. In such conditions, the soil under the foundation becomes more compressible.