February 25, 2007
Subsoil Drainage
The first step in grading is to strip and separate topsoil from the areas in which the level is to be changed. Even if the grading is for construction of a stone or concrete terrace, saving the topsoil is important. In this case, spreading the topsoil in areas which are thin, or using it in the flower garden, can save you a good deal of money.
Once the topsoil is stripped, the subsoil can be graded to the contours desired, leaving sufficient space for adding the topsoil you have already removed. Remember to plan on a slope. For a lawn, a gentle slope is best, most experts recommending a minimum of 6 inches in slope for every 100 feet in lawn.This same measurement can be effectively applied to stone terraces as well, to prevent the development of pools of water in rainy weather.
Subsoil Drainage for Lawns and Gardens
Where the subsoil is thick or clayey, it is essential for the well-being of the lawn that subsoil drainage be installed. Even in sandy soil, it is a good idea to use subsoil drainage, since it brings about the quick and even distribution of moisture throughout the lawn or garden area. The first problem in drainage is to find an area to receive the flow. If you are on low ground, on to which water from higher areas flows, this run-off area is extremely important. On high ground, an underground pipe leading out over a slope will be enough.
If you are building your own drainage run-off, perhaps the easiest is the dry well. The dry well is nothing more than a pit, 4 to 6 feet in depth and diameter, and filled with rubble and rock. Your dry well should be marked after it is covered, so that you know where it is if water starts to back up on your lawn. Subsoil drainage is best accomplished by the use of tile lines. The semi-circular lines of tile are laid in the topsoil, about 1-| to 2 feet deep, in lines from 2 to 4 feet apart. The tile lines should be covered with about A foot of cinder or crushed stone before the soil is re-laced.
Filed under Landscape Design, Soil by Yardist
