Grades are something a college student never has to worry about after leaving university – unless that student heads into the world of civil engineering. Grades are one of the most important things to understand as a civil engineer because it is a term used to describe the elevation of the earth. When civil engineers grade a site, they change the slopes of the surrounding earth to create an even surface to build on and ensure that that water drains away from any given structure.
A typical grading plan will have contour lines showing the existing and proposed grades. Spot elevations are utilized to show points that are set higher than the surrounding grade to divert water to inlets or yard drains. Some grading plans may also include swales, ridges, berms, and retaining walls. These are special grading features implemented when the natural terrain is difficult to grade to create proper drainage.
Grading a site needs to be done with care; if not, it can cause serious problems. The most obvious issue is that water can infiltrate a house and damage the foundation and structure. Excessive grading will disturb soils and sediments, leaving the ground destabilized and more prone to erosion. However, when a site is properly graded, the land is more maintainable and safer for homeowners to use for future home additions!