How to Create a Berm
- 1). Design the berm. Decide on a location, a height and a width. Plan the berm to be five or six times as wide as it is high and to slope gradually, or feather, into the surrounding lawn. Use a straight berm or a curved one, depending on location, elevation of the lawn and purpose for the berm. Run a drainage berm along a line that will flow naturally to an outlet for rainwater. Use a tape measure and stakes with string to lay out the basic line of the berm.
- 2). Determine the amount of material needed to build the berm. Use tape measure to get the length, height and width, then use those dimensions to calculate how much material will be required. Multiply the height (say 2 feet) by width (12 feet) to get 24 square feet, then 24 times the length, 20 feet, for 480 cubic feet. Divide by 27 to get 17.7 cubic yards of material needed for that berm.
- 3). Decide on materials. Top soil may be preferable but expensive. Look at construction sites for fill dirt from excavations, rubble removed in clearing a lot, old asphalt and other debris that can be compacted. Use clay soil if you can find it as it compacts into a firm base; at least an inch of clay is recommended over any other type of fill. Avoid gravel; even compacted it will allow water and dirt to seep through and over time will erode the berm from within.
- 4). Remove the grass and any dirt needed to provide the proper slope for the berm; it should not slant the same on both sides but should have one high side and one gentler slope. Build the basic shape by shoveling in fill material to the general shape of the berm. Compact the fill thoroughly, with a hand tamper. Cover the berm with at least 6 inches of top soil, more if you plan to put flowers or other plants in the berm. Rake the berm smooth and cover with sod.
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