Build Berms

A berm is a wall or mound of dirt that keeps rainwater within a defined area. Used with retention grading, berms reduce runoff and create a temporary water storage area.

How to create a berm

Berms are typically located around a lawn or garden area or at the base of the property. Consider if you have an area of your property that can use a berm along its edges to prevent water flowing onto the driveway, sidewalk or street. Note that before implementing this infiltration technique,  it is highly recommended to determine the soil permeability.

Berm basics:

  1. Pile dirt up using soil from either the surrounding landscape or purchase topsoil. Use the topsoil formula to determine how much you need.
  2. Compact the berm by jumping up and down on it and tamping it down well. This will ensure it doesn’t wash away when it rains.
  3. Plant the berm using drought-tolerant shrubs and groundcover.
  4. Cover any exposed soil with a 3 to 4-inch layer of mulch to prevent the soil from drying out and eroding.

How much topsoil do I need?

Measure the different areas that need berms, in feet. Use the formula below to figure the amount of topsoil needed in cubic yards.

  1. Multiply the width by the height of the berm: (width in ft) X (height in ft.) = (area in sq. ft.)
  2. Multiply the area by the length of the berm: (area in sq. ft.) X (length in ft) = (cubic ft)
  3. For cubic yards, divide by 27: (cubic ft) ÷ 27 = (cubic yards)
  4. Add together the amount needed for all areas of the property.
  5. Total amount of topsoil needed: _______ cubic yards

Is this practice right for you?

Consult a professional if you're not sure. Also, see our web pages discussing maintenance issues, costs and other factors.