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How to Install a Surface Water French Drain

By Cameron Easey

A French drain is is used to remove excess water from low-lying areas that tend to get saturated. These types of drains consist of a trench that is dug and filled with gravel or stone and a top layer of sand. It is inexpensive and easy to install. The first step in installing a surface water French drain is deciding where the system should be located.

Dig a trench in the area of your yard where excess water accumulates. The trench should be from four to six inches wide and up to 12 inches deep.

Create a slope in the trench so that the water will be able to drain away. Check the trench at every two or three feet with a level to make sure there is a consistent slope. Or you can first finish digging the trench and then go back and add loose dirt to create a reasonable slope.

Put a layer of gravel at least four to six inches deep in the trench.

Add a layer of coarse sand on top of the gravel. The sand acts as a filter that only allows water to go down to the gravel. The sand should be at lest three inches thick.

Place a layer of soil on top of the sand to cover the trench. You can then plant grass seed or add sod to complete the project.

Adding a Drainpipe

Place a two- to four-inch layer of gravel in the trench.

Lay a perforated drainpipe on top of the gravel. The pipe should be at least four inches in diameter.

Place a filter fabric, or fabric used to keep weeds out of gardens, over the top of the pipe.

Add another two-inch layer of gravel on top of the drain

Fill in the remainder of the trench with dirt or topsoil.


Things You Will Need

  • Shovel
  • Gravel
  • Sand
  • Level
  • 4-inch diameter pipe
  • Filter fabric


  • The length of the trench should be long enough to properly drain water away from a building or other structure. Sand does not need to be added to the trench when using a drainpipe.


  • If you don't sand that is coarse (wihout a drainpipe), water may not properly drain through to the gravel. Dirt and mud can clog the drainpipe if you don't use filter fabric.

About the Author


Cameron Easey has over 15 years customer service experience, with eight of those years in the insurance industry. He has earned various designations from organizations like the Insurance Institute of America and LOMA. Easey earned his Bachelor of Arts degree in political science and history from Western Michigan University.