How to get clay soil to drain

Updated February 21, 2017

Clay soil is composed of fine particles which are easily compacted and waterlogged. High traffic areas are especially susceptible to compaction and flooding. Even if topsoil is aerated and porous, below this an extremely dense and compacted layer of earth exists in some clay rich regions. This layer can prevent water from draining. Removing excess water does not require a complex drainage system. Provide waterlogged soils with much needed underground reservoirs by creating French drains or gulleys.

Locate an area of your lawn or garden prone to flooding.

Remove the turf or sod.

Dig a hole that is 1.8 metres (6 feet) deep and 90 cm by 90 cm (3 feet by 3 feet) wide.

Line the hole with fabric liner.

Fill the hole with 90 cm (3 feet) of gravel or broken masonry.

Fold the fabric over the gravel.

Wedge a drain pipe into the wall of the trench. Angle the pipe slightly towards the gravel. The pipe should be no more than 60 cm (2 feet) from the ground's surface.

Backfill the hole.

Replace the turf or sod.


Use a lightweight, corrugated plastic pipe. A light pipe won't sink in the dense soil and the plastic will not leach corrosive chemicals. In case of debris build up these pipes are easily replaced.

Dense clay soils benefit from trench-style gulleys. The 1.8 metres (6 feet) depth remains but extend the length.

Check gulleys and pipes annually. Re-digging is necessary as silt can pile up.


Check with utility companies and local council planning offices before digging.

Things You'll Need

  • Garden spade
  • Fabric liner
  • Broken brick, stone or gravel
  • Drain pipe
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About the Author

Catherine Duffy's writing can be found on gardening blogs, tech sites and business blogs. Although these topics seem quite different, they have one area in common: systems and design. Duffy makes systems and design (as they pertains to plants, supply chains or software) entertaining and welcoming to general readers.