Ways to improve water-carrying capacity of soil when infiltration is compromised

If infiltration of water is impeded at all depths, it is necessary to improve the water- carrying capacity of the soil, through shallow drainage techniques such as moling, gravel moling or subsoiling, in tandem with collector drains.

These soils that have no obvious permeable layer and very low hydraulic conductivity are more difficult to drain. The aim of these drainage techniques is to fracture and crack the soil and to form a network of closely spaced channels.

Mole drainage is suited to soils with a high clay content, which form stable channels. Mole drains are formed with a plough comprised of a torpedo-like cylindrical foot attached to a narrow leg, followed by a slightly larger diameter cylindrical expander.