Cohesive or compact soil may be successfully covered with three-dimensional anti-erosion biodegradable blankets on up to 30% gradient slopes. Advantages include partial water infiltration into the soil; when the biodegradable blanket saturates, water flows over its surface and is quickly and efficiently drained.
A further significant advantage is the biodegradable blanket is flexible, molding itself over the soil with no cracks. Sediment retainers may be used for sub-surface and deep drainage; they are flexible, do not clog and provide successful drainability.
The drainage system must be adequately designed; a mixed solution may be used, including biodegradable blanket-covered troughs and cement water drainage channels for optimal results.