Erosion Control & Flood Defence
Erosion removes fertile soil rich in nutrients and organic matter, which reduces the ability of plants to establish, grow and remain healthy. A reduction in plant growth and subsequent plant residue causes less soil cover, allowing the erosion process to perpetuate and become worse. Ultimately, this process could lead to infertile land void of topsoil.
Research has shown that the use of compost as a `soil blanket’, actually used to mulch the slope, or as a trapezoidal berm is more effective than typical technologies, such as sediment fencing, straw bales, woven blankets, etc. It can also compete economically.
Compost used in this application also provides the added benefit than it can encourage the quick (and more extensive) establishment of vegetation, which is often the long-term goal on sites treated with erosion and sediment control measures.
The use of compost in these applications is typically confined to areas affected by water in sheet flows, not in channel flow conditions. Compost is also used as a barrier to retain soil on construction site, or to restrict soil movement off sloped areas.
Typically, compost that contains some coarser wood is more effective in this application.
When incorporated into the soil compost controls erosion by:
- Reducing run-off and soil particle transport
- Increasing water infiltration into the soil surface
- Increasing plant growth and soil cover
- Increasing water holding capacity of soil
- Increasing soil structure, thereby alleviating soil compaction
- Establishing new vegetation
As a filter berm, compost:
- Reduces sediment from reaching surface water by acting as a filter
- Binds and degrades a variety of chemical contaminants, but binds nutrients
- Reduces fertilisers and other pollutants from reaching surface waters in water runoff situations
- Is an ideal waste reduction material
- Economically competitive with current erosion/sediment control techniques and products.