Soil erosion is one of the most inconvenient and environmentally destructive natural phenomena. It is especially a nuisance near mining sites, construction sites and in areas with steep slopes. This is because the soil is loosely held to the ground and thus easily carried away by erosion agents such as wind and rainwater.
Fortunately, there are many ways of dealing with erosion and these include using planting grass or trees, mulching, terracing, provide draining channels and silt fencing. Silt fencing is especially popular in North America and is commonly practiced by construction companies.
What are silt fences?
Silt fences are simple structures that are set up around construction sites aimed at hindering passage of soil carried by runoff water after rain. They are also known as sediment fences or filter fences. They are mostly installed when the site is in close proximity with a water body that could be contaminated with soil from the location.
How are silt fences installed and how do they work?
Setting up a silt fence is relatively easier and cheaper than other methods including terracing and growing vegetation around the site. All that is needed for the fence installation is filter fabric, fence stakes and wire mesh. The stakes can be wooden or metallic and are planted into the ground in the direction of water run-off. The filter fabric is fixed from pole to pole on the opposite side of the erosion flow then reinforced using the wire mesh.
During the construction process, soil is loosened and left exposed to agents of soil erosion. When it rains, water carries the loose top layer of soil. The silt and sediment fences work by trapping the soil and water thus nothing can through the filter to surrounding areas.
Application of silt fencing in hydro seeding
Hydro seeding refers to a seed planting method that involves mixing of the seed with mulch and slurry liquid mixtures then sprayed over the ground. It is a faster and easier alternative to manual planting methods. The spraying can be done using hand pumps, trucks or helicopters.
The fact that it is a liquid being sprayed onto the soil means that it more or less acts a rain. It is therefore no surprise to see farm owners installing sediment fences around their farms especially on hilly areas. This helps to prevent loss of not only the soil but also the precious seed as the liquid flows down the slope. The silt fence can be said to "catch" the flowing goods which allows the farmer to collect and replant thus minimizing wastage. The silt fences also help a lot in hydro seeding by protecting nearby water bodies from fertilizers, pesticides and other chemicals in the liquid mixture.