Silt control can be accomplished by diverting water away from rivers, streams, and storm drains, stabilizing the soil in construction areas, and creating holding ponds to contain sediment. If work is being done near storm drains, they can be temporarily sealed until nearby soil is stabilized. The silt that accumulates can be removed to prevent it from entering the wastewater system. Using mulch and vegetation to hold dirt are other effective silt control measures.
Temporary drains can be constructed to divert run-off water away from areas where soil is loose. They can be made with pipes, tubes, hoses, or other materials so water can flow to vegetated areas less likely to erode. Concrete drains are usually effective on sloped, permanent sites to allow soil and vegetation to remain untouched.
On some larger construction sites, silt control is handled by building a silt fence around the perimeter of an area before grading begins. Special mesh material is attached to poles to contain the water run-off and prevent it from traveling into waterways or storm drains. The holding pond can be seeded once the project is complete to stabilize the soil and keep it in place. Construction companies might wash trucks leaving construction areas, or use gravel paths to knock dirt off the tires, to help keep silt on site.
On steep slopes, erosion control blankets might be necessary. These materials are attached to the top of the slope with staples to ensure they remain in place. Sometimes these blankets are used along mountain highways, where deep cuts in the earth are necessary to build the road. They can be purchased in rolls of natural or synthetic fibers and cut to size.
Several methods for silt control can be done by property owners without much effort. If work is done during the dry season, it is less likely that soil will wash away. The disturbed area can be covered with mulch and seeded before the rainy season begins, to allow new plants to grow. Topsoil can also be saved to be put back in areas where work was done to provide nutrients to new seedlings.
When silt control is not used, topsoil displaced by construction or severe weather can pollute waterways and harm aquatic life. Run-off sediment that enters flood control channels can clog the pipes and create flooding to adjacent properties. If too much silt flows into harbors, they sometimes become shallower over time and could eventually become useless.
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