Silt protection encompasses several types of tools that prevent the movement of silt and sediment into and through bodies of water, usually from construction sites or other activities that disturb the soil. On land, those tools might include silt fences, sediment basins and sediment traps or other types of erosion controls, like grading or riprap. Other types of silt protection are designed to operate in the waterway itself, where sediment is already present. Dredging operations are a good example of such a situation, where the bottom of the watercourse is dug up, releasing vast amounts of fine silt. Silt curtains can also be employed in cases where land based mitigation is not 100% effective.
Silt and sediment present significant risks to aquatic and shoreline vegetation, aquatic and land animals, and even human populations downstream. Soil washing into the waterway from farming or construction operations may contain harmful pesticides, fertilizers, or other contaminants. Sediment stirred up from the bottom may harbor dangerous microorganisms, parasites, or even dinoflagellates that trigger deadly red tides. When these are present in small amounts, they may not cause illness or trigger a bloom, but if water is carrying many times the normal load in suspended silt particles, outbreaks of severe illness can follow. On a more mundane level, excessive amounts of silt and sediment can clog channels, damage equipment, and destroy valuable ecosystems.
