Silt refers to the dirt, soil, or sediment that is carried and deposited by our water. While some silt in water is normal and healthy, many additional tons of silt find their way to our water every year, negatively impacting water quality. This pollution, known as siltation, results from erosion and land disturbing human activities, such as agriculture and construction.
Siltation negatively impacts ecosystems in many ways. Excessive silt clogs gills, and smothers eggs and nests. It can bury habitat aquatic insects need for survival, which impacts organisms up the food chain that eat these insects for survival. Siltation can also interfere with photosynthesis in aquatic plants resulting in a decrease in needed dissolved oxygen. Important components of aquatic habitat, which native aquatic species rely on for survival, are altered by siltation. These include the amount of light, the temperature, depth, and flow of water. In addition, pollutants like fertilizers, pathogens, pesticides, and heavy metals can be attached to soil particles that find their way to our water.
Siltation also increases levels of treatment needed for drinking water, fills up reservoirs and navigation channels, and increases a waterbodies likelihood of flooding.