Siltation is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation of fine sediments on bottoms where they are undesirable. Siltation is most often caused by soil erosion or sediment spill.
Siltation of a waterway
Siltation caused by fecal sludge collected from pit latrines and dumped into a river at the Korogocho slum in Nairobi, Kenya.
Siltation caused by raw sewage sludge and industrial waste in the New River as it passes from Mexicali to Calexico, California.
Siltation caused by sewage sludge from shipyard in Rio de Janeiro.
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil or as sediment mixed in suspension with water. Silt usually has a floury feel when dry, and lacks plasticity when wet. Silt can also be felt by the tongue as granular when placed on the front teeth.
Windrow of windblown silt, Northwest Territories, Canada
A stream carrying silt from fields in Brastad, Sweden
A silted lake located in Eichhorst, Germany