Varying proportions of sediment from eroding fields may be delivered to surface ponding basins depending on topography, distance, and land cover. Sediment harms ponded water when excessive amounts collect clouding the water and coating the leaves of plants. That deprives them of sunlight needed for growth. The deposition of sediment reduces the useful life of reservoirs, clogs ditches and irrigation canals, blocks navigation channels, resulting in increased dredging costs. The most dramatic effect of sediment buildup is the raising of stream beds and burying streamside wetlands.
Sediment can also increase the likelihood and severity of floods.
In addition, suspended sediment can increase the cost of water treatment for municipal and industrial water users. According to EPA, siltation is one of the leading pollution problems in U.S. rivers and streams, and among the of four problems in lakes and estuaries. The USGS Report concludes that San Joaquinw Valley well water is the exclusive source of drinking water for nearly 3 million Valley residents and is safe to drink. Water Quality in the San Joaquin-Tulare Basins . By The Fresno Daily Republican Newspaper.