We All Live Downstream (Southern California)
As rivers flow, they pick up solid compouds such as salts, metals, and minerals, as well as some organic compounds from the landscape they flow through. These solids dissolve and affect the chemistry of the water. Although this process is natural, human activities can raise the concentrations of these dissolved solids to unhealthy levels, especially during drought years. More than half (56 percent) of the dissolved solids in the rivers and streams of the Southwest are attibuted to farming and ranching. In coastal southern California, dealing with dissolved solids in imported Colorado River water can cost up to 300 million dollarsper year.
Viewer Tip: Ultimately, reducing the amount of dissolved solids that make it into the water saves everybody money. One way to reduce the amount of dissolved solids inlocal waters is to cut down on pesticide and fertilizer use. If you do use these products, use no more than the prescribed amount and avoid application if rain is in the forecast. Also, avoid damaging streamside or wetland vegetation. This vegetation acts as a pollutant filter, helping to keep excess chemicals out of the water.
Seasons: Spring, Summer, Fall, Winter
(Sources: United States Geologic Survey: National Water Quality Assessment Program “Dissolved Solids in Basin Fill Aquifers and Streams in the Southwestern United States.” 2006. Accessed Online 29 November 2007 <http://pubs.usgs.gov/sir/2006/5315/sir2006-5315.pdf> and United States Environmental Protection Agency: Office of Wetlands, Oceans and Watersheds. Wetlands Facts. Accessed Online 29 November 2007 <www.epa.gov/owow/wetlands/facts/contents.html>)
