Erosion is the detachment of soil particles from clods and the soil surface. Most of this occurs during rain storms which can detach or loosen up to 100 tons of soil per acre in a severe storm. The detached soil can be transported by agricultural runoff which dislodges additional soil particles as it flows across unprotected soil surfaces. Heavier soil particles may settle out in bottomlands and on footslopes before reaching a body of water. This eroded soil can cover and destroy young plants and cause future drainage problems.
Sediment fills streams, rivers, reservoirs, lakes and roadside ditches, reducing their useful life.
In addition to loss of storage capacity, the sediment fills water bodies and can impair water quality. When runoff enters a water course, the lighter soil particles may remain in suspension and block sunlight vital to the growth of desirable, oxygen-producing plants living in the water. Sediment-darkened water also absorbs more heat from sunlight than clearer water, thus causing warming. The combination of warm and muddy water leads to the replacement of desirable fish species with less desirable types more tolerant to these conditions. Nutrients and pesticides that may be present in agricultural runoff also cause serious problems.