426-722 (HORT-242NP) Soil erosion occurs when soil particles are carried off by water or wind and deposited somewhere else such as into a stream or at the bottom of a bay. Often soil particles are carried by runoff, water that does not soak into the ground, but flows over the surface and runs to another area â€“ such as into storm drains, streams, or lakes. In addition to soil sediment, runoff can wash fertilizer and other pollutants along with it. Sediment makes up most of the pollutant carried by runoff, however, and most of the phosphate and pesticides entering Virginiaâ€™s waters are attached to these sod particles. Therefore, controlling erosion will make a significant contribution to the control of water pollution. Runoff entering lakes and stream, in addition to carrying pollutants, is water that is needed to soak through the soil to resupply our groundwater. Reducing erosion and runoff is important to protect both our soils and our water supplies. Erosion and runoff in the home landscape also create unsightly bare areas and deposit mud and dust on driveways and walkways that is then tracked into the house.