Erosion is the process by which soil particles are detached from the earth at one location and transported somewhere by the forces of moving water or by wind. Sedimentation is the deposition of these eroded soil particles at another often undesired location. While erosion is a natural process that occurs continuously at differing rates at varied locations, human activities can accelerate this process by construction and development. The attachment of contaminants such as nutrients and heavy metals to eroded soil particles and the fine soil particles themselves can present a potential threat to water resources.

Erosion control is the practice of using various measures to stabilize exposed areas and/or other areas prone to erosive forces, such as riverbanks. Erosion control measures are varied and are used to stabilize bare soil conditions and concentrated flow channels such as waterways, diversions, and ditches. Temporary erosion control measures during construction, such as mulching, serve to protect the soil surface against detachment of soil particles during rain events. Permanent erosion control measures, such as stone-lined road ditches serve to protect the underlying soil from being detached from concentrated flows for the long term. Properly planned and installed erosion control measures help to minimize the potential downstream impacts of erosion and sedimentation.

A stone-lined reinforced bank often called "rip-rap" is a common erosion control method, shown here on the shoreline of a lake, used to help stabilize the bank from the continued erosive forces of wave action and ice movement, especially when vegetative measures are not strong enough to stabilize these areas.
An open top culvert, shown here being installed, is generally constructed of treated wood and is used to divert and direct runoff away from the gravel roadway into a stabilized area, such as a well vegetated area, to diminish the potential of runoff flows detaching soil particles off the roadway further downhill.
Steps filled with small stone, shown here at a home near a lake, is a method used to terrace a hillside and encourage infiltration of precipitation into the underlying soil rather than running off, potentially carrying soil and/or nutrients with it.
A winding path, shown here, shows a thick layer of bark mulch installed, used to help cover and stabilize a bare soil condition in close proximity to the lake.