Erosion control is an important part of the restoration of waters. Collapsing banks and the leaching of nutrients and sediment as a result of fluctuating water levels turn water turbid, increase nutrient concentrations, and make water bodies silted up and shallow. In flowing waters, the spawning gravels of fish are particularly susceptible to silting.
The need for protection against erosion should be assessed on a case-by-case basis for each restoration plan. Erosion protection is generally used to prevent banks from washing away, in which case the protection is based on vegetation or geotextiles. In channel erosion control, means of erosion protection can be placed at the bottom of the channel. Bottom sills are the usual method used.