Water Erosion

Most soil loss due to water occurs because of high runoff events, such as heavy rainstorms. Soils are subject to water erosion throughout Alberta. Extreme rainstorms have led to serious soil loss events on farmland from Medicine Hat to Fort Vermillion. Measurements on a continuously cropped farm field near Tofield reported soil losses as high as 10 tonnes per hectare for the summer of 1996 as a result of a number of moderate rainstorms.

Fields with poor water infiltration as a result of clay-enriched, compacted, or hardened subsoil, are at increased risk of water erosion. These soils rapidly reach the point where they are unable to absorb more water. Any additional rainfall is then forced to move as surface runoff, carrying away the topsoil. Some soils are more prone to erosion for other reasons, such as steep slope. Protecting soil through good agricultural land management is the single most important factor in preventing serious water erosion.

Department of the Environment. State of the Environment Report, Terrestrial Ecosystems. Edmonton: n.p., 2001. With permission from Alberta Environment.