Changes

[[Image:EthiopianGullyPlug.jpg|thumb|right|300px|Rehabilitated gully in Adaga Lemne watershed, Axum, Tigray Province. Photo: Johan Rockstrom.]]

A check dam is a small, temporary or permanent dam constructed across a drainage ditch, gully, swale, or channel to lower the speed of concentrated flows (like an overflow weir) for a certain design range of storm events. They may be more categorized as a type of floodwater rather than a runoff harvesting technique. A check dam can be built from logs of wood, stone, pea gravel-filled sandbags or bricks and cement. They have been used widely in Kenya and India. These dams can also be made as [[leaky dams]]. Dams that have been built in riverbeds with no coarse sand transport ([[Sand dam]]s) may end up being used in this way. These structures are relatively cheap and can last about 2-5 years.