Rhyne

A rhyne (Somerset), rhine/rhyne (Gloucestershire), or reen (South Wales) (all pronounced /ˈriːn/ "reen"; from Old English ryne or Welsh rhewyn or rhewin "ditch") is a drainage ditch, or canal, used to turn areas of wetland at around sea level into useful pasture.

Water levels (and hence the level of the water table) will usually be controlled by a system of sluice gates and pumps, allowing the land to become wetter at times of the year when this will improve grass growth. Rhynes represent an early method of swamp or marsh drainage. Large sections of swampland were surrounded by trenches deep enough to drain the water from the encircled mound and leave the land relatively dry. Regular clearing and dredging is necessary to keep the rhynes clear of debris so that they flow freely.

Rhynes have been used extensively in the United Kingdom, especially on marshy coastal areas such as the Somerset Levels, and the North Somerset Levels. Other examples in England still exist in the Framilode and Saul area of Gloucestershire, where they drain into either the River Severn or Sharpness Canal, and around Easter Compton, South Gloucestershire. In southeast Wales, they can be found on the Caldicot and Wentloog Levels. Many of them are still in use today.