Ditch A ditch is usually defined as a small to moderate depression created to channel water . In Anglo - Saxon , the word " dïc " already existed and was pronounced " deek " in northern England and " deetch " in the south . The origins of the word lie in digging a trench and forming the upcast soil into a bank alongside it . This practice has meant that the name " dïc " was given to either the excavation or the bank , and evolved to both the words " dike " / " dyke " and " ditch " . Thus Offa ' s Dyke is a combined structure and Car Dyke is a trench , though it once had raised banks as well . In the midlands and north of England , and in the United States , a dike is what a ditch is in the south , a property boundary marker or small drainage channel . Where it carries a stream , it may be called a running dike as in " Rippingale Running Dike " , which leads water from the catchwater drain , Car Dyke , to the South Forty Foot Drain in Lincolnshire ( TF1427 ) . The Weir Dike is a soak dike in Bourne North Fen , near Twenty and alongside the River Glen . A ditch can be used for drainage , to drain water from low - lying areas , alongside roadways or fields , or to channel water from a more distant source for plant irrigation . A trench is a long narrow ditch . Ditches are commonly seen around farmland especially in areas that have required drainage , such as The Fens in eastern England and the Netherlands . Roadside ditches may provide a hazard to motorist s and cyclists , whose vehicles may crash into them and get damaged , flipped over or stuck , especially in poor weather conditions , and in rural areas . Sustainability of drainage ditches . Drainage ditches play major roles in agriculture throughout the world . Improper drainage systems accelerate water contamination , excessively desiccate soils during seasonal drought , and become a financial burden to maintain . Industrial earth - moving equipment facilitates maintenance of straight drainage trenches , but entrenchment results in increasing environmental and eventually profound economic costs over time . Sustainable channel design can result in ditches that are largely self - maintaining due to natural geomorphological equilibrium . Slowed net siltation and erosion result in net reduction in sediment transport . Encouraging development of a natural stream sinuosity and a multi - terraced channel cross section appear to be key to maintain both peak ditch drainage capacity , and minimum net pollution and nutrient transport . Flooding can be a major cause of recurring crop loss — particularly in heavy soil s — and can severely disrupt urban economies as well . Subsurface drainage to ditches offers a way to remove excess water from agricultural fields , or vital urban spaces , without the erosion rates and pollution transport that results from direct surface runoff . However , excess drainage results in recurring drought induced crop yield losses and more severe urban heat or desiccation issues . Controlled subsurface drainage from sensitive areas to vegetated drainage ditches makes possible a better balance between water drainage and water retention needs . The initial investment allows a community to draw down local water table s when and where necessary without exacerbating drought problems at other times .