A guelta (Arabic: قلتة, also transliterated qalta or galta; Berber: agelmam) is a pocket of water that forms in drainage canals or wadis in the Sahara. The size and duration will depend on the location and conditions. It may last year-round through the dry season if fed by a source such as a spring. When a river (wadi) dries up, there may be pockets of water remaining along its course (c.f. oxbow lake). In Western Sahara, gueltas correspond with oases.