A structure across a river or estuary, built in order to restrain or use water. Brichieri-Columbi and Bradnock (2003) Geog. J. 169, 1 discuss the development of a barrage for the Ganges–Brahmaputra–Meghna waters: which ‘would cause negligible population displacement, and making maximum use of existing river channels would minimize the environmental impacts associated with large canal or dam construction’.