The urban development of Cardiff Bay underwent significant changes over the 20th century. In the 19th century, Cardiff Bay prospered as an industrial port due to its coal and iron resources. However, in the 20th century exports declined as overseas markets were lost in the wars and other countries produced steel cheaper. By the 1980s, the area was largely derelict with unemployment and empty buildings. To regenerate the area, the Cardiff Bay Development Corporation was created in 1987 and constructed a barrage to create a freshwater bay, attracting new housing, services, and tourism but flooding important tidal habitats.