Cardiff Bay Barrage: planning and design

Abstract

In 1986 Mr Peter Walker, Secretary of State for Wales, accepted the view that the Cardiff Bay area was in urgent need of urban renewal. The government, with support from the Vale of Glamorgan, the county of South Glamorgan and the City of Cardiff, created the Cardiff Bay Development Corporation (CBDC). Its remit was to regenerate some 1100 ha in this area of south Cardiff. The keystone to this strategy was the construction of the Cardiff Bay Barrage, to impound the estuaries of the rivers Taff and Ely, creating a 200 ha fresh water lake and about 12 km of attractive waterfront. Works of this magnitude and scope on tidal waters at that time required an Act of Parliament. The 1100 m long barrage includes sluices, locks, an outer harbour, fish pass, embankment and bridges. The sluices have a capacity of 2300 m3/s, to discharge combined flood flows from the Taff and Ely. The gates close to exclude the highest tides, allowing bay water levels to be controlled even in extreme conditions. A large fish pass allows migratory fish to move easily between the rivers and the sea. The paper describes the overall objectives of the Cardiff Bay Barrage, and the design of the barrage.