Cardiff Bay Barrage

Abstract

Cardiff Bay Barrage is one of the key elements in the urban regeneration of South Cardiff. This paper outlines the need for that regeneration and takes an overview of the barrage project. It considers the legislative process and the economic considerations that were necessary before the £120m structure could be constructed. Environmental considerations were important. The effect of the barrage on over-wintering wading birds and the loss of a Site of Special Scientific Interest had to be mitigated, a £10m fresh water habitat was constructed. Groundwater rise within the City of Cardiff consequent on construction of the barrage was reduced by provision of a dewatering system and a system of surveys on 25 000 properties ensure that any possible damage due to groundwater rise is identified and can be rectified. Water quality issues including oxygenation of the bay are considered. The barrage design is outlined as an introduction to subsequent papers. The contractual issues are discussed, the out-turn cost was only 5% above the estimated out-turn cost when the project commenced on site. The development outputs predicted when the project was under consideration have been achieved and the economic return on the project shows a pay back period of less than 2 years