Cardiff Bay barrage: management of groundwater issues Available to Purchase

The Cardiff Bay barrage, a 1·1 km long structure across the mouth of Cardiff Bay impounding a 200 ha freshwater lake, was central to the UK government's urban development programme to regenerate the docklands area of Cardiff. The Cardiff Bay Barrage Act 1993 included a groundwater protection scheme for buildings, providing owner/occupiers with recourse to remedial works or compensation should circumstances prove that construction of the barrage caused or probably caused groundwater damage. To allow a comparison of pre- and post-impoundment groundwater levels underlying south Cardiff, a groundwater monitoring system comprising 236 automated data loggers covering an urban area of 15 km² was established between 1995 and 1999. To mitigate the possibility of a rise in groundwater levels in certain identified areas, various types of groundwater control systems were installed prior to impoundment in November 1999. Management (including collection and interpretation of data) and maintenance of such an extensive system have required great effort, resourcefulness and logistics. This paper presents a brief history of the scheme and an overview of the management of such a diverse and challenging groundwater project.