Flood defence in an urban environment: the Lewes Cliffe scheme, UK

Abstract

Flood defences are designed to help reduce the risk of inundation to people and property in the urban environment. Yet these areas are often the most difficult to fit new infrastructure assets into, particularly given historical riverside development, planning regulations and constraints. The southern UK town of Lewes, near Brighton, has a history of significant flooding events. The 2000 event inundated over 800 properties in up to 3·6 m of water, causing many months of disruption. In response, lead flood operating authority the Environment Agency has recently installed new river defences through the Cliffe part of the town. The justification, design and construction of the scheme, in confined spaces, through a conservation area with listed structures, several landowners and in an affordable way for the taxpayer, have raised myriad issues. This paper looks at how this scheme progressed and fitted into the Environment Agency's capital programme, and identifies the key challenges for the designers which were particular to the project, but which have a wider application to other works. The paper examines how an iterative approach and close working within a multidiscipline team helped to resolve the many technical and managerial challenges, which has led to the award-winning project being successfully completed on time and within budget.