DTI SAM - System Based Analysis and Management of Urban Flood Risks: Project Overview

The responsibility for urban flooding is, at present, broadly divided between the water companies (with responsibility for the urban drainage systems), the local authorities for road and rural drainage and the Environment Agency (with responsibility for management of fluvial and coastal floods). This project builds upon the widely recognised belief that, to be effective, flooding has to be managed in a more integrated manner. Such an approach would consider flooding from fluvial, coastal and pluvial sources and all possible management responses (including modification to surface/sub-surface infrastructure). The need for a system-based management approach has been reinforced through a number of recent documents, including: the Foresight Future Flooding project (by the OST); Living with Rivers (by the ICE); and the Defra strategy Making Space for Water. The techniques and technologies to enable a fully integrated risk based assessment of urban flooding and the appraisal of strategic portfolios of options are, however, not yet developed. This project will provide new tools to model the complex urban drainage system and facilitate the delivery of a procedure for an integrated flood risk management approach.
The key innovation lies in the development of a risk based method of approach capable of exploring the performance of multiple flood management strategies within a single coherent analysis framework. Achieving this represents a significant challenge. In particular, systematic techniques to enable options to be tested and appraised within the context of a large-scale and complex system of sources, pathways and receptors of flood risk will need to be developed and proven. To add further difficulty, the urban system is dynamic in time. An understanding of how the system and management options behave over time will also need to be considered for developing strategic management choices. The methods will, therefore, necessarily also reflect the temporal processes and require a whole life comparison of benefits and costs.