Reflecting Societal Values in Designing Flood Risk Management Strategies

Abstract

In 2006, the Office of Public Works (OPW) began the National Catchment-based Flood Risk Assessment and Management (CFRAM) Programme through a series of pilot studies. A Multi-Criteria Analysis (MCA) Framework was developed through the pilot studies that integrated a number of objectives related to a wide range of potential impacts and benefits into the core of process of appraising and selecting suitable flood risk management measures for a given area or location, and then for prioritising national investments for different schemes and projects. This MCA Framework, that provides a systematic process of developing a non-monetised but numerical indicator of benefit and impact, has since been implemented nationally in the preparation of the Flood Risk Management Plans (FRMPs). A key feature of the MCA is that it should represent societal values. To this end, nationally representative quantitative research was undertaken to determine global weights that reflect the perceived importance of each of the objectives for reducing economic, social and environmental / cultural risks in flood management strategies. Saaty’s Analytical Hierarchy Process (AHP), in conjunction with a pair-wise comparison of criteria relating to these risks, was utilised to determine weights. In excess of 1,000 structured interviews were completed where the relative importance of these objectives were assessed using a seven-point scale. The weighting given to each of the 13 specific objectives identified broadly followed expectations, with risk to people followed by risk to homes and properties being respectively the first and second most important, although some were given greater or less weighting than expected. The national application of the MCA Framework, using the weighted objectives based on this process, through the CFRAM Programme has generally lead to the identification of appropriate and, based on local consultation, acceptable options for each community.