Since the early 1980s there has been a growing awareness that flood risk management strategies need to be implemented in parallel with measures to protect the aquatic environment. In the United Kingdom various reports and publications have highlighted the benefits of this approach (Soper and Purseglove, 1989; Gardiner, 1991; Fleming, 2001; Defra, 2005). All of these argue for the integration of natural flood management approaches with other flood risk management measures, such as, flood defence infrastructure and flood warning schemes. In fact this combined approach is enshrined in EU legislation through the Water Framework Directive, the overarching aim of which is to ensure, "long-term sustainable water management based on a high level of protection of the aquatic environment" and the Floods Directive requiring Member States to "assess if all water courses and coastlines are at risk from flooding, to map the flood extent and assets and humans at risk in these areas and to take adequate coordinated measures to reduce this flood risk."
Clearly, natural flood management approaches possess the potential to enhance sustainable water management and reduce flood risk. The key question however is to what extent the protection they afford is adequate, in the sense required by the Floods Directive. At the present time the implementation of natural flood management approaches is limited by a lack of hard evidence regarding their long-term performance, robustness, scalability and maintenance needs. This paper will review the increasing evidence base on the performance of natural flood management processes and draw conclusions of their future role in a portfolio approach to effective flood risk management. 1. Soper, T. and Purseglove, J., 1989, Â“Taming the Flood: History and Natural History of Rivers and WetlandsÂ”, A Channel Four Book. 2. Gardiner, J.L., 1991, Â“River Projects and Conservation: A Manual for Holistic Appraisal, John Wiley and Sons, Chichester, UK 3. Fleming, G., 2001, Â“Learning to Live with RiversÂ” Proceedings of the ICE - Civil Engineering, Volume 150, Issue 5, 01 May 2002 , 4. Defra, 2005a. Making Space for Water: Taking Forward a New Government Strategy for Flood and Coastal Erosion Risk Management in England. First Government Response to the Autumn 2004 Making Space for Water Consultation Exercise, London: Department for the Environment, Food and Rural Affairs. 5. Defra. 2005b. Making Space for Water: Taking Forward a New Government Strategy for Flood and Coastal Erosion Risk Management in England. Delivery Plan, London: Department for Environment, Food and Rural Affairs. 6. European Commission, Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy 7. EU. 2007. Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks. Official Journal of European Communities, L288/27