EUROPEAN COMMISSION Ecoflood Guidelines HOW TO USE FLOODPLAINS FOR FLOOD RISK REDUCTION Edited by M.S.A. Blackwell and E. Maltby with A.L. Gerritsen, M. Haasnoot, C.C. Hoffmann, W. Kotowski, E.J.T.M. Leenen, T. Okruszko, W.E. Penning, H. Piórkowski, M. Platteeuw, E.P. Querner, T. Siedlecki and E.O.A.M. de Swart Directorate-General for Research 2006 Sustainable Development, Global Change and Ecosystems EUR 22001 Europe Direct is a service to help you find answers to your questions about the European Union Freephone number: 00 800 6 7 8 9 10 11 LEGAL NOTICE: Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information. The views expressed in this publication are the sole responsibility of the author and do not necessarily reflect the views of the European Commission. A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa server (http://europa.eu.int). Cataloguing data can be found at the end of this publication. Luxembourg: Office for Official Publications of the European Communities, 2006 ISBN 92-79-00962-1 © European Communities, 2006 Reproduction is authorised provided the source is acknowledged. Printed in Belgium PRINTED ON WHITE CHLORINE-FREE PAPER The Ecoflood Project This document is the result of the Ecoflood Project “Towards natural flood reduction strategies” funded by the European Commission. Ecoflood Consortium Partners Grontmij, Consulting Engineers, The Netherlands (Project Co-ordinators) Evalyne de Swart, Imke Leenen, Frank Vliegenthart Department of Nature Protection in Rural Areas – Institute for Land Reclamation and Grassland Farming IMUZ,Poland Wiktor Kotowski, Hubert Piórkowski, Tomasz Siedlecki Research Institute for Inland Water Management and Waste Water Treatment (RIZA), The Netherlands Maarten Platteeuw Department of Hydraulic Engineering and Environmental Recultivation - Warsaw Agricultural University (SGGW), Poland Tomasz Okruszko, Dorota Morawska WL Delft Hydraulics, The Netherlands Ellis Penning, Harm Duel, Marjolijn Haasnoot National Environment Research Institute (NERI), Denmark Carlos Hoffmann Alterra, The Netherlands Erik Querner, Alwin Gerritsen Royal Holloway, University of London, UK Edward Maltby, Martin Blackwell Now: Institute for Sustainable Water, Integrated Management and Ecosystem Research (SWIMMER), University of Liverpool Graphic design and layout of inside pages: Wydawnictwo IMUZ, Falenty, Poland 7∆ΕΟΗ&ΡΙ&&ΡΘΩΗΘΩς& Acknowledgements..........................................................................................................................................7 Executive summary (Edward Maltby, Martin Blackwell) .................................................................................9 3∃57&,&″&,ΘΩΥΡΓΞΦΩΛΡΘ...................................................................................................................15 About these guidelines (Martin Blackwell, Edward Maltby)...........................................................................17 What are the objectives of this publication?...........................................................................................17 Who should use these guidelines?.........................................................................................................17 What is the scope of the guidelines?......................................................................................................18 3∃57&,,&″&%∆ΦΝϑΥΡΞΘΓ ...................................................................................................................19 Flooding in Europe (Evalyne de Swart) .........................................................................................................21 Why do we need to do something about flooding? ................................................................................21 Why has flood risk and vulnerability increased? ....................................................................................22 Restoration of flooding on floodplains (Martin Blackwell, Edward Maltby).................................................24 Why should we restore flooding on floodplains? ...................................................................................24 How have floodplains been impacted?...................................................................................................24 Flood risk management (Evalyne de Swart)..................................................................................................27 What are flood risk and risk management? ...........................................................................................27 What approaches can be taken to flood risk management? .................................................................27 What problems are associated with technical flood risk reduction measures? .....................................30 What is a natural flood defence? ...........................................................................................................30 Floodplain processes, functions, values and characteristics (Edward Maltby, Martin Blackwell)............33 What are floodplain processes and functions? ......................................................................................33 How can we benefit from restoring naturally functioning floodplains? ...................................................34 What is floodplain rejuvenation? ............................................................................................................34 The main characteristics of naturally functioning floodplains (Evalyne de Swart, Tomasz Okruszko, Hubert Piórkowski).................................................................................................................................36 What are the interactions between river channels and floodplains?......................................................36 Which factors shape floodplains? ..........................................................................................................36 3∃57&,,,&″&∗ΞΛΓΗΟΛΘΗς....................................................................................................................39 Natural flood defences can contribute to flood risk management (Tomasz Okruszko, Erik Querner).....41 What are the main hydrological functions of naturally functioning floodplains?.....................................41 What hydrological factors should I consider when implementing a natural flood defence scheme? ....46 How can I determine the effectiveness of different measures? .............................................................46 Naturally functioning floodplains affect water and soil quality (Carlos Hoffmann, Martin Blackwell)......46 What are the main functions and processes performed by floodplains that affect water and soil quality? ..............................................................................................................................48 What should I consider with regard to floodplain biogeochemistry when restoring floodplain functioning?............................................................................................................................55 Floodplain restoration contributes to nature conservation (Maarten Platteeuw, Wiktor Kotowski) .........60 How do plants and animals respond to natural river dynamics?............................................................60 What has been lost and why? ................................................................................................................64 What should I consider with regard to nature conservation when restoring floodplain functioning? .....64 The roles of floodplains from a socio-economic perspective (Ellis Penning, Alwin Gerritsen, Erik Querner, Evalyne de Swart, Marjolijn Haasnoot, Imke Leenen).....................................................71 How can I assess the socio-economic values of floodplains? ...............................................................71 How can I assess the socio-economic consequences of changing floodplain use? .............................71 What should I consider with regard to socio-economics when restoring floodplain functioning? ..........74 What should I consider with regard to floodplain landscape when restoring floodplain functioning? ....74 What should I consider with regard to human health when restoring floodplain functioning? ...............79 Organising a floodplain restoration project (Ellis Penning, Maarten Platteeuw, Carlos Hoffman).............83 Where do I start?....................................................................................................................................83 What are the main things I should do?...................................................................................................86 What are the main obstacles I am likely to encounter?..........................................................................90 How can I fund a floodplain restoration project? ...................................................................................90 What are the characteristics of a successful floodplain restoration scheme?........................................93 Existing international policy and floodplain management? (Maarten Platteeuw, Tomasz Okruszko, Edward Maltby).......................................................................................................................................94