Integrated Flood Risk Analysis and Management Methodologies Evaluating flood damages: guidance and recommendations on principles and methods Date January 2007 Report Number T09-06-01 Revision Number 2_2_P44 Deliverable Number: D9.1 Due date for deliverable: October 2005 Actual submission date: January 2007 Task Leader UFZ FLOODsite is co-funded by the European Community Sixth Framework Programme for European Research and Technological Development (2002-2006) FLOODsite is an Integrated Project in the Global Change and Eco-systems Sub-Priority Start date March 2004, duration 5 Years Document Dissemination Level PU Public PU PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) CO Confidential, only for members of the consortium (including the Commission Services) Co-ordinator: HR Wallingford, UK Project Contract No: GOCE-CT-2004-505420 Project website: www.floodsite.net FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 DOCUMENT INFORMATION Evaluating flood damages: guidance and recommendations on Title principles and methods Frank Messner, Edmund Penning-Rowsell, Colin Green, Volker Lead Authors Meyer, Sylvia Tunstall, Anne van der Veen Sue Tapsell, Theresa Wilson, Joerg Krywkow, Christiaan Logtmeijer, Contributors Amalia Fernández-Bilbao, Peter Geurts, Dagmar Haase, Dennis Parker Distribution Public Document Reference T09-06-01 DOCUMENT HISTORY Date Revision Prepared by Organisation Approved by Notes 30/9/05 1_1_Pn44 Meyer UFZ Messner 12/10/05 2_1_Pn44 all Chapter 2: UFZ 3, 5 & 7: FHRC 4 & 6: UT 14/10/05 3_0_Pn44 Messner UFZ 24/10/05 3_2_Pn44 Haase UFZ Meyer Contribution on Inundation Modelling 15/12/05 3_3_Pn44 Meyer UFZ Messner Include comments in section 2 from CG and CL 20/01/06 4_0_Pn44 Meyer, all Chapter 1&2: Messner • New: Chapter 1&2 UFZ/FHRC • Revision of all other chapters Ch. 3: UFZ Ch. 4, 6, 8: FHRC Ch. 5, 7: UT 23/01/06 4_1_Pn44 Messner UFZ and Task meeting this version will be discussed in task comments of meeting in Braunschweig FHRC on chapter 2 27/03/06 5_0_Pn44 All Messner Revision after Braunschweig meeting 26/04/06 5_1_P01 J Bushell HRW Formatting changes, addition of due date for deliverable, adjustment of dissemination level to PU 09/05/06 5_2_P01 J Bushell HRW Correction of deliverable number to D9.1, minor edits, formatting 09/05/06 1_0_P01 J Bushell HRW Change of name from ‘30_03_06_Guidelines_for_socio- economic_flood_damage_evaluation_ v5_2_P01’, insertion of summary text and final formatting 10/01/06 2_0_P44 Meyer UFZ Messner Final Revision: Inclusion of comments received from experts 27/01/07` 2_1_P10 Penning- FHRC Meyer Minor edits, new edition of chapter 8 Rowsell, Parker, Tapsell 15/02/07 2_2_P44 Meyer UFZ Messner Change of title, as agreed after task review 04/04/07 J Bushell HRW Final formatting for publication T09_06_01_Flood_damage_guidelines_D9_1_v2_2_p44.doc 16 02 2007 ii FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 ACKNOWLEDGEMENT The work described in this publication was supported by the European Community’s Sixth Framework Programme through the grant to the budget of the Integrated Project FLOODsite, Contract GOCE-CT- 2004-505420. DISCLAIMER This document reflects only the authors’ views and not those of the European Community. This work may rely on data from sources external to the FLOODsite project Consortium. Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data. The information in this document is provided “as is” and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and neither the European Community nor any member of the FLOODsite Consortium is liable for any use that may be made of the information. © FLOODsite Consortium T09_06_01_Flood_damage_guidelines_D9_1_v2_2_p44.doc 16 02 2007 iii FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 Page intentionally blank T09_06_01_Flood_damage_guidelines_D9_1_v2_2_p44.doc 16 02 2007 iv FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 SUMMARY Recent events like the 15 extreme floods that occurred 2002 in various parts of Europe showed that floods continue to pose serious risks in many EU countries. Indeed there is evidence that flooding is getting more serious over time, in terms of the number of floods occurring as well as the damage and the loss of life being caused. The social purpose of flood risk management is to reduce flood damages. Since flood risk management strategies can require a significant diversion of resources from other purposes, it is desirable to determine whether the reduction in flood damages justifies the resources so expended. Equally, only if we are in a position to evaluate alternative intervention strategies in terms of their relative benefits and costs we are able to make ‘better’ choices and introduce more effective flood risk management strategies. As a consequence, the quantification and evaluation of flood damage is practised in a growing number of EU countries as an important factor to be considered in the decision process about particular flood risk management measures. Unfortunately, the methods used are quite diverse and they sometimes do not reflect the state-of-the-art in flood damage evaluation. The major purpose of these guidelines is, therefore, to give guidance for practitioners of governmental authorities and executing bodies dealing with ex-ante flood damage evaluation in order to appropriately appraise public flood defence projects or strategies on different spatial scales. With these guidelines we want to address a large community. On the one hand, we want to give guidance to countries just starting with flood damage evaluation studies. For this group we want to demonstrate how to proceed step by step in flood damage evaluations (especially chapters 3-4). Chapter 3 describes the state-of-the-art in evaluating direct, tangible flood damages. This chapter can be used by practitioners of countries with few or even no experience in flood damage evaluation in order to find an appropriate start into the endeavour of applying flood damage evaluation as a decision support tool. Chapter 4 reveals the principal rules and the procedure of building up a proper flood damage data base in order to ensure a consistent set of flood damage data, which is needed if flood damage evaluation is to be used as a long-term decision support tool. On the other hand, we want to address flood damage evaluators in countries which already possess some experience in this field and we offer our guidelines to them as a checklist and want to inspire them to improve their evaluation methodology, e.g., by including methods for damage types which have been neglected hitherto in their work (especially chapters 5-9). Chapter 5 outlines the approaches to evaluate flood effects on industrial production. Chapter 6 indicates possible procedures to include social flood effects. Environmental flood effects and methods of their evaluation are described in chapter 7. Thereafter, chapter 8 focuses on damage reducing effects of flood warning in order to support specific decisions on flood warning systems. Chapter 9 gives an overview of flood damage categories which have not been considered in more detail in these guidelines and indicates relevant literature sources for further reading. Last but not least we want to provide fundamental standard knowledge, specify key principles for economic evaluation of damages and reveal the sources of uncertainty that need to be considered. Hence, we want to help preventing errors in flood damage studies (chapter 2). T09_06_01_Flood_damage_guidelines_D9_1_v2_2_p44.doc 16 02 2007 v FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 Page intentionally blank T09_06_01_Flood_damage_guidelines_D9_1_v2_2_p44.doc 16 02 2007 vi FLOODsite Project Deliverable D9.1 Contract No:GOCE-CT-2004-505420 CONTENTS Document Information ii Document History ii Acknowledgement iii Disclaimer iii Summary v Contents vii 1. Introduction: Purpose of these guidelines ............................................................................. 1 1.1 Floods and the damage that they cause..................................................................... 1 1.2 Our target audience: stakeholders in flood damage assessment ............................... 2 1.3 The purpose of these Guidelines............................................................................... 3 1.4 The content of these Guidelines ............................................................................... 3 1.5 A ‘health warning’.................................................................................................... 3 2. Fundamental issues in the economic evaluation of flood damage ........................................ 5 2.1 Principles of good enquiry........................................................................................ 5 2.2 Validity and reliability.............................................................................................. 5 2.3 Flood damage evaluation as a decision support........................................................ 6 2.4 Types of flood damages............................................................................................ 9 2.5 Six key principles of economic evaluation............................................................