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Foresight future floding Ian Meadowcroft, Environment Agency JimHall

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  1. Foresight future floding Ian Meadowcroft, Environment Agency JimHall University of Bristol, Department of Civil Engineering Paul Sayers, HR Wallingford

  2. Use best available science to provide a vision for flood and coastal defence, 2030 - 2100 Independent look Broad scope Sustainability analysis - economic, social and environmental consequences Aim of the project

  3. Phase 1 - Conceptual model, drivers and responses Phase 2 - Impacts (assuming no change in current policy) Phase 3 - Responses Reporting / hand over Project stages

  4. Overview of approach - The flooding system

  5. Probability and consequences Source - Pathway - Receptor Recognise a wide range of drivers and responses Holistic risk model ‘glued’ the team together - over 60 experts involved in providing information and data Also enabled integrated analysis of river, coastal and urban flooding Conceptual risk model

  6. . Drivers (Phase 2) Processes that change the state of the system Change in risk System descriptors System analysis Sources rainfall sea level marine storms etc. Pathways beaches, flood defences, urban surfaces fields, floodplains Receptors people houses industries infrastructure ecosystems Risk economic, risk to life, social, natural environment etc Change in risk Responses (Phase 3) Interventions that modify the behaviour of the system Overview of approach to risk

  7. Portfolios for catchment-scale flood-risk management National wealth does not keep pace with increasing risk. Abandonment of fluvial and coastal floodplains. Reinstatement of natural systems. Diversity of approaches across UK regions Low regulation and limited emphasis on the environment. Piecemeal engineering measures to reduce risk, centrally-managed with limited local capabilities Common menu of responses implemented under the four scenarios Free market provision of measures to reduce impacts of flooding and hedge risks. Major engineering measures to keep pace with increasing risk. Strategic regulation of development, management of runoff and reduction of impacts. Strategic soft engineering of rivers and coasts. Universal protection through public-private schemes

  8. Summary of Expected Annual Damage from the baseline analysis of flood risk Developing scenarios of future flood risk reduction policies

  9. Scenarios of engineering responses

  10. Quantified analysis of theresponse portfolios

  11. Distribution of the Indicative Flood Plain (2002)

  12. Dominant Valley Class (2002)

  13. Results are presented using six risk metrics Number of people living within the floodplain. Annual probability of flooding. Number of people at high risk of flooding. Expected Annual Damage (residential and commercial properties). Expected Annual Damage (agricultural). Social flood vulnerability. Results of quantified risk analysis

  14. No. of people within Indicative Flood Plain

  15. Emphasis on “managing” probability and impacts Emphasis on “defence” and reducing flood probability Probability of inundation - 2080s

  16. Probability of inundation - 2080s

  17. No. of people living with a high probability of being flooded - 2080s

  18. Expected Annual Damage (Property) - 2080s

  19. Expected Annual Damage (Property) - 2080s

  20. Aim: To provide an indication of the relative costs of implementation under each scenario Example - under GS scenario: Using engineering only: Cost £52 billion Using engineering and non-engineering: Cost £22 billion Analysis of implementation costs

  21. Note: Only the costs of engineering measures have been estimated (excluding non-structural interventions) Exclude land purchase, compensation or significant environmental mitigation Typical costs based on the Environment Agency national cost database Results of investment cost analysis

  22. Sensitivity analysis - High growth / low emissions scenario

  23. These are not the only flood risk management portfolios that would be consistent with the four future scenarios Major flood risk reduction is achievable under all scenarios Non-structural measures can make a major contribution to reducing the need for (and hence costs and impacts of) engineered flood defences. Achieving a low emissions future could reduce flood risk by 25% assuming a high growth economy is maintained - a significant contribution to reducing flood risk but not a panacea. Conclusions

  24. Continuing with existing messages is not an option Should we accept increasing risk, seek to maintain present risk, seek to reduce the risk? Risks need to be tackled across a broad front: Sustainable responses, particularly increased investment in defences, catchment-wide storage, land use planning and realigning coastal defences Reduce global emissions Need to develop science, skills and governance issues Action Plan published and the baton passed to Defra, EA and others. Big messages

  25. The project combined a new paradigm for combining cutting-edge science and futures analysis to inform policy. Information at Reports available from DTI Publications: Executive Summary Action Plan Volume 1 and 2 technical reports Finally...