Flood and Coastal Risk Management - A Risk Based Approach David Rooke Head of Flood & Coastal Risk Management 20 March 2009
Risk Significant risks to the delivery of Defra s outcomes in this area Consequence Flood and coastal erosion are natural events that cannot always be prevented or predicted in advance. Flooding can happen at any time. Policy is about managing the risk proactively - not eliminating all flooding and not waiting to shut stable doors. Requires long term commitment funding pressures often increase following major flooding but more effective to invest strategically in advance. Hence importance of long term investment strategy. Current infrastructure provides a variable standard of service and there are big residual risks despite ongoing programme (over 1 billion remaining average annual economic damage) which arise from a combination of relatively low protection in some areas and extreme events. Floodplain, coastal and socioeconomic development Flood / erosion warning & awareness; development control and improved resilience Maintained & improved infrastructure Deteriorating infrastructure & climate change Probability
Managing flood risk (Reduce, share, transfer, eliminate, accept) New, improved and well maintained defences Steer development away from high flood risk areas Diverting flood water to unpopulated land Better land management More serious consequences of flooding Floods of greater severity due to climate change Higher value property and contents Loss of insurance cover New development in high flood risk areas Lower likelihood of flooding Current flood risk Higher likelihood of flooding Good flood forecasts and widely received warnings Improved property-level protection Effective preparation and emergency response Help with recovery Less serious consequences of flooding More frequent and more severe extreme weather Deterioration of defences Hardening of surfaces due to development Deforestation and loss of vegetation cover Soil degradation
Risk Based Approach
Flood Risk Model Pathway (e.g. defence) Receptor (floodplain) Source (River or sea)
Evidence and Current Position What is the problem that we are trying to tackle? River and tidal flooding threat is widespread Annual estimated damages from flooding over the long term: With current measures: 1bn per year Do nothing: more than 3bn per year Could increase to 27bn per year by 2080 without mitigation measures Over 2 million properties in flood risk areas. Forecasting and Warning systems important for evacuation and reducing risk to life Government annual investment in risk management currently 600m. Major capital bid in SR07 importance of long term investment strategy Map shows the extreme flood outline in blue (areas having a chance of being flooded in any year by a 1 in 1000 probability event). Managing risk involves effective use of a broad portfolio of measures, not just building bigger defences.
Changes in Risk economic damages
Sources e.g. rivers, seas, sewers Planning Policy Statement 25 (PPS25) Strategic risk based approach to development taking account of all forms of flood risk Directs vulnerable development away from high risk areas Accept some development may be needed for broader reasons Reduce existing and future flood risk to communities
Pathways e.g. flood defences & floodplain We want to reduce the likelihood of flooding by improving the condition and maximising the performance of the flood defence asset infrastructure over the whole life cycle.
Receptors e.g. people, property & environment national risk assessment allows us to identify those areas at highest risk we provide flood maps to help the public identify their risk of flooding and offer a free flood warning service to those in flood risk areas Environment Agency Flood Map
Living out of harm s way eliminate? Number planning applications 8,000 6,000 2,543 6,232 4,000 2,393 Withdr awn 2,000 0 124 of whic h 16 were major developments Approved against EA advice 32 Referred to Secretary of State 1,140 Rejected Local Authority action Amend ed Amended Developer action EA not notified of outcome EA flood risk objections Data from High Level Target 5 report for 2007-08
Impact of flooding HIGH e.g. LUB A/B or Habs Regs sites protected. MEDIUM e.g. LUB C, or SSSI's protected LOW e.g. LUB D/E 1 2 3 4 HIGH HIGH HIGH HIGH 5 6 7 8 LOW MEDIUM MEDIUM HIGH 9 10 11 12 LOW LOW LOW MEDIUM Low -Negligable risk to life. e.g. small/medium w atercourses, defences protecting agricultural land, Category D FSRs. Medium- Time likely to be available for evacuation in event of failure. e.g. significant w atercourses w ithout raised defences, diversion channels, Category C FSRs, etc High- Little w arning of flooding to residential or commercial property e.g raised defences. Very High- Little w arning of failure. Possible loss of life/major injury. Sudden impact to vulnerable groups. e.g. very significant raised defences or category A/B FSRs. Very significant structures. Potential Impact on People from System Failure taken from Environment Agency Work Instruction 148_05, 2005 Risk matrix for asset management
Protecting communities flood defences 60% Condition of linear defences 50% Leng gth of defences Total number of households with improved prote ection since 2003 40% 30% 20% 10% 0% 450000 400000 350000 300000 200000 150000 100000 50000 0 Cumulative households Cumulative expenditure 250000 Very Good Good Fair Poor very poor Asset Condition grade % fit for purpose Environment Agency 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 or 2011/12 maintained Year 1800 1600 1400 1200 1000 800 Defences E.g. flood walls and embankment s 600 400 200 0 ovements Total capital expenditure since 2003 on impro programme ( m) Structures E.g. pumping stations, barriers, sluices and outfalls 95.0% 96.4% 3rd party maintained 87.2% 96.5%
Keeping essential services running Railways Major Roads Wastewater Treatment Works Water Treatment Works Sewage Treatment Works Pumping Station Gas Works Gas Sub-Station Gas Station Gas Distribution Electricity Sub-Station Electricity Generating Station Communication Stations Prisons Stadia Ambulance Stations Hospitals Fire Stations Police Stations Day Nurseries Campsite & Caravan Park School Surgeries / Health Centre Community/Leisure Centres 0.0% 10.0%20.0%30.0%40.0%50.0%60.0%70.0% Significa nt Percentage (%) Data from NaFRA 2008
Properties at flood risk across regions and local areas South East England Boston Regional District Assembly South East West Lindsey Regional District Assembly East Midlands North Regional Somerset Assembly Windsor and Maidenhead Yorkshire & Humber Assembly City of Kingston upon Hull East of England Regional Assembly Shepway District Greater London Authority Sedgemoor District North West Regional Assembly East Riding of Yorkshire West Midlands Runnymede Regional District Assembly North East Regional Warrington Assembly 0 0 20,000100,000 40,000 200,000 60,000 300,000 80,000 400,000 100,000 500,000 120,000 600,000 140,000 Low chance Moderate chance Significant chance Data from NaFRA 2008
Catchment Flood Management Plans Policy 1 Areas of little or no flood risk where we will continue to monitor and advise Policy 2 Areas of low to moderate flood risk where we can generally reduce existing flood risk management actions Policy 3 Areas of low to moderate flood risk where we are generally managing existing flood risk effectively Policy 4 Areas of low, moderate or high flood risk where we are already managing the flood risk effectively but where we may need to take further actions to keep pace with climate change Policy 5 Areas of moderate to high flood risk where we can generally take further action to reduce flood risk Policy 6 Areas of low to moderate flood risk
Figure 1 Flood Warning risk matrix for fluvial risk locations 10000 1:10,000 1:1,000 1:100 50 25 1:10 5 1:1 LHH LHM HHH(a) HHH(b) 1000 LHL HHM 100 rties Proper LLM HLH 10 LLL HLM HLL 1 LO 10.01% 0.1% 10 Probability 100 1% 1000 10% 10000 100% HO 2 3 4 5 6 7 8 9
Investment Long Term Investment Strategy (LTIS) Recommended by Pitt Review and the EFRA Select Committee (2008) Covers investment needs for 2010-2035 Looks at risk, how to manage it and costs over the next 25 years