UK Climate Risk Independent Assessment (CCRA3) Technical Report Chapter 4: Infrastructure Lead Authors: David Jaroszweski, Ruth Wood, Lee Chapman Third UK Climate Change Risk Assessment Technical Report 1 Contributing Authors: Sarah Bell, Richard Betts, Geoff Darch, Emma Ferranti, Simon Gosling, Ivan Haigh, Paul Hughes, Domenico Lombardi, Erika Palin, Kevin Paulson, Maria Pregnolato, Geoff Watson, David White, Paul Watkiss Additional Contributors: Amy Bell, Jade Berman, Kathryn Brown, Gemma Holmes, Martin Hurst, Rob Knowles, Cara Labuschagne, Robert Mair, Jane McCullough, Alan Netherwood, Catherine Payne, Andy Russell, David Style This chapter should be cited as: Jaroszweski, D., Wood, R., and Chapman, L. (2021) Infrastructure. In: The Third UK Climate Change Risk Assessment Technical Report. [Betts, R.A., Haward, A.B., Pearson, K.V. (eds)] Prepared for the Climate Change Committee, London Third UK Climate Change Risk Assessment Technical Report 2 Third UK Climate Change Risk Assessment Technical Report Contents Key Messages 4 4.1. Introduction 7 4.1.1 Scope of Chapter ........................................................................................................................ 7 4.1.2 The challenges of assessing climate risks to infrastructure ..................................................... 12 4.1.3 Adaptation: Policy Considerations ........................................................................................... 14 4.2. Risks to infrastructure networks (water, energy, transport, ICT) from cascading failures (I1) 15 4.2.1 Current and future level of risk (I1) ......................................................................................... 15 4.2.2 Extent to which current adaptation will manage the risk (I1) ................................................. 24 4.2.3 Benefits of further adaptation action in the next five years (I1) ............................................. 28 4.2.4 Looking ahead (I1) .................................................................................................................... 30 4.3. Risks to infrastructure services from river and surface water flooding (I2) 30 4.3.1 Current and future level of risk (I2) ......................................................................................... 31 4.3.2 The extent to which current adaptation will manage the risk (I2) .......................................... 40 4.3.3 Benefits of further adaptation action in the next five years (I2) ............................................. 47 4.3.4 Looking ahead (I2) .................................................................................................................... 48 4.4. Risks to infrastructure services from coastal flooding and erosion (I3) 49 4.4.1. Current and future level of risk (I3) ........................................................................................ 49 4.4.2 The extent to which current adaptation will manage the risk (I3) .......................................... 56 4.4.3. Benefits of further adaptation action in the next five years (I3) ............................................ 59 4.4.4. Looking ahead (I3) ................................................................................................................... 61 4.5 Risks to bridges and pipelines from flooding and erosion (I4) 61 4.5.1 Current and future level of risk (I4) ......................................................................................... 62 4.5.2 The extent to which current adaptation will manage the risk (I4) .......................................... 67 4.5.3. Benefits of further adaptation action in the next five years (I4) ............................................ 69 4.5.4. Looking ahead (I4) ................................................................................................................... 70 4.6. Risks to transport networks from slope and embankment failure (I5) 71 4.6.1 Current and future level of risk (I5) ......................................................................................... 71 4.6.2 The extent to which current adaptation will manage the risk (I5) .......................................... 77 4.6.3 Benefits of further adaptation action in the next five years (I5) ............................................. 80 4.6.4 Looking ahead (I5) .................................................................................................................... 81 4.7. Risks to hydroelectric generation from low or high river flows (I6) 82 4.7.1 Current and future level of risk (I6) ......................................................................................... 82 4.7.2 The extent to which current adaptation will manage the risk (I6) .......................................... 88 Chapter 4 – Infrastructure 1 Third UK Climate Change Risk Assessment Technical Report 4.7.3 Benefits of further adaptation action in the next five years (I6) ............................................. 90 4.7.4 Looking ahead (I6) .................................................................................................................... 92 4.8. Risks to subterranean and surface infrastructure from subsidence (I7) 92 4.8.1 Current and future level of risk (I7) ......................................................................................... 93 4.8.2 The extent to which current adaptation will manage the risk (I7) .......................................... 96 4.8.3 Benefits of further adaptation action in the next five years (I7) ............................................. 97 4.8.4 Looking ahead (I7) .................................................................................................................... 98 4.9. Risks to public water supplies from reduced water availability (I8) 98 4.9.1 Current and future level of risk (I8) ......................................................................................... 99 4.9.2 The extent to which current adaptation will manage the risk (I8) ........................................ 110 4.9.3 Benefits of further adaptation action in the next five years (I8) ........................................... 120 4.9.4 Looking ahead (I8) .................................................................................................................. 124 4.10. Risks to energy generation from reduced water availability (I9) 124 4.10.1 Current and future level of risk (I9) ..................................................................................... 125 4.10.2 The extent to which current adaptation will manage the risk (I9) ...................................... 129 4.10.3 Benefits of further adaptation action in the next five years (I9) ......................................... 131 4.10.4 Looking ahead (I9) ................................................................................................................ 132 4.11. Risks to energy from high and low temperatures, high winds and lightning (I10) 133 4.11.1 Current and future level of risk (I10) ................................................................................... 133 4.11.2 The extent to which current adaptation will manage the risk (I10) .................................... 146 4.11.3 Benefits of further adaptation action in the next five years (I10) ....................................... 150 4.11.4 Looking ahead (I10) .............................................................................................................. 152 4.12. Risks to offshore infrastructure from storms and high waves (I11) 152 4.12.1 Current and future level of risk (I11) ................................................................................... 153 4.12.2 The extent to which current adaptation will manage the risk (I11) .................................... 162 4.12.3 Benefits of further adaptation action in the next five years (I11) ....................................... 164 4.12.4 Looking ahead (I11) .............................................................................................................. 165 4.13. Risks to transport from high and low temperatures, high winds and lightning (I12) 165 4.13.1 Current and future level of risk (I12) ................................................................................... 166 4.13.2 The extent to which current adaptation will manage the risk (I12) .................................... 175 4.13.3 Benefits of further adaptation action in the next five years (I12) ....................................... 179 4.13.4 Looking ahead (I12) .............................................................................................................. 181 4.14. Risks to digital from high and low temperatures, high winds and lightning (I13) 182 4.14.1 Current and future level of risk (I13) ................................................................................... 182 4.14.2 The extent to which current adaptation will manage the risk (I13) .................................... 187 4.14.3 Benefits of further adaptation action in the next five years (I13) ....................................... 189 Chapter 4 – Infrastructure 2 Third UK Climate Change Risk Assessment Technical Report 4.14.4 Looking ahead (I13) .............................................................................................................. 191 4.15 Case Study - Toddbrook Reservoir 191 4.16. References 193 Chapter 4 – Infrastructure 3 Third UK Climate Change Risk Assessment Technical Report Key Messages Flooding remains a key risk to infrastructure