Title

Preparing for the impacts of floods and droughts

Professor Jim Hall FREng24th April 2013

Adaptation Sub‐Committee

Established by Climate Change Act:• advise on preparedness of UK for climate change

• monitor progress in adaptation

Lord John KrebsChairman

Prof Anne Johnson

Sir Graham Wynne

Dr Sam Fankhauser

Prof Martin Parry

Prof Jim Hall

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Cabinet Office National Risk Register

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Responding to flood risk

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Reducing flood waters: flood abatementKeeping the water out of harms’ way:• Flood storage• Flood conveyance• Flood defenceReducing the damage potential• Land use planning• Property-level protection• Flood warning and evacuationEnabling recovery from damaging floods• Insurance

Reducing runoff in urban areas: SuDS

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How is flood defence reducing risk?

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Controlling (?) development in floodplains

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Development in high risk floodplains

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Controlling (?) development in floodplains

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Local authority development plans

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What the future holds

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2000 2005 2010 2015 2020 2025 2030 2035

Millions

Year

ONS Population projections: London and the Southeast Per capita water

consumption

Risk of water shortages 

Responding to risks of water shortage

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Increasing water supply: • Reservoirs• Transfers• Groundwater• Desalination• Direct reuseReducing water demand• Leakage• Domestic• Industrial• Agricultural

Water companies plan to address supply demand deficits 

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There is greater scope to improve resilience by reducing demand

Action: Low‐regret opportunities for adaptation – water efficiency measures 

New build

End‐of‐life upgradeRetrofit

Cost‐ben

efit ratio

Rain water system Grey water system

Dual‐flush WC

Ml/year

New build package at zero additional cost: 115 l/person/day

85 l/person/ day standard

End‐of‐life upgrade at zero additional cost: Low‐flow shower, taps, WC

Click‐lock taps

Low‐waterwashing machine 

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How significant could demand management be?

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Leakage

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Adaptive planning of supplies

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Projected deficits          

Adaptation pathways

medium low 

2050s medium 

2080s high

Groundwater

Pathway 3Pathway 3

Pathway 1

Pathway 2

high 

2020s 

Deficits

Can we fill the gap?

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Monitoring progress: the ASC’s approach

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Next steps for the ASC

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June 2013: Fourth ASC annual report, focusing on the natural environment, including catchments and coasts

November 2013: Defra publishes the first National Adaptation Programme (NAP)

2015: ASC makes its first statutory assessment to Parliament on progress made in implementing the NAP

Domestic water demand

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Percentage of households with meters

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Are we metering where it matters?

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Risks of water shortage (CCRA)

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