1. Safe & SuRe A new approach to water management in cities UKWRIP/ESKTN Workshop on ‘Water and Cities’ Birmingham, 27 th February 2014 David Butler EPSRC Established Career Fellow Professor of Water Engineering Co-director, Centre for Water Systems, University of Exeter

2. The vision Safe Resilient Sustainable Safe & SuRe

3. Replacing 19 th century Fail Safe thinking based on: apparently unlimited resources (water, energy) catering for unrestrained demand assuming a stable climate exploiting and controlling nature. with 21st century SuRe thinking: building resilience to operationalise sustainability managing change and uncertainty dealing with the unknown becoming ‘Safe to Fail’. The vision

4. Resilient Sustainable Safe 19 th Century Safe & SuRe 21st Century ? ?

5. Safe & SuRe framework – emphasis on intervention Safe Threat/hazard – stress/shock Sustainable and resilient Impact - Level of service Consequence - Vulnerability City Water Infrastructure Society Economy Environment Climate Energy Population Regulation Water supply Flooding River water quality Mitigate Mitigate threat reduce carbon emissions reduce city imperviousness improve system maintenance Adapt Adapt system anticipate threats/impacts learn from experience increase flexibility Cope Cope with impact modify buildings teach self help approaches develop emergency plans

6. Threats / hazards InternalExternal Stress (slow/chronic) Shock (quick/acute) Climate change: averages Urbanisation Population growth Demographic change Consumption patterns Environmental regulation Financial regulation Climate change: extremes Natural disaster Other infrastructure failure Sabotage/vandalism War/riot Epidemic Water system degradation e.g. leakage, infiltration Resource depletion / degradation Skills depletion Incremental innovation Budget constraints Water system failure e.g. burst, pumps Accident Error Industrial dispute Based on Westrum (2006); Dawson et al. (2010)

7. Definitions Reliability (safety): = ability to minimise failure frequency under routine/design conditions = min(failure: frequency) Resilience = ability to withstand shock and continue to function (OFWAT, 2010) = ability to reduce the magnitude and/or duration of disruptive events (NIAC, 2009) = min(failure: magnitude, duration) Resilience: ‘bouncebackability’

8. Attribute based (general resilience): – set of design principles, descriptive – all hazards, including unknown unknowns – e.g. well-connected, redundant systems. Performance based (specified resilience): – operational goals / standards, prescriptive – individual hazards, known unknowns – e.g. resilience of city centre to flooding Key challenge: Linking performance to attributes. Dimensions of resilience

9. Resilience – key attributes

10. General ideas Specific rules Mitigation

11. Multi-scale, hierarchical structure Reference: Toward Resilient Architectures 1: Biology Lessons http://www.metropolismag.com/Point-of-View/March- 2013/Toward-Resilient-Architectures-1-Biology-Lessons/ Global Medium Local

12. Example 1– flood resilience Global Medium Local Flood-resilient kitchen…, etc. Flood-resilient house Flood-resilient community

13. Subsystem 4 Subsystem 5 Subsystem 1 Subsystem 4 Subsystem 3 Subsystem 2 Example 2– Water supply resilience

14. A Basic Motif Motifs organized in multi- scale, hierarchical structure DMA 1 DMA 4 and 5 DMA 2 and 3 DMA 4 DMA 5 DMA 2 DMA 3 Global Medium Local Su bsy ste m 4

15. Low tech (e.g. green infrastructure, water sensitive urban design, sustainable drainage) High tech (e.g. smart metering, real time control). Scale (e.g. centralised, decentralised, heirarchical) Flexibility (e.g. option portfolios, incremental build) Fit for purpose water (e.g. rain, grey, black, yellow). Policy change (e.g. Planning controls, building regs). Behavioural change (e.g. water/energy efficiency). Safe  Safe & SuRe?

16. Safe & SuRe A new approach to water management in cities UKWRIP/ESKTN Workshop on ‘Water and Cities’ Birmingham, 27 th February 2014 Thanks to the Safe & SuRe team: Guangtao Fu, Raziyeh Farmani, Kegong Diao, Maryam Astaraie-Imani and many amazing PhD & EngD students David Butler d.butler@exeter.ac.uk