1. Richard Walker Climate Change Case Study Water Quality Implications Water Safety Conference 2010

2. Water Safety Conference November 2-4 2010, Kuching, Malaysia Impact of Climate Change Drier 2030 Wetter Warming will change general climatic patterns and there will be greater climatic variability

3. Climate Change and Water Safety Plans – Case Study Water Safety Conference November 2-4 2010, Kuching, Malaysia

4. Supply Infrastructure Surface water source Dam capacity 1.7 GL Commissioned 1994 Augmentation expected 20 plus years Water Safety Conference November 2-4 2010, Kuching, Malaysia

5. Climate change/Drought By early 2000’s supply became problematic Pump back direct from River commenced 2002 = winter from hell Water Safety Conference November 2-4 2010, Kuching, Malaysia

6. Water Safety Conference November 2-4 2010, Kuching, Malaysia Case Study – Scheme Supply Figure 1. River pump back, demand and storage levels 2000 to 2009.

7. Water Safety Plan Development 2004 – WSP’s commenced Town scheme was reviewed Dam catchment - Some private land - Cattle - L3 source River source characterised as high risk (unsuitable) - No source protection - High E Coli detected - High C&G risk - High turbidity - High colour No barrier to C&G Water Safety Conference November 2-4 2010, Kuching, Malaysia

8. Water Safety Plan Action Plan Water Safety Conference November 2-4 2010, Kuching, Malaysia Turbidity limits on pump back (immediate) PCP = 5NTU Relocate pump back pipe to back of dam UV on dam outlet (months) CCP = 40ms/cm2

9. Water Safety Conference November 2-4 2010, Kuching, Malaysia

10. Water Safety Conference November 2-4 2010, Kuching, Malaysia Long Term Plan The use of the high risk River pump back and reliance on a single UV barrier was a catalyst to commence planning to stabilise the long term water supply to the town. This process was instrumental in establishing the water quality principles of the ADWG in the guidelines used by planners for selecting new sources. Relevant statements in the ADWG include:“the greatest risk to consumers of drinking water is pathogenic micro-organisms” (ADWG 1-1) “prevention of contamination provides greater safety than removal of contaminants by treatment, so the most effective barrier is protection of source water to the maximum degree practical” (ADWG 1-2).

11. Water Safety Conference November 2-4 2010, Kuching, Malaysia Long Term Plan This resulted in the Corporation establishing a preference order for new sources based on pathogen risk as set out below Confined groundwater Unconfined groundwater Surface water (large dam) Surface water (small dam) Pump back only acceptable if dam not operated for min 30 days after pump back ceases The long term planning for the town has subsequently recommended using a confined aquifer source.

12. 2007 Winter Water Safety Conference November 2-4 2010, Kuching, Malaysia Low runoff to Dam % River water> 50% Breached colour and turbidity PCPs on dam outlet Single barrier may be compromised Corporate incident declared Stopped pumpback Decision to install MF on dam outlet (8-10 MLD)

13. Action Plan Water Safety Conference November 2-4 2010, Kuching, Malaysia $10M for dam outlet too expensive $5M for pump back only (4MLD) Upgrade UV treatment on dam outlet Bought the private catchment land and fenced New source due 2012

14. Water Safety Conference November 2-4 2010, Kuching, Malaysia

15. Water Safety Conference November 2-4 2010, Kuching, Malaysia

16. Water Safety Conference November 2-4 2010, Kuching, Malaysia

17. Water Safety Conference November 2-4 2010, Kuching, Malaysia

18. Water Safety Conference November 2-4 2010, Kuching, Malaysia

19. Water Safety Conference November 2-4 2010, Kuching, Malaysia

20. Water Safety Conference November 2-4 2010, Kuching, Malaysia Current Situation These actions have considerably reduced the water quality risks at the town while the long term solution is implemented (now expected in 2012). All waters entering the dam are now considered “low risk” with respect to cryptosporidium and giardia. The UV on the outlet of the dam is a robust second line of defence for the treated water supply. The micro filtration and UV plants are both designed to “fail safe” which means failure to achieve PCP & CCP targets result in the supply shutting down automatically.

21. Water Safety Conference November 2-4 2010, Kuching, Malaysia Lessons Learnt Climate change/drought has seriously undermined system yield for many schemes New source development is expensive and takes many years There is pressure to use high risk sources (of unknown pedigree) to augment supply in the short term Application of WSP principles should be applied to those temporary sources to Minimise risk to customers Demonstrate due diligence