Draft WRMP19 Technical Report – Supply forecasting Contents 1. Introduction .............................................................................................................................................................. 4 2. Defining our water resource zones .......................................................................................................................... 5 2.1 Approach ........................................................................................................................................................... 5 2.2 Change in assumptions from our 2015 Plan ..................................................................................................... 5 2.3 Previous developments in our water resources capability ............................................................................... 8 2.3.1 Leakage and demand management .......................................................................................................... 8 2.3.2 Changes within our resource zones .......................................................................................................... 8 2.4 Levels of service ................................................................................................................................................ 9 3. Risk based planning for our supply forecast .......................................................................................................... 11 4. What is included in our supply forecast ................................................................................................................. 12 5. Baseline deployable output.................................................................................................................................... 13 5.1 Deployable output comparison between our 2015 and 2019 plans .............................................................. 13 6. What is covered in our deployable output forecast .............................................................................................. 16 6.1 Deployable output approach .......................................................................................................................... 16 6.1.1 Aquator™ modelling software ................................................................................................................ 16 6.1.2 Testing deployable output ...................................................................................................................... 18 6.1.3 Hydrological data .................................................................................................................................... 19 6.1.4 Groundwater sources .............................................................................................................................. 21 6.1.5 Asset constraints and licences ................................................................................................................ 21 6.1.6 Demands ................................................................................................................................................. 22 6.1.7 Level of service representation ............................................................................................................... 23 6.1.8 Dead water and emergency storage ....................................................................................................... 25 6.1.9 Reservoir compensation over-releases ................................................................................................... 26 6.1.10 Hands off flow buffers ............................................................................................................................. 27 6.2 Strategic Resource Zone ................................................................................................................................. 27 6.2.1 Deployable output .................................................................................................................................. 27 6.2.2 Strategic Resource Zone emulator model .............................................................................................. 29 6.2.3 Demand side drought restrictions .......................................................................................................... 29 6.3 Barepot Resource Zone ................................................................................................................................... 30 6.4 Carlisle Resource Zone .................................................................................................................................... 30 6.4.1 Abstraction Licence Constraints .............................................................................................................. 30 6.4.2 Demand Side Drought Restrictions ......................................................................................................... 30 6.5 North Eden Resource Zone ............................................................................................................................. 31 7. Our role in achieving sustainable abstraction ........................................................................................................ 32 7.1 Baseline position ............................................................................................................................................. 32 7.2 Future changes – Strategic Resource Zone ..................................................................................................... 33 7.3 Future changes – Barepot Resource Zone ...................................................................................................... 34 Copyright © United Utilities Water Limited 2017 1 Draft WRMP19 Technical Report – Supply forecasting 8. Invasive non-native species .................................................................................................................................... 35 9. Abstraction reform – evidence needs .................................................................................................................... 36 10. Climate change .................................................................................................................................................... 37 10.1 Basic vulnerability assessment ........................................................................................................................ 38 10.2 Calculating river flows ..................................................................................................................................... 38 10.3 Calculating deployable output impacts .......................................................................................................... 39 10.4 Scaling and uncertainty ................................................................................................................................... 41 11. Water transfers ................................................................................................................................................... 43 11.1 Existing transfers ............................................................................................................................................. 43 11.2 Future transfers .............................................................................................................................................. 44 12. Drinking water quality ......................................................................................................................................... 46 13. Outage allowance ............................................................................................................................................... 47 13.1 Planned and unplanned outage events .......................................................................................................... 47 13.2 Methodology and assessment ........................................................................................................................ 47 13.3 Our percentile choice ...................................................................................................................................... 48 13.4 Our outage allowance ..................................................................................................................................... 48 14. Raw water and process losses ............................................................................................................................ 50 15. Water available for use ....................................................................................................................................... 52 16. Level of service .................................................................................................................................................... 54 16.1 Testing different levels of service ................................................................................................................... 54 16.1.1 Strategic Resource Zone ......................................................................................................................... 54 16.2 Final planning level of service ......................................................................................................................... 55 16.2.1 Strategic Resource Zone ........................................................................................................................