Bristol Water Final Water Resources Management Plan 2019 August 2019 August 2019 Document Control Sheet Report Title: Final Water Resources Management Plan 2019 Release Date: August 2019 Report Status: FINAL Report Author(s): Liz Cornwell, Patric Bulmer Related Reports: Bristol Water: Drought Plan (June 2018) Document History Version Authorised Approved Date Mel Karam, CEO Patric Bulmer, Head of Water Resource and Environment FINAL August 2019 2 bristolwater.co.uk August 2019 Contents 1 Executive Summary ....................................................................................................... 4 2 Introduction .................................................................................................................. 11 3 Engagement with customers, stakeholders and regulators .......................................... 26 4 Background information ............................................................................................... 38 5 Problem Characterisation ............................................................................................. 49 6 Water Supply ............................................................................................................... 51 7 Water Demand Forecast .............................................................................................. 78 8 Baseline metering, leakage control and water efficiency ............................................ 101 9 Sustainable Abstraction ............................................................................................. 116 10 Climate Change ...................................................................................................... 120 11 Target Headroom ................................................................................................... 133 12 Baseline Supply-Demand Balance ......................................................................... 142 13 Options Appraisal ................................................................................................... 144 14 Environmental Appraisal ......................................................................................... 159 15 Programme Appraisal ............................................................................................. 180 16 Final Water Resources and Demand Strategy ........................................................ 188 17 Testing the WRMP ................................................................................................. 203 18 Future developments .............................................................................................. 207 19 National security and commercial confidentiallity .................................................... 209 Glossary of Terms ............................................................................................................. 210 References and Reference Documents Use ..................................................................... 212 A set of Appendices (A-J) are published alongside this plan, see Section 2.4 . This is supported by a range of technical documents which are available by request. 3 bristolwater.co.uk August 2019 1 Executive Summary This is Bristol Water's final Water Resource Management Plan (WRMP19), updated with various revisions taking account of the feedback we received on our consultation on the draft version of the plan during March to May 2018. It presents our approach to the management of water resources for the benefit of our customers, the wider community and the environment in the period 2020 to 2045. The plan proposes the most affordable programme of action to ensure that we can provide a reliable and resilient supply of water to our customers, even in the face of severe drought. Customer preferences have been included in every phase of the development of the Plan, with over 12,000 customer surveys carried out ranging from simple annual surveys to detailed whole-day customer workshops; and the process of development for our draft Plan has included collaborative discussions with other water companies through new and existing partnerships such as the West Country Water Resources Group and the River Severn Working Group. The Bristol Water Board has full ownership of this plan, which has been developed under a formal process of external assurance and review. The WRMP19 is closely linked with the findings of our process to develop our Drought Plan (published in 2018). The programme of water resource management actions identified in the WRMP19 has also been used in the development of our Business Plan for the 2019 Price Review (PR19) - a plan which includes our investment proposals for the next five year period (2020-2025) along with proposed research and investigations to refine and develop our WRMP approach in future years. Development of WRMP19 has been informed by the structured guidance issued by the Environment Agency (EA), and formal pre-consultation meetings have been held with EA and other key stakeholders to test the development of the plan in order to ensure that it takes a proportionate and evidence-based approach to the management of water resources in our supply area. We regard the provision of safe, high-quality drinking water as our top priority in planning for the service we provide and none of the options in our preferred plan would lead to any deterioration in water quality. In addition, our proposals for options which might need to be implemented in various different scenarios would also allow for provision of safe high-quality drinking water with no deterioration from the high standards that our customers rightly expect. Bristol is a rapidly developing area and the population in the Bristol Water supply area is projected to grow during the period 2020-2045 from approximately 1.2 million people to approximately 1.5 million. However, thanks to ongoing improvements in domestic water efficiency and a projected increase in water metering, we do not forecast a large increase in overall demand for water during this period. Similarly, although we anticipate that climate change will reduce the water we have available for public water supply, the integrated nature of our supply network and the range of water sources we have available both help to 4 bristolwater.co.uk August 2019 mitigate this impact. We therefore anticipate that the impact of climate change on the water available for use in our area over the next 25 years at least is likely to be relatively low. As a result of this position, we anticipate that changes in the demand for water can be addressed in the short to medium-term by further reducing our already low levels of leakage, an action that will further increase our resilience to drought. This is an area that our customers have told us they consider a very high priority, and this has been reinforced in the responses we received as part of our draft WRMP19 consultation. We plan to reduce leakage by 15% by 2025 as detailed in this WRMP19. In the longer term, we have also confirmed that we can address any future deficit in the planning period to 2045 through further leakage reductions as well as a reduction in losses on raw water systems. Our WRMP19 differs from the previous 2014 plan (WRMP14) in the following ways: • We have not made any specific allowance for large new non-household water supply, although we have included the possibility of this in our modelling of other scenarios. • This WRMP plans for a 1 in 200 year severe drought instead of against the design drought of 1943/1944, which is less severe than the 1 in 200 year drought. For the WRMP19, we have tested our drought planning approach using an innovative computer-generated set of "synthetic droughts" in order to ensure that our plan is tested against droughts more severe than those seen in the historic record and that we can continue to supply water without severe restrictions, even in a drought so severe that it might be seen only once every two hundred years. • Our approach on Headroom now includes an updated approach to risk, with increased acceptance of risk across the duration of the planning period to 2045, in line with current best practice for water resource planning. • Our approach on climate change modelling follows the latest water industry and EA guidance, which in the case of Bristol Water indicates there will be a slightly lower projected impact of climate change on the resilience of our supply than was the case in WRMP14. • The outcome of these changes are: • Bristol Water faces a minor supply deficit from 2035, largely driven by a growing population in our supply area. • The baseline supply deficit in 2035 is 0.87 Ml/day, gradually rising to 9.18 Ml/day by 2045 (end of AMP11). Our options appraisal work indicates that demand management options such as reduction in leakage, reduction in raw water losses and increased household metering alongside further water efficiency activities 5 bristolwater.co.uk August 2019 can fully address this deficit at a lower cost than implementing new water resources. Agreed reductions to the bulk water supply export to Wessex Water after 2025 will also contribute an additional reliable supply of 6.97 Ml/day for Bristol Water’s customers to our baseline supply forecast. Our preferred approach to maintaining the supply-demand balance is therefore focused on optimising the use of our existing water sources while continuing to drive down leakage and water consumption to achieve a more sustainable use of water resources. This accords vey well with