LP/Ev/4h Bracknell Forest Council Water Cycle Study: Phase 2 Outline Report Final Report October 2018 Bracknell Forest Council Time Square Market Street Bracknell Berkshire RG12 1JD JBA Project Manager Paul Eccleston JBA Consulting 8a Castle Street Wallingford Oxfordshire UNITED KINGDOM OX10 8DL 01491 836688 Revision History Revision Ref / Date Amendments Issued to Issued Version 1.0 / 12 February 2018 Bracknell Forest Council Version 2.0 / Amendments in response to BFC Bracknell Forest Council 17 May 2018 and EA comments Version 2.1 Further amendments in response to BFC, TWUL, AW and SEW Bracknell Forest Council 04 July 2018 comments Version 2.2 FINAL Bracknell Forest Council 10 September 2018 Version 2.3 FINAL (including further comments Bracknell Forest Council 09 October 2018 from BFC) Contract This report describes work commissioned by Bracknell Forest Council, by an email dated 11th November 2017. Bracknell Forest Council’s representatives for the contract were Marie O'Sullivan and Julia Greene. Richard Pardoe, Nathan Chapman and Paul Eccleston of JBA Consulting carried out this work. Prepared by .................................................. Richard Pardoe MEng MSc Analyst Nathan Chapman BSc Assistant Analyst Reviewed by ................................................. Paul Eccleston BA CertWEM CEnv MCIWEM C.WEM Technical Director Purpose This document has been prepared as a Final Report for Bracknell Forest Council. JBA Consulting accepts no responsibility or liability for any use that is made of this document other than by the Client for the purposes for which it was originally commissioned and prepared. JBA Consulting has no liability regarding the use of this report except to Bracknell Forest Council. 2017s6937 - Bracknell Forest Council - WCS II v2.3.docx i Acknowledgements JBA Consulting would like to thank Bracknell Forest Council, the Environment Agency and Thames Water for their assistance in preparing this report. Copyright © Jeremy Benn Associates Limited 2018 Carbon Footprint A printed copy of the main text in this document will result in a carbon footprint of 305g if 100% post-consumer recycled paper is used and 388g if primary-source paper is used. These figures assume the report is printed in black and white on A4 paper and in duplex. JBA is aiming to reduce its per capita carbon emissions. 2017s6937 - Bracknell Forest Council - WCS II v2.3.docx ii This page is intentionally left blank 2017s6937 - Bracknell Forest Council - WCS II v2.3.docx iii Executive Summary Introduction Following completion of the Phase 1 Water Cycle Study (WCS) for Bracknell Forest, JBA Consulting were commissioned in November 2017 by Bracknell Forest Council (BFC) to undertake a Phase 2 WCS in order to assess the potential issues relating to future development within Bracknell Forest and the impacts on wastewater collection and treatment, water quality and the impact of climate change on the assessments conducted. The Water Cycle Study is required to assess the constraints and requirements that will arise from potential growth on the water infrastructure. The Phase 2 WCS builds upon the Phase 1 study and, where assessments have been added to repeated, supersedes the Phase 1 study. New homes require the provision of clean water, safe disposal of wastewater and protection from flooding. The allocation of large numbers of new homes in certain locations may result in the capacity of existing available infrastructure being exceeded, a situation that could potentially cause service failures to water and wastewater customers, adverse impacts to the environment, or high costs for the upgrade of water and wastewater assets being passed on to the bill payers. In addition to increased housing demand, future climate change presents further challenges to the existing water infrastructure network, including increased intensive rainfall events and a higher frequency of drought events. Sustainable planning for water must now take this into account. The water cycle can be seen in Figure 1 below and shows how the natural and man-made processes and systems interact to collect, store or transport water in the environment. Figure 1: The Water Cycle Source: Environment Agency – Water Cycle Study Guidance This study will assist the council to select and develop sustainable development allocations where there is minimal impact on the environment, water quality, water resources, infrastructure, and flood risk. This has been achieved by identifying areas where there may be conflict between any proposed development, the requirements of the environment and by recommending potential solutions to these conflicts. Objectives As a WCS is not a statutory instrument, Local Planning Authorities are advised to prioritise the different phases of the WCS to integrate with their Local Plan programme. This Phase II outline study report is intended to form part of the evidence base for the Bracknell Forest Local Plan (BFLP) and to identify whether a detailed WCS is required. Specific requirements, specified by the project brief, were to: 2017s6937 - Bracknell Forest Council - WCS II v2.3.docx iv Provide an outline report, taking into account guidance in the NPPF, NPPG, The Water Framework Directive, The Thames River Basin Management Plan and the EA Water Cycle Study Requirements and Guidance – Thames Area (October 2016); Produce an effective water cycle study in the context of the outline phase so that: o New development takes place only within environmental constraints; o New development occurs in the most sustainable location, in relation to the water environment; o Water cycle infrastructure is in place before new development is occupied and; o Opportunities for more sustainable infrastructure options are realised. Identification of the issues and questions to be considered with regards to water quality; Gather, assess and use existing data and evidence available, in order to prepare the outline report and address specific questions; Specifically address the following questions with regard to water quality: o Can the proposed growth be accommodated at the Wastewater Treatment Works (WwTWs) being assessed without causing deterioration in water quality? o Will the proposed growth compromise the ability to achieve good ecological status (GES) or potential? o If growth is likely to impact on water quality, can the WWTW be upgraded to prevent any deterioration from occurring or is the permit already at current limits of technology? o Could the development cause greater than 10% deterioration in water quality? o Could the development cause deterioration in WFD class of any element? o Could the development alone prevent the receiving watercourse from reaching Good Ecological Status or Potential? Where relevant, cross reference with the replacement Strategic Flood Risk Assessment; Include the outcome of stakeholder engagement within the Outline Study, in particular, engagement with the EA and Thames Water; Establish whether a Detailed Study is required. Since the phase 1 scoping study, a number of new sites have been identified (and some removed as allocations having already received planning consent). A number of sites have also been allocated to different treatment works by Thames Water. Consequently, the assessments of wastewater network capacity and wastewater treatment capacity were updated based upon the latest site data. Assessments which concluded in phase 1 that no further assessment was required in phase 2 (odour and flood risk from additional wastewater flow) were repeated using the latest site information. The water resources and supply assessments were not affected by the change of sites and were not, therefore, updated. The odour assessment method was amended to take account of the size of the WwTW when assessing the potential extents of odour risk. Conclusions The phase 2 outline Water Cycle Study has been carried out in cooperation with Thames Water, and with the advice of the Environment Agency with respect to the water quality methodology. The overall assessment is that no strategic-scale water or wastewater constraints on growth have been identified within Bracknell Forest. Thames Water are in the process of preparing a growth study covering Bracknell Forest, but the timescale for this completing did not fit with the preparation of the Bracknell Forest Local Plan. Thames Water has, however, made sufficient assurances regarding the primary area of concern around wastewater treatment capacity at Ascot, Bracknell and Easthampstead Park to conclude that no additional Phase 3 water cycle study is required. A site-by-site summary of the results of the assessments undertaken is included in Appendix A. Development Scenarios and Policy Issues 2017s6937 - Bracknell Forest Council - WCS II v2.3.docx v In September 2017 the UK Government entered into a consultation entitled "Planning for the right homes in the right places: consultation proposals"1. This set out a new standard methodology to calculate a local authority's Objectively Assessed Need (OAN) for new housing. This would result in an increase in Bracknell Forest Council's OAN from 635 units/year to 670 units/year, an increase of 6% or 630 homes over the 18-year plan period. Although this is yet to be adopted, BFC decided to use the higher figure within their Draft Bracknell Forest Local Plan in order to ensure the robustness of their housing supply, and this WCS is based on assessing growth at that rate over the plan period. This Water Cycle Study is an assessment of the impacts of planned