Drainage Strategy – Sidlesham We’ll update and republish this Drainage Strategy as we continue to engage with our customers and stakeholders. (Manhood Peninsula) You can find further information on how to share your feedback via our website: southernwater.co.uk/drainagestrategies Southern Water Southern House Yeoman Road Worthing West Sussex BN13 3NX 4593_04.18 Page 2 Drainage Strategy – Sidlesham Drainage Strategy – Sidlesham Page 3 Executive summary Environment Agency and other organisations The Drainage Strategy for Sidlesham Long-term outcomes Current issues and future challenges (Manhood Peninsula) focuses on to find and fix the causes of pollution which for Sidlesham (Manhood Peninsula) are preventing the bathing water from being the current pressures and future Our Five-year Business Plan 2015 to 2020 sets out details of the improved water and consistently rated as ‘excellent’. Some challenges that will impact on the Over the next 25 years, population growth is wastewater services we will provide in expected to result in a 12% increase in domestic rivers, groundwater and other water bodies sewerage network and wastewater the future. It was developed as a result of properties connecting to our sewers in the in the catchment were classified as ‘bad’ treatment works. the company’s biggest ever consultation Sidlesham wastewater catchment. Climate to ‘moderate’ status in 2015 according to programme which included feedback from change and urban creep are expected to add the Water Framework Directive (WFD) and more than 34,000 customers and stakeholders. to surface water flows into our sewers which, in require improvement to ‘good’ status by 2027. It will enable us to take a more strategic Partnership working will be key to achieving the approach to drainage planning across the area, The business plan is built around the delivery turn, will increase the number of properties at risk from surface water flooding. higher environmental standards required under providing a long-term (25-year) strategy to of six outcomes which our customers and the WFD. ensure we deliver a reliable and sustainable stakeholders told us were their priorities. For Maintaining and improving bathing water wastewater service for the region while each outcome, we have developed a clear set quality is essential for encouraging tourism and We have assessed the risks to the delivery of accommodating population growth, new of promises that detail what we will achieve for supporting economic prosperity in the region. our key outcomes if we were to do nothing, development, climate change and stricter our customers. Three of these outcomes are The Manhood Peninsula has a ‘Blue Flag’ summarised in table 1. These risks will be environmental quality standards. relevant to the Drainage Strategy for Sidlesham award for its West Wittering beach. At Selsey, identified, assessed and reduced through our and are shown in figure 1 below alongside the ‘business as usual’ activities. The Sidlesham wastewater catchment we are working with the local authorities, the relevant promises associated with them. includes the villages of Almodington, Birdham, Bracklesham, Selsea, Sidlesham, East/West Table 1. Key outcomes at risk in the Sidlesham catchment (Manhood Peninsula) if we do nothing Wittering and West Itchenor in the Manhood Peninsula, south of Chichester. Risk of not delivering the outcome by: Key outcome Comments 2020 to 2025 2040 Figure 1. Outcomes relevant to the Drainage Strategy for Sidlesham (Manhood Peninsula) Maintain compliance at Medium to high High Sidlesham Wastewater Treatment Works is currently operating at wastewater treatment its treatment capacity and is likely to require an uplift in treatment Removing wastewater Looking after Better information works capacity and dry weather flow consent in line with the anticipated growth in new connections. Additional capacity could be delivered in effectively the environment and advice parallel with development. Minimise flooding due to Medium Medium to high The Sidlesham network can accommodate approximately 53% of the • Minimise flooding due to • Minimise wastewater pollution • Improve advice on how to wastewater forecast new wastewater connections over the next 25 years without wastewater and surface water so that by 2020 there will be prevent blocked drains to help an unacceptable deterioration in our wastewater service. Additional with a 25% reduction in internal no serious (Category 1 & 2) reduce blockages capacity could be delivered in parallel with development. sewer flooding incidents by 2020 pollution incidents caused by our Minimise flooding due Medium Medium to high Groundwater infiltration is considered to be significant across the operations. We are also aiming to surface water and catchment and has been an issue in the village of Sidlesham where to halve the number of minor groundwater repairs have been carried out. Groundwater levels may get higher as a consequence of rising sea levels due to climate change. (Category 3) incidents from 2017 onwards Surface water flooding has been a significant issue due to the limited capacity of the land drainage system. Flooding is likely to increase • Maintain wastewater treatment due to more intense storms caused by climate change and more works compliance by ensuring run-off due to urban creep. that any releases to the Minimise pollution Low Low to medium The number of pollution incidents in 2015 and 2016 were relatively environment comply with permit low. The likelihood and severity of pollution incidents may increase conditions due to additional wastewater, surface water and groundwater in the sewerage system. • Maintain ‘excellent’ bathing Improve water bodies Medium Medium Nine out of 11 water bodies on the Manhood Peninsula are predicted water quality and improving (river, lake, coastal to achieve ‘good’ status by 2027 with the remaining two at other bathing waters groundwater) ‘moderate’ status. Partnership working will be key to achieving the higher environmental standards required under the WFD. Maintaining ‘excellent’ Low to medium Low to medium Three out of four bathing waters in the region have generally bathing water quality ‘excellent’ bathing water quality. At Selsey, we are working with partners to improve bathing water quality to ‘excellent’ by 2019–20. Page 4 Drainage Strategy – Sidlesham Drainage Strategy – Sidlesham Page 5 Table 3. Action plan for the Drainage Strategy for Sidlesham (Manhood Peninsula) No. Action Lead Supporting Due date Action delivery status action action owner owners 1 Through the SW WSCC, EA, End of 2016 A draft drainage strategy was issued to external stakeholders in drainage strategy, CDC November 2016 for comment and discussion. Feedback has been We are assessing a range of traditional identify current received from WSCC, CDC and the EA during the winter of 2016-17. engineering and alternative strategies to Next steps drainage issues, key risks, shared tackle the current drainage issues and future We will update and revise this drainage outcomes and risks that have been identified for the area. strategy to reflect consultations with our potential actions We are also investing in the development customers and stakeholders in the region. 2 Publish the drainage SW All Following The drainage strategy will be updated with feedback from external of innovative techniques that will bring a We will continue to work with the local strategy on the stakeholders receipt of stakeholders before publication. significant improvement to our capabilities and community to gain important feedback from Southern Water comments performance. Potential strategies are being our customers and local stakeholders which we website from assessed against whole life costs, constraints will use to shape our solutions. We have already external Customers and other stakeholders will have the opportunity to and benefits to both the environment and stake- provide feedback on the final drainage strategy. begun discussions with our regional drainage holders stakeholders. Table 2 lists the key outcomes at partners and we will work collaboratively to risk and offers potential strategies which could agree and implement a strategy that ensures a 3 Improve Selsey’s SW WSCC, EA, 2019–20 In May 2017, Selsey was named as one of seven bathing waters be implemented to overcome the issues and reliable and effective wastewater service bathing water CDC to be improved to ‘excellent’ as detailed in the action plan for the quality to ‘excellent’ bathing water. challenges that threaten them. for the region in the long term. 4 Review the needs SW WSCC, EA, End of 2017 In March 2015, a meeting was held with external stakeholders to Table 3 provides an action plan for this strategy and options CDC identify risks in the Sidlesham catchment to inform the DAP. which we will implement in partnership with identified in the Sidlesham DAP Structural, operational, growth, flooding and environmental needs other stakeholders in the region. and potential options have been identified and are being reviewed. 5 Produce an action SW WSCC, EA, Summer A Sidlesham DAP action plan is provided in appendix B of this Table 2. Key outcomes at risk and potential strategies for Sidlesham (Manhood Peninsula) plan following CDC 2017 drainage strategy. completion of the Key outcomes at risk Potential strategies Sidlesham DAP Maintain compliance at • Collaboration with the local authority and developers to understand the timing, size and location of 6 Complete the SW 2018 The Pagham DAP will be produced