Water infrastructure

IN3: Water infrastructure Water supply 1. Developments are required to demonstrate how they will be served by adequate water supply infrastructure. Capacity of distribution systems must be demonstrably adequate prior to occupation of development. The location of, and likely impact on, private water supplies within Buckinghamshire must also be considered in ensuring that there is adequate water infrastructure capacity in place to serve development. Wastewater 2. Developments are required to demonstrate how they will be adequately served with foul drainage, wastewater and sewage treatment without leading to significant problems for existing users or contamination of waterbodies and water supply. 3. Planning applications must demonstrate that adequate capacity of distribution systems is available or can be provided within the foul sewerage network and at wastewater treatment works in time to serve the development. 4. The Council will expect new development (new buildings such as new dwellings and employment units) to connect to mains foul drainage and will restrict the use of non-mains drainage for foul water disposal, in line with Environment Agency guidance. Delivery 5. Phasing conditions will be attached to planning permissions to ensure that new developments are not occupied until the required water supply, and wastewater capacity is in place. New and Enhanced Water Services Infrastructure 6. Applicants are not required to demonstrate the need for water infrastructure developments. In considering proposals for water supply, drainage and wastewater development, substantial weight should be given to: a) The benefits of providing the capacity needed to serve proposed development as well as improving the security of supply and capacity for existing users (both residential and commercial, including agricultural users); and a) Improving water quality and reducing water-borne pollution. 7.375 Water resources need to be safeguarded from the potentially negative impacts of development. This includes pollution from wastewater. 7.376 The Local Plan for Buckinghamshire provides information on the growth required and estimated during the plan period and the National Planning Policy Framework supports the need to make sufficient provision for water supply in those locations. 7.377 Buckinghamshire Council working in partnership with key stakeholders has developed a Water Cycle Study that sets out existing issues at the time of the study and where upgrades are needed. The outcome of the Water Cycle Study is fed into the Local Plan which then can be used by water companies to finalise future asset management plans. 34 of the Wastewater Treatment Works require an upgrade to accommodate the local plan housing growth. The Study also identifies odour buffers for sites including 28 site allocations due to proximity to a treatment works. At Princes Risborough and RAF Halton treatment works, there is a possibility that growth may impact on the flood risk of receiving waterbodies. Water quality modelling has found that local plan growth would result in a deterioration at around half the modelled wastewater treatment works. In terms of water quality, the study confirms that growth alone will not prevent a good ecological status being achieved in watercourses. 7.378 Early engagement between developers and water supply and wastewater companies through their developer advice service, as well as with the council, to demonstrate adequate infrastructure capacity is / will be in place before development coming forward is necessary and will have to be evidenced. 7.379 The council will use phasing conditions to ensure development only proceeds to completion and occupation with adequate water services infrastructure. Safeguarded strategic water services infrastructure IN4: Safeguarded strategic water services infrastructure Galley Lane wastewater facility 1. As shown on the Policies Map, Land at Galley Lane near Stoke Hammond is safeguarded for water services infrastructure as part of the Grand Union Canal Water Transfer Project, as defined by Water Resources East Regional Plan 2025. 2. Any development in the vicinity of the safeguarded site must not prejudice its construction or operation. Strategic Water Treatment Works (WTW) west of Iver 3. To support the security and resilience of drinking water supplies for Buckinghamshire and wider areas in line with the published relevant Water Resources Management Plan, land to the west of Iver WTW and the M25, as shown in the Policies Map, is safeguarded for drinking water treatment and water transfer infrastructure. 4. The Council will support proposals for development of a drinking water treatment works and associated development at this site if the Thames to Affinity Transfer (T2AT) project remains in a Water Resources Management Plan. 7.380 Strategic water infrastructure is key in delivering secured water supply in the subregion. It is also key in reducing water abstraction from the Chalk aquifer in our area. By safeguarding two sites in this plan, the Council is ensuring that the objectives of the Water Resources East and Water Resources Southeast Management Plans can be met. Grand Union Canal Transfer Project 7.381 The Grand Union Canal Transfer Project is a central component of both the Water Resources in the Southeast (WRSE) Regional Plan and Affinity Water’s statutory Water Resources Management Plan 2024 (WRMP24) in supplying water resilience for Affinity Water customers in Hertfordshire and Northwest London. It is also part of the Regulators’ Alliance for Progressing Infrastructure Development’s (RAPID) programme of Strategic Resource Options (SROs) to help meet the water needs set out in the Environment Agency’s National Framework, which will benefit customers and wider society and help to protect and enhance the environment. 7.382 Several alternative sites were considered for the treatment and storage of water abstracted from the Grand Union Canal before distribution to Affinity Water customers. This included site options within both Buckinghamshire and Central Bedfordshire as set out in the Site and Route Evaluation Report September 2024. The outcomes from this consultation have been considered alongside further assessment work, which were presented at the Second Public Consultation in February 2026. 7.383 Through this ongoing work and analysis, the Project Partners have now identified a specific site from which to abstract water from the Grand Union Canal and on which to locate the water treatment works and water storage elements of the Project. This site (referred to as Site B in the Site and Route Evaluation Report (September 2024) and now known as Galley Water Treatment Works) along with an approximately 1km of the transfer pipeline, are located within Buckinghamshire. The draft Preliminary Development Consent Order limits that have been prepared for the purposes of the Second Phase Public Consultation show the land within Buckinghamshire that is required for the Project. Thames to Affinity Transfer Project 7.384 The Thames to Affinity Transfer (“T2AT”) is a proposed water transfer project from Thames Water to Affinity Water. It aims to deliver a resilient supply of drinking water to Affinity Water’s Central Region. T2AT proposes to transfer water from Thames Water’s existing Wraysbury reservoir to Harefield service reservoir in Hillingdon via the Iver Water Treatment Works in Buckinghamshire. This would utilise an existing tunnel owned by Affinity Water from Wraysbury to Iver and then a new pipeline from Iver to Harefield. A water treatment works to treat the raw water from Wraysbury to drinking water standard for Harefield service reservoir would be needed along the route of the transfer pipelines. 7.385 One leading option under consideration for the drinking water treatment works is to develop this at Iver through utilising a land parcel a short distance west of the existing Iver WTW. T2AT is an acknowledged long-term Strategic Resource Option (SRO) for the security of drinking water supplies provided by Affinity Water. 7.386 Affinity Water has conducted an extensive site search and options appraisal for potential WTW development locations and a pipeline route which would connect from the Iver tunnel, to the WTW and then to Harefield service reservoir. Key site constraints, such as the requirement for an area of land of sufficient size, the feasibility of pipeline routes, environmental constraints and surrounding community/business land uses have been considered when shortlisting possible sites. 7.387 Additional screening criteria and input from expert advisors in engineering, environment, planning and land value further refined the sites and pipeline routes. T2AT’s capacity is needed by 2040-45. Affinity Water must plan for this by ensuring each part of the T2AT project can be delivered in time, including a suitable site for a WTW and a route for the transfer pipeline. In this long-term process, safeguarding suitable land is critical for the viability of the T2AT project, and hence for the future resilience of water supply in Buckinghamshire and neighbouring authority areas.