Guidance

Water supply, wastewater and water quality

Advises on how planning can ensure water quality and the delivery of adequate water and wastewater infrastructure.

Planning practice guidance will, where necessary, be updated in due course to reflect changes to the National Planning Policy Framework (the new version of which was published in July 2018). Where any hyperlinks direct users to the previous National Planning Policy Framework (2012), please disregard these. If you’d like an email alert when changes are made to planning guidance please subscribe.

Where plans are being prepared under the transitional arrangements set out in Annex 1 to the revised National Planning Policy Framework, the policies in the previous version of the framework published in 2012 will continue to apply, as will any previous guidance which has been superseded since the new framework was published in July 2018.

Water supply, wastewater and water quality – introduction

Why should planning be concerned with water supply, wastewater and water quality?

Adequate water and wastewater infrastructure is needed to support sustainable development. A healthy water environment will also deliver multiple benefits, such as helping to enhance the natural environment generally and adapting to climate change.

The EU Water Framework Directive applies to surface waters (including some coastal waters) and groundwater (water in underground rock). It requires member states, among other things, to prevent deterioration of aquatic ecosystems and protect, enhance and restore water bodies to ‘good’ status. Local planning authorities must, in exercising their functions, have regard to the river basin management plans on the Environment Agency website that implement the Water Framework Directive. These plans contain the main issues for the water environment and the actions needed to tackle them.

The National policy statement for waste water forms part of the overall framework of national planning policy.

Related policy:

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Water supply, wastewater and water quality – considerations in plan making

What are the water supply, wastewater and water quality concerns that Local Plans need to address?

These will vary depending on the character of the local authority area, the type of issues the Local Plan will need to grapple with and the contribution that can be made to a ‘catchment-based approach’ to water. Wastewater treatment plants are waste developments and handled by the waste planning authority so it is important in 2-tier areas for district and county councils to work closely on these matters.

Early discussions between local planning authorities and water and sewerage companies, so that proposed growth and environmental objectives are reflected in company business plans, will help ensure that the necessary infrastructure is funded through the water industry’s price review. More information about funding wastewater infrastructure.

In plan-making, there are a number of broad considerations relevant to water supply and water quality:

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What is a catchment-based approach?

Defra has published a policy framework to encourage the wider adoption of an integrated catchment-based approach to improving the quality of the water environment:

  • to deliver positive and sustained outcomes for the water environment by promoting a better understanding of the environment at a local level; and
  • to encourage local collaboration and more transparent decision-making when both planning and delivering activities to improve the water environment.

The framework explains that adopting the approach will promote the development of more appropriate river basin management plans (which underpin the delivery of the objectives of the Water Framework Directive) but will also provide a platform for engagement, discussion and decisions of much wider benefits including tackling diffuse agricultural and urban pollution, and widespread, historical alterations to the natural form of channels.

A ‘catchment’ is a geographic area defined naturally by surface water hydrology. Catchments can exist at many scales but within this context it means management catchments that the Environment Agency uses for managing availability of water for abstraction as a starting point. Further information, including information about catchment partnerships, is available from the Environment Agency.

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How is wastewater infrastructure funded?

Ofwat, the economic regulator for the water industry, sets a cap on the charges that water companies can levy. This is known as the price review and takes place every 5 years (the next review is 2019). These price limits are determined by working out how much revenue each company must collect from its customers to run their businesses efficiently and meet their statutory obligations. Companies are subject to a statutory duty to ‘effectually drain’ their area. This requires them to invest in infrastructure suitable to meet the demands of projected population growth. There is also statutory provision for developers to fund additional sewerage infrastructure required to accommodate flows from a proposed development (Ofwat has provided information for developers where a development would require a new water main or sewer).

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Infrastructure

Plan-making may need to consider:

  • Identifying suitable sites for new or enhanced infrastructure. In identifying sites it will be important to recognise that water and wastewater infrastructure sometimes has particular locational needs (and often consists of engineering works rather than new buildings) which mean otherwise protected areas may exceptionally have to be considered where consistent with their designation. Plan-making will also need to take into account existing and proposed development in the vicinity of a location under consideration for water and wastewater infrastructure. In 2-tier areas there will need to be close working between the district and county councils.
  • Considering whether new development is appropriate near to sites used (or proposed) for water and wastewater infrastructure (for example, odour may be a concern).
  • Phasing new development so that water and wastewater infrastructure will be in place when needed.

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Water quality

Plan-making may need to consider:

  • How to help protect and enhance local surface water and groundwater in ways that allow new development to proceed and avoids costly assessment at the planning application stage. For example, can the plan steer potentially polluting development away from the most sensitive areas, particularly those in the vicinity of potable water supplies (designated source protection zones or near surface water drinking water abstractions)?
  • The type or location of new development where an assessment of the potential impacts on water bodies may be required.
  • Where particular types of sustainable drainage systems may not be practicable.

Related policy:

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Wastewater

Plan-making may need to consider:

  • The sufficiency and capacity of wastewater infrastructure.
  • The circumstances where wastewater from new development would not be expected to drain to a public sewer.

Related policy:

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Cross-boundary concerns

Plan-making may need to consider:

  • Water supply and water quality concerns often cross local authority boundaries and can be best considered on a catchment basis. Liaison between local planning authorities, the Environment Agency, catchment partnerships and water and sewerage companies from the outset (at the plan scoping and evidence gathering stages of plan-making) will help to identify water supply and quality issues, the need for new water and wastewater infrastructure to fully account for proposed growth and other relevant issues such as flood risk. The duty to cooperate across boundaries applies to water supply and quality issues.

Related policy:

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Using strategic environmental assessment and sustainability appraisal

Plan-making may need to consider:

  • Water supply and quality are considerations in strategic environmental assessment and sustainability appraisal which are used to shape an appropriate Local Plan, for example by establishing the ‘baseline’ and appropriate objectives for the assessment of impacts and proposed monitoring. Sustainability appraisal objectives could include preventing deterioration of current water body status, taking climate change into account and seeking opportunities to improve water bodies.

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Information about the water environment

Where is there information about the water environment?

The river basin management plan prepared by the Environment Agency is the key over-arching source of information on the water environment including the condition of water bodies and measures to help meet Water Framework Directive objectives.

Other sources of information on the water environment include:

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What are river basin management plans?

River basin management plans describe the river basin district and the pressures that the water environment faces. For the purposes of river basin management, the water environment is divided into units called water bodies. These can be sections of rivers and canals, lakes and reservoirs, estuaries, coastal waters and groundwater. The plans show long term objectives, what these mean for the current state of the water environment and how organisations and communities will work together to improve the water environment. There are 8 river basin management plans covering England. They are produced by the Environment Agency and approved by the Secretary of State for Environment, Food and Rural Affairs.

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What is a water cycle study?

A water cycle study is a voluntary study that helps organisations work together to plan for sustainable growth. It uses water and planning evidence and the expertise of partners to understand environmental and infrastructure capacity. It can identify joined up and cost effective solutions, that are resilient to climate change for the lifetime of the development.

The study provides evidence for Local Plans and sustainability appraisals and is ideally done at an early stage of plan-making. Local authorities (or groups of local authorities) usually lead water cycle studies, as a chief aim is to provide evidence for sound Local Plans but other partners often include the Environment Agency and water companies.

The Environment Agency has published advice on undertaking water cycle studies.

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What is a drainage strategy?

A drainage strategy can be prepared by water and sewerage companies and sets out how they intend to deliver statutory drainage functions and meet customer needs within a particular catchment. It will explain how the water company will do this in partnership with other organisations. Drainage strategies are expected to become an integral part of water and sewerage companies’ business plans. The Environment Agency and Ofwat have published a Drainage Strategy Framework which sets out principles and best practice for water and sewerage companies to develop catchment based drainage strategies.

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How can the Environment Agency help?

The Environment Agency can often provide help to local planning authorities and applicants by:

  • identifying the circumstances in which water quality is likely to be a significant planning issue and, where it is, the scope and content of any assessments that may be needed;
  • advising whether an environmental permit or other consent is likely to be required before the proposed development can start operating (they have published guidance for developments requiring planning permission and environmental permits). And, if so, whether there are any significant water issues that may arise at the permitting stage – so there are ‘no surprises’ and to help ensure that regulation is not duplicated by planning and permitting;
  • clarifying any special permit requirements that might affect the likelihood of getting planning permission.

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Water and neighbourhood planning

Are water issues relevant to neighbourhood planning?

Protecting and improving water bodies may be relevant when drawing up a neighbourhood plan or considering a neighbourhood development order. It is always useful to consult the local planning department about whether water could be a concern.

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Water supply, wastewater and water quality – considerations for planning applications

When is water likely to be a consideration in making a planning application?

This will depend on the proposed development, its location and whether there could be concerns about water supply, water quality or both.

Water supply

Planning for the necessary water supply would normally be addressed through the Local Plan. Water supply is therefore unlikely to be a consideration for most planning applications. Exceptions might include:

  • large developments not identified in Local Plans that are likely to require a large amount of water; and/or
  • where a Local Plan requires enhanced water efficiency in new developments as part of a strategy to manage water demand locally and help deliver new development.

Water quality

Early engagement with the local planning authority, the Environment Agency and relevant water and sewerage companies can help to establish if water quality is likely to be a significant planning concern and, if it is, to clarify what assessment will be needed to support the application. Water quality is only likely to be a significant planning concern when a proposal would:

  • involve physical modifications to a water body such as flood storage areas, channel diversions and dredging, removing natural barriers, construction of new locks, new culverts, major bridges, new barrages/dams, new weirs (including for hydropower) and removal of existing weirs; and/or
  • indirectly affect water bodies, for example,
    • as a result of new development such as the redevelopment of land that may be affected by contamination, mineral workings, water or wastewater treatment, waste management facilities and transport schemes including culverts and bridges;
    • through a lack of adequate infrastructure to deal with wastewater.

Assessing impacts on water quality

Where water quality has the potential to be a significant planning concern an applicant should be able to explain how the proposed development would affect a relevant water body in a river basin management plan and how they propose to mitigate the impacts. Applicants should provide sufficient information for the local planning authority to be able to identify the likely impacts on water quality. The information supplied should be proportionate to the nature and scale of development proposed and the level of concern about water quality.

Where it is likely a proposal would have a significant adverse impact on water quality then a more detailed assessment will be required. The assessment should form part of the environmental statement, if one is required because of a likely significant effect on water.

When a detailed assessment is needed, the components are likely to include:

  • the likely impacts of the proposed development (including physical modifications) on water quantity and flow, river continuity and groundwater connectivity, and biological elements (flora and fauna).
  • how the proposed development will affect measures in the river basin management plan to achieve good status in water bodies.
  • how it is intended the development will comply with other relevant regulatory requirements relating to the water environment (such as those relating to bathing waters, shellfish waters, freshwater fish and drinking water) bearing in mind compliance will be secured through the Environment Agency’s permitting responsibilities.

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Good status in water bodies

Good status for surface water bodies depends on biological quality (such as fish), physico-chemical conditions (for example oxygen or ammonia) and hydromorphological conditions (physical characteristics, such as size, shape and structure of a channel, and hydrology – the flow and quantity of water). Good status for groundwater bodies takes account of quantity and chemical status.

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Can planning permission be granted for developments that harm water bodies?

Changes to scheme design and mitigation will often avoid harm to water bodies. In the few cases where a detailed assessment indicates that development will have a significant adverse impact on water quality then the proposed development will only be acceptable where the conditions in Article 4.7 of the Water Framework Directive having regard to the river basin management plan. The Environment Agency may be able to advise on meeting those requirements.

There is a general duty on all public bodies to provide information and such assistance as the Environment Agency may reasonably seek in connection with exercising their responsibilities for implementing the Water Framework Directive. Where this has been requested by the Environment Agency, the local planning authority should notify the Environment Agency if planning permission is granted for a new development likely to lead to a deterioration of a water body.

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What to think about if there are concerns about water supply/quality?

This will depend on the concern, location and character of the proposed development. But there are likely to be options for mitigating the impact that has caused the concern. Mitigation should be practicable and proportionate to the likely impact.

Multiple benefits for people and the environment can be achievable through good design and mitigation. For example, flood risk can be reduced and biodiversity and amenity improved by designing development that includes permeable surfaces and other sustainable drainage systems, removing artificial physical modifications and recreating natural features. Water quality can be improved by protecting and enhancing green infrastructure and further information on this can be found in the planning practice guidance on the Natural Environment.

Local planning authorities can use planning conditions and/or obligations to secure mitigation and compensatory measures where the relevant tests are met. They can, for example, be used to ensure that new development and infrastructure provision is aligned and to ensure new development is phased and not occupied until the necessary works relating to sewage treatment have been carried out.

Planning obligations can be used to set out requirements relating to monitoring water quality, habitat creation and maintenance and the transfer of assets where this mitigates an impact on water quality.

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Are there particular considerations that apply in areas with inadequate wastewater infrastructure?

In the planning system, the preparation of Local Plans should be the focus for ensuring that investment plans of water and sewerage companies align with development needs. If there are concerns arising from a planning application about the capacity of wastewater infrastructure, applicants will be asked to provide information about how the proposed development will be drained and wastewater dealt with. Applications for developments relying on anything other than connection to a public sewage treatment plant should be supported by sufficient information to understand the potential implications for the water environment.

When drawing up wastewater treatment proposals for any development, the first presumption is to provide a system of foul drainage discharging into a public sewer to be treated at a public sewage treatment works (those provided and operated by the water and sewerage companies). This should be done in consultation with the sewerage company of the area.

The timescales for works to be carried out by the sewerage company do not always fit with development needs. In such cases, local planning authorities will want to consider how new development can be phased, for example so it is not occupied until any necessary improvements to public sewage treatment works have been carried out. Read further information.

Where a connection to a public sewage treatment plant is not feasible (in terms of cost and/or practicality) a package sewage treatment plant can be considered. This could either be adopted in due course by the sewerage company or owned and operated under a new appointment or variation. The package sewage treatment plant should offer treatment so that the final discharge from it meets the standards set by the Environment Agency.

A proposal for a package sewage treatment plant and infrastructure should set out clearly the responsibility and means of operation and management to ensure that the permit is not likely to be infringed in the life of the plant. There may also be effects on amenity and traffic to be considered because of the need for sludge to be removed by tankers.

Septic tanks should only be considered if it can be clearly demonstrated by the applicant that discharging into a public sewer to be treated at a public sewage treatment works or a package sewage treatment plant is not feasible (taking into account cost and/or practicability).

Related policy:

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A package sewage treatment plant

A package sewage treatment plant is like a mini-sewage works and produces much cleaner effluent than septic tanks. Package treatment plants are more sophisticated than septic tanks and require a source of power as well as regular maintenance. They also accumulate solid matter (sludge) that is settled out from the sewage, and require de-sludging.

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A new appointment or variation

The new appointment and variation regime is set out in sections 6-8 of the Water Industry Act 1991. It provides the opportunity for a limited company to provide water and/or sewerage services for a specific area in place of the former provider. Ofwat considers new appointments and variations applications.

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Published 23 March 2015