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Nutrient Neutrality

About nutrient neutrality

Alongside all other local planning authorities in Norfolk, the council has received a letter dated 16 March 2022 from Natural England concerning nutrient pollution in the protected habitats of the River Wensum Special Area of Conservation and the Broads Special Area of Conservation and Ramsar site. The letter advised that new development within the catchment of these habitats comprising overnight accommodation has the potential to cause adverse impacts with regard to nutrient pollution. Such development includes, but is not limited to:

  • new homes
  • student accommodation
  • care homes
  • tourism attractions
  • tourist accommodation
  • permitted development (which gives rise to new overnight accommodation) under the Town and Country Planning (General Permitted Development) (England) Order 2015
  • any development not involving overnight accommodation, but which may have non-sewerage water quality implications

The Conservation of Species and Habitats Regulations 2017 require local planning authorities to ensure that new development does not cause adverse impacts to protected habitats such as the Broads prior to granting planning permission. At present there are no identified mitigation solutions available locally to resolve these impacts. 

The council as the Competent Authority cannot lawfully grant planning permission unless it can conclude that development within the catchment of the Broads Special Area of Conservation and Ramsar site will not have an adverse effect.  This process is considered through a Habitats Regulations Assessment.

See government guidance on the Habitats Regulations Assessment.

What does an applicant need to do to demonstrate nutrient neutrality if their development is affected?

  • You will need to calculate the level of nutrients arising from your development and in order to help you to do this you can use the published calculator which has been drafted by the Norfolk Authorities. Tools are set out in the relevant section below.
  • Once you have established your nutrient impact you will need to identify mitigation. The council will not be able to lawfully grant permission unless deliverable mitigation to address those impacts is identified and secured. See below for an update on national and local work on mitigation strategies.
  • An applicant will need to submit a shadow Habitats Regulation Assessment (HRA) to the council assessing the impacts and identifying appropriate mitigation and its management and maintenance to demonstrate there are no adverse effects on the integrity of the protected sites.
  • Natural England offers a Discretionary Advice Service which can be used by developers to seek advice on specific schemes.
  • The council wants to work positively with you however will be unable to positively determine these applications until the mitigation is identified and addressed through the HRA. Case officers will therefore seek appropriate extensions of time for the determination of the application to enable you time to continue to address this matter.

Nutrient Budget Calculator tools

Norfolk Authorities have produced a Norfolk Nutrient Budget Calculator which can be used as an alternative to the Natural England Calculator tool.

Read Natural England's response to the Norfolk Nutrient Budget Calculator.

In relation to the use of Natural England Nutrient Calculators and the Habitats Regulations process, the Court of Appeal decision in R (Wyatt) v Fareham BC and Natural England was issued on 15 July 2022. This confirms that Local Planning Authorities can rely on the guidance of Natural England via their nutrient calculator tools. However, these are not the only tools that can be used when calculating nutrient loading, they are merely one way of carrying out an “appropriate assessment” and their use is not therefore mandatory. However, the Court of Appeal decision suggests that a planning authority ought to follow the methodology suggested by the statutory nature conservation body unless it has good reason not to do so.  

Natural England published a calculator tool alongside their letter of the 16th March 2022. View full details of the advice received from Natural England and the methods for calculating the nutrients generated by proposals below:

What this means for you 

The Norfolk Nutrient Budget Calculator can be used for proposed developments in the Norfolk catchments impacted by Nutrient Neutrality.

This is a Norfolk specific calculator, we know other calculators are available including the Natural England Calculator.  

The Norfolk Calculator however uses local data to provide a more refined nutrient calculation having regard to specific local characteristics.

The Norfolk Calculator provides a rapid calculation of net phosphate and nitrate loadings from developments. This includes phosphate and nitrate offsetting calculations for on-site and off-site locations. It is a clear decision making tool for the Local Planning Authority and developers.

The calculator is made up of the River Wensum SAC and Broads SAC Nutrient Budget Calculator and the Norfolk Nutrient Budget Calculator Technical Report. It contains a help section to assist with the stages of the process. 

The calculator is reviewed regularly.  At the moment, the current version contains a rainfall data map, which is very difficult to read. You can view the Norfolk average rainfall map 2001-2021 in greater detail.

View the calculator here

Video guide on how to use the calculator.

Calculator technical reference report

The area of risk

You can view maps of the affected catchment areas below:

The catchment area map has identified the areas served by various wastewater treatment works  WwTWs). Please note:

  • That we cannot guarantee the accuracy of the WwTW data and you should contact Anglian Water for further information.
  • Developments within the catchment area that will drain to a WwTWs within the catchment will need to complete stages 1-3 of the calculator.
  • Developments located outside of the catchment area but that will connect to a WwTWs that drains to the catchment should not complete Stages 2 and 3.
  • Where a site is located within the hydrological catchment but drains to a WwTWs outside of the catchment then mitigation is not required.

More help with the calculator

If you need help to complete the calculator, we recommend using a specialist consultant.

We will be adding more guidance to help use the calculator in response to queries we receive.


In July, the Government issued further information about Nutrient Neutrality and steps to be taken to assist with the delivery of mitigation schemes to help enable development to proceed. Mitigation schemes within the affected areas will be necessary to enable further development such as housing growth to be permitted. 

A written Ministerial Statement made by George Eustice (Secretary of State for Environment, Food and Rural Affairs) was issued on 20 July 2022.

This sets out that the government will: 

  • Place a legal duty on water companies to upgrade wastewater treatment works by 2030 in nutrient neutrality areas 
  • Require Natural England to establish and deliver a Nutrient Mitigation Scheme 

The government advice was followed by a letter about nutrient neutrality and habitats regulations assessment from Joanna Averley (Chief Planner) issued 21 July 2022. 

The Norfolk Authorities are working together to ensure consistency of approach on Nutrient Neutrality. The contents of the Written Ministerial Statement and Chief Planner letter are therefore being considered carefully to establish whether this provides a basis for enabling permissions to be issued now with conditions/restrictions or, whether there is a need to wait until there is better understanding of mitigation schemes to be delivered by Natural England and confirmation that those schemes are deliverable. Further updates will be provided once clarity has been established. 

Royal Haskoning are continuing with their work on behalf of the Norfolk Authorities which includes the development of a bespoke nutrient calculator for the Norfolk catchments. They are also exploring the identification of mitigation solutions for the short, medium, and long term.

Royal Haskoning have published their final report: Norfolk Nutrient Mitigation Solutions Report.

The work being carried out by the Norfolk Authorities on mitigation does not preclude developers seeking their own mitigation solutions.

You can also see answers to frequently asked questions.

Copies of the slides from the Agents Forum.

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