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Nutrient Neutrality information for developers

This webpage contains a summary of the information needed to accompany applications which are affected by nutrient neutrality.

All the information on this webpage should be read in conjunction with the Natural England Advice [pdf] 1422KB.

What information do I need to submit with my application?

If your application site is located in the Stour catchment and your development is required to demonstrate nutrient neutrality you will need to submit the following information:

Once all this information has been submitted to the council, we will conduct an Appropriate Assessment to determine whether the development proposal demonstrates nutrient neutrality.

Nutrient calculations

In order to calculate the total nutrients generated by a development, the council has prepared a calculator for public use.

The calculator is based on the methodology adopted by Natural England and can be used to calculate the nutrients generated from development that is connected to both mains drainage (Method A) and non mains drainage (Method B).

Download the nutrient calculator [xlsx] 69KB

To assist with using the calculator, the council has set out average occupancy rates for specific types of developments, such as flats or hotels.  These values can be used in the nutrient calculations.

Accommodation type


(per bedroom)


(per unit)

Dwelling - house   2.4
Dwelling - flat   1.75
Hotel / B&B 1.75  
House of Multiple Occupation (HMO) 1.75  

Any applicant wishing to deviate from these values will be required to provide robust evidence in support of their application in order to justify their approach.

Non-mains drainage

If the development does not connect to the mains sewer network, the nutrient calculations should be completed using the methodology for ‘Non-mains drainage’ (Method B) of the Natural England Advice and nutrient calculator.

For development proposals that connect to non-mains drainage, information about the type, location and efficiency of Package Treatment Plant (PTP) must be provided, together with details of the monitoring and maintenance of the PTP(s).

Evidence to support the PTP efficiencies could include:

  • Test result documents from the lab
  • Measured effluent concentrations from real world applications

What counts as mitigation?

Mitigation, for nutrient neutrality, acts to reduce the overall nutrients released from development.

Examples of mitigation include:

  • Wetlands
  • Sustainable Urban Drainage Systems (SUDs)
  • Taking land out of agricultural land use

For any mitigation proposal, information should be given to show the design, location and efficiency of any mitigation and how this results in the development achieving nutrient neutrality.

Wetland mitigation

The effectiveness of wetlands at removing nutrients is highly dependent on the design and maintenance.

Natural England sets out that wetlands must:

  • Be at least 2ha in size
  • Have a permanent input of water
  • Have a detailed design of the proposed wetland to accompany the planning application
  • Calculate wetland specific Nitrogen and Phosphorus removal rates
  • Include details of the monitoring and maintenance of the proposed wetlands in perpetuity (minimum 80 years)

Borough Mitigation Strategy

For development proposals, which can’t mitigate on-site, the Council is preparing a borough Mitigation Strategy. This Mitigation Strategy will be a series of short, medium and long term solutions.

Work is currently ongoing to prepare the Mitigation Strategy.

In the interim, should you choose to submit an application that relies upon the borough Mitigation Strategy, please continue to prepare the nutrient calculations and provide these together with any additional information required (in accordance with the guidance above) and submit these as part of the planning application. Please also confirm in a covering letter that you intend to wait for the borough Mitigation Strategy.