Solent Disturbance Mitigation Project (SDMP)

Since July 2014 all applications for new residential planning permissions across the city need to provide a means of mitigating the development's impact upon the ecological importance of the Special Protection Areas within and around the Solent.

Whilst applicants may propose alternative measures to mitigate the direct impact of their development on the Solent SPA, the simplest way of mitigating will be through the Solent Disturbance Mitigation Project.

The Solent Recreation Mitigation Strategy (December 2017) has a revised sliding scale of contribution, which was approved by Southampton City Council Cabinet on the 20 March 2018, and sets out the following payment schedule for new residential development from 1 April 2019

  • £346 for each 1 bedroom dwelling
  • £500 for each 2 bedroom dwelling
  • £653 for each 3 bedroom dwelling
  • £768 for each 4 bedroom dwelling
  • £902 for each 5 bedrooms or more

These new charges will be implemented for all planning applications determined on or after the 1 April 2019.

This requires applicants to either:

  • Make a financial contribution in line with the revised Charging Schedule set out above before planning permission is granted by completing the SDMP Agreement and sending the completed form along with mitigation contribution to the Planning Agreements Officer at the Local Planning Authority. 


  • By completing the Unilateral Undertaking before planning permission is granted with an undertaking that the payment in line with the revised charging schedule set out above will be made before the development is implemented. Please note that on submission of the Unilateral Undertaking, to the Planning Agreements Officer at the Local Planning Authority, a £180 fee/cheque will also need to be submitted to cover checking fees by the council's legal team. 

Please note that the council's legal costs (£180) are a minimum charge where the council's draft template is used with no amendments save for the matters to be inserted by reference to the footnotes. Any further amendments may incur further costs to the applicant.

Apply for mitigation

Please choose one of the following options:

SDMP Agreement 
Fill in the Habitats Mitigation Contribution Agreement and submit to the Local Planning Authority, along with the relevant SDMP Mitigation Contribution per residential unit.

Unilateral Undertaking 
Fill in and submit the council's standard Unilateral Undertaking with the planning application, along with the £180 checking fee.

For either option please submit the necessary information to the Planning Agreements Officer early enough to ensure the application process isn't delayed or refused.

Further information on the calculation/setting of the SDMP is available from the Solent Recreation Mitigation Strategy (December 2017)

If your enquiry relates to a specific planning application please contact the planning case officer on 023 8083 2603.

How can I make payment?

You may pay the planning obligation using the following payment methods:

1. Online: The best way to make a payment is by paying online:

Pay online

You will need your Planning Application Number (starting with the year, e.g. 18/0****/***), which can be found on the correspondence you will have received.

2. BACS: Please ensure you enter your Planning Application Number (starting with the year, e.g. 18/0****/***), which can be found on the correspondence you will have received, as the payment reference. The account details are:

Sort code: 30-00-00
Account no: 00332526