'Dirty Water'? Nutrient Neutrality in The Solent

9th August, 2019

The Partnership for South Hampshire (PfSH) (formerly ‘PUSH’) has called a halt to the granting of planning permissions for new housing and certain other developments across South Hampshire further to Natural England (NE) issuing new advice to Local Planning Authorities (LPAs).  This has had a significant affect for many current projects.  In this article, we look at the background to this and the current situation.

NE’s advice concerns the potential for some new development, including residential, to cause harm by increased nutrient levels (nitrogen and phosphorus) in the water environment of the ecologically sensitive Special Protection Areas (SPAs) in The Solent.

This advice is based on the March 2018 Integrated Water Management Study (IWMS) which identified a need for improvements at various Wastewater Treatment Works (WwTW) in the South Hampshire region to reduce the amount of nitrates leaching into the watercourses that eventually discharge into The Solent, causing dense algae growth. 

In April 2018, A Court of Justice of the European Union (CJEU) ruling known as 'People over Wind', decided that “it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on the site." 

Following this ruling, the National Planning Policy Framework (NPPF) and Planning Practice Guidance was updated, and Paragraph 177 of the NPPF now states:

“The presumption in favour of sustainable development does not apply where the plan or project is likely to have a significant effect on a habitats site (either alone or in combination with other plans or projects), unless an appropriate assessment has concluded that the plan or project will not adversely affect the integrity of the habitats site.”

The IWMS found that existing development already has this adverse impact on these protected habitats and species within or that rely on the SPAs.  NE acknowledges that whether new development will exacerbate these impacts is at present uncertain.  It is the subject of on-going research.

Meantime, LPAs in The Solent region have adopted a precautionary approach, on advice from NE.  Currently all proposed residential development and some other developments in the region must now demonstrate that it will be ‘Nutrient Neutral’ (NN) before planning permission can be granted. 

This applies to even a single dwelling including by change of use or conversion and irrespective that the site may be greenfield, urban and/or brownfield previously developed land (or indeed even if already allocated for development in a Local Plan but planning permission not yet granted).

It also applies to already submitted, undetermined planning applications and to new planning applications (and to undermined appeals and Court judgements).  This could also apply to applications for ‘reserved matters’ pursuant to outline planning permission already granted where Appropriate Assessment on this matter was not undertaken at outline stage.  Applications to amend current planning approvals might also be affected, depending on the nature of the change and whether the original application was subject to Appropriate Assessment.

For affected projects, there are currently three scenarios:

  1. If the development is NN (and/or if it does not drain eventually to The Solent), then there is no harm to the SPAs and this is not a barrier to the granting of planning permission.  NE has provided a methodology to calculate and so evidence whether NN can be achieved.
  2. If the development is not NN, then mitigation will be required to ensure there is no adverse effect to the SPAs, before planning permission can be granted.

    Mitigation can be ‘direct’ by upgrading the WwTW or through alternative measures such as interceptor wetlands (which do not drain wastewater eventually to The Solent); or ‘indirect’ by offsetting the nitrogen generated from new development by taking land out of nitrogen intensive uses (such as where fertilizer is applied to crops, which then otherwise drains eventually to The Solent).

    However, it is not yet entirely clear how each LPA (and NE) expect suitable and appropriate mitigation to be secured and delivered through the mechanism of a planning application.  Aside from this uncertainty, there may also be additional delay in the timescale for determination of existing and proposed planning applications.
  3. Delay the proposed development until there is more certainty from NE about whether NN remains necessary and/or until LPAs have clarified expectations for mitigation. 

The team at Pro Vision continue to monitor the situation and regularly attend Planning Agent’s forums with LPA’s.  This is clearly an evolving issue that may have implications for some of our clients.  This is a general overview of the situation.  If you would like to know more about these issues or you want to discuss how these changes might affect a specific project, please contact us on: 01794 368698 or info@pro-vision.co.uk


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