Nutrient Mitigation for New Housing Development

Most of the rivers within the Partnership for South Hampshire (PfSH) area drain into the Solent. The Solent is internationally recognised for its range of rare habitats and has been designated to protect the wildfowl and wading species that rely on it. Under Regulation 63 of the Conservation of Habitats and Species Regulations, local councils, as “competent authorities”, can only approve planning projects that will not have a significant effect on these protected areas. As a part of this, a Habitats Regulations Assessment (HRA) must be completed alongside any planning applications to prove that the project won’t negatively impact on protected areas.

In 2019, Natural England introduced a requirement that any new overnight accommodation development in catchments draining into the Solent must be “nutrient neutral”. This means that developments in these catchments must find ways to mitigate the increase of nutrients entering the Solent from urban runoff and sewage treatment for the development’s life cycle (usually 80-130 years depending on the authority). This is to prevent any further damage to the protected areas of the coast caused by nutrient loading from development. Without evidence of mitigation, a HRA would not be able to show that sites would not be impacted and planning permission cannot be granted.

This change to the planning system has caused issues across the country and remains a controversial issue for many stakeholders and within government. Within the PfSH area, nutrient neutrality has been addressed by the provision of strategic planning support to facilitate the creation of a network of mitigation sites and schemes around Hampshire. Developers obtain mitigation credits to offset the impact of their new developments directly from the credit providers, using a simplified process underpinned by a legal agreement. PfSH has led the way in finding nutrient mitigation solutions and is a great example of what effective collaboration and communication between local planning authorities, stakeholders and landowners can create.

Further information can be found across our website:

Background and importance of the Solent

A summary of why the Solent needs to be protected and links to other websites for further information on the Solent’s wildlife

What nutrient neutrality does

An explanation of what the policy aims to do for the environment, access to Natural England’s nutrient budget calculator and information on the different forms mitigation can take

Partnership for South Hampshire and nutrient neutrality

An overview of our activity since nutrient neutrality was introduced to the Solent

Nutrient mitigation

Information on what nutrient mitigation credits are available and where the mitigation sites are

Supporting documents

A list with links to different documents that are relevant to nutrient neutrality and development in the Solent