Nutrient Neutrality and Housing Delivery

11 May 22

Whilst nutrient neutrality started off as a relatively localised issue in the Solent in 2019, it has quickly become a barrier to development across the country, with Natural England releasing advice that development which results in overnight stays cannot proceed if it increases levels of nutrients.

An increasing number of local authorities are now affected, an additional 42 as of March 2022, making a total of 74 since 2020.

In the context of housing need, this is an issue which could have significant and long-running implications. The Home Builders’ Federation (HBF) recently published research suggesting up to 100,000 homes are currently delayed as a result.

This estimate is likely to increase given the time it will take authorities to develop and adopt mitigation measures and subsequently implement them. Although mitigation measures have been initially successful in the Solent, it is clear that there are no quick fixes.

A new strategic wetland, in line with the approach being put forward by Ashford Borough Council, needs two growing seasons to be established before development tied to it can be occupied. Ashford has set out a tight target to have strategic wetlands fully operational by Autumn 2024.

However, the authority has just a 3.5-year supply of housing based on the deliverability of sites affected by nutrient neutrality, and this position is likely to worsen for a number of years, even if allocated sites develop their own on-site mitigation in the meantime.

Ashford is just one example within the wider catchment of Stodmarsh Nature Reserve where Canterbury is also significantly affected, as well as parts of Maidstone, Dover, Folkestone and Hythe and Swale. Approaching this issue, a number of housing developments in these areas are looking to install on-site Wastewater Treatment Works (WwTW) or proposals for wetlands.

Going forward, will the Government provide support to generate a national strategy? Or ensure the upgrade of existing wastewater facilities is fast-tracked by water companies? Do local authorities have any way to fund the work required to understand the issue in more detail? If wetlands are the solution, where is the land coming from and how can it be delivered?

A strategic solution is required, removing the need for geographically piecemeal strategies, particularly given the additional hurdle it now represents in achieving the target of 300,000 homes each year.

The Department for Levelling up, Housing and Communities (DLUHC) has recently said they will fund additional support for local authorities affected by this issue and we hope this will provide LPAs with the necessary in-house experience to deal with this issue effectively.

In the meantime, Iceni Projects have reviewed the guidance in detail and would be happy to discuss the implications for your project.

Sophie Innes Associate,Planning