Nutrient neutrality rules are an opportunity not a barrier

This summer the UK government announced that it is scrapping rules that protect water from pollution from building work to provide new homes more quickly. But Natural England’s nutrient-neutrality rules offered critical protections – and supported new ways to create nature-based solutions, argues Gabriel Connor-Streich

As of 2019, England’s nutrient-neutrality rules required developers to secure measures to prevent excess nutrients entering protected waterbodies when they submit their planning applications to build new housing.

These measures, to provide nutrient mitigation and avoid polluting local water courses, generally used nature-based solutions to capture and store nutrients.

Nature-based schemes to reduce nutrients aren’t new, but the rules required developers to secure nutrient mitigation, quantified in kilograms per year, to offset the equivalent nutrient pollution that their development produces. Natural England ruled that nutrient-mitigation schemes should include long-term measures to remove nutrients for 80-125 years.

Nature-based approaches to meet these two requirements included creating wetlands, managing drainage ditches, mimicking beaver dams, creating riparian buffers and fallowing agricultural land. Most schemes so far looked to fallowing or wetland creation.

The nutrients that schemes mitigate were to be traded as nutrient credits in nutrient-mitigation markets. Several schemes had delivered credits to those markets and new schemes were being proposed all the time.

Our research indicated that England had a pipeline of schemes to mitigate nutrients to 72,000 proposed homes. We expected the market to unlock a large supply of credits – and to do so faster.

Greenshank Environmental, the company I co-founded, has been working with Natural England to scale up mitigation opportunities and to bring schemes forward quickly and robustly. And Natural England was working to bring forward its own schemes to increase the supply of mitigation.

Nutrient neutrality U-turn

The nutrient-mitigation markets started from scratch three years ago and had made good progress. Government’s announcement this summer will change that. No sooner do we have the tools to tackle nutrient neutrality than Rishi Sunak’s government plans to scrap them.

It justifies that decision, announced in late August, arguing that scrapping the nutrient-neutrality rules enables England to press ahead building 100,000 homes that the nutrient-neutrality rules have blocked.

The announcement introduces new uncertainty into delivering nutrient mitigation that will slow, not speed up, progress. Abolishing the nutrient-neutrality rules undermines future spend on ways to mitigate nutrients, including investment in innovative new ways to tackle water pollution – a problem that is hitting the headlines almost every day now.

To date, the nutrient-neutrality requirements had driven huge public and private spending. We identified at least £5.3 million worth of public spending – all of it in vain if government pulls the plug.

Greenshank is lobbying government. Earlier this summer it wrote an open letter, signed by 37 bodies in rural land and environmental management including CIWEM, to explain why scrapping nutrient neutrality is bad news. This autumn we are pressing the opposition and the government to turbo-charge delivery of nutrient mitigation through a few simple measures.

Why are so many big environmental NGOs defending the current nutrient-neutrality rules? Nutrient pollution doesn’t affect just a small number of protected habitats. It’s an international problem that affects some 413,000km of rivers across 30 European countries.

The nutrient-neutrality rules led new wetlands to be created, to provide tertiary treatment at WTWs or capture and treat agricultural runoff. Greenshank and other parties have worked on proposals and frameworks to deploy solutions across river catchments.

Using the right solution – be it riparian buffers, drainage-ditch management or mimicking beaver dams – in the right place is a simple way to manage diffuse nutrient pollution.

We’ve modelled these types of projects’ potential nutrient-load removal. We need monitoring to verify that research, creating new datasets to calculate how efficiently these approaches manage nutrients.

Nutrient-neutrality markets

Nutrient neutrality was one of the first functioning nature markets to launch in the UK. Government has been pushing new markets through its Nature Markets Framework to drive private investment in nature-recovery projects. Lessons from nutrient-credit generation and sales can shape future nature markets.

The evolving nutrient-credit market was also laying the groundwork for how nutrient markets could operate outside nutrient-neutrality areas and could benefit other habitats that are polluted by excessive nutrients. It’s a critical test case.

Here’s one example. Greenshank proposed a nutrient-mitigation scheme to tackle polluted surface-water runoff and streamflow, working with a farmer in Somerset. The pilot featured riparian buffers, manage drainage ditches and deploy water-retention features to manage diffuse nutrient pollution from surrounding farmland and towns.

Some measures are standard practice in rural sustainable-drainage systems. Others, such as managing drainage ditches, are techniques developed in US agriculture, now being adopted more widely in Europe. These measures boost flood and water-resource management, drought resilience and wildlife habitats.

Our team mapped surface-water runoff across a large farm. Where surface water collects from surrounding areas, we designed interventions to slow flows downstream. Slowing and storing water in the landscape supports physical and biogeochemical processes to store and remove nutrients.

These proposed mitigation measures don’t take up much land. And we’ve calculated that the farmer can continue to work the land while keeping more than 100kg of phosphorus a year out of local water courses. A typical agricultural fallowing scheme would need to remove more than 100 ha of land from production to manage that quantity of nutrients.

This scheme is the first of its kind nationally. We’ve been working with Natural England to have it approved in line with the Habitats Regulations that underpin nutrient neutrality. If we succeed, we believe that this scheme can open huge new mitigation opportunities and, critically, do so without removing lots of farmland from production.

Action plan for water

Greenshank has now published an action plan, suggesting six actions to resolve nutrient neutrality quickly, to avoid further harm to the environment.

We urge government to commit quickly and unequivocally to an environmental approach, building on the progress we have made. We have drawn up an alternative funding model for nutrient-mitigation schemes, proposing a levy on new development to create catchment-level funds that would finance nutrient-mitigation schemes.

We urge government to work with Natural England to streamline approvals for mitigation schemes and to give clear guidance to explain to providers what is and is not acceptable.

If government backs our approach, we can build much-needed new homes while still protecting the environment. If it doesn’t, we risk more environmental damage – for which polluters will not have to pay.

We urge government to deliver more nutrient-mitigation schemes, not to abolish them. We agree that house builders in affected areas have been stuck for too long, but our solution is to strengthen environmental approaches to tackling nutrient neutrality. These offer speed and the ecosystem-services benefits that only nature-based mitigation measures can deliver.

The lessons we learn from the nutrient-neutrality rules will help to create and shape other nature markets. To scrap nutrient neutrality now would threaten all these benefits – and signals that government really isn’t serious about protecting our environment.


In 2018, the European Court of Justice’s ruling on the so-called Dutch Nitrogen case changed the way we interpret the Habitats Regulations.

Where habitats sites’ hydrological catchments have such high concentrations of nutrients that they’re classed to be in “unfavourable condition”, authorities will approve development only where the builder sets out measures to manage the additional nutrient pollution that the development may create.

England has 27 affected catchments, in which Habitats Regulations Assessments (HRAs) for projects and plans must demonstrate measures to offset any additional nutrient pollution. The impact has been most acute in residential development.

New housing almost always raises the risk of nutrients polluting local watercourses, creating a de facto planning moratorium, halting approvals to build new homes in areas affected by nutrient-neutrality regulations.

In these areas, residential development can only secure planning consent through nutrient mitigation, offsetting nutrient impacts on the habitats site and complying with the Habitats Regulations via an HRA.

Providers of nutrient mitigation are working in affected areas to deploy nature-based solutions that remove or manage pollutants in order to reduce the risk of nutrients entering local waterbodies.

Developers can purchase nutrient credits that enable housing developments to secure nutrient-neutral status, pass an HRA and achieve planning consent.

Dr Gabriel Connor-Streich is the co-founder of Greenshank Environmental, a company set up to deliver nutrient-mitigation solutions

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