Natural England's duty to avoid deterioration of protected sites: R (Harris) v Natural England

On 9 October 2026, the High Court (Lieven J) handed down judgment in R (on the application of Harris) v Natural England [2026] EWHC 2488 (Admin), finding that Natural England (NE) had breached its duty under Regulation 9(1) of the Conservation of Habitats and Species Regulations 2017 (the "Habitats Regulations") and Article 6(2) of Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (the "Habitats Directive") by failing to take appropriate steps to protect Catfield Fen, which forms part of a Special Area of Conservation (SAC).

Freeths acted in the earlier Harris litigation, Harris and another v Environment Agency [2022] EWHC 2264 (Admin), concerning the Environment Agency’s (EA) obligations in relation to water abstraction and protected habitats. Penny Simpson (Partner and Head of Nature Capital Law) previously commented on this judgment in September 2022. The latest Harris judgment concerns a different pressure, agricultural pollution, and a different regulator. It returns, however, to a closely related question: What does the duty under the Habitats Directive to protect designated habitats from deterioration and disturbance require regulators to do in practice?

The judgment provides important guidance on the scope of the duty under Regulation 9(1) and Article 6(2). While the court rejected the suggestion that the identification of a risk of deterioration necessarily requires immediate substantive intervention, it found that, on the facts, the evidence had reached a point at which further investigation was not enough. In essence, the problem was so obvious, and so much time had passed, that NE was required to take “some active steps to protect the SAC” (para 96). Applying public law principles, the court found that NE’s failure to do so was outside the range of reasonable regulatory responses.

The judgment also comes at a significant point in environmental policy. Defra’s Habitats Regulations General Implementation Report, published in January 2026, records that only 3% of habitat types assessed in England were in favourable conservation status, while 48% were unfavourable and deteriorating. Meanwhile, the Environmental Delivery Plan (EDP) and Nature Restoration Fund (NRF) framework envisages a significant role for NE in delivering conservation measures. This new Harris case therefore raises questions beyond Catfield Fen: When is investigation alone no longer sufficient, and what lessons does the judgment offer for the implementation of the new regime?

Background

Catfield Fen is a wetland of around 63 hectares, forming part of the Ant Broads and Marshes Site of Special Scientific Interest (SSSI) and the wider Broads SAC. Its eastern part is owned by the claimant, while its western part is owned by Butterfly Conservation and managed by the Royal Society for the Protection of Birds (RSPB). The claimant’s principal concern was that run-off containing phosphates and nitrogen flowed from Mr Alston’s farmland, across Fenside (an adjoining public road also known as “the Lane”), and through drainage channels (“grips”) dug by Norfolk County Council (NCC) into the northern side of the Fen, causing eutrophication and ecological harm.

The claimant’s land agent first wrote to NE in April 2021 about the cutting of the grips and the resulting run-off into the Fen. The claimant subsequently took water samples and, in January 2024, provided NE with a report by Howland Associates which found phosphate concentrations between three and seventeen times the water quality target for the SAC. Nitrogen levels were more variable, although several readings also exceeded the relevant target.

Following a site visit in February 2024, NE produced its own internal Enforcement Questionnaire which identified agricultural land as the apparent primary source of diffuse pollution and recorded a clear pollution pathway from the farmland through the grips into the Fen. NE subsequently produced a Catfield Fen Pollution Reduction Plan in August 2024, identifying a number of “achievable actions”. Of the measures identified in the Plan, only a buffer on Mr Alston’s land was implemented, and this was ploughed up in January 2025, leaving little or no effective protection against run-off.

NE decided to undertake its own water quality sampling in September 2025, after judicial review proceedings had been issued in July 2025. Laboratory errors affected the first sampling exercise, and further sampling was undertaken in February 2026. The resulting April 2026 report showed phosphate concentrations exceeding the SAC target at all sampling points, with exceedances at two points on the northern dyke described by the court as “extremely high” (para 28). NE nevertheless maintained that there was insufficient evidence that pollution in the northern dyke was causing harm across the wider site and relied on that uncertainty in resisting further protective action.

The case

The claimant, Mr Harris, argued that NE’s response amounted to a breach of its statutory duties. Regulation 9(1) of the Habitats Regulations requires nature conservation bodies to exercise their nature conservation functions “so as to secure compliance with the requirements of the Directives”. Article 6(2) of the Habitats Directive requires appropriate steps to be taken to avoid the deterioration of protected habitats and significant disturbance of protected species.

The claim was advanced on two alternative bases:

• While NE had discretion over which steps to take, it had no discretion over the timing of action: Once aware of the relevant risk, it was required to take immediate action to prevent deterioration, and its failure to do so constituted a breach

• Alternatively, given the evidence available to NE, the scale and persistence of the exceedances and the time elapsed, its response fell outside the range of reasonable regulatory responses and was therefore unlawful on ordinary public law principles

The court rejected the first argument, concluding that it imposed too high an obligation on NE. The court acknowledged that there is a spectrum of reasonable responses, including investigation and assessment. What constitutes a reasonable response will be highly fact-specific, and the time reasonably required to complete those steps will vary. Referring to CG Fry & Son v Secretary of State for Housing, Communities and Local Government [2025] UKSC 35, the court explained that the precautionary principle applies, but the choice of appropriate steps remains a matter of regulatory judgement, subject to ordinary public law duties (para 83).

The position was different on the claimant’s second argument. NE had been on notice of the problem since 2021 and had clear evidence of the probable pollution pathway by early 2024. Even if the Howland report was insufficient to justify further intervention, NE then waited nearly two years to undertake an effective survey of its own. The court described the pathway by which phosphates and nitrates entered the northern dyke as appearing to be “wholly incontrovertible” (para 91). In those circumstances, its failure to take further protective steps was irrational.

The court also rejected NE’s reliance on the belated requirement for NCC to seek assent before cutting grips. The existing grips remained, and preventing further grip-cutting was not a solution to the underlying pollution problem: The court observed that phosphate-polluted rainwater would instead flood the Lane (paras 35–36 and 92).

Importantly, Lieven J rejected the suggestion that NE could defer further protective action until deterioration across the wider Fen had been demonstrated. Article 6(2) is preventive. Given the clarity of the evidence and the extent to which NE accepted it, further investigation alone was insufficient: NE was required to take “some active steps to protect the SAC” (para 96). The court found a breach of Regulation 9(1) and Article 6(2), leaving the question of any further orders to subsequent submissions (para 97).

Commentary

A wake-up call for other protected sites?

Harris is not authority that every identified risk requires immediate enforcement. Investigation and assessment may constitute appropriate steps, and regulators retain professional judgement over their response. However, that judgement remains subject to public law limits: On these facts, the clarity of the evidence, the time elapsed and the inadequacy of the measures taken required active protection.

The wider question is whether responses to pressures at other protected sites remain appropriate to the evidence available. Where a damaging pressure has been monitored over a prolonged period and its source and pathway are sufficiently understood, further investigation or voluntary engagement alone may no longer satisfy Article 6(2).

A failure of the framework… or its implementation?

That question assumes particular significance given the wider conservation status of habitat types in England. Alongside the figures noted above, Defra’s Habitats Regulations General Implementation Report identified agricultural activities, including those leading to water pollution, among the principal pressures affecting habitats and non-bird species.

These are assessments of habitat types across England, not findings about compliance at individual protected sites. They do not, in themselves, establish equivalent breaches of Article 6(2) elsewhere. They do, however, raise questions about compliance with duties which were designed to protect our most important habitats and species.

Article 6(1) requires necessary conservation measures for SACs, while Article 6(2) requires appropriate steps to avoid deterioration and significant disturbance. Harris provides a striking example of a public body failing to implement existing protective duties. The tragic state of our most important habitats is therefore attributable less to deficiencies in the legal framework than to the consistent failure of public bodies over many decades to comply with their duties to take the necessary steps to protect those habitats.

Socio-economic considerations do not justify doing nothing

Although Harris does not expressly address the relationship between Articles 2(3) and 6(2), Article 2(3) provides an additional perspective. It requires measures taken under the Habitats Directive to take account of economic, social and cultural requirements, as well as regional and local characteristics. Those considerations give competent authorities flexibility in choosing and implementing the conservation measures required by Article 6(1) and the appropriate steps required by Article 6(2). That flexibility concerns how those duties are discharged, not whether they are discharged. Article 2 certainly does not justify indefinite inaction or allow the required measures or steps to be postponed indefinitely.

Looking beyond new development

Harris also brings existing land-use pressures into focus. Assessment of new plans and projects under Article 6(3) is only one part of the Habitats Directive’s protective framework. Effective protection also depends on conservation measures and action to prevent deterioration arising from existing activities. Measures designed to address the additional effects of new development do not remove the need for action on established agricultural pollution.

That distinction matters when considering strategic approaches to nutrient mitigation. The question is not whether new development should address its own effects, but how those measures sit alongside action to tackle existing pollution at source.

What does this mean for Environmental Delivery Plans?

The judgment also has wider policy significance as NE prepares to deliver EDPs under the NRF framework established by Part 3 of the Planning and Infrastructure Act 2025. The draft Norfolk EDP concerns nutrient pollution affecting the Broads SAC (Yare and Bure), Broadland Ramsar site and River Wensum SAC. Developer levy payments would fund conservation measures delivered by NE. Under the Overall Improvement Test, by the EDP end date the effects of those measures must materially outweigh the negative effects of the development covered by the EDP on the conservation status of each identified environmental feature.

The principal lesson from Harris for the new regime concerns delivery. The EDP framework envisages NE monitoring conservation measures and responding where they prove ineffective. Yet at Catfield Fen, NE considered that uncertainty about the extent of deterioration across the wider site justified further investigation rather than additional protective action, despite clear evidence of the pollution pathway. The court concluded that, by that stage, this response was no longer within the range of reasonable regulatory responses. Although this does not establish that EDPs will encounter the same problems, it raises concerns about reliance on monitoring by NE and the mechanisms for ensuring timely action where measures prove ineffective.

Additional funding may strengthen delivery capacity, but new responsibilities also require staff, expertise and sustained oversight. The question is whether NE will have the capacity to secure, monitor and, where necessary, adapt strategic conservation measures while continuing to discharge its existing duties.

Conclusion

Harris illustrates the difference between having protective duties on paper and discharging them effectively in practice. Regulators retain judgement over how to investigate risks and select appropriate measures, but that discretion has limits. The Article 6(2) duty has teeth. As new environmental delivery mechanisms develop, the lesson is not simply that further duties or funding are needed: existing and new responsibilities must translate into timely, effective protection on the ground.