In a letter sent to the council last month, the wildlife regulator said the River Camel Special Area of Conservation (SAC) was at risk from the effects of eutrophication caused by excessive phosphates.
Furthermore, the regulator said, mitigation measures put in place such as improvements to some sewage treatment, catchment sensitive farming advice to reduce agricultural pollution and measures set out in the council’s River Restoration Plan, “will not reduce phosphate levels sufficiently to restore the condition of the SAC features”.
NE said it therefore advised that Cornwall Council, “considers the implications of these matters on the River Camel SAC”.
Before permitting any further development, which has the potential to result in additional phosphate loads entering the catchment, an appropriate assessment of plans and projects will be required, NE said.
“Having carried out that assessment, permission for the plan or project may only be given if the assessment allows you to be certain that it will not have an adverse impact on the integrity of the site,” it added.
Cornwall Council said it would temporarily pause decision making in the River Camel catchment area while it reviewed advice from NE and sought legal advice. “We cannot approve new developments unless they can show they are nutrient neutral,” it said.
This will impact planning applications currently in the system, including new residential units, development that supports agricultural intensification and anaerobic digesters.
The council added: “We know this will cause concern if you have or are planning to submit an application in this area. We will work with Natural England to provide a way forward as soon as we can.”
NE said Cornwall Council would have no doubt been aware that local authorities elsewhere have needed to review planning policy and their approach to development management in the light of the Dutch case judgment.
NE updated its advice on nutrients in 2019 after a Court of Justice of the European Union ruling relating to farmers in the Netherlands whose cattle grazing and fertiliser applications were having a deteriorative effect on EU-protected habitat, including air quality.
The court found that under Article 6(3) of the Habitats Directive, the mitigation measures put in place could not be guaranteed to be successful at the time of an appropriate assessment, which needed to be carried out.
Since then dozens of councils have had to stop issuing planning permissions for thousands of new homes.