Cornwall Council has suspended grants of planning permission in a river catchment area after concerns from Natural England over phosphate pollution.
Natural England said in a letter to the council that excessive phosphates had entered the River Camel Special Area of Conservation, which was designated under the Habitat Regulations 2017. This covers some 69km of the river.
Natural England said excessive phosphates caused eutrophication leading to a dense growth of plants that endangered various species of marine life, and current mitigation measures were insufficient.
A Cornwall statement said: “The council is taking precautions by pausing decision making in the River Camel catchment area.
“We cannot approve new developments unless they can show they are nutrient neutral.”
This would affect new residential units, development for agricultural intensification, anaerobic digesters and changes of use for buildings to become dwellings.
The case is similar to one that caused residential planning permissions to be paused in the Solent area in 2019 because of concerns over nitrate pollution.
The High Court in February gave permission for two legal challenges to Natural England’s advice note there to be heard together later this year.
Barristers chambers FTB said at the time: “Both cases raise important questions about the interpretation of the Habitats Directive and about the issues surrounding excess nutrients in the Solent region.”