East Devon District Council (EDDC) has been told it should no longer grant planning permission to any development that could increase phosphate levels in the River Axe, which are said to be causing a "significant issue".

Natural England has informed the district council that levels of phosphates in the River Axe are having a detrimental impact of local wildlife, and areas designated as a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC) are of particular concern.

This means that EDDC – the local planning authority – can no longer approve any developments in the area that would increase the discharge of phosphates into the river.

Phosphate is a chemical that contains the mineral phosphorus. It is naturally occurring and is released slowly, at low levels, from natural sources such as bankside erosion. However, phosphates can also enter rivers from land management practices, sewerage and foul water that can contain detergents and food waste.

High levels of phosphate can lead to the prolific growth of algae in rivers, which at worst can kill plants and animals and even pose a risk to human health.

A significant proportion of phosphates in the River Axe come from residential uses, and this means that developments for new dwellings and holiday accommodation – whether through new build or conversion – will now not be permitted unless the applicant can mitigate the phosphate discharge from the development, largely from greywater discharge, so that their impact on nutrient levels is neutral.

This is also likely to mean that agricultural developments that increase livestock within the area will be considered in this way, as they cause similar issues.

A number of planning applications in the Axminster area are now being put on hold until mitigation measures can be found.

In summary, the following types of developments in the catchment area may be affected:

• New residential units (but not annexes) – including holiday and tourist accommodation, gypsy sites/pitches, agricultural workers dwelling
• Commercial development – where overnight accommodation is provided
• Agricultural development – additional barns, slurry stores etc, where it is likely to lead to an increase in herd size
• Prior Notification of agricultural development where, as a result of the development, the herd size may increase. Also prior notifications for change of use to dwellings
• Anaerobic Digesters
• Reserve matters applications for residential development
• Appeals (for schemes including residential and agricultural etc outlined above)
• This may include Discharge of conditions to the above development types of development but we are unsure of this at present

A spokesperson for EDDC said: "We have already been holding some major developments at Axminster pending mitigation measures being in place but this new guidance means that even developments of a single dwelling will have to be refused unless the impacts from phosphates can be fully mitigated.

"Unfortunately it is very unlikely that individual developments will be able to mitigate their own impacts as on-site measures such as water efficiency measures and greywater recycling will be insufficient in themselves.

"Large scale strategic mitigation measures will be needed to address the issue. Officers have been working to deliver these measures but identifying projects that deliver mitigation in perpetuity is very challenging.

"For many years, grants have been available from Natural England and the Environment Agency to try and reduce phosphate discharge from farming in the area and I understand that this work continues. However, these tend to be short term projects.

"We have identified a range of similar short term projects through our work, however, in order to satisfy the guidance and mitigate for the impacts of new dwellings the mitigation will need to be in place for at least 80 to 120 years.  

"It is likely that projects such as new wetlands and reed bed systems will need to be created to fulfil this requirement."

The guidance also has implications for plan-making both in terms of neighbourhood plans and the local plan, which will need to ensure that any allocations for development within the catchment area are appropriately mitigated.

The spokesperson added: "Alongside the guidance issued by Natural England, the government has announced £100,000 of funding to come to the Axe catchment area to help the delivery of mitigation measures.

"It is also understood from a meeting last week with South West Water that they are committing resources to addressing these issues as well.  

"It is hoped that with these additional resources and our own district ecologist now in post that progress can be made to provide a mitigation strategy for the area which will enable the impacts of development to be mitigated such that planning permissions for dwellings and other phosphate generating uses can be taken forward again in the near future."

A report is to be presented to EDDC's Strategic Planning Committee on April 5 explaining in greater detail the issue and the work that is being undertaken to address it. The report should be formally published early next week.

The spokesperson continued: "With regard to development, this currently means that we cannot approve any existing applications in the catchment that involve the above bullet-pointed work streams. Such applications are highly likely to be refused until we have mitigation in place.

"In light of this, you way also wish to hold off submitting applications in the catchment for the foreseeable future.

"We are working through the implications of this but, in the meantime, as this is new to us, we would be grateful if you could bear with us until we understand the full implications.

"We will hopefully have a fuller understand over the next 10 days and will post updates here on the website.

"We must re-iterate, however, that this is all fairly new to us, quite complicated and as such the above is subject to change as we work through it.

"If you have currently have applications submitted with us, we will be in touch to advise if your application is affected by the proposal and what options are available to you.

"However, as this is new to us, it may be a week or so before we are in a position to advise of the exact implication for each proposal."

You can find more details here.