Some planning applications in the district are affected by guidelines on water quality.
In July 2020, Natural England published advice about the deteriorating water quality in the Stodmarsh lakes, which is an internationally protected wildlife site.
The advice was that outfall from wastewater treatment works (WwTWs) within the Stour Valley river catchment area is contributing to a deterioration in the water quality in the lakes. This comes from the traces of prosperous and nitrogen within the treated outflows.
Under the Habitat Regulations, we cannot lawfully grant planning permissions that would worsen the water quality in the lakes.
The effect of this is that no new housing development (or overnight sleeping accommodation) in this area can be granted permission unless mitigation for this impact on the lakes has been secured. This means developers would have to show that all development would be ‘nutrient neutral'.
WwTWs in the Canterbury district that discharge water directly or indirectly into the Stour are:
You can see properties within these catchment areas on a map. This does not include the purple, orange and yellow areas.
For advice on a specific site, you can contact Southern Water.
We have been actively working to support initiatives that will provide mitigation nutrient neutrality credits that can be used to unlock housing developments.
Planning permissions have been recently granted using both permanent and temporary credits from the following suppliers:
The first thing that you need to do is to calculate how many credits you will need to mitigate your development.
All developments will require permanent credits. If the development will be occupied before 1 April 2030, you will also need temporary credits. This date is when the government have confirmed that upgrades will have been made to many WwTWs. This means the efficiency of those sites will improve and the impact of new development connected will be less.
You will need to input the relevant average occupancy rate as part of the calculation.
We have used the Natural England average occupancy rates for houses, but in the case of developments with flats, we would accept a reduced occupancy rate as set out below, based on our formula for calculating open space contributions for new housing developments.
For houses, the average occupancy rate per unit is 2.4.
For flats, the average occupancy rate per unit is 1.6.
If your development is in Herne Bay, then the credits you will need to buy will be significantly fewer than the rest of the district. To work out how many you need for this area, reduce the number you get from the calculator by 99.87%. This means only 0.13% of the standard amount of credits is needed for Herne Bay.
Calculate your nutrient neutrality credits
If your application has been delayed for more than two years, any ecology assessments submitted might need to be updated.
If there have been any other material changes in site circumstances and/or planning policies relating to your application, then you might need to give us additional or revised information. Contact our planning team for more help.
Once you have worked out the credits you need, you will then need to secure permanent credits from a supplier (and temporary credits if the development will be occupied before 1 April 2030).
It is your choice which option you propose as mitigation for your development.
When you have secured credits, we will then need to draft an Appropriate Assessment for your development under the Conservation of Habitats and Species Regulations 2017, and consult with Natural England.
If we have no objections from Natural England, we will adopt the Appropriate Assessment and then make a decision on your planning application.
The Natural England nutrient neutrality calculator is based on a water use rate of 120 litres per person, per day. A condition will be added to planning permissions to limit water consumption in line with this.
If you are not buying temporary credits, then a condition will be added to planning permissions to stop occupation until after 1 April 2030.
Where we grant prior approval for new homes, you will also need separate approval under the Conservation of Habitats and Species Regulations 2017.
For us to be able to grant this separate approval, you will need to secure credits from a supplier in the same way as for any other planning application.
It is important to note that if you have already been given prior approval for your development, you cannot lawfully carry out the development until you have also been given this separate approval.