Update September 2022
Development in the district of Dover is no longer affected by the water quality and nutrient neutrality advice issued by Natural England in relation to Stodmarsh SPA/SAC/Ramsar site.
Following the completion of hydrological connectivity and water quality modelling work, and subsequent review by Natural England, Dover District Council has demonstrated that any additional nutrients reaching Stodmarsh SAC/SPA/Ramsar as a result of new connections to Dambridge WwTW would not have a significant effect on Stodmarsh site (either alone and in combination with other plans or projects).
Natural England has confirmed that it will be formally updating its advice on the Stodmarsh catchment in due course.
Planning applications that have been held up by this issue may now be determined without the need for an Appropriate Assessment of the implications of the application for the Stodmarsh site. Dover District Council will seek to determine these applications as quickly as possible and case officers will contact agents directly to provide an update on likely determination timescales.
Letter from Natural England
Letter from DDC to Natural England
Connectivity Study Dambridge WwTW and Stodmarsh August 2022
Previous Advice
Stodmarsh lies east of Canterbury and is a Special Protection Area (SPA), Ramsar site, Special area of Conservation (SAC), and a Site of Special Scientific Interest (SSSI) and parts are a National Nature Reserve (NNR). It is a site of national and international importance for a range of water dependent habitats and wildlife that relies upon them.
During 2017/18, a review of the internationally designated lakes at Stodmarsh identified that some of the lakes there had raised nitrogen and phosphate levels, leading to eutrophication of the lakes which occurs when an excessive amount of nutrients within a water body are present, resulting in increased plant growth that reduces the oxygen content in the water. This process makes it difficult for aquatic insects, invertebrates or fish to survive, in turn removing a food source from the food cycle.
In July 2020, Natural England (NE) issued advice to the Council on this matter in light of the relevant European case law. This advice was updated by Natural England in November 2020 and recently again in March 2022. The advice and associated documents can be viewed from the links below.
Natural England Advice March 2022:
NE Water Quality and Nutrient Neutrality Advice 16.03.2022
NN Stodmarsh Catchment Map
Nutrient Budget Calculator Guidance Stodmarsh
NN Principles
NN – a summary guide
Stodmarsh SAC Nutrient Budget Calculator (excel)*
*Please note that the Nutrient Budget Calculator was updated in June 2022
Natural England Advice 2020:
NE letter to authorities in Stour Valley Catchment
Stodmarsh NN methodology Nov 2020
Stodmarsh Non-Technical summary
Stodmarsh FAQs
DEFRA has published a policy paper in relation to the issue:
https://www.gov.uk/government/publications/nutrient-pollution-reducing-the-impact-on-protected-sites/nutrient-pollution-reducing-the-impact-on-protected-sites#our-protected-sites-and-nutrient-pollution