Published: 06:00, 11 October 2020
Poor water quality levels at an internationally-important nature reserve have stalled housing developments across east Kent.
The wetlands at Stodmarsh, outside Canterbury, which are a haven for wildlife, are deemed to be suffering from high levels of nitrogen and phosphorous.
Experts at Natural England say there is “sound evidence these nutrients are causing eutrophication” - a process which causes pollution and promotes excessive algae growth.
Waste water discharges from existing housing developments filtering into the River Stour catchment area and Stodmarsh’s lakes are the cause of the problem at the reserve.
Nearby Collard’s Lake is also in the same category due to pollutants.
Councils have been forced to put decisions on housing projects on hold while the best course of action to tackle the reserve’s deteriorating water quality is decided upon.
In Canterbury, the 4,000-home Mountfield Park scheme, which will swallow up more than 550 acres of fields to the south of the city, was due to be decided upon by the council’s planning committee last Thursday.
But in the wake of Natural England’s discoveries, it was pulled from the agenda after the council took legal advice on how best to handle the situation.
It is now unclear how long a decision on the controversial project will be delayed for.
City council spokesman Leo Whitlock said: “Natural England believes water quality in the lakes has deteriorated, and at the same time, European water quality targets have been made more onerous.
“This means before we approve any new housing development within the River Stour catchment area, or that would discharge waste water into it, applicants for planning permission need to satisfy Natural England they have made sure there are enough mitigation measures in place to stop this happening.
“When it comes to our big strategic housing sites, there are a number of approaches we can take including requiring developers to install waste water treatment works.
“We are close to reaching an agreement with Natural England on the best way of limiting the effect our strategic sites have on the Stodmarsh Nature Reserve, so do not expect long delays. We are also working on solutions for smaller development sites. This is a dynamic and fast-moving situation.”
The fresh setback is another frustration for Mountfield Park developers Corinthian Land.
Despite gaining the green light in December 2016 for the project on farmland between Canterbury and Bridge, the scheme has consistently been stalled by lengthy legal battles - causing the planning permission to lapse.
Last week’s decision would likely have seen that permission be renewed but the water quality at Stodmarsh has thrown another spanner in the works.
Investigations into how to prevent further deterioration of the lakes are being carried out.
A report from Natural England states: “Until this work is complete, the uncertainty of new growth’s impacts on designated sites remains, therefore there is potential for future housing developments across the Stodmarsh catchment to exacerbate the existing impacts thereby creating a risk to their potential future conservation status.”
Meanwhile, Ashford council says "housing developments cannot be determined until a process of formal assessment of the potential effects on the Stodmarsh Lakes has been undertaken, considered and approved by the council".
Authority leader Gerry Clarkson said: “It is important that this additional planning requirement is seen in context. It is an additional assessment to ensure development is not harmful to the wider environment.
"As a responsible authority this is a process with which we will wish to comply to ensure our borough and the wider environment in general is protected.”