Natural Resources Wales defends River Dee phosphate monitoring following criticism

Alec Doyle, Local Democracy Reporter

Natural Resources Wales has defended itself over criticism related to the phosphate levels in the Lower River Dee amid claims it has left over 100 planning applications in limbo.

Earlier this week some Wrexham councillors raised concerns over how the NRW records and uses data following a report which stated that in March 2025 – but for a single high-phosphate test – the river’s phosphorous levels were within acceptable boundaries.

High levels of phosphorous are harmful to biodiversity and wildlife and are typically caused by water run-off from agricultural processes and sewage discharges linked to residential housing.

For five years Wrexham Council has put more than 100 planning applications on hold as a result of the Lower Dee’s phosphate status.

Now NRW has said that the decision to put those developments on hold was Wrexham Council’s – as its health rating for the river does not automatically restrict development.

Earlier this week at Wrexham Council’s Planning Committee, members considered an update report which suggested that had it not been for this single result, the Lower Dee could have been given a clean bill of health – something Wrexham Council says will mean planning can be considered once more.

Cllr Hugh Jones was scathing in his criticism of NRW at the time.

“Natural Resources Wales have demonstrated a level of professional ineptitude which in my view is beyond belief,” he said. “This points also to a significant failure on the part of the previous Welsh Government to challenge NRW when it was self-evident that they got it wrong.”

He also claimed NRW’s position on phosphates was having a detrimental impact on Wrexham’s economy by preventing housing and business planning applications from going ahead and called for it to be broken up.

But NRW says that there is no statutory responsibility for local authorities to stop planning activity based on its phosphate reports and defended its responsibility to monitor and protect the health of Wales’ waterways.

“Our statutory responsibility is to assess and provide advice on the condition of designated river habitats,” said an NRW spokesperson.

“The recent compliance assessment identified a phosphorus target failure influenced by a single high monitoring result. We investigated the result in line with our established processes and found no issues with the sample collection, handling, or laboratory analysis.

“While the result could not be discounted under the multi-national methodology, we considered the specific circumstances when determining our advice.

Nutrient neutrality 

“Based on our latest assessments, we recommended that this waterbody would not require nutrient neutrality and this is reflected in our published guidance.”

Nutrient neutrality is where planing officers require a development to mitigate its phosphorous impact so as not to increase levels in a nearby waterway.

“Local planning authorities can take a range of factors into account when determining planning applications, including whether to apply nutrient neutrality requirements such as where development may cause status failure,” said the spokesperson.

“Monitoring data collected by the Environment Agency has also been available to them and we may consider this data in our next assessment (of the River Dee) scheduled for 2027.

“Wrexham County Borough Council may use additional monitoring data in any decision-making processes as a competent authority within the boundaries of the Habitats Regulations.

“Protecting and improving river health while enabling sustainable development requires collaboration across a number of sectors and organisations.

“We remain committed to working constructively with all partners to support both objectives.”