What are the Implications for Planning Applications and Development?

Natural Resources Wales' Planning Guidance on Nutrient Neutrality

Natural Resources Wales (NRW) has published guidance and advice for planning authorities in relation to planning applications. This advice provides guidance and answers to common questions about particular developments. Developers and applicants preparing planning applications need to follow this guidance.

The guidance sets a Nutrient Neutrality requirement for all new development within SAC catchments. Nutrient Neutrality is in place to prevent new development from resulting in a net increase in phosphorus levels in Welsh river SACs.

The Habitats Regulations

Under The Conservation of Habitats and Species Regulations 2017, (as amended), Powys Local Planning Authority is a competent authority and has a duty to assess the impact of planning applications (development proposals) on a river SAC.

Planning applications in or affecting river SAC catchments will be assessed to determine if the development poses a 'likely significant effect' on the SAC. Where a risk of a significant effect is identified, measures are likely required to demonstrate nutrient neutrality, or betterment, to avoid an adverse impact to the SAC. Where appropriate, applicants will be asked to submit evidence with planning applications to enable the Authority to undertake an Appropriate Assessment in accordance with the Habitats Regulations. NRW's Planning Guidance provides more information about this.

NRW's Environmental Permit Reviews of Wastewater Treatment Works (WwTWs)

NRW is in the process of reviewing the environmental permits of larger WwTWs in the SAC catchments. Further information is provided in NRW's planning guidance (see above).

These reviews will add a phosphorus limit of 5mg/l (backstop limit) or lower to the environmental permit for each WwTW.

As a consequence, the reviewed permit may reveal capacity for Dwr Cymru Welsh Water to accept new connections from development and comply with the phosphorous limit, although WwTWs may be subject to other capacity issues.

Nutrient Calculator (in development)

As part of the Welsh Government Action Plan, a Wales-wide nutrient calculator is being developed to assist applicants and planning authorities to calculate the net amount of phosphorus generated by a new development.

Mitigation Measures

NRW has produced a mitigation measures menu. This describes measures to mitigate phosphorus pollution. Each method was investigated using best evidence to determine details like cost, maintenance, nutrient removal rate, wider benefits and regulatory requirements.

Water Quality Compliance Assessment

In 2024 NRW published a further Compliance Assessment Report for Welsh river SACs on the compliance of water quality targets for: organic pollution (Dissolved Oxygen, Biochemical Oxygen Demand, Total Ammonia and Unionised Ammonia), metrics regarding acidity (pH and Acid Neutralising Capacity), and Trophic Diatom Index. The findings have not altered NRW's Planning Guidance on Nutrient Neutrality for the Powys river SAC catchments.