On 17th December 2020 NRW published the long awaited ‘Compliance assessment of the River Wye SAC against phosphorus targets’. The report concludes that over 60% of the River Wye and its catchments fail against phosphate limits.
NRW will be working with local planning authorities, including Powys, with a view to ensuring that proposed new developments which have the potential to increase phosphate levels in the river and its catchments are not approved unless they can demonstrate phosphate neutrality or betterment. The Regulatory Position Statement and Planning Position Statement provide some further information but specific advice on the assessment of planning proposals in relation to phosphates is still in development.
The report does not identify the major sources of the Wye’s excess phosphate and NRW state that in the accompanying press release they have not found a direct connection between phosphate levels and the rapid increase in recent years in the numbers of poultry units in the catchment. This is not surprising given the complex and various pathways by which phosphates may reach river waters and the potential for ‘legacy phosphate’ built up in soils over time to leach into rivers years later. However, the most recent modelling carried out by the Environment Agency attributes 66% of phosphates in the cross-border Upper Wye and Lugg sub-catchments to arable and livestock farming, 25% to sewage treatment works, with the remaining 9% attributed to other sources including highways, urban areas, industry, combined sewer overflows and other sources of sewage.