PARTS of the River Wye and Usk have failed to reach phosphate testing standards, Natural Resources Wales (NRW) has said.

For the first time since stricter targets for phosphate levels were set for Wales’ rivers, NRW on Thursday published an evidence package outlining phosphate levels for all river Special Areas of Conservation (SACs) across Wales.

There are nine river SACs in Wales – Cleddau, Eden, Gwyrfai, Teifi, Tywi, Glaslyn, Dee, Usk and Wye. These rivers support some of Wales’ most special wildlife like Atlantic salmon, freshwater pearl mussel, white-clawed crayfish and floating water-plantain.

The Joint Nature Conservation Committee (JNCC) recommended that UK nature conservation organisations adopt tighter targets after considering new evidence about the environmental impacts of phosphate. In addition, the predicted warmer and drier weather resulting from climate change could reduce river flows during the summer, and so increase phosphate concentrations.

Following the new measures, evidence shows that overall, phosphorus breaches are widespread within Welsh SAC rivers with over 60 per cent of waterbodies failing against the challenging targets set.

The river with the highest level of phosphate failures was the Usk – whose source originates at Fan Brycheiniog in the Black Mountains region of south Powys – with 88 per cent of its water bodies failing their target. Previously published data about the Wye, as well as new data on Cleddau, shows that over 60 per cent of river sections failed their targets. The lower Teifi and parts of the Dee also failed to reach the standards.

All waterbodies in three rivers in north Wales – the Eden, Gwyrfai and Glaslyn as well as the Tywi –passed their targets.

Ruth Jenkins, NRW’s head of natural resource management, said: “Phosphate can cause significant ecological damage to rivers and can lead to the process of eutrophication in rivers, a highly problematic issue.

“Conservation standards were tightened as a means of safeguarding the river environment and countering the impacts of climate change. The new targets set for phosphate levels in our rivers are challenging, but rightly so.”

Phosphate is naturally occurring, and is released slowly, at low levels, from natural sources, from natural bankside erosion for example. However, phosphates can also enter rivers from land management practices, sewerage and foul water that can contain detergents and food waste.

Each river and section of rivers will need different approaches and NRW will work with people and partners to create both national and local solutions. The report suggests a number of areas where work can be focused and includes working with planning authorities across Wales to help them understand what the findings of the investigation could mean for their planning processes.

Ms Jenkins added: “By sharing this information, we can all better understand how nutrient levels such as phosphate affect our rivers and we can work together with policy makers, businesses, land managers and residents to protect the river and the natural resources it provides for people.

“We all have a part to play to make sure that Wales’ rivers are healthy for future generations and we want to work with others to find innovative solutions.

“Simple changes we can each make in our everyday lives can help make a positive contribution to the reduction of phosphate levels and other forms of pollution affecting our rivers.”

NRW will commission further reports to understand how Wales’ rivers comply with other ecological targets and will share the findings so that together everyone can contribute to making sure we have healthy river environments.