The \"Sylvan Wye\" at Glasbury. PLANNERS will have to consider the level of phosphates a development might produce, in planning applications near both the rivers Wye and Usk. Last week the Welsh Government environment body, Natural Resources Wales published new stricter targets for phosphate levels in rivers that are Special Areas of Conservation. Of the nine in Wales, two flow in Powys, the rivers Wye and Usk. Following the review, NRW said phosphorus breaches are widespread within rivers in Wales' conservation areas, with more than 60 per cent of water bodies failing against the challenging targets set. The river with the highest level of phosphate failures was the Usk with 88 per cent of its water bodies failing to hit the target.