We have received notification from Dwr Cymru Welsh Water that they “are planning on testing the operation of the reservoir scour valve(s) at Ystradfellte on 20/04/2021. The test involves a short opening of the bottom outlet valve(s) of the reservoir to ensure its efficient functioning.” They have added that “we do not envisage any problems with any increased flooding risk downstream or the possible release of turbid water during this short release and there are no algal blooms present”, but providers using Porth yr Ogof or the Mellte gorge that day should be aware that they might experience a rise in river levels.