What is happening on the Myddfyi?
The Myddyfi rises from a network of ditches and drains to the north of Salem, in the heart of rural Carmarthenshire, and flows first to the southwest, and then southwards towards Pentrefelin, before joining the Tywi at Cilsan.
It appears to enjoy good health along much of its 8km length, as witnessed at Birdshill Bridge, only a little over a kilometre from its confluence with the Tywi:
Just a short distance downstream of a confluence with a small stream which passes close to a stock feeding station, evidence of siltation is clearly visible:
Half a kilometre downstream and now on the valley floor, the Myddyfi shows increasing signs of nutrient enrichment with extensive algal growth covering the whole of the riverbed:
Finally, at its confluence with the Tywi, the combined nutrient load of both rivers results in extraordinary amounts of filamentous algae clinging to every available surface:
Richard Garner Williams, of S&TC Cymru, said,
“A certain amount of algal growth is to be expected at this time of year, particularly under the exceptional weather conditions we are currently experiencing, but this is far in excess of what would be expected with a natural bloom.
That the Myddyfi shows such a dramatic change in nutrient levels over such a short distance strongly suggests that external agents are having a profound impact along its lower reaches.”