As reflected by its name, the rivers systems of Rhondda Cynon Taff are fundamental landscape and biodiversity features. This is a land of river and streams, indeed it a place in the heart of the South Wales Valleys. These watercourses range from tumbling waters of narrow, deeply incised upland streams which feed the fast-flowing Rhondda and upper Taff and Cynon, to the slower flowing, ‘pool and riffle’ sequences of the more lowland runs of the Cynon, Taff and Ely. The Rivers of RCT are geographically short, reaching the Bristol Channel in a matter of only thirty or forty miles. They are characterised by huge ranges in flow, often rising high in a few hours after periods of prolonged or intense rainfall, and then falling just as quickly as the Atlantic front or summer storm passes over.

 

The ‘spatey’ nature of our rivers and streams has a significant impact on river flows, and bankside and river margin habitats. Anything living within the rise and fall of water levels much be adapted to extremes. At least partly because of these extremes, our streams and rivers don’t have rich aquatic floras, although in recent years the summer drifts of white flowers of thousands of water-crowsfoot on the surface of the River Taff in Pontypridd, has been a joy to behold.  These rivers aren’t home to the wide emergent fringes of more lowland rivers, and, in many urban locations, the riverbanks are engineered flood-banks and walls. However, elsewhere, our streams and rivers support wooded banksides and wet woodlands, superb floodplain grasslands and riverside fens and swamps.

 

The network of watercourses, large and small, functions as a corridor for wildlife movement throughout the Borough, linking wetland sites and bringing wildlife into the heart of our urban centres. Rivers and streams also provide important corridors of wildlife movement across Unitary Authority boundaries, linking the biodiversity of Rhondda Cynon Taff with the rest of Glamorgan.  

  

The recovery of the rivers and streams of RCT is one of the great environmental advances of the last half century. The industrial rivers and streams of the nineteenth and most of the twentieth centuries were highly polluted and biologically dead. The decline in heavy industry and the rise of stronger environmental legislation has directly resulted in the cleaning of the rivers and the return of flora and fauna. However, with the potential for periods of more intense rainfall, and a history of ‘mis-connections’ there is a continued problem of periodic sewage discharge into our river systems. There is also an on-going spread of Japanese knotweed, Himalayan balsam and other invasive non-native plant species which pose a particular threat to riverbank habitats.  

  

The return of otter, sea trout and salmon are heralded successes for the rivers of RCT, although recent salmon and sea trout reports for the Taf and Ely suggest that progress for these species may have stalled. Dipper and grey wagtail are common river and stream birds benefiting from rich aquatic invertebrate communities, and sand martin colonies nest in river wall drainage pipes in our riverside towns. Kingfishers are regularly seen in the winter although nesting opportunities are more limited, due to water level changes, and goosander and cormorant are also characteristic winter birds. Water voles are now known to use upland streams associated with the upland bogs in parts of RCT.