Still water habitats support a wide range of aquatic and wetland flora and fauna. Oligotrophic (nutrient-poor) waters account for the great majority of the water-bodies in RCT. These, often acidic water-bodies, encompass a wide range of habitat types including; small flooded mine workings, peaty upland pools, land reclamation lakes and upland reservoirs (such as Llyn Fawr, nr Hirwaun and Lluest Wen in Rhondda Fach). Upland water-bodies are generally of low productivity, with naturally specialised floras, that can include characteristic species such as quillwort (restricted in Glamorgan to Llyn Fawr and Llyn Fach), alternate water-milfoil, bog pondweed and marsh St. John’s-wort. Upland dragonflies and damselflies flourish in acid pools and lakes. The scarce blue-tailed damselfly, black darter, common hawker and keeled skimmer are characteristic upland pool species, together with upland water beetles. In RCT, oligotrophic water-bodies support important amphibian populations. Palmate newt and frog are very common (often in extremely exposed upland situations) and great crested newts have colonies on our Merthyr boundary in pools in old mine working areas and in a number of ponds in the south of the County Borough.  Water voles are now known to use upland ponds. 

  

In contrast, nutrient-rich (mesotrophic and eutrophic) water bodies are less common and are restricted to lowland areas. These more productive water-bodies can support dense fringes of swamp vegetation and more diverse aquatic floras. Floating, curled and Canadian pondweed are important aquatic species. Diverse aquatic invertebrate communities include damsel and dragonfly communities and nesting birds such as coot, moorhen and little grebe. Smooth newt and common toad colonies occur together with the ubiquitous common frog, and great crested newts have a scatter of colonies across the southern, lowland parts of the County Borough. 

  

Where lakes and ponds have been created on the line of a watercourse, as often happened in land reclamation schemes, there is often an on-going process of silting. This is a wholly natural process which is a reflection of the unsustainable way such ponds were designed. The problem is that wherever a stream reaches still water it will drop the sediment it is carrying. From a geomorphological perspective it is fascinating to witness, but the silting of lakes/ponds at Dare Valley Country Park, Clydach Vale Country Park, Shoni’s Pond, and others does represent a loss of open water. How to sustainably manage such concerns is the source of much on going thought, and it is an example of where any ecology approach of allowing natural processes to express themselves, may not always be in accord with local community aspirations.  

 

As small features, natural ponds are particularly vulnerable. They will quickly grow over without  livestock grazing or physical conservation management to periodically control emergent vegetation and thereby maintain open water. A recent trend in Council schools has been the removal of ponds for health and safety reasons, ponds which were original dug for educational reasons. Whatever the rights and wrongs of this practice, it is likely that common frog breeding ponds have been lost, and it prompts a conversation about how children can safely interact with nature.  Garden ponds are a common and must support many breeding populations of both common amphibians and aquatic invertebrates and provide sources of water for garden birds and mud for bird nests, as well as hours of enjoyment for pond owners. 

 

With the recent increased focus on sustainable drainage solutions for planning developments and remediation schemes, there is potential to incorporate some potentially useful standing water habitat into such programmes. However, if undertaken in areas of flushed, marshy grassland or swamp, pond creation can also cause significant habitat loss. Unfortunately, a cursory review of aerial photos can depressingly often pick out ponds dug in places that were previously important wetland habitats. A full and proper understanding of the habitat and ecology value of sites is needed before pond construction should be considered. It is important that in pond creation proposals we do not metaphorically rob Peter to pay Paul.   

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A floristic survey of 50 ponds and lakes in RCT was undertaken in 2000 and this served to illustrate the wide range and diversity of standing water habitats.  Ponds are perhaps a particularly well-suited habitat for citizen science.  

 

Canals, although constructed and developed as one of the principal commercial arteries of the Industrial Revolution, are valued biodiversity habitats. In Rhondda Cynon Taff, the Glamorgan Canal ran the length of the River Taff, and the Aberdare Canal shadowed the Afon Cynon. Both of these canals have been derelict for many years. Most sections have been completely lost, leaving only remnants. Some of these still hold water and, although overgrown, support freshwater communities. For maintenance reasons the long-term future of all remaining sections of canal habitat is very uncertain. Management is continually required and existing budgetary and man-power constraints threatens the long-term viability of these sites.