There are no litter bins in the valley as it has been proved in the past that they cause more litter from overflowing, and animals getting into them, particularly sheep. At busy weekends people would add to overflowing bins or even bring their rubbish to empty out here. It was also felt that bins looked unsightly in a countryside property. So now regular litter sweeps are carried out by the Wardens, especially in the summer months when visitor numbers are high.
There is an assumption that responsible visitors will take home their own litter.
This problem is difficult to monitor or control. Some birds have relocated their nesting sites within the valley. Stream and pondlife could perhaps decrease in diversity, due to people paddling and dogs swimming. Other wildlife will have relocated in quieter valleys. People who let their dogs run through the undergrowth often do not realise how ground nesting birds and small mammals will be frightened away.
Erosion is the biggest problem in the valley, and can be put into three different categories:-
- Erosion by natural processes
- Visitor pressure
Erosion by water is the major natural process taking place. The action of streams gradually eroding and deepening the valley, and carrying down material that causes abrasion and erosion of the streambed and banks which formed the valley during the Ice Age is a continual slow process.
Run-off down the valley sides is also slowly causing erosion, as does frost action breaking up the soil and making it easier for wind and water to carry off the topsoil.
These processes are slow, and alone are not a major problem, but they are accelerated by visitor pressure and animal movements. Climate change however has recently created periods of intense outwash. In May and July 2007 two periods of high water levels swept down some 40 tons of bedload into the stone trap at the base of the valley. Whereas this stone trap was usually emptied every 18 months it is now emptied every 9 months. Two stream edges show the effects of the 2007 erosion. One is just below the middle car park where there once stood four tree protection fences. There are now three! Some 3 metres depth and 17 metres length of bank were swept away. Further up mid valley where 5 gabions (steel cages filled with rocks) were once buried. The path burying these cages has been washed away and the middle cage seriously undercut.
There are about 20 ponies grazing the hills, but sheep are the main cause for wear on the hill slopes (see Usage by Man)
When the heathland vegetation dies out grass and bracken grow in its place. Grass is now the dominant vegetation in the valley. Tree roots hold the soil together very well, but grass does not have such an effective root system; therefore, coupled with the impact from the feet of sheep together with people's feet - as mentioned previously - and natural run-off, the valley sides are beginning to crumble and slip. Bracken is spreading quickly and is a problem to control for if it is killed on valley slopes there is a fear that by removing the root system there is nothing to keep the soil in place. The soil could then easily become weathered away and we would have large areas of bare rock.
Approximately 250,000 people visit Carding Mill Valley each year - which means that 500,000 feet and the same number of wheels use the valley!
Both feet and cars wear away vegetation down to the bare soil, and this is when serious problems begin to occur. The root systems of vegetation help to hold the soil together and protect it from harsh elements. When the soil is exposed, erosion occurs in both dry and wet conditions. When it is dry the almost ever-present strong wind in the valley blows the topsoil away gradually; when it rains the run-off down the valley sides takes the topsoil with it.
Erosion also occurs on popular footpaths. When footpaths are reduced to soil, they become soft and boggy; people will always take the easiest and driest route, so they will walk around boggy patches if possible and thereby widen the footpaths. Paths also get deeper as each layer of soil disappears; this is a big problem on slopes when it rains as water follows the easiest route downhill, runs into the indentation of a footpath and through "gullying" increases the erosion of the path. Thus you will see drainage channels cut into most paths. These need regular maintenance by our excellent TTF (Tuesday Task Force of volunteers) and do greatly reduce erosion by run-off. Drainage traps occur about every 10 metres (5 metres apart on steep paths).
The valley sides also suffer erosion damage from people climbing straight up to the top and not using the footpaths which take a less steep but also less direct route. Children too wear away vegetation by sliding down the hillsides.