Cwmrheidol Nature Trail

Central Electricity Generating Board, Rheidol Power Station,

Capel Bangor, Aberystwyth,


On unclassified road 3 miles off A44 at Capel Bangor-signposted Cwmrheidol. Also access from Aberffrwd Halt on Vale of Rheidol Light Railway (BR, Aberystwyth -Devil’s Bridge). Trail starts at CEGB visitor centre

Map reference: SN697

2j–mile trail around a river valley dammed for a hydro-electric scheme — fascinating natural oak woodland, fish ladder and beautiful scenery

Car parking; illustrated trail guide from Visitor Centre; exhibition about the hydro-electric scheme; power station tours

Rising on the boggy slopes of Plynlimon, source of the River Wye and River Severn, the River Rheidol has carved a magnificent valley through the mid-Wales hills on its short journey to the sea at Aberystwyth. The considerable energy of its fall from the mountains is harnessed in three stages by a remarkable hydro-electric scheme in which a chain of lakes has been created, culminating in the Cwmrheidol reservoir and power station deep in the heart of the beautiful Vale of Rheidol.

Around the reservoir, which is the final holding pond of the system, has been designed a nature trail which shows off the great sensitivity with which the scheme has been

engineered and landscaped into this deep cleft. Dams, culverts, buildings and bridges are all built to a scale and with materials that blend into the environment very successfully — ever more so as the years go by. The trail starts at the power scheme’s Visitor Centre, where the hydro-electric system which includes two other lakes some fifteen miles north on Plynlimon, is explained in a permanent exhibition.

Taking an anti-clockwise direction around the lake, the trail follows the road over the new Felin Newydd bridge, its abutments and terraces faced with multi-hued stones from a disused local quarry specially re-opened for the scheme’s construction in the early Sixties. From the terraces, you may be able to see trout and salmon in the lower sanctuary pool. Migratory fish enter a fish lift here which gives them access to the reservoir waters above the main dam. A second ladder at the upstream end of the reservoir enables them to by-pass the Rheidol Falls and continue upriver to the gravel beds which are their spawning grounds.

As the trail leaves the road, it follows a track skirting the lower edge of the valley’s wooded slopes. The woodland around Cwmrheidol is predominantly oak which was heavily cropped in the early part of this century. In a few places on both sides of the valley, the sessile oak which flourishes in acid soils) has been supplanted by conifers such as the Japanese larch which is unusual in that it sheds its leaves in. winter like a deciduous species.

The path shows an interesting mix of typical woodland ground flora and plants that inhabit the marshy meadow which falls away to the new lake. Bluebells shade the wood floor with a blue haze in the spring but the plants die back to leave the stage to wood sorrel, the buttercup, yellow flowers of the lesser celandine and the tiny green leaves of pignut In the marshy areas you will see the spiked clumps of common rush, the mixed white and purple flowers of the tall, spiny marsh thistle and large moss clumps.

From this side of the reservoir, there is a good view of an area of wasteland high on the

opposite valley side called The Stag. This is the spoil heap of a large lead mine – the seepage of poisonous metal salts from the waste rock pre-vents plant growth. The large number of lead mines in the Rheidol area used to pollute the river considerably and even today the CEGB has a small chemical plant to treat tributary stream water that runs off the spoil heaps. It actually removes .the toxic elements.

Boundary between the oak and the newer conifer woods. Around the bridge are many water-loving species on ground fed by spring water including water forget-me-not, bog stitchwort and marsh arrowgrass. The poisonous hemlock, water dropwort, is present here and close to the bridge are examples of the unusual, late-flowering western dwarf gorse. The trail

Almost halfway along the southern section of the path is one of the older lead workings called the Gothic Mine. Little can be seen of the mine now except for a large bucket which was once a part of the ore transport system. Around the mine waste scree are the very old stumps (or ‘stools’) of oak from which new young growths have been generated. Depending on the size of timber required the trees were cropped in this way every fifty to a hundred years in those parts of the wood that were primitively managed.

The bark of the trees supports a fascinating flora of primitive organisms known as epiphytes. This is a group which includes mos-ses and liverworts. Some older trees have at least three epiphytic species clinging to them, each one settling in an area offering the particular blend of light exposure and moisture that it requires. Thus damp-seeking mosses will be at the base of the trunk and light-seeking ones on higher boughs. Ivy twines around the trees, offering, in its thicker clumps, a harbour for birds. There are several examples of trees bedecked with wild honeysuckle.

There is a considerable variety of bird life in the woods and the valley. Nest boxes have been posted throughout the woods to encourage the breeding of pied flycatchers – other insect feeders in the woods are tits, finches, warblers and the darting tree-creeper. Overhead you may be lucky enough to see the hovering buzzard, although a commoner sight is ravens and carrion crows. Down at the water’s edge, mallards breed.

At the reservoir’s north end, the trail follows the water edge and leads to a footbridge from which to see the tumble of the water over Rheidol Falls and a terrace to view the fish ladder. You may see fish in the water under the bridge preparing to make the leaps from pool to pool. Half way up the valley side, you can see the track of the 1ft llin-gauge Rheidol light railway which marks, for the most part, the returns to the Visitor Centre past the power station which generates electricity from the water from Dinas Reservoir along the road.

The car is not the only way to visit Cwmrheidol – you can take the railway to Aberffrwd Halt from Aberystwyth station and enjoy, en route, the unique railway nature trail prepared by the West Wales Naturalists’Trust. A book describing the sights to be seen from the little steam line can be purchased at the main termini (the line ends at Devil’s Bridge). Now the local fishing association has stocked the Rheidol’s water with both salmon and trout, the fishing is really looking up. Several sections of the river can be fished by visitors with a day ticket and the CEGB itself stocks and controls the waters of the Dinas and Nant-y-Moch reservoirs in the Rheidol headwaters. Aberystwyth is a major sea angling centre and the headquarters of the Shark Club of Wales.

The town is a sedate resort that has changed little this century. It is a university centre and is the location of the National Library of Wales where many rare books and documents can be viewed. There are campsites at Aberystwyth itself and four miles north east at Llandre.

Beaches along this part of the coast are fairly stony, although there are extensive sands at Borth, where the remains of a petrified forest can be seen at low tide. At the end of the beach is one of Wales’ many small National Nature Reserves. The Ynyslas Reserve provides a fas-cinating seaside nature trail that would be a fitting contrast to the woodlands of Cwmrheidol for another day’s outing.