Lake Vyrnwy

The Lake Vyrnwy is in an area of land situated in Powys, Wales, surrounding the Victorian reservoir. It’s a masonry-built dam, and was the first of its kind in the world. The sole purpose was to supply Liverpool and Merseyside with fresh water, which it still does to this day.

The village of Llanwddyn

Llanwddyn churchThe old village included a post office, an inn and a parish church just like other Welsh villages of the period. The villagers remained in the village whilst the dam was being built, but down the valley, in front of the new dam, the Liverpool Corporation built the new village, retaining the original name of Llanwddyn, ready for when the valley was flooded. In total, two chapels, three inns, ten farmhouses, and 37 houses were all lost to the reservoir. Even the graves from the chapels’ cemeteries were removed, and respectfully re-buried in the new church cemetery. The old village can still be seen during drought conditions when the reservoir is very low, and the foundations of several buildings still survive.

The village is small, but still supplies for the many thousands of visitors who come to the lake each year, as well as the community. The village is equipped with cafes, an RSPB Shop, and several gift shops which sell local crafts and produce. The village is in a prime location for visitors, as it is near the border of Snowdonia National Park, and lies between the Cambrian Mountains and the Berwyn range. The image is of St Wddyn’s Church.

The Dam

The Dam at Lake Vyrnwy

The Dam was started in 1881, completed seven years later and it was the first large masonry-built dam in the United Kingdom. It is built partly out of great blocks of Welsh slate and when built cost £620,000 – is around £22,000,000 today. The dam is 44 metres (140 ft) high from the bottom of the valley, and 39 metres (130 ft) thick at the base. The dam’s length is 357 metres (1,170 ft), and has a road bridge running along the top. It is decorated with over 25 arches and two small towers (each with four corner turrets) that rise 4 metres (13 ft) above the road surface.

Vyrnwy was the first dam to carry water over its crest instead of in a channel at the side. At the bottom of the dam is a body of water known as the Stilling Basin, this is necessary to absorb the energy when the water flows over the crest and into the valley, and stops the water from eroding the foundations of the dam.

Underneath the West Tower is a building known as the Power House, inside is an electrical generator which is driven by water leaving the reservoir. Before mains electricity arrived in the 1960s this was Llanwddyn’s only source of power.

The Straining Tower

The Straining Tower and Aqueduct

The purpose of this tower is to filter, or strain out, any material in the water with a fine metal mesh before the water flows along the aqueduct to Liverpool. Its architecture is Gothic and built at the same time as the dam. Just less than 70 miles of aqueduct bring water into Liverpool. The aqueduct originally consisted of two pipelines, made largely of cast iron, but to help maintenance work on the 9ft diameter cast-iron tunnel which took the aqueduct under the Mersey, riveted steel piping was also used.

The lake / reservoir

On a clear day the lake, along with many others in North Wales, can be seen from space. There are 31 streams, waterfalls, and rivers that flow into the lake. Some are no more than a trickle, while others have waterfalls which cascade down the mountains. The 6 rivers that flow into the lake are all named from the mountains or hillside it flows from. From the west side of the dam, clockwise, their names are: Afon Hirddu, Eunant, Afon Eiddew, Afon Naedroedd, Afon Cedig, Afon Y Dolau Gwynion.

On the Northern Edge of the lake is a small hamlet called Rhiwargor where the rivers Afon Eiddew and Afon Naedroedd meet. Up the valley of Afon Eiddew, there is an impressive waterfall, one of the largest surrounding the lake. Known locally as Pistyll Rhyd-y-meincau, it is commonly known as Rhiwargor Waterfall. In 1889, shortly after completion, the lake was stocked with 400,000 Loch Leven trout.

A slightly obscure fact about the lake – it is also the water source used in the manufacture of Bombay Sapphire gin.

Only 9 miles from Gwaenynog

Nature Reserve & Conservation

Lake Vyrnwy is also a Nature Reserve. The RSPB has several bird hides around the lake, where several rare species of bird are known to be breeding, such as the Peregrine Falcon, the Pied Flycatcher, Redstart, Siskin and the Wood Warbler. RSPB host a Dawn Chorus tour every spring.

Around 90 species of bird have been recorded to be breeding on the reserve, and six species of bat, including the pipistrelle and brown long eared bat. Butterfly species include Purple Hairstreaks, commas, and peacocks. Dragonflies include Golden Ringed, Common Hawker and Four spotted chaser.

A project to restore the Heather Moorland that grows on the mountains around the lake is mostly completed. The restoration of heather moorland is becoming increasingly common in Britain. The heather is usually burnt, cut, and the seeds collected to be sowed where the heather has gone. This management of the moorland helps improve the habitat for Red Grouse and the Short-eared Owl. Sheep, cattle and ponies also graze on the heather.

Broadleaf trees are being planted in replacement of coniferous trees, and even manmade things are being restored, such as hedgerows and dry-stone walls. Wild flowers areas are also being restored to help insects, birds, and other wildlife.

Sculpture Trail

New Hawk and Andy Hancock, sculptor extraordinaire! See

Llanwddyn has a sculpture trail in the valley below the dam; started in 1995 by local artist Andy Hancock, it contains dozens of wooden carved sculptures, all carved by a variety of individual sculptors who have come from as far afield as Australia and Eastern Europe; there are many other sculptures placed at picnic sites around the lake itself. For instance, there are large wooden picnic benches in the shape of leaves and trees on the west side of the lake at Llechwedd Ddu. Near the Old Village on the beach is a sculpture of dolphins, which when the lake rises in a flood, gives the impression that they are jumping out of the water. Several totems can be seen carved into standing trees; many others have been carved from fallen trunks and re-erected. Picture shows the New Hawk and Andy Hancock, sculptor extraordinaire! See


Activities in the area include sailing, hiking – Glyndwr’s Way comes by the lake, plus there’s rock climbing, cycling and horseback riding.

The lake also hosts a half-marathon every year, the Vyrnwy Half Marathon.

For more information, please go to the Lake Vyrnwy website.