History, Heritage and Location

The 1200 acre Lake Vyrnwy was created by Liverpool Corporation to supply Liverpool with a reliable and plentiful supply of water.

Liverpool was a growing City. The first water company was set up in 1799 followed by another. Water came from springs and deep wells. By 1840 the water supplies were inadequate, and polluted causing cholera, dysentery and typhoid.

In 1847 an Act enabled the City Corporation to take over private companies, purchase catchment areas and construct reservoirs at Rivington.

By 1865 demand for water exceeded output and in 1866 the search was on for a new source of water. Over a period of years the search focused on the Vyrnwy Valley.

On 6th August 1880, the Liverpool Corporation Waterworks Act received the Royal Assent and gave the Liverpool Corporation authority to commence work constructing the Dam. Provisions had to made for daily compensation water which resulted in the dam design changing. This was the largest masonry dam in Britain, the largest artificial reservoir in Europe and the first to carry the overflow over its crest.

On 14th July 1881 the first commemorative stone was laid by the third Earl of Powys who was one of the owners of the land and the village of Llanwddyn which would be drowned by the reservoir.

Llanwddyn consisted of the church, 2 chapels, 3 public houses and 37 houses and 10 farmsteads in the valley. The population was rehoused downstream of the dam. A new church, dedicated to St Wddyn, was built to replace the Church of St John in the old village.

On 25th October, 1882, the foundation was cleared of overlying material and the first masonry laid. The stone was obtained from a quarry specially opened about a mile from the dam. Other materials had to be brought by horse and cart from the railhead at Llanfyllin.

On 26th November, 1888, the valves in the dam were closed.

On 23 rd November the dam first overflowed.

The first instalment of the whole Vyrnwy scheme (The lake without the Cownwy and Marchnant diversions) was opened by H.R.H. the Duke of Connaught in July 1892

By 1909 the Cownwy and Marchnant diversions were completed and on the 16th March 1910 HRH the Prince of Wales visited and commemorated the occasion by planting an oak tree by Bont Cynon.

The Tower. Constructed of concrete faced with masonry for filtering the water through strainers. The strainers being operated by hydraulic machinery, run entirely by a water supply laid from a small reservoir in the hill beyond, which powers all its machinery.

The Lake Vyrnwy Hotel. Built at the time of the dam. In 1905 a major reconstruction of the main building was carried out. 1930 further extensions. In 1985 the freehold was purchased. Further substantial refurbishments and additions have been made.

Forestry. Between 1890 and 1912, 900 acres were planted. By 1936, 4000 acres had been planted. In 1946 a joint scheme with Forestry Commission and Liverpool Corporation managed all the forestry.


Houses purchased 28

1880 - 1914  19 houses built

1914 – 1939  22 houses built

1939- 28 houses built

In 1950 the School and Community Centre was designed and built by the Montgomery County Architect along with 14 houses and 6 bungalows.

Many of the houses have been sold as the directly employed work force has decreased.

Farming. Originally all the land remaining after the flooding the valley was let. As the farms became vacant or were taken in hand the plantable land was planted and the mountain land was merged with farms managed by the Corporation. A few let farms remained.

Conservation. In 1977, an agreement was reached with the RSPB to create a wildlife reserve on 16000 acres. The Reserve is designated as a National Nature Reserve, a Site of Special Scientific Interest, a Special Protection Area, and a Special Area of Conservation.

Tourism. In1979 the Chapel by the Dam was converted into a visitor centre. Further developments are the RSPB shop, conversion of farm buildings to a café and craft shops, and the Old sawmill opposite to the chapel to a café and shop. There is sailing on the lake. Fishing on the Lake and Shooting are managed by The Lake Vyrnwy Hotel.

Key Features

The Catchment area

Vyrnwy direct : 7,396 ha

Cownwy diversion : 1,296 ha

Marchnant diversion : 740 ha

Total : 9,432 ha


Length : 7.6 km

Maximum width : .8 km

Area :454 ha

Maximum depth : 25.6 m

Gross capacity : 59,666,000 m3

Top Water Level : 251.9 m

The Dam

Length at top water level : 357.5 m

Height overflow sill above foundations : 43.9 m

Approx weight : 518.000 tonnes

Cost of Dam: £620,000


The Estate

Farmed by RSPB 4,444 ha

Forestry 1,984 ha

Let to tenants 2,020 ha


The information has been taken from the Booklet “Llanwddyn & Lake Vyrnwy” by David W.L.Rowlands.

The following Booklets “Llanwddyn & Lake Vyrnwy”, “The Policeman’s Story”, and the DVD “The Changing Valley”(The story of Lake Vyrnwy) are available from M J Duggleby at mdug99@aol.com . All proceeds go to St Wddyns church

Other sources of information