Llyn Trawsfynydd is a large man-made

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

situated near the village of

Trawsfynydd Trawsfynydd (; Welsh for "across hemountain") is a linear village in Gwynedd, Wales, near Llyn Trawsfynydd reservoir, and adjacent to the A470 north of Bronaber and Dolgellau and 10 km (6 miles) south of Blaenau Ffestiniog. The total com ...

Gwynedd Gwynedd (; ) is a county and preserved county (latter with differing boundaries; includes the Isle of Anglesey) in the north-west of Wales. It shares borders with Powys, Conwy County Borough, Denbighshire, Anglesey over the Menai Strait, and C ...

North Wales , area_land_km2 = 6,172 , postal_code_type = Postcode , postal_code = LL, CH, SY , image_map1 = Wales North Wales locator map.svg , map_caption1 = Six principal areas of Wales common ...

. With a total surface area of the reservoir is slightly more extensive than Wales's largest natural lake, Llyn Tegid at .

History

The lake was created between 1924 and 1928 by building four dams in order to supply water for

Maentwrog power station Maentwrog power station was built by the North Wales Power Company and supplied electricity to North Wales, Deeside and Cheshire. It exploits the water resources of the Snowdonia mountains, using water turbines to drive electricity alternators. T ...

. More than twenty properties, some of historical significance, were lost in the creation of the lake but there was little local objection at the time. Included were at least two farms, Brynhir and Llwynderw. Indeed, the power station was regarded as a good thing because it could supply the whole of North Wales' electricity needs. However local landowners and farmers did object to the loss of rights of way across their former lands. In order to avoid long detours round the new lake, a small road was built along the western shore and a footbridge was erected across the narrowest part of the lake. In 1965 the lake became the source of cooling water for the

Trawsfynydd nuclear power station Trawsfynydd nuclear power station ( cy, Atomfa Trawsfynydd) is a decommissioned Magnox nuclear power station situated in Snowdonia National Park in Gwynedd, Wales. The plant, which became operational in 1965, was the only nuclear power station in ...

which began generating electricity for the UK National Grid. To increase the volume of water in the lake, one of the lake's dams had been rebuilt in the early 1960s. This was because of priority over usage. Previously the Maentwrog power station had taken all of the water in the lake, but the needs of the nuclear plant dictated that the hydro plant would only be able to use the top of water. In 1991 the nuclear power station was shut down and

decommissioning Decommissioning is a general term for a formal process to remove something from an active status, and may refer to: Infrastructure * Decommissioned offshore * Decommissioned highway * Greenfield status of former industrial sites * Nuclear decommi ...

began. It will not be completed until 2083. Since the plant's closure, the lake has cooled to natural levels allowing fauna and flora to regenerate. Water continues to be used for hydroelectricity generation.

Notes

External links

Official Site
Maentwrog Trawsfynydd

Tourism in Gwynedd

Tourism in Snowdonia {{Gwynedd-geo-stub