Coedty Reservoir is a reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 in Snowdonia

Snowdonia

Snowdonia is a region in north Wales and a national park of in area. It was the first to be designated of the three National Parks in Wales, in 1951.-Name and extent:...

, North Wales

North Wales

North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...

. It is fed by the waters of Afon Porth-llwyd

Afon Porth-llwyd

Afon Porth-llwyd is a river in Snowdonia, North Wales. It flows from Llyn Eigiau on the south-eastern edge of the Carneddau range to join the river Conwy.Its waters are trapped at Coedty reservoir before flowing down to pass under Pont Newydd in Dolgarrog...

 which flows from Llyn Eigiau

Llyn Eigiau

Llyn Eigiau is a lake on the edge of the Carneddau range of mountains in Snowdonia, North Wales.The name Eigiau is thought to refer to the shoals of fish which once lived here. Early maps refer to it as Llynyga...

. The reservoir lies at a height of 900 feet (274 m), and measures some 12 acres (48,562.3 m²) in size. It contains brown trout

Brown trout

The brown trout and the sea trout are fish of the same species....

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The original dam was built in 1924 to provide hydro-electric power

Hydroelectricity

Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

 to the aluminium smelting works in Dolgarrog. In 1925, the Eigiau dam broke, and the flood of water from that also burst Coedty dam. The resultant flood caused the loss of 17 lives in Dolgarrog

Dolgarrog

Dolgarrog is a small village in the Conwy County Borough in North Wales situated between Llanrwst and Conwy, very close to the Conwy River. The village is well known for its industrial history since the 18th century and the Eigiau dam disaster, which occurred in 1925...

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The dam was rebuilt in 1926, and altered again in 1956.

Water from the reservoir is carried via a large metal pipe down to the hydro-electric power-station in Dolgarrog.

Coedty dam is a balance tip dam; water flows from it automatically when it reaches high levels. This excess water flows into a spectacular gorge used by outdoor pursuit groups. Gorge walking here, however, can be dangerous because of the sudden releases of water from the reservoir which can occur.

The eastern side of the lake is skirted by the trackbed of the former Eigiau Tramway

Eigiau Tramway

The Eigiau Tramway might refer to the Eigiau Quarry Tramway or to the Eigiau Reservoir Tramway.- Eigiau Quarry Tramway :The Eigiau Quarry Tramway was a narrow gauge mile-long horse-powered tramway which operated from c1863 to c1888 and served the Eigiau slate quarry [ref SH702635], near Llyn Eigiau...

, created to aid the construction and maintenance of Llyn Eigiau dam. Nearby the Cowlyd Tramway branched off, built to aid the construction of the dam at Llyn Cowlyd

Llyn Cowlyd

Llyn Cowlyd is the deepest lake in North Wales. It lies in the Snowdonia National Park on the edge of the Carneddau range of mountains, at a height of above sea level. The lake is long and narrow, measuring nearly long and about a third of a mile wide, and covers an area of...

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