Ffynnon Llugwy is a

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

in the

Carneddau The (lit. 'the cairns'; is a Welsh language, Welsh plural form, and is sometimes anglicised to ''Carnedds'') are a group of mountains in Snowdonia, Wales. They include the largest contiguous areas of high ground (over or high) in England and W ...

range of mountains in

Snowdonia Snowdonia, or Eryri (), is a mountainous region and National parks of the United Kingdom, national park in North Wales. It contains all 15 mountains in Wales Welsh 3000s, over 3000 feet high, including the country's highest, Snowdon (), which i ...

North Wales North Wales ( ) is a Regions of Wales, region of Wales, encompassing its northernmost areas. It borders mid Wales to the south, England to the east, and the Irish Sea to the north and west. The area is highly mountainous and rural, with Snowdon ...

. It lies at a height of about and covers an area of some . It has a maximum depth of . Since the early twentieth century water has been taken from its outflow,

Afon Llugwy River Llugwy () is a tributary of the River Conwy, and has its source at Ffynnon Llugwy, a lake in the Carneddau range of mountains in Snowdonia in north-west Wales. Location and catchment area The average annual rainfall in the catchmen ...

to feed

Llyn Cowlyd Llyn Cowlyd is the deepest lake in northern Wales. It lies in the Snowdonia National Park at the upper end of Cwm Cowlyd on the south-eastern edge of the Carneddau range of mountains, at a height of above sea level. The lake is long and narro ...

via a series of

leat A leat (; also lete or leet, or millstream) is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Othe ...

s. Since the mid-1970s the lake has additionally acted as a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

for Bangor and eastern

Anglesey Anglesey ( ; ) is an island off the north-west coast of Wales. It forms the bulk of the Principal areas of Wales, county known as the Isle of Anglesey, which also includes Holy Island, Anglesey, Holy Island () and some islets and Skerry, sker ...

, which necessitated the laying of an 11-mile pipeline to the water treatment works at Mynydd Llandygái.''Cyfrinachau Llynnoedd Eryri'', by Geraint Thomas, y Lolfa, 2011 It is the source of the

River Llugwy River Llugwy () is a tributary of the River Conwy, and has its source at Ffynnon Llugwy, a lake in the Carneddau range of mountains in Snowdonia in north-west Wales. Location and catchment area The average annual rainfall in the catchment ...

() which flows via

Capel Curig Capel Curig (; meaning " Curig's Chapel") is a village and community in Conwy County Borough, Wales. Historically in Caernarfonshire, it lies in the heart of Snowdonia, on the River Llugwy, and has a population of 226, reducing slightly to 206 ...

and

Betws-y-coed Betws-y-Coed () is a village and community (Wales), community in Conwy County Borough, Wales. The village is located near the confluence of the River Conwy and the River Llugwy and is on the eastern edge of Snowdonia. The population of the co ...

before becoming a tributary of the

River Conwy The River Conwy (; ) is a river in north Wales. From its source to its discharge in Conwy Bay it is long and drains an area of 678 square km. "Conwy" was formerly anglicised as "Conway." The name 'Conwy' derives from the old Welsh words ''c ...

References

{{authority control Capel Curig Reservoirs in Conwy County Borough Reservoirs in Snowdonia