Ffynnon Llugwy is a lake in the Carneddau range of mountains in Snowdonia, North Wales.
| Ffynnon Llugwy | |
|---|---|
 looking south | |
  Ffynnon Llugwy | |
| Location | Snowdonia, North Wales |
| Coordinates | 53°8′45″N 3°57′23″W / 53.14583°N 3.95639°W |
| Type | natural, reservoir |
| Primary outflows | Afon Llugwy |
| Basin countries | United Kingdom |
| Surface area | 40 acres (16.19 ha) |
It lies at a height of about 1,786 feet (544 m) and covers an area of some 40 acres (16.19 ha). It has a maximum depth of 146 ft (45 m).[1]
Since the early twentieth century water has been taken from its outflow, Afon Llugwy to feed Llyn Cowlyd via a series of leats.
Since the mid 1970s the lake has additionally acted as a reservoir for Bangor and eastern Anglesey, which necessitated the laying of an 11-mile pipeline to the water treatment works at Mynydd Llandygái.[2]
It is the source of the River Llugwy (Welsh: Afon Llugwy) which flows via Capel Curig and Betws-y-coed before becoming a tributary of the River Conwy.