| Ffynnon Llugwy | |
| Coords: | 53.1458°N -3.9564°W |
| Type: | natural, reservoir |
| Pushpin Map: | UK Wales Snowdonia |
| Basin Countries: | United Kingdom |
| Area: | 40acres |
Ffynnon Llugwy is a lake in the Carneddau range of mountains in Snowdonia, North Wales.
It lies at a height of about 1786feet and covers an area of some 40acres. It has a maximum depth of 1460NaN0.[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 which flows via Capel Curig and Betws-y-coed before becoming a tributary of the River Conwy.