Llyn Eigiau

Llyn Eigiau is a lake on the edge of the Carneddau range of mountains in Snowdonia. The name Eigiau is thought to refer to the shoals of fish which once lived here.

Early maps refer to it as Llynyga. It is thought that a small number of Arctic char exist in the lake (as they do in neighbouring Llyn Cowlyd) after they were transferred here from Llyn Peris, and certainly it is one of the few lakes in Wales to have its own natural brown trout.

Today the lake covers an area of about 120 acres, and has a depth of about 32-foot (9.8 m). After the construction of the dam its area would have been twice this.

Water is fed into Llyn Eigiau by a tunnel from the stream below Llyn Dulyn, and another larger tunnel takes water from Llyn Eigiau to Llyn Cowlyd.

The main feeder of Llyn Eigiau is Afon Eigiau, a small river which flows down Cwm Eigiau. The outflow from Llyn Eigiau is called Afon Porth-llwyd, and this flows via Coedty reservoir before passing under Pont Newydd in Dolgarrog. This then flows into the River Conwy.

In 1911 a dam ¾ mile long and 35-foot (11 m) high was built across part of its eastern side to supply water for the power station at Dolgarrog, which in turn provided