Send Print
Lake Ercina
Cangas de Onís (Eastern Asturias)
8 Ha. km2
Maximum elevation
1.108 m.

Access Plan Lagos de Covadonga by public transport, 2017.

- From April 8th to 16th
- From April 29th to May 1st
- From July 1st to September 15th
- From October 12th to 15th
- From December 6th to 10th

More information and rates ►

  • Lake Ercina is accessed via the road to the lakes, heading for La Picota at Lake Enol, after a drive of 12 km from Covadonga.

  • Plant life

    Two well-represented groups in this lake are birdlife and dragonflies.

    The amphibians include the palmate newt (Triturus helveticus), Alpine newt (T. Alpestris), common midwife toad (Alytes obstetricans), common toad (Bufo bufo) and brown frog (Rana temporaria).

    The most abundant waterfowl is the coot (Fulica atra), but there are also numerous mallard (Anas platyrhynchos).


    With its shallow basin, Lake Ercina is a fertile environment in terms of macrovegetation. Plant communities rooted in the lake bed occupy most of the basin, although at first glance many of the plants are not easily discernible due to being permanently submerged or because their reproductive organs only come to the surface for a short period of time.

    The local herdsmen call the floating bog that trembles when walking on it "tapín" or "trema del llagu", but there is a great risk of sinking in this bog as it is generally very saturated and it has false sediments. It consists of concentrations of herbaceous grasses, rushes, reeds, bulrushes and shrubs. Other species include Carex diandra, which, due to being abundant, contributes after fruiting to the change in colour of the lake from green to ochre. Lakeside bulrush (Scirpus lacustris) is found here also, forming reedbeds or emerging from the water in isolated groups. Another species found in the floating mass, as well as on the shores of the lake, is branched bur-reed (Sparganium erectum). Finally, the variety of willow called grey willow (Salix atrocinera) is abundant in the vicinity of the lake.

    The development of vegetation, and even the appearance of a lake, can change a lot, not only in the different seasons, but during the same dates in successive years, and it is clear that not everything depends on climatic variations, there being many other factors at play.

The basin of Lake Ercina comprises a long, flat pool, the final size of which was greatly influenced by the Buferrera Mine, as a 1.5-m-high dam was built at one end of the lake to impound water which was lost through the sump, thus doubling the original length.

The depth of the lake remains almost constant, being about 2.20 m in the deep part in the summer, sometimes reaching 3 m.

Its waters are transparent, though when there are strong winds, they become turbid due to stirring of the clays on the lake bed and the formation of currents and waves. As to the colour of the lake, this varies with changes in lighting and aquatic vegetation, ranging from light green to dark green, even sometimes taking on yellowish, greenish-blue or even reddish hues.

Lake Ercina