Lac de Calacuccia

Lac de Calacuccia is a reservoir in the Haute-Corse department of France formed by damming the Golo river. It provides hydroelectric power and water for irrigation in the dry season.

Location
The Lac de Calacuccia is formed by damming the Golo river just south of the village of Calacuccia. It is at an elevation of 793 m. The eastern part of the reservoir is in the canton of Calacuccia while the western part is in the commune of Casamaccioli. The northwest of the reservoir, where the Golo enters, is in the commune of Albertacce. Other inflows include the Ruisseau de Lavertacce and Ruisseau de Ruggi from the south, and the Ruisseau di u Mulinellu, Ruisseau de Sialari and Ruisseau de Vergoleilu from the north.

The lake is in the upper Golo valley in the heart of the Niolu region, a wild micro-region of the Parc naturel régional de Corse (Corsica Regional Natural Park). Surrounding peaks include Paglia Orba, Cinque Frati and Monte Cinto. The climate differs from the rest of Corsica due to its position in the center of the island and the surrounding high peaks. Summers are dry but cool, while winters are wet and temperate.

Ecology
The reservoir is of low biological interest. Flora includes Spanish juniper (Juniperus thurifera). Fauna include Geoffroy's bat (Myotis emarginatus), carrion crow (Corvus corone cornix), brown trout (Salmo trutta) and great green bush-cricket (Tettigonia viridissima).

Dam
In August 1964 five hundred people led by all the elected representatives of the canton of Corte demonstrated against construction of the dam. They proclaimed "their fierce determination to oppose by all means in their power to the realization of this project, which, in its current conception, would lead to the ruin of the valley of their ancestors and cradle of their children". The dam would submerge 140 ha of land, or which a quarter was planted with gardens and orchards. However, in January 1964 the departmental assembly had voted 52 to 5 in favour of the concessions requested by Électricité de France and the semi-public Société d'aménagement pour la mise en valeur de la Corse (Somivac) for the agricultural development of Corsica.

The Barrage de Calacuccia is a multiple arch dam used for hydroelectricity. The concrete dam was built between 1965 and 1968. It came into service in 1968. It has a crest length of 265 m and crest altitude of 794 m. It has an estimated hydraulic head of 74 m at low water. The dam impounds 23400000 m3 of water. The lake covers 119.6 ha and is fed by a 127 km2 watershed. Fish cannot pass the dam.

The water is fed to turbines in two power plants in Corscia and Castirla, then returned to the Golo. The Barrage de Calacuccia is the most powerful hydroelectric facility in Corsica, generating 57 MW of the total 199 MW produced by hydroelectricity on the island. It provides 10% of the electricity consumed in Corsica. Every year 25000000 m3 of water are allocated to irrigation of cultivated land. Somivac takes the water at a dam at Prunelli-di-Casacconi, 40 km downstream from the Calacuccia dam, to feed a network of pipes that supports irrigation of 10000 ha of land in the Bastia plains.