The Eel-Friendly Dam

Published on Wednesday, 22 March 2017

“The artificial lake can contain 240 million cubic metres of water: a reservoir that is essential not only for bringing electricity to the northern region of Sardinia but also for permitting the irrigation of fields and crops in the area.”

The three horizontal-axis generators that ran until 1991 allowed for the illumination of houses and buildings at full efficiency. After more than sixty years of loyal service, they gave way to one single vertical-axis Francis turbine, which has the same level of performance: it has worked for two decades with an average of 4,000 hours a year, without requiring any special maintenance.

Thanks to an overall review of the plant, done in 2016 by the Business Hydro Sardinia Unit of Enel, and the support of the units of Operation and Maintenance Hydro, the Coghinas hydroelectric group at the Muzzone dam will now be able to stay in service for another 20 years.

Biodiversity at the Forefront

The plant is able to produce 70,000 MW a year for a basin of 25,000 households with the reduction rate of carbon dioxide emissions of about 45,000 kilograms.

Our focus on the environment is a distinctive trait of the plant. The 1,740 square kilometres of its catchment area have strategic value, also in terms of agriculture and tourism: every year, the dam, 58 metres tall with a 158-metre long crown, provides 80/90 million cubic metres of water, protecting fish populations at the same time.

“In 2015, the Coghinas plant opened a ladder system to facilitate the reproduction of eels, allowing them to move continuously between the artificial lake and the river bed.”

This project, for the protection of biodiversity, involves the Coghinas plant as well as the one downstream, Casteldoria, helping to enhance the entire river where the two dams stand.

Financed and prepared by the Province of Olbia-Tempio, the project involved collaboration with the towns of the area, with the common goal of continuing our shared commitment of protecting the environment of this evocative corner of Sardinia, full of history.