The Villarino power station in the Tormes basin, part of the largest hydroelectric complex in Spain

Iberdrola España has a presence in three hydroelectric plants in the basin of the Tormes River, a tributary of the Duero, as it passes through Salamanca and Zamora. A total of 882 MW of installed capacity with the capacity to provide sustainable energy to almost 584,500 homes in Spain. The Almendra reservoir, the third largest in Spain, together with the Villarino plant and its pumping capacity, form a key part of the largest hydroelectric complex in Spain, in coordination with the nearby Aldeadávila and Saucelle dams, already on the Duero River.

Presa Almendra

Hydroelectric plants in the Tormes basin

Number of hydroelectric plants 3
Total installed capacity 882 MW
Number of households benefited 584.500
Year of first installation 1960

The Tormes River is a tributary of the Duero on its left bank, which rises in the Sierra de Gredos, in Navarredonda de Gredos, in the province of Ávila, crosses the province of Salamanca and flows between Salamanca and Zamora until it reaches its mouth in the Duero basin, where it crosses the border with Portugal. From Iberdrola España, uses this water resource, according to the priorities defined in the Water Law, through the three reservoirs of the Tormes, its dams and power plants, distributed along the course of the river through Castile and Leon

The Villarino power station at the Almendra dam is of vital importance to the area with its 856,5 MW of installed capacity. It is accompanied by the Santa Teresa and Villagonzalo plants, with a combined installed capacity of almost 882 MW. In this way, we generate clean, renewable hydroelectric power to supply almost 585.000 families, and we create an environmental and social benefit for the communities surrounding the hydrographic basin. 

Tormes Reservoirs

The water potential and the characteristics of the river Tormes, with a length of 284 km, have led to the creation of reservoirs and waterfalls to facilitate the regulation of the water level and guarantee the water supply to the population centres in the summer season. At the same time as the Tormes reservoirs provide a response to this priority use, as well as for irrigation, they allow the potential energy of the bodies of water at different heights to be harnessed through their different types of dams, generating clean, renewable electricity. In cases such as Villarino, this energy can also be stored by means of pumping technology, contributing to the flexibility of renewable energy production and guaranteeing its integration into the system.

From Iberdrola España, we are active in three reservoirs on the Tormes. Following the downstream direction of the river: Santa Teresa, Villagonzalo and Almendra.

Santa Teresa Reservoir

The Santa Teresa reservoir, a property of the Confederación Hidrográfica del Duero, is located between the municipalities of Montejo and Salvatierra de Tormes, in the province of Salamanca. With a total capacity of 496 hm³ and a surface area of 2,579 hectares (ha), the reservoir was inaugurated at the end of 1960 to ensure the supply of water to the province in summer and the irrigation of the irrigable area in its area of influence. Today, in addition to these uses, it is used for recreational purposes by the citizens through sailing, fishing and bathing and provides hydraulic energy through the Santa Teresa dam, in Montejo, a gravity dam 54 metres high and with a crest of 400 metres.

Villagonzalo Reservoir

The Villagonzalo reservoir, in the Salamanca municipality of Villagonzalo de Tormes, has a total capacity of 6 hm³ of water and a surface area of 208 ha and supplies water to the city of Salamanca. The reservoir has a 12-metre gravity dam, inaugurated in 1965 for the production of hydroelectric energy.

Almendra Reservoir

The Almendra reservoir is located between the provinces of Zamora and Salamanca, on the lower course of the river Tormes near its mouth on the Duero. With a total volume of 2,586 hm³ of reservoir water, it is the third the third largest capacity reservoir in Spain, after Alcántara (also managed by Iberdrola España) and La Serena, both located in Extremadura. The reservoir, inaugurated in 1970, has a surface area of 8,650 ha.

The Almendra Dam, also known as the Villarino Falls, is a dome-shaped dam located 5 km from the town of Almendra in Salamanca and 7 km from the town of Cibanal in Zamora. At 202 metres high, it is the highest dam in Spain. the highest dam in Spain , which, together with its 567 metre crest, makes it an impressive work of hydroelectric engineering that attracts visits from experts and tourists alike.

(*) All the data provided on reservoir capacity and surface area come from the specialised website External link, opens in new window..

Hydroelectric Power Stations of the Tormes River Basin

Our hydroelectric power plant with the largest installed capacity in the Tormes basin is Villarino, located in the lower section of the basin in the province of Salamanca. Further upstream along the river, also in Salamanca, are the Santa Teresa and Villagonzalo power stations, completing this group of hydraulic structures.

Our commitment to sustainability and the promotion of renewable energies is reflected in this commitment to hydroelectric generation in the Tormes basin. In addition to providing a clean and affordable source of electricity, the construction, management and maintenance of all these hydraulic infrastructures has a significant positive impact on the area: generating local jobs, stimulating the economy, strengthening the infrastructure and promoting sustainable development in the community of Castile and León.



Villarino is an underground hydroelectric power station located in the Salamanca town of Villarino de los Aires, near the two villages that were built to provide shelter for the workers, fed by the Almendra reservoir and draining into the Aldeadávila reservoir on the river Duero. Its total installed capacity is 856,5 MW, enough to supply nearly 567,000 households with renewable energy.

Villarino has four waterfalls of almost 398 metres each and two others of 386 metres, some of them inaugurated in 1970 and some in 1977. The turbine-alternator groups are reversible, which means that it can operate as a pumping station and reverse its operation and pump water from the Aldeadávila reservoir in the lower part (Duero basin) to the Almendra reservoir in the upper part (Tormes basin) and use and store surplus energy when energy demand is lower, such as at night.

Saint Theresa

The Santa Teresa outdoor power plant, located in Montejo in the lower area of the Santa Teresa reservoir, was commissioned in 1960 and has a waterfall of almost 53 metres and an installed capacity of 21 MW. This renewable power has the capacity to benefit approximately a 14,700 households.


The Villagonzalo outdoor hydroelectric power station is located in the town of Villagonzalo de Tormes and has been generating hydroelectric power since 1995. With a head of 9.3 metres, it has an installed capacity of almost 4 MW

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