El Salto de Villalba: a hundred years of light on the Júcar

A project for Madrid

In 1926 a hydroelectric station began operating in Villalba de la Sierra that villagers called, and still call, the Salto. Its purpose was to supply electricity to Madrid, which was growing and needed light. It was promoted by Unión Eléctrica Madrileña, according to elDiario.es, which marked the centenary in July 2026: after successive mergers the station passed to the Naturgy group, its current owner and also owner of the settlement. The newspaper dates the inauguration by Alfonso XIII to 15 June 1926 and explains that power first travelled to Bolarque station in Guadalajara, of very similar design and built earlier, and from there to the capital. Vestal Etnografía’s documentary names another company, Eléctrica de Castilla; the sources could not be cross-checked.

Water came from La Toba reservoir. A channel carried it to Laguna de Uña, which had to be dammed and increased in size. From the lake the channel continued along the limestone cliffs: thirteen tunnels, several aqueducts and a siphon, Rollo Frío, according to the documentary Vestal Etnografía filmed for the centenary. The channel was almost twenty kilometres long according to elDiario.es and more than twenty according to the documentary. At the end the water reached a forebay above the station and descended through pipes to the turbines.

Water took about three hours to travel between Uña and the station. If the turbines had to start at seven, the water was requested at four. The forebay regulated the difference: water from the channel came in, and what the machines needed went out. A single family lived at the forebay itself, responsible for maintenance and regulating flow to the turbines: one of the children, one of eight siblings, lived there for thirty-five years, went down to school morning and afternoon and back up for lunch, until he became an apprentice at the Salto. La Toba reservoir was planned for about 35 hm³ and ended up at 9.7; on the radio the difference has been attributed to the Civil War, which does not fit a station inaugurated in 1926 and remains to be clarified.

Timber passed through too

Before providing light, the Júcar provided timber. Each spring pine logs went down towards Cuenca, and the station could not block their passage. The solution was for the timber to use the same channel. At the Rollo Frío siphon a metal aqueduct was laid for the logs, and from the forebay a separate channel returned them to the river, bypassing the cliffs of Uña.

Among the witnesses are people who saw timber drives pass there and remember logs being taken out at the loading point with mules and loaded onto lorries at the end of the track.

A radio account says that around 1930 a section of channel collapsed just as a timber expedition was passing and was rebuilt in a week so as not to stop it. A document confirming this is missing.

The settlement

A settlement organised by trade was built at the foot of the station. Workers lived below; senior staff above. On the open ground stood the station, the church and the management house, where the managers stayed. A man who started work in 1960 counted 149 employees that year: gardeners, carpenters, plumbers, electricians, painters. ElDiario.es speaks of more than a hundred families and about 118 workers at its peak, according to local historian Joaquín Carboné’s estimate; the documentary, of about fifteen families. The three figures disagree.

The Salto had what the village did not yet have. Electric light, when people in the village still heated their homes with wood stoves, and drinking water, filtered from the channel through layers of earth, before Villalba had it. A school. A priest employed by the company who said mass daily. A village doctor who held consultations two days a week in a clinic that surprised visitors. And an economato, a company shop selling at cost price: orders were written in a notebook, the amount deducted from wages and a lorry delivered from house to house. Each family also had a henhouse on the higher ground, with rabbits, pigs or pigeons.

Midnight mass was held at the Salto, not in Villalba. Villagers came down the path with lights, like a nativity scene.

Villalba before and after

For the village, the project brought a change of scale. Outsiders came to work on construction and had to be housed and fed. One interviewed family’s grandfather came from Paracuellos de la Vega for the works and stayed as a watchman; another’s began helping with construction in 1926 and ended up as a gardener. For decades many Villalba inhabitants worked at the Salto and walked there and back. One witness sums it up by saying Villalba went from a few small houses to almost the capital of those villages. Around 1950–1960 the municipality reached about 1,100 inhabitants, including the Salto’s people, according to elDiario.es; today it has about 600.

Automation

Over the years the station was automated and many trades were no longer needed. Retiring workers’ posts were no longer filled. A couple from among the settlement’s last families say their parents retired around 1990–1995. In the end three children remained in the settlement. When the two older ones turned fourteen and went down to study in Cuenca, the youngest had to leave too: the school would not remain open for one pupil.

At the centenary, some houses had been restored as accommodation for company workers. The rest of the buildings, according to former residents, were in ruins. The station still operates: Naturgy puts its output at about 23,800 MWh a year, the consumption of about 8,000 households, according to elDiario.es, which quotes councillor Juan Expósito as giving one direct company employee and three subcontracted workers.