High in the southern mountains of Spain, about 40 people armed with pitchforks and spades cleared rocks and clumps of grass from an earthwork canal built centuries ago and still keeping the slopes green.
“It’s a matter of life”, said Antonio Jesús Rodríguez García, a farmer from the nearby village of Pitres, home to 400 inhabitants. “Without this water, the farmers cannot grow anything, the village cannot survive.”
The extreme heat sweeping across much of southern Europe this week is just the latest reminder of the challenges climate change has imposed on Spain, where temperatures reached 109 degrees Fahrenheit on Tuesday, putting half the territory on orange and red weather alert. . Such heat and extended droughts posed the threat that three-quarters of the country could be engulfed in a crawl. deserts during this century.
Faced with this reality, Spanish farmers, volunteers and researchers reached deep into history for solutions, turning to a vast network of irrigation canals built by the Moors, the Muslim population that conquered and settled in the Iberian Peninsula in the Middle Ages.
The canals – called “acequias”, from the Arabic “as-saqiya”, which means water conduit – made life possible in one of the driest regions of Europe, supplying the springs of the majestic Alhambra palace and turning the region, Andalusia, into an agricultural power
Many acequias fell into disuse around the 1960s, when Spain turned to an agricultural model that favored reservoirs and pushed many Spaniards to leave rural areas for cities. As the use of the network faded, so did the ancient knowledge and traditions that brought water to the most remote corners of Andalusia.
Now, the complicated system, seen as a cheap and effective tool to mitigate drought, is being revived, one abandoned acequia at a time.
“The acequias have been able to withstand at least a thousand years of climatic, social and political change,” said José María Martín Civantos, an archaeologist and historian who is coordinating a major restoration project. “Then why do without it now?”
Mr. Civantos, a burly man with a beard, said the Moors built at least 15,000 miles of acekis across the Andalusian provinces of Granada and Almeria, in what was then Al-Andalus. He explained that before the acequias, it was difficult to grow food in the unstable climate of the Mediterranean, with periodic droughts.
The “genius of the system,” he said, is that it slows the flow of water from the mountains to the plains to better retain and distribute it.
Without sagebrush, snowmelt from mountain peaks would flow directly into rivers and lakes that dry up during the summer. With them, the melting is diverted to multiple acekias winding through the hills. The water soaks into the soil in a “sponge effect”, and then circulates slowly through aquifers and emerges months later, downslope, in springs that water crops during the dry season.
Traces of the system are everywhere in the southern Alpujarra Mountains, on the southern slopes of the Sierra Nevada. Water gushes from the mountains at every bend in the road. It softens the soil of the high plains. It springs from fountains in the typical whitewashed villages of the region.
“The Moors didn’t just leave us the acequias, but also the landscape they created with them,” said Elena Correa Jiménez, a researcher on the restoration project led by the University of Granada.
Holding a shovel, she pointed to the green lands that stretched out below. “None of this would exist without the acequias,” she said. “There would be no water to drink, no fountains, no crops. It would almost be a desert.”
Water was so essential here that locals talk about it as if it were a crop itself. Water is not absorbed from the subsoil, it is “seeded”. It is not collected for irrigation, it is “harvested”.
When Spain replaced many acequias with the more modern water management systems, in the Sierra Nevada alone, up to a fifth of the acequias were abandoned, according to government data.
The agricultural revolution helped turn Andalusia into Europe’s backyard, with huge quantities of pomegranates, lemons and barley sent across the continent. But it also led to an insatiable thirst for water that depleted the region’s aquifers, exacerbating droughts.
To make matters worse, climate change has exposed Spain to increasingly frequent heat waves. This spring was the hottest recorded in Spain, according to the the country’s meteorological agencywith April temperatures exceeding 100 degrees in Andalusia.
Cañar, a small town nestled in the Alpujarra, was strongly affected by the combination of intensive agriculture, higher temperatures and the abandonment of a nearby acequia.
Several of the village’s agricultural plots are now deserted. In a cafe, a sign reads: “I’m looking for an irrigated farm.” And most of the area’s mountain streams now bypass Cañar, feeding a river in a valley below that supplies greenhouses growing avocados. No one in the village works there.
Ramón Fernández Fernández, 69, a farmer, said he remembers when village houses would collapse under the weight of winter snow. Asked when it last snowed in the area, he laughed.
“The bad years then are the good years now,” he said of the droughts.
In 2014, the village became the test for Mr. Civantos’ acequia restoration project. For one month, he and 180 volunteers dug up the earth under a burning sun to recover the channel.
“Some farmers who were 80 or older were crying because they thought they would never see the water flowing again,” Mr. Civantos said. He remembered an older resident standing in the ditch when water started pouring in, gesturing with his arms as if to guide the water towards the village.
Francisco Vílchez Álvarez, a member of a group of residents who manage irrigation networks in Cañar, said that restoration of the acequia has enabled some residents to grow cherries and kiwis again.
So far, Mr. Civantos and his team have recovered more than 60 miles of irrigation canals, taking diverse groups of researchers, farmers, environmental activists and locals across the Alpujarra, gardening tools in hand.
The initiative spread to Spanish regions in the east and north. But Mr. Civantos and several farmers said they still lack financial support because politicians and businesses often view aqueducts as inefficient compared to modern hydraulic networks.
“It’s hard to change mindsets,” he said. “But if you understand efficiency in terms of multifunctionality, then the traditional irrigation systems are much more efficient. They retain water better, they recharge the waters, they improve the fertility of the soils.”
But the biggest challenge to save acequias is perhaps to preserve the ancient knowledge behind their existence.
In villages like Cañar, where residents still use a 19th-century logbook to allocate water to farmers, the rural exodus threatened the transmission of techniques that had been passed down orally.
One resident who knew every branch along 22 miles of acequias in the area recently died, taking “precious knowledge, ancestral knowledge” to his grave, Mr. Vílchez said.
Taking a break during the clean-up operation, Mayor José Antonio García de Pitres, 58, said “a lot of wisdom” had gone into the acequias.
“Now we have the opportunity to use this ancient wisdom to fight climate change,” he said. “Well, let’s go.”