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A small town in southern Ecuador has solved the drought problem by using an ancient rainwater collection system used in the past by the indigenous people of the pre-Inca era, the Paltas.We are talking about Catacocha, a town located in a province known for its extremely dry conditions.The rains only appear two months a year, between January and February, and climate change is only exacerbating this.The unexpected solution therefore arrived by looking at the past, a an ancient system of artificial lagoons which the native peoples used to cope with the already intense aridity.The local historian who discovered it, Galo Ramón, convinced the inhabitants of Catacocha to apply it and the results were surprising.Nine years later, the change that has taken place is visible.
In 2005, the community recreated, on one of the highest points of Catacocha, Cerro Pisaca, this water collection and supply system created by the Palta, an indigenous community that lived in the area more than a thousand years ago.The system, consisting of 250 artificial lagoons on the mountain, has allowed the inhabitants of this arid city to store rainwater and thus always have sufficient water resources for crops and livestock.Before the construction of the indigenous hydraulic system, in August, there was almost no water left to the point that the inhabitants only had it for an hour a day.Now, however, the system ensures that the water collected in the first two months of the year lasts until the next rainfall.Historian Galo Ramón discovered the indigenous system while conducting one of his investigations into documents from 1680 that spoke of a land conflict between the municipalities of Coyana and Catacocha.The dispute concerned a lagoon in Pisaca, of which a drawing was also reported.«The Paltas – explained Galo Ramón – they created this system because they knew about the drought.The rains here can concentrate in one or two months.These are violent rains that lead to the fall of over 700 millimeters of water in less than 60 days.Storing rainwater, measuring infiltration and recharging the aquifers was the only way to cope with such aridity."
The system, in fact, does not only include banal tanks for collecting rainwater, but rather adequate management of runoff through small retaining walls.«The Paltas – added Ramón – knew where there was more permeability in the ground by observing what I call the green line.This line can be observed in August or September, when in the absence of rain the plants with deep roots resist by absorbing water from the subsoil and allow us to see where the aquifer is located.That's where they created the lagoons."Galo Ramón is today the head of the Fundación Comunidec, an organization that fights for human rights through which the local inhabitants were able to rehabilitate the two largest lagoons built by the Paltas and, in five years, build the other 248.The two largest lagoons, at the center of the system, collect rainwater which begins to flow from lagoon to lagoon underground until it reaches and feeds natural springs.The storage capacity of the 28 lagoons closest to Cerro Pisaca it is 182,482 cubic meters.This is estimated in the book "Ecohydrology and its implementation in Ecuador", published with the support of UNESCO.In fact, the success of the indigenous Catacocha lagoon system has been such that, in 2018, UNESCO's International Hydrological Program included the area in its list of ecohydrology demonstration sites.
[by Simone Valeri]