From the top of a hill, Yeni Szlapelis, 46, looks out over the arid plateaus of south-central Argentina at the sources of her greatest worries. To the east, dust clouds emerge from the remains of a dry lake the size of New York City: the Colhué Huapí. To the west, Lake Musters, an essential source of water for the region shimmers under the scorching sun.
Szlapelis, an agronomist who grew up in the area, often visits this spot on her trail runs and follows the receding shores of the two lakes. As a researcher at the National Institute of Agricultural Technology (INTA), she knows the region’s valleys and farmland well, having worked there for 20 years. Her verdict is clear: if nothing is done to improve water management, the disappearance of both lakes will be irreversible.
“The sad thing is that it’s getting worse,” she says.
Lakes Colhué Huapí and Musters have always been the lifeblood of the farmers and residents of her hometown, Sarmiento, whose green pastures and tall poplars stand out against the grey landscape.
However, Lake Colhué Huapí, a shallow body of water that once spanned almost 800 sq km, has all but disappeared after years of drought and water-management decisions made with limited resources. Its sister, Lake Musters, lies just a few kilometres to the west. It has half the surface area but nearly six times the depth that Lake Colhué Huapí once had, yet it too has been shrinking.
The Senguer River basin and its two main lakes have been at the forefront of Chubut province residents’ and officials’ concerns as decades of drought, crumbling infrastructure and limited resources created a water crisis in the region.
As more than half of the world’s lakes are shrinking, according to a 2023 meta-study published in Science, people in the Senguer River basin have been searching for solutions to desertification in their region for decades. Climate projections show that the water supply is threatened on all fronts, and officials are working to improve the situation.
The loss of Lake Colhué Huapí is a result of a history of management decisions in a losing battle to protect water levels in Lake Musters, which serves as a reservoir for the region.
In the upper basin, water is diverted from the Senguer River to flood fields, creating mallines (wet meadows) for cattle, an agricultural practice used by many ranchers. In the lower basin, Lake Musters holds a reserve of water that is exposed to the Patagonian sun and intense winds, leading to high evaporation rates. From there, water is carried by aqueducts to several cities on the Atlantic coast – Comodoro Rivadavia, Rada Tilly and Caleta Olivia.
More than 500,000 people in these areas depend on water from the Senguer River basin. And the strain is growing alongside the region’s population.
Luis Kruger, 78, loved passing his days in his small, single-storey lakeside home tucked away in the arid heart of Chubut province. The house, quaint and just a few steps from the shore of Lake Colhué Huapí, sat amid his family’s 15,000-hectare (37,000-acre) property, bought in the 1940s.
The lake’s blue waters used to offer a refuge from the arid Patagonian landscape and the intense heat of the summers in Sarmiento. It also provided water for the thousands of sheep the family grazed on their land.
“We used to sail and fish and play in the waters,” he says. “It was a beautiful place.”
Kruger enjoyed his home until 2020, when he was rushed to a clinic because his blood-oxygen levels were so low that the tips of his fingers turned blue. Over the years, as the shoreline beyond his porch crept farther and farther away, the land turned to dust and the particulates Kruger was breathing in began to damage his lungs.
Ultimately, Kruger’s farm, house and business were abandoned. “It was a lifetime of work lost,” he says, looking over what today is little more than a puddle.
The pace of environmental change has quickened over the last few decades. As Lake Musters cycles with the seasons, reduced snowpack means almost every dry season sees a further receding shoreline. On 5 April 2022, the lake reached a historic low not seen since 1999. A hundred miles away in Comodoro Rivadavia, the water was being cut off up to four times a week, and severe dust storms blew into the city from the dried lakebed in Sarmiento.
A 2022 report by the national representative for Chubut, Ana Clara Romero, cited the climate emergency, diminishing snowpack and precipitation, and faulty aqueducts as the origin of the crisis.
“In addition to changes in precipitation and average temperature, climate change has produced changes in the frequency, intensity, spatial extent and duration of extreme events. In this framework, all indicators determine an unfavourable climate outlook, so no horizon will improve the chances of rain, and droughts are far from being reversed, at least in the medium term,” her report says.
Occasionally, weather fluctuations mask these systemic changes. In late 2023, rain from El Niño brought relief to the region. In November 2023, the Senguer River and Lake Musters were at their highest levels in years. But diminishing snowpack from the Andes – as much as 45% by mid-century, according to Nasa – indicates the reprieve is temporary, and officials know it.
The provincial water institute (IPA) for Chubut is stretched for resources in its efforts to drastically change how farmers and ranchers use water in the region.
“We have an efficiency rate of about 30%,” says the IPA president, Esteban Parra. “What does this mean? If I take 10 litres of water from the river, three reach the plant. The rest is lost in transit or through poor application to farms.”
When Lake Musters’ shoreline began receding in 2017, local people began urging action. The grassroots group Abrazo El Musters was formed, and a handful of Sarmiento teachers, parents and citizens began protesting regularly. They called for action and demanded more transparency from government officials on their plans.
“We have to think about solutions, not just for one’s own life, but for the coming generations,” says Guille Gettig, 57, a retired primary school teacher who co-founded the group. “I don’t want my grandson to leave because he is forced to, because it’s uninhabitable. If he leaves here it should be because it was his choice.”
In March, researchers with the Senguer River basin observatory group at the National University of Patagonia San Juan Bosco issued a report pointing to a red flag in the system. By measuring flow rates at more than 45 different irrigation sites in the upper basin, they found nearly seven times more water was being extracted for agricultural use than was being carried by the aqueducts to supply water to the three coastal cities.
Despite this statistic, lead author and geologist José Paredes says the research falls short. “These reports show the problems, but we need solutions,” he says.
Parra says the IPA aims to confront the issue on two levels: socially and organisationally. This involves cooperating with farmers to reshape how irrigating from the river is managed and improve working practices.
“Our hope is that everyone who takes water from the river must have at least an irrigation permit,” Parra says. “They have to have an intake point, a gate and an instrument to measure the flow they are taking from the river.”
And after years of collaborations, meetings, research and public pressure, the IPA announced its grand infrastructure solution: a dam.
The Azud Lago Fontana is a hydroelectric dam planned 200 miles (322km) upstream from the lakes, on the Senguer River.
For Parra, it’s the project they need. In 2020, the IPA uploaded a video to its YouTube channel with a 3D model of the dam. The video highlighted its various features: fish steps, hydroelectric generation and, most important, control of the Senguer River flow during periods of drought.
“The goal is to maintain the historic levels of Lake Musters,” Parra says. It would be one tool in the toolbox for adapting to an era of changing climate and diminishing rainfall. “If we start to improve water use, we can start to balance out that lack of water,” he adds.
The cost of the project is estimated at nearly 3bn Argentine pesos (£2.35m). The Argentine public works website suggests a 2025 completion date but, as yet, no funding has been allocated, nor has there been any physical work done on the dam.
And for people such as Luis Kruger, concerns continue to grow with every drop of water lost from the basin. After three years of having to use an inhaler, Kruger has finally recovered from the damage Lake Colhuè Huapí’s dust has done to his lungs.
“I don’t know the solution,” he says. “The rains are scarce here in Patagonia, and I accept this. I know what is happening here is happening in many parts of the world.”