Ice stupas have become a popular water management tool in the Himalayas. But can they work in Chile?
Every winter in the Himalayas for decades, man-made reservoirs capture glacial meltwater from streams and preserve it as ice. By slowing melting water or spraying it into the air, people cause it to refreeze, often in forms called stupas, after the domed Buddhist shrines they may resemble. The ice can then melt the following year, allowing irrigation that supports longer agricultural seasons in high mountain areas.
Now a group of Chilean engineers are trying to transfer that technology to their country’s high mountain glaciers in what they call the Nile Project. In 2021, engineers developed their first prototype in a private park in the Cajón de Maipo region south of Santiago, the national capital. The area was chosen because of both its easy access and its proximity to the Maipo, a glacier-fed river descending from the Andes that provides fresh water to Santiago and the surrounding region. During the Southern Hemisphere winter of 2021, their prototype collected 550,000 kilograms of ice that melted in just under two months. Although smaller than the Himalayan reservoirs, it offers an early proof of concept.
These efforts caught the attention of University of Pennsylvania researcher Kristina Lyons, who learned about the project while she was conducting anthropological research on indigenous Mapuche communities and their relationship to the surrounding glaciers around Santiago.
“I was totally fascinated by this idea,” she said in an interview with GlacierHub, recalling that it was the distinctive South-South knowledge transfer between the Himalayas and Chile that first got her there. marked. “I was really interested in this technology, what it could do and how it was framed.” Lyons began working with the engineers and published an article analyzing the unique socio-political context of the Nilus project. earlier this year.
Satellite photography dates the construction of the Himalayan Ice Reservoirs to at least the 1960s. Sometimes called “artificial glaciers” – a catchy but scientifically inaccurate term because they don’t accumulate long-term ice or move across land – these reservoirs reduce the loss of glacial meltwater by taking advantage of frequent freeze-thaw cycles in cold and arid regions. environments. Unlike lakes, which freeze from the top down, ice reservoirs freeze from the bottom up. By creating a slow trickle of meltwater from the mountains – whether by creating a cascade of loose steps, redirecting the water to a more shady spot with a large surface area, or sending it through pipes that spray it into ambient air – ice reservoirs allow water to refreeze into ice before flowing further. Over time, layers of ice form on top of each other, creating a water storage system.
In recent years, community leaders and NGOs have collected important attention beyond the Himalayan communities and the whole world. This is how these projects first caught the attention of Chileans. THE recent expansion of ice reservoir projects across the Himalayas represents an excellent example of locally designed and community-led water management solutions.
“Their priority was really empowering communities to solve their own problems and creating an education system to train people in the area to (do it),” Lyons said.
Marcus Nuesser, a professor at the University of Heidelberg, has studied the history, evolution and effectiveness of the practice in mountain communities in the Himalayas. “These types of ice reservoirs have a long history in places like (the Indian region of) Ladakh,” he said in an interview with GlacierHub.
Nuesser notes that the particular type of ice reservoir on which the Chilean engineers model their project, the ice stupa, is a relatively new iteration of an old practice. Ice stupas work by spraying small water droplets to create and store ice. Conceived and popularized by Ladakhi engineer Sonam Wangchuk around 2015, a surge of interest and funding followed. “They had something like a contest between different villages – which village built the highest,” Nuesser recalls.
However, a significant obstacle to the success of an ice stupa depends on adequate manpower for maintenance. In Ladakh, many early projects were scaled up by NGOs that received international funding. Nuesser notes that once projects started and funding ran out, communities often struggled to keep ice stupas running. This was partly due to the dwindling agrarian labor force in this region, which has long been characterized by massive emigration.
“These structures (require) a lot of maintenance,” Nuesser said. “When the money ran out, I saw many cases where they just dropped them. … When the hype is over, the structure faces problems. Nuesser said during his visit to Ladakh last winter, he saw many once impressive structures in disrepair.
The need for adequate labor also presents a significant challenge in Chile, where very few people live in the mountainous areas around which glacial meltwater could be captured. Without eyes to look for burst pipes, slow flows, or other issues, the project can be in jeopardy. However, Nilus engineers are testing remote sensing and artificial intelligence technologies to control how and where ice forms on top of the structure.
The Chilean context adds another unique barrier: a privatized water rights structure which dictates how downstream water can be used. Water privatization was first enacted by the dictatorship of Augusto Pinochet in 1980, which created a formal market for the buying, selling and leasing of water rights in the country. Last year, Chileans rejected a new constitution that would have largely fact supply.
The law draws a fine line between the privatization of glaciers and the privatization of their waterways. “You can’t privatize water from a glacier in the sense that you can’t just put a pipe up there and say, ‘Whatever comes out is mine,'” Lyons explained. “But as the water melts, like every season right now because of climate change, it belongs to someone. And so that’s one of the complications: where will the water go? is for whom?”
Nuesser agrees. “It’s a whole different set of issues,” he said, noting how the expansion of the Chilean mining sector adds yet another layer of problems, as mining operations usually require large amounts of water and may be of interest for the water supply of the new ice stupa. Still, Nuesser is cautiously optimistic. “It can work if they keep people informed of the ownership of this,” he said.
For Lyons, the issue of water rights in Chile highlights the limits of what a private company can do to address regional water scarcity. “I know they have very good intentions,” she said. She cited continued water stress exacerbated by internal migration from other parts of Chile to the Santiago region. “But they are also always caught in a model themselves, economically. What can they do if they need to start a business and pay employees? In such a privatized system, what flexibility do you have for the project to actually become (a climate solution)? »
Nuesser also notes that even if the project succeeded in retaining glacial meltwater until the end of the agricultural season, it would not mitigate the loss of glaciers as a whole.
“They (ice reservoirs) are very effective concepts to fill this critical water scarcity gap. But in another way, there is no additional water coming into the system,” said “It helps meet the water demand for this year, and maybe next year. But it won’t help in the long term, when primary water sources dwindle.”
Lyon agrees. “I think for the Chileans, they would like to feel like they have something to do to address the retreat of their glacier,” she said. “What I see is that in this time of heightened awareness of climate change and global warming, it would seem like it would be helpful if ice stupas could do something like this. It’s still very speculative .
Efforts in Chile to expand the pilot project near Santiago will show if this much-loved example of South-South technology transfer is working.
Glacier Hub is a climate communication initiative led by Ben Orlove, an anthropologist at the Columbia Climate School. Many GlacierHub writers are students or alumni of The Climate School.