The Ice Stupas Artificial glaciers at the edge of the Himalayas.

A stupa—the word comes from the Sanskrit, meaning “to heap” or “to pile up”—is a Buddhist monument that often houses a relic. Over the millennia, stupas have been built from many materials—wood, stone, earth, clay, brick—and have taken many forms, from simple domes to ornately tiered towers. The ﬁrst ice stupa was created in 2013, in Ladakh, in Kashmir. Villages in Ladakh, a high mountain-desert region bordered by the Himalayas, largely depend on glacial runoﬀ for water. As the glaciers recede, owing to climate change, the ﬂow of water has become more erratic. Sometimes there’s too much, producing ﬂash ﬂooding; often, there’s too little. The ice stupa, a kind of artiﬁcial glacier, is the brainchild of a Ladakhi engineer named Sonam Wangchuk. In a way, it, too, is designed to house relics.

Step 1: Polyethylene tubing connects the ice stupa to a source on higher ground, drawing water downhill. Step 2: Galvanized-iron piping carries water from the base of the ice stupa to a sprinkler system. The sprayed water collects and freezes on a domed structure covered with netting. Step 3: As ice accumulates, more piping can be added to increase the height of the structure. Step 4: A fifty-foot ice stupa, which can be created in less than a month, stores more than a quarter of a million gallons of water. Step 5: Ice stupas are often constructed on top of streambeds, augmenting the communal water supply. One idea calls for water from the ice stupas to be collected in reservoirs or tanks connected to drip-irrigation systems. 1 of 5 Diagram by Francesco Muzzi

The stupas are created in winter, using runoﬀ or spring water that’s been piped underground and downslope. The water is released at night, when temperatures can drop below zero degrees Fahrenheit. It shoots through a sprinkler into the air and freezes. In the course of the season, elaborate conical structures take shape, with the contours of the drip castles that kids make on the beach. Ice stupas can reach the height of a ten-story building. They start to melt in March, and at higher elevations—some villages in Ladakh sit more than ﬁfteen thousand feet above sea level—the process can last through July. The meltwater helps farmers get through the crucial spring planting season, when they sow vegetables, barley, and potatoes. (Rainfall in the region averages only around four inches a year.)