The farmers all remember when glacier-fed rivers flowed year round throughout Ladakh, in India’s northern-most state, and they could harvest bumper crops of barley, wheat, fruits, and vegetables every summer. But now the same rivers and streams run dry in the spring, forcing the farmers to wait two months for the summer rains before they can begin planting their crops. Normally, there's plenty of water during the rest of the year—exactly when they don't need it—like the harsh winter, when household taps are opened full blast to keep the pipes from freezing. The villagers all blame climate change as they watch nearby glaciers shrink, melting faster each year.
To work around the yearly water-stoppage, Sonam Wangchuk, a local mechanical engineer, recently built a marvel that had never been witnessed before: a tall, winter ice pyramid near the capital of Ladakh. When spring came in 2014, his artificial glacier slowly melted, sending farmers enough water so they could begin planting their crops on time. This ingenious, home-grown solution, stores water without expensive infrastructure like storage tanks or high concrete dams.
Creating vast fields of ice
Wangchuk is the first to admit that artificial glaciers aren't new. He's just improved on traditional sources he'd seen since childhood, when people in Ladakh and Baltistan trekked high into the cold mountains—sometimes over 14,000 feet—just to grow glaciers; their methods were simple and not very productive. But that changed in the 90's when a retired Ladakhi civil engineer, Mr. Chewang Norphel, tweaked the idea by freezing water into vast fields of ice.
Norphel had his "ahaa" moment after retiring in 1995. He was outside in his yard when he noticed that water from a stream had frozen in the shade of a tree, but still flowed freely in the sun. After a series of experiments, he started diverting mountain runoff into specially built channels that emptied into a shaded valley, where low stone dams captured the water, and over several months it grew into thicker and thicker frozen sheets. By spring, when the ice started to thaw, he released the water down rock-walled channels just in time for the growing season.
Bringing the technology down off the mountain
Years later Mr. Chewang asked Mr. Wangchuk not only to help him improve his water diversion technology but also to make it available to people living below 14,000 feet. He also wanted to overcome the need for sun protection. Mr Wangchuk soon realized that if he reduced the surface area of the ice, he could slow the thaw at a lower altitude. The obvious choice was to build a tall ice cone. This shape left much less ice exposed than the flat ice fields pioneered by Norphel. The benefit was striking. For example, a 40m by 40m Ice cone, now called an ice stupa by Wangchuk, could store sixteen million liters of water. If the same amount of water were stored as a flat, 2m-thick ice field—with five times greater surface—it would melt five times faster.
Building the cone was the next trick. Wangchuk developed a simple and very effective solution based on the principle that water always maintains its level. He was able to make the water at the pipe's downstream sprinkler end rise many stories high, simply by starting the upstream feeder-end higher on the mountain.
Last winter, to test his idea, Wangchuk built an 18 foot-high prototype on a riverbank fully exposed to the sun. Even more challenging, it was sited at 10,300 feet, the lowest altitude in the area. When his prototype supplied irrigation water until mid-May, he immediately decided to go with a 90 footer this winter.
Can this storage solution be used in other countries?