
Every morning as a child, Bhagwati Agrawal would accompany his mother to fetch water from the nearby well. One day, she chided him for not filling the buckets of an elderly woman. The lesson stuck with him.
Decades later, after moving to the U.S. and working in its tech industry, Agrawal knew he wanted to help others harvest and share water in Rajasthan, India’s driest state.
“That was the power of my mother’s words,” he said.
Aakash Ganga: ‘River from the Sky’

In much of Rajasthan, water shortages have become normal, and climate change likely will lengthen and deepen droughts there. Already, wells that have not dried up are often salty and unhealthy. “It has gotten quite worse,” Agrawal says, since his childhood.
Aakash Ganga, or “River from the Sky,” is his response. It’s a network of traditional rooftop rainwater collectors that divert half the captured water to a large communal reservoir. By storing the heavy monsoon rains from July to September, the system can provide households and communities with water for the entire year. So far, this combination of ancient Indian practices and newer water-management strategies collects 15 million liters of clean drinking water a year for 10,000 residents of six Rajasthan villages.
But as Agrawal learned working in the tech industry, one key question remained: Would it scale up?
Six villages to 600,000?
For the river in the sky to succeed for more Indians, Agrawal knew he had to follow the precepts of any business. To grow, his creation would need to pay its own way and would have to meet its customers’ needs. Too often in the tech field, he said, “I saw so many technologies that were born in a lab, nurtured in a lab, and eventually died in the lab.”
He devised a way for Aakash Ganga to sustain itself. Agrawal “rents” the rooftop collection rights from villagers and sells produce grown with harvested rainwater to support the system’s upkeep.
He also learned from his customers. One day during the design phase, he noticed an older man sitting on a fence, shaking his head.

“I went up to him and asked, ‘Baba, you keep saying it will not work. Will you tell me why?'”
In Agrawal’s initial plans, the home reservoir was dome-shaped and located in the courtyard — just where residents slept during the hot summers, when their homes were too warm for a good night’s sleep. No one could sleep on top of a dome. The solution? Flat reservoirs, like the one at right.
Making changes each time, “it took me eight years to understand how to work with the people in the villages,” he said. But now, he’s ready to scale up.
Named a 2015 CNN Hero and with grants from the Indian government, MIT and the World Bank, Agrawal hopes to demonstrate Aakash Ganga in 50 to 100 more villages to prepare for further expansion. India has 600,000 villages and a warming climate, so there’s room to grow. For Agrawal, it’s not a daunting number, but a duty.
“What my mother told me, that was the difference.”