New Delhi (CNN)Hundreds of empty plastic jugs wait in rows on the cracked, dry, dusty earth. Hovering expectantly nearby, the residents of Vasant Kunj slum in South Delhi, one of the city's largest and poorest, stand waiting for a government water tanker to arrive.
Water every 10 days: The families on the front line of India's environmental crisis
It's been 10 days.
Ten days since they last received a drop of water. For many families, their containers ran out days ago. They are thirsty and dirty.
"It's very difficult to live like this," said Fatima Bibi, 30, who is in charge of organizing water for the slum. "Everything comes from this water. Everything. Drinking, cooking, cleaning, washing."
Ten minutes away are Delhi's upscale shopping malls, where you can buy a pair of sneakers for $1,000. But in this part of the city, people live in tightly packed corrugated-iron huts. In the 40 C (104 F) heat, it feels like a furnace inside them.
As the tanker rolls into the compound, shouts rise up from the crowd. Men and women sprint forward with green rubber pipes to feed the tanker's water into their containers.
They are given 600 liters (158.5 gallons) per household -- barely enough to survive on until the next rations arrive.
India is facing the worst water crisis in its history, with 600 million people dealing with high to extreme water shortages, according to a recent report by Niti Aayog, a policy think tank for the Indian government. An average of 200,000 Indian lives are lost every year due to inadequate supply or contamination of water.
Twenty-one major Indian cities are estimated to run out of groundwater by 2020 -- just a year away. As India develops and grows to support its 1.3 billion people, those on the front lines of the crisis say it's only going to get worse.
"We have too many people for too little water," said Jyoti Sharma, founder and president of FORCE, an Indian NGO working on water conservation and sanitation. "It's unfortunate that people don't see how frightening it really is."
As arid countries like India get drier due to climate change, Sharma warned that water could soon become a global disparity issue.