Train brings water to parched Chennai. India's motor city is today surviving on the water brought by these trains.
Amid the green Yelagiri hills of southern India, the train inches along the tracks, careful not to spill any precious cargo: drinking water bound for Tamil Nadu state's parched capital city of Chennai. Demand for water in India's Motor City, manufacturing and IT hub on the Bay of Bengal, far outstrips supply, forcing authorities to take extreme and costly measures to deliver potable water to its residents.
Like other fast-growing cities in the developing world, Chennai's water woes have been in the works for some time.
Years of urban sprawl, rapid population growth and poor management of water resources have now reached a breaking point.
Hose-pipes are used to fill train wagons with drinking water piped in from the Mettur dam on the Cauvery River, at Jolarpet railway station, about 216 kilometers (135 miles) from Chennai in Southern Indian state of Tamil Nadu. 
On its daily 216-kilometre (134-mile) sojourn, the 50-tank train carries two and a half million litres (132,086 gallons) of drinking water - a small but critical source for Chennai's water board, which is employing an army of trucks to deliver 500 million litres (132,086,026 gallons) of water a day since desiccated reservoirs and fast-diminishing groundwater forced the city to turn off the taps for millions of users in June.
The train, carrying water piped in from the Mettur dam on the Cauvery River 363 kilometres (225 miles) southwest of Chennai, is classic Indian "jugaad," the Hindi word for a makeshift solution to a complicated problem.
Paying about 94 million US dollars over six months to import the water by rail for six months, it's among several costly and inefficient projects Chennai is employing to shore up water supplies.
How to distribute water from the Cauvery has been disputed by Tamil Nadu and the neighbouring state of Karnataka since the British colonial era.
But water scarcity has worsened in cities like Chennai as water management has failed to keep pace with a population that has more than tripled in three decades, taking up jobs in pharmaceuticals research and development labs, auto factories and IT tech parks.
Poor maintenance of the city's four reservoirs, informal settlements and ineffective sewage systems that encroach on rivers and streams and monsoon shortfalls have left Chennai, India's sixth-largest city with 10 million people, high and dry.
In early July, the Tamil Nadu government tendered a bid for a quick turnaround engineering project to move surplus water from the Mettur dam to Chennai by rail.
Indian Railways supplied the 50-wagon rake, repurposed from transporting edible oil, and has promised three more.
Executive engineer K. Raju's team had just 10 days to lay 650 metres (about half a mile) of pipeline to connect to a storage tank in a village 3 kilometres (1.8 miles) away from the Jolarpet tracks, and install a pumping system to get the water into the train wagons.
Does he think this is the best engineering solution to Chennai's water problem?
"No, this is not, but this is a timely way to help and that's all. This is not a permanent solution," Raju said.
As he describes the logistics of the project, casually dressed young men leap from train car to train car with a level to make sure the water gushing from the pipes doesn't exceed its permitted limit.
Finally, as the sun sets, the train's horn blows as it rolls toward Chennai.
Just after midnight, the water train screeches into the city's mostly deserted Villivakkam railway station.
Men in hard hats and reflective vests connect slinky blue pipes that snake from underground to the wagons. It takes four hours for the train water to decant into the veins of the city's public water system.
In this Thursday, July 18, 2019, photo, a water truck carrying drinking water arrives at a locality in Chennai, in the Southern Indian state of Tamil Nadu. Demand for water in India’s Motor City, a manufacturing and IT hub on the Bay of Bengal, far outstrips supply, forcing authorities to take extreme and costly measures to deliver potable water to its residents.
The following morning at one of the city's water distribution stations, Ranganathan, a longtime water truck driver in Chennai, pulls his colourfully painted truck underneath a wide, vertical tap, taking his load to nearby neighborhoods.
He describes the 16-hour workdays, struggling at his own home with water scarcity and the elation and relief with which he is greeted when he arrives at a drop-off point to deliver water.
"People get excited once they see our lorries. Earlier we used to go home by 8, now it takes (till) 12 a.m. to go home and sleep. There is no time to even eat. I take bath in the night. On days if it becomes late, people will start panicking. What to do? They are like my mother and sister who are worried due to water scarcity, so we help," Ranganathan, who goes by only one name, said.
At one drop-off point, a neighbourhood of low slung one-room houses called Thousand Lights, K. Devi, a 41-year-old mother, says the six pots of water she receives daily from the water board mean only bathing and washing clothes once a week.
Sometimes she supplements her supplies by purchasing cans of water for 35 rupees (about 50 cents) apiece.
She's happy to have extra water, regardless of the distance it's traveled to reach her Chennai slum.
"(If) they are voluntarily giving water, then why should we refuse? Six pots of water aren't sufficient for us. We should bathe, wash vessels, wash clothes in those six pots. So, we should take water from Jolarpet," she says.
This isn't the first time the water train has rolled into Chennai.
When the city experienced a severe drought in 2001, it decided to import water by rail from Erode township, more than 400 kilometres (about 250 miles) southwest of Chennai.
After that, the state government mandated that Chennai households install a rainwater harvesting system.
The city water board began purchasing water from farmers and built two desalination plants, shoring up the volume of public water but still falling short of ever-growing demand.
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