After my visit to Tsho Rolpa, I didn’t have to travel far to find a community that had already been hit by an outburst flood from a similar glacial lake. (Not far by Nepalese standards: A linear distance of 47 kilometres, covered circuitously through a 15-hour downhill hike; then 9 hours alongside live chickens on a local bus plying roads of deep mud that sent it rocking hilariously close to its tipping point; and finally what felt like a rather therapeutic 90 minutes in a pickup truck.)
Officially Tatopani is a village, although its weird topography makes that term feel somehow inappropriate. It’s really a series of ramshackle buildings in sporadic clusters, built beside a clifftop road running along the west bank of the Bhote Koshi, a river that originates in the barren peaks of southwestern Tibet.
For Tatopani, its proximity to the Chinese frontier had long been its greatest asset. The Bhote Koshi here forms the border between the two countries; immediately after leaving Tatopani to the north, the road running through it takes a sharp right over a bridge and lands in Tibet. This had been a trading post for as long as anyone could remember, and as the Chinese economy grew, so Tatopani benefited from the surging flow of goods over the border. But on the night of 5 July 2016, what rolled in from Tibet was something horrifically different.
Karma, a mother of three then aged 49, was in her kitchen washing plates after dinner when she heard a distant roar. The family had moved into this home a few months earlier; it was still a work in progress, built with the profits from the tea shop they had been running for about a decade. It was 8:30 in the evening and her husband had retired to bed, leaving Karma and her youngest daughter to handle the dishes.
She stepped into the street to see one of the village’s larger buildings swaying from the vibrations beneath it. Like every other resident I spoke to, Karma’s first thought was that this must be another earthquake, following one that had damaged many homes — and the bridge to China — the previous year. She roused her husband, who hurriedly pulled on a T-shirt, and they began clambering up the sheer slope on the other side of the road, dragging their nine-year-old between them.
Peering down in the darkness from amid the trees on the hill above, Karma couldn’t see what was happening to her home or those around it, but her ears gave her a sufficient idea. Behind her, the deep rumble had grown into a deafening rush of water accompanied by the violent crash of boulders hurled by the engorged river against its sides. The family began walking through the night to Karma’s home village of Listikot, safely ensconsed in the hills above the river but nearly ten miles distant. When they returned days later, their home was gone, along with the ground it stood on and all their possessions. In its place was thin air above a near-vertical muddy slope, which ran from the edge of the now fractured road to the river below, still clogged with the rubble of about 20 homes destroyed by the flood.
The family left for Kathmandu, and after seven months in the painfully polluted capital, had saved enough to return and rent a space to relaunch their tea shop, where I met Karma, her tattooed hands covered in chapati flour, hoop rings dangling from elongated earlobes. Each time she left the shop, she could see, just up the road, the empty space that once contained the house where she’d expected to spend the rest of her life. Now the family rented a small room in a nearby settlement, and it would be years before they would be able to think about another house of their own. “That flood came,” Karma said, “and stole our dreams.”
Across the street, a scruffy old man in a red beanie hat was sitting on the steps outside a shop, chuckling along to the conversation of a group of residents who were gently ignoring him. At 78 Bir Bahadur Tamang had spent his whole life here, working mostly as a porter dealing with goods coming over the border from China. Eventually he had saved enough to buy two buildings in Tatopani’s northern section, one to live in with his two children and daughter-in-law, the other containing a shop that would support the family in his old age. “They were just over there,” he said, pointing at a void in the road behind a small yellow-striped safety barrier. For a moment he looked as if he were about to cry, but he converted the impulse into a burst of wheezing laughter, as he seemed to do every time he shared a detail of the appalling turn his life had taken.
Tamang’s son and daughter-in-law had left after the flood and didn’t send money back, he said. He and his daughter, who has a mental disability, now lived in a small hut a little downstream from here. They subsisted on his $18 monthly pension and — I presumed chiefly — the generosity of their former neighbours. I invited him for a lunch of egg noodles at Karma’s tea house. This man, who had diligently provided for his retirement, now looked certain to face extreme poverty for as long as he remained alive. “My grandfather lived to over a hundred,” he said abruptly, halfway through our meal. He paused for a moment, and then descended into helpless giggles.
A few miles downstream from Tatopani, the river ran into a major manmade obstruction: a huge artificial mound of earth and rock, behind which ran a collection of thick concrete walls bedecked with Chinese characters, with yellow-helmeted labourers milling on and around them. The construction work at the Upper Bhote Koshi Hydroelectric Project was nearing completion; the imposing height and thickness of its dam resembled the base of a coastal fortress. Yet this plant too had been wrecked by the flood, and had yet to resume operations three years on.
In terms of hydropower, Nepal is the Norway of Asia, with about 94 per cent of its electricity generation coming from the rivers that course through its mountains. But the Himalayas’ melting glaciers mean that many Nepali power plants are now under increasing threat from outburst floods. And this scarred operation showed quite how grave that danger could prove.
“The wall here,” the company’s chief executive Bikram Sthapit told me, as we stood in the mud on the downstream side of the dam, “was blown onto the other side of the river.” I stared at him for a few seconds before I realised he was serious. The wall in question was a mammoth hulk of concrete, as tall as a decent-sized apartment building. It ran parallel with the river on its eastern side, housing a basin where silt was removed from the water before it was sent through a 2-mile pipeline to the turbine at a powerhouse lower in the valley. The flood had blown the wall apart and into the sky.
Bikram had been in Kathmandu on the day the flood hit the plant, then still undergoing repair work from the previous year’s earthquake, which had damaged the powerhouse and water pipeline. The only people at the squat brick powerhouse that evening were two guards, who looked outside the building to see prefabricated cabins collapsing. They ran. “We were very lucky that it happened at night,” Bikram told me. “If it had happened in the day there would have been 50 or 60 workers in the powerhouse. Someone would definitely have died.”
He arrived at the plant some days later to find the powerhouse had been comprehensively flooded, destroying millions of dollars’ worth of brand-new electronics. The scene at the dam was worse. The desilting basin on its eastern edge was smashed to pieces, with fast brown water coursing through it. On the river’s western bank, a white-water rapid had formed after the flood destroyed a curved section of the dam. Only the dam’s strongest central section had held – but it was now crowned with huge boulders, and the flow was rushing right over it, so clogged was the riverbed with debris thrown down by the flood. One of the rocks found near the dam was 17m long, about the size of seven Holstein cows.
Now, at a cost of about $70m — roughly the same, Bikram told me, as building the whole thing from scratch — the plant’s reconstruction by China’s Sinohydro was a few months away from completion. On the western bank, where water had blown through the wall, a new diagonal section had been put in place, to channel water towards the centre of the dam where it was more robust. The wall around the desilting basin had been completely rebuilt to withstand far higher pressure; at the powerhouse, a higher protective wall had been built, and windows bricked up.
I asked if it would be enough to protect the dam in the event of another flood, with the number of upstream glacial lakes having quintupled since work started on this plant over 20 years ago. “If the same flood happened again,” he replied, the design changes made to the rebuilt plant meant any damage would be far smaller than last time. In the event of a larger flood, he conceded, no such guarantees could be made.
Which brings me to one of the most unsettling elements of the Bhote Koshi flood story. In the immediate aftermath of the flood, there was total confusion as to its cause, with initial news reports blaming heavy rains. Bikram commissioned a study from a Chinese consultancy, which the following year reported that the cause had been the outburst of a Tibetan glacial lake called Gongbatongshacuo, 20km northeast of the plant. He showed me the satellite photos they had provided. In the first, taken before the flood, Gongbatongshacuo showed as a green bullet amid the grey and white of the mountain slopes. In the second it was gone.
That was pretty striking. But still more so was the size of the vanished water body. A short way to its south it I could see the still waters of the better known Cirenmaco, the object of increasingly worrying research on outburst flood risks, which was about seven times its size. Tsho Rolpa, in turn, is over four times the size of Cirenmaco.
Gongbatongshacuo was less than 200 metres long. By the standards of Himalayan glacial lakes — by the standards now, let alone after the melting of the years and decades to come — this one was tiny.