The Lake That Ate the Highway
On 4 January 2010 a hillside above the village of Attabad slid into the Hunza river, killed about twenty people and dammed the valley, and over the following months a lake rose behind it that drowned some nineteen kilometres of the Karakoram Highway. Pakistan and China decided not to drain it — they tunnelled around it instead, and the road reopened in September 2015 above water that had not existed when it was last driven.
The tunnel mouth comes up twenty minutes north of Karimabad and the road goes into the hill. When it comes out there is a lake below the window, turquoise in the way that only rock flour suspended in cold water is turquoise, with jet-skis on it in summer and a line of tea shacks along the near shore. Nobody driving it for the first time reads it as anything other than scenery. It is in fact a burial: under that water lie four villages, several thousand apricot and cherry trees, and about nineteen kilometres (12 mi) of the road you are on.
The Karakoram Highway is the only surfaced route between Pakistan and China and the only road link between the upper Hunza valley and the rest of the country. When it closes, Gojal — the sub-district above the lake, some twenty-five thousand people — is not inconvenienced, it is cut off. In January 2010 it closed, and it stayed closed to vehicles for five years and eight months. What happened in between is the most instructive engineering argument in the mountains, because the answer the two governments reached was not to remove the obstacle.
A road that is never finished
The highway was built between 1966 and 1978 by Pakistani and Chinese crews working from both ends, and opened to the public in 1986. It runs about 805 km (500 mi) from Hasan Abdal in Punjab to the Khunjerab Pass at 4,693 m (15,397 ft); the 1,300 km (810 mi) usually quoted for it counts the Chinese half as well, on to Kashgar. It is often described as a feat of construction, which it was, and less often as a feat of maintenance, which is the harder half. The route follows the Indus and then the Hunza through gorges cut across the collision zone where the Indian plate is still driving into Asia at roughly four to five centimetres a year. It crosses the suture itself near Jaglot, where the Nanga Parbat massif shoves the plate boundary back across the river. Nanga Parbat, immediately above the southern section, is rising faster than almost any mountain on earth and shedding material at the same rate. The valley walls are not stable and were never going to be. Rockfall, debris flow and washout close sections of the road most years, and a maintenance force with heavy plant is stationed along it permanently for that reason. The death toll from the original construction is usually given as around eight hundred Pakistani and roughly two hundred Chinese workers; the figures are disputed and no authoritative register was kept, but a small Chinese cemetery in Gilgit holds a fraction of them.
The morning of 4 January 2010
The failure at Attabad was not a surprise to anybody who had been watching the hillside. Cracks had opened above the village around 2002 and had been surveyed, warnings had been issued, and part of the population had already been resettled. On the morning of 4 January 2010 the slope came down into the gorge, took houses with it, and killed about twenty people. The debris crossed the Hunza river and stopped it. The river kept arriving. Over the next five months the water rose behind the blockage at a metre or more a day, flooding upstream through Attabad itself and then Sarat, Ainabad, Shishkat and the lower part of Gulmit — the old capital of Gojal — until the lake stood at around twenty kilometres (12 mi) long and more than a hundred metres (330 ft) deep, submerging the highway and its bridges along the way. Roughly six thousand people lost their homes or their land.
The mountain did not do anything unusual. It did the ordinary thing at an inconvenient scale, in the one place where the country had put a single road and no alternative to it.
The argument about the dam
The immediate fear was not the lake but its failure. A landslide dam is loose material with a river behind it, and when it goes it goes at once. There was precedent within sight: in December 1840 a slide off Nanga Parbat dammed the Indus, and when that barrier gave way the following June the flood ran hundreds of kilometres down to the plains and destroyed a Sikh army encampment near Attock. Pakistan's National Disaster Management Authority put excavators on the debris to cut a spillway and lower the crest, evacuated villages downstream as far as Gilgit, and waited. The water overtopped the spillway on 29 May 2010 and, in the outcome that mattered, drained over the barrier rather than through it. The dam eroded gradually and held. There were arguments through 2010 and 2011 for breaching it properly and restoring the river to its bed, and they lost — partly because the debris had consolidated and cutting it down was itself likely to trigger a surge, and partly because by then the lake had become a fact that people were living around.
Five years of boats
What Gojal did in the meantime was improvise a ferry economy. Government and private boats ran the length of the lake, taking an hour or two depending on the craft and the weather, and everything the sub-district needed — flour, fuel, cement, school textbooks, patients — crossed on them. Freight rates went up several times over. The apricot and potato crops that Gojal sells down-country largely could not reach a market, and there is a generation of Hunza farmers who simply lost those years of income. The boats were open, overloaded and unlicensed, and people drowned. Trade with China through Sost, which is the reason the road exists in strategic terms, collapsed and then partially rebuilt itself as a container-and-boat operation that nobody involved described as satisfactory.
Building around the water
The decision, agreed in 2012, was to accept the lake permanently and move the highway above it. The China Road and Bridge Corporation built a realignment of roughly twenty-four kilometres (15 mi) along the eastern wall of the gorge, including five tunnels totalling around seven kilometres and several new bridges, at a reported cost near US$275 million funded through Chinese lending. It opened on 14 September 2015. The engineering is unremarkable by Chinese standards and completely remarkable in context: driving-bore tunnels at that altitude, on that slope, with the only access road under water. Filed afterwards under the China–Pakistan Economic Corridor, the project actually predates that label, which is worth noting when the tunnels are cited as evidence of what CPEC has delivered.
What the lake is now
Attabad is a destination. There are hotels along the shore, boat operators, a resort with cabins, and domestic tourists from Punjab arriving in numbers Hunza had not previously seen. The income is real and it is not going to the same households that lost the orchards, because those households were compensated by the state at rates they contested for years and the land they held is under a hundred metres of water. Meanwhile the underlying condition has not changed. On 7 May 2022 the Shisper glacier, which had surged and dammed a side valley near Hassanabad twenty kilometres downstream, released the lake behind it, and the flood took out the Hassanabad bridge on the Karakoram Highway and cut the road again. A temporary crossing restored the link within weeks; the permanent replacement took years. That is the honest summary of this road: not a route that was built once and now exists, but a piece of infrastructure that is continuously being rebuilt against a mountain range in the middle of a collision, and Attabad is simply the largest single instalment so far.