Two decades ago, a glacier lake outburst flood (GLOF) at Lugge Tso, a lake in central Bhutan, coursed down a river valley, killing 17 people, destroying 730 hectares of fields and pastures, and washing away four bridges. Most prominently in the minds of Bhutanese, it also damaged a dzong—a set of culturally significant buildings—in the town of Punakha. The flood was big news throughout the Himalayas, and concern about the decade-long reconstruction, financed principally by the governments of Bhutan and India. Today, glacial lake outburst floods are becoming a bigger hazard in the Himalayas and around the world, as glacial melt compromises the integrity of glacial lakes. These GLOFs threaten human lives, infrastructure and ecosystems.
On a trip to Bhutan, I recently stayed in the town of Lobesa, which neighbors Punakha, and visited the site of the dzong to get a better understanding of the impact that the giant GLOF had on the community and its infrastructure. Dzongs are the most dramatic element of traditional Bhutanese architecture. They are massive fortresses, most of them located on hillsides, with high defensive walls and a tall interior watchtower. Within these walls are courtyards which hold administrative offices and temples, as well as many rooms for residences and storage which allowed residents to withstand a long siege. Though a few dzongs are recent, most date back to the last three or four centuries, when regional lords battled each other, and when armies from Tibet or India would invade Bhutan.
As we neared Punakha, the driver stopped at the standard spot where tourists and Bhutanese alike take photographs of the dzong. From this vantage, the viewer can see how the dzong stands high above the confluence of two rivers. The driver explained that the wider Po Chhu to the east—the one that flooded–is male, and the smaller Mo Chhu to the west is female.
Like its counterparts that dot the country, the Punakha dzong has religious and historic associations. Guru Rinpoche, the figure who brought Buddhism to Bhutan in the 8th century, foretold that someone with the name of Namgyal would someday travel to a hill shaped like an elephant. Centuries later, Zhamdrung Namgyal, the leader who unified Bhutan into a single kingdom, saw the hill where the dzong is located, and noted that its elephant-like form, with the strip of land between the Po Chhu and Mo Chhu resembling the animal’s trunk. Zhamdrung, who defeated an invasion from Tibet, constructed the dzong in the 1630s and it has retained its importance to the present. The dzong was the seat of the government of Bhutan until the capital was moved to Thimphu in 1955 and the wedding of the present king was held there in 2011.
I took the whole morning and part of the afternoon to explore the fortress. The first courtyard holds an enormous chorten (a Buddhist stupa) and a beautiful specimen of a Bodhi tree, the kind of tree under which Buddha achieved enlightenment. In one corner with government offices, county representatives were attending a meeting on budgeting procedures. People would come out of the meeting to make phone calls and send text messages. Evidently there is good cell coverage inside the dzong.
At the other end of the courtyard, on the side near the Po Chhu, was a small shrine, the only one that was not located inside a temple and, as a consequence, the only one that I could photograph. (Red-robed monks were on the alert to prevent tourists from sneaking pictures of the images of Buddha, Guru Rimpoche and other religious figures inside the temples.) The butter lamp burning in front of the shrine was a familiar sight, but I was puzzled by the rocks that I saw near the shrine, quite different from other offerings that I had seen.
I continued on to the southern courtyards, and found one spot which, I thought, might still show some damage from the 1994 GLOF. I asked a monk standing nearby about it, but he spoke no English. To my surprise, two nuns who were within earshot replied to my question. They did not know about the possible damage. It turned out that they, like me, had arrived from Lobesa that morning, on a kind of pilgrimage. They asked me if I would like to join them in their visit to the inner watchtower, an invitation which I gladly accepted. We clambered up a set of steep ladders, where on each floor the monk in charge unlocked the door to a temple. He let us in and waited while the nuns made a series of prostrations. He accepted the offerings which they and I placed on the altars, and then poured some water into our cupped hands as a kind of blessing. In the third temple, one of the nuns touched her forehead to an image in a mural with a graceful gesture that suggested to me both reverence and familiarity. When their circuit of the temples was complete, the nuns left to return to their convent in Lobesa, and I strolled around the dzong for another hour. Unready to leave this extraordinary structure, I found a spot to sit with a view of the Bodhi tree, and watched the different kinds of people passing through—monks, local people attending the meeting of county representatives, and foreign tourists with guides.
Sangay, the taxi driver who drove me back to Lobesa, remembered the flood when I asked him about it. He had been a boy at the time. Like the others I spoke with, he mimicked its eerie sound, a low “oo” somewhere between a moan and a roar. It awakened him and his family, and frightened them into stumbling up the hillside behind their house. He added a detail that nobody else mentioned: the unpleasant smell of mud that arrived with the flood and lingered for days. He told me that the flood waters were filled with fish that were easy to catch. Pointing to his eyes and his ears, he explained that the turbidity of the waters prevented the fish from seeing, and the sediments clogged their gills so they came close to the surface, where he could easily catch them. Older people told him and his friends that the fish were poisonous, but they ate them anyway.
I asked him about the image in the shrine that I had photographed, which he recalled it right away, once I described its location in the courtyard. The being is a female local deity, rather than one of the larger figures in the pantheon who are revered in many sites. Her name is Tsomem, a combination of the word tso, a body of water, and mem, person. She is a Himalayan mermaid, with the upper body of a woman and the lower body of a fish. Though she is usually happy and stays in the river, she can on occasion become unhappy. At these times, she may leave the river and become destructive. To keep her happy, local people bring offerings, including money and butter-lamps that are common throughout temples in Bhutan, and a special gift only for her, round river rocks. These rocks remind her of her river home, and keep her happy.
Though two decades have passed since the flood, it remains fresh in the memory of people in Bhutan. A brief and striking video, “Tsomem’s perspective of Punakha Dzong,” shows the concreteness with which it is recalled. Government agencies monitor glacier-fed lakes to evaluate the changing risk of GLOFs. It seems only a matter of time until the next flood rushes down a valley, threatening lives and structures, whether historic dzongs or the new monuments of Bhutan: the hydropower dams like the one currently being built downstream of the Punakha dzong below Lobesa.