Chencho Dem

Punakha—Once a quiet roadside settlement, Changyuel in Punakha is undergoing major transformation, turning into a small town of sorts by the Mochhu (river).

It now boasts new restaurants, shops, and even a futsal ground. Some 15 new buildings have mushroomed along the banks of Mochhu. The ancestral home of Changyuel Bum Galem is also located here, drawing both local and tourists alike.

Amid this rapid development, a danger looms— the ever-present threat of flooding.

With their homes and businesses situated a few metres away from Mochhu, local residents live in constant fear of floods, especially during monsoon when the river swells to dangerous levels, surging close to the road’s edge.

A local resident of Changyuel, Kalu, 39, who has lived here for 15 years now, said that it has become a routine to flee in the middle of the night whenever they hear a flood warning.

“I had to flee from my house twice in the middle of the night when we heard a flood was coming,” she said.

She said that during monsoon, she and her family live in constant fear, especially when there is heavy rainfall. “These days, the weather is strange—one moment it’s sunny, and the next, it starts pouring heavily. We have to be constantly on our toes.”

Another resident, Namgay, said although the residents are aware of the danger they also do not have a choice. “We have no other place to go.”

The National Centre for Hydrology and Meteorology (NCHM) has issued warnings about rising water levels.

On August 25 last year, early warnings indicated high water levels at Tashithang and Yebesa, prompting alerts for settlements along the Mochhu, including Changyuel. The water at Yebesa reached 3.5 metres, signaling a potential flood threat.

Settlements along the river banks like Changyuel, and Samdingkha in Toewdang gewog were alerted and residents were asked to be ready for evacuation if the water level rises.

On October 8 last year, flash floods were reported in Draagchhukha chiwog of Goenshari gewog at around 12:30am, prompting an evacuation alert for Changyuel residents.  Many fled their homes with only essential items, while others sought refuge in Khuruthang town.

NCHM officials have stated that August and September are still part of the monsoon season. They advise residents, particularly those living near riverbanks, to remain vigilant and keep a close watch on weather and flood warnings.

A study by NCHM also highlighted the potential for catastrophic flooding in Punakha due to Glacial Lake Outburst Flood (GLOF). In a worst-case scenario, the collapse of the Thorthomi moraine dam could unleash 53 million cubic metres of water—the result of the combined GLOF from Thorthomi and Raphstreng Lakes—creating a flood three times more severe than the 1994 GLOF.

“Flood volume of 53 million cubic metres of water was the research result of a collaborative project with the experts from University of Austria in the late 1990s and early 2000s. This figure is the estimated volume obtained through various lake breaching and hydrological models,” an NCHM official said.

The official said that all the measures put in place along Phochhu and Punatsangchhu were based on such scientific information.

Following two smaller GLOF incidents from Thorthormi Lake in Lunana, both triggered by rising temperatures, the NCHM assessment team concluded that the GLOF hazard level from the lake has increased. “The relocation programme in Lunana was also based on the recommendation of the assessment team,” the NCHM official added. 

Despite past GLOF incidents from Thorthormi Lake, which were triggered by rising temperatures, no relocation plans are currently in place for Changyuel residents.

The Mochhu and Phochhu rivers, originating from glaciers and lakes in the region, pose ongoing threats. Mo Chu’s sources include Gangche Tag and Masagang, while Pho Chu originates from Tsendegang and Table Mountain.

There are two potentially dangerous glacial lakes identified in the headwaters of Mochhu and nine at the source of Phochhu.

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