7 Dead, 16 missing in July 20 Bhutan Hydro Project Disaster

Yungichhu HEP disaster in Bhutan in July 2023. Photo- Kuensel via SANDARP

July 23, 2023SANDRP

At least seven people were killed and 16 others missing in Bhutan after flash floods and landslides triggered by heavy rains washed away a section of a hydroelectric plant on July 20 2023[i]. They were washed away by the sudden burst at the residential area next to the worksite at Ungar village, according to a press release from the Prime Minister’s Office. Prime Minister Dr Lotay Tshering, who is in Lhuentse, said the devastating flashflood presented one of the biggest loss of lives and properties in recent memory, and shook the core of the nation.

Rescue and search teams have rushed to the area, authorities said. Prime Minister Lotay Tshering has arrived at the site and is taking stock of the situation and guiding rescue and search operation. The flash flood struck Onggar chiwog in Lhuentse. Rescue operations are ongoing. One more female body was retrieved on July 22, 2023[ii] from a place called Dung, approximately  4 km from the Unggar flash flood site. The flash flood also damaged rice fields and killed about 10 cattles which were along the stream.

Of the 23 people, one was a Desuup (Volunteer worker) and five were DGPC staff. The rest were the family members of the staff. The officials were working for the Yungichhu Hydropower Project. The flash flood washed away machines of DGPC and vehicles belonging to the staff. The flash flood also buried 10 cattle and paddy fields of Oong-gar village. According to the officials, the cause of flash flood has not been ascertained.[iii]

A section of the 32 MW Yungichhu Hydro Power Project in a remote area in the east of the country was washed away, but the main part was not hit. Five of the seven killed have been identified. “It is a major disaster,” Bhutanese quoted an unnamed official from Druk Green Power, which is in charge of the plant’s construction, as saying. The missing included project staff.

Huge, sudden, short duration floods – due to landslide dam? Dechen Pelden, 28, staying close to the disaster site, heard a rumbling sound and the earth beneath them shake at 7.40 pm on July 20 2023. “I thought we were going to die when I heard the rumbling of the boulders crashing down the valley. I was shocked,” said Dechen Pelden. Dechen said she had never seen a disaster of such magnitude and scale. The flood swept away the entire camp and buried several vehicles including excavators. Tashi Gyeltshen, 30, a resident, said that the weather was clear for three days, and that only on Thursday evening it was raining. “I suspect heavy rainfall at high mountains could be the cause of floods,” he said. “It is the first time we have experienced such a disaster in our village.”[iv]

Considering that the sudden flash floods lasted about 20 minutes and without too much rain, there is possibility that a landslide dam may have been created in the upstream, the breach of the dam could have led to sudden, huge flash flood that passed away within minutes.

Foot print of climate change? An editorial in The Kuensel on July 22 2023[v] said: “But what we have to realise is that we are no longer a blessed country in the face of natural disasters, especially induced by climate change… it is the melting glaciers, landslides, and flash floods that are a threat” for a mountain country like Bhutan. The Edit further says: “What we could do is prepare for the impending disasters. Adaptation and mitigation is the only way forward. Are we prepared? Is it a priority? As a country located in a fragile Himalayan ecosystem, we need to be more concerned about the impact of climate change.”

THE PROJECT The construction of the headworks complex of the 32 MW Yungichhu Hydropower Project (Head 506 m, design discharge of 7.46 cumecs[vi]) on Yungichhu River (a tributary of Kurichhu River, which in turn is a tributary of Drangmechhu, the biggest river basin of Bhutan) in Maedtsho Gewog in Lhuentse was inaugurated on Dec 7, 2022[vii]. The Headworks complex comprises the temporary water diversion, barrage, intake structures (elevation 1706 masl, catchment area 125 sq km) and desilting chambers that will divert and deliver water to the powerhouse for power generation. The construction is expected to complete in three years and project cost is estimated at Nu 3.5 Billions.

SANDRP (ht.sandrp@gmail.com)

Source: https://sandrp.in/2023/07/23/july-2023-bhutan-hydro-project-disaster-23-dead-and-missing/