Landslide-formed lake overflows on Nepal-China border, halting rescue efforts

A lake formed by a landslide on the Nepal-China border began overflowing on Friday, threatening areas already devastated by this week's flash floods and halting rescue efforts, authorities said.

"We have received a notice saying that the lake has broken its banks," Narendra Pariyar, the most senior bureaucrat of the hard-hit Rasuwa district, told DW. "We can see that the level of water in the river is rising."

Residents in Nepal's border district of Rasuwa were seen fleeing up hillsides as they braced for a surge in river levels, Reuters reported.

Due to the risk of the lake bursting, all Chinese rescue personnel were told to withdraw to a safe area, state broadcaster CCTV said. Nepal authorities also paused rescue operations for the next 90 minutes, an army official told Reuters.

Rescuers have been racing to find hundreds of people still missing, two days after a catastrophic flash flood struck the Himalayan border between Nepal and China.

Nepal police said Friday morning the country's death toll had risen to 469, up from 390 a day earlier. China has updated its earlier count of three to five deaths in Tibet. The two countries said more than 1,000 people remained missing, including as many as 540 foreigners from more than 30 countries.

What is the latest update from China?

Wednesday's disaster, triggered by a glacial collapse that sent rock and meltwater surging into rivers below, left a new danger in its wake: a barrier lake formed upstream by debris dams.

China's Ministry of Water Resources said the lake held roughly 2 million cubic meters of water as of Thursday and was expected to receive another 3 million cubic meters — equivalent to about 1,200 Olympic swimming pools — over the following three days, with peak flow expected around September 1.

Chinese national broadcaster CCTV said the lake's barrier sat more than 10 kilometers (6.2 miles) from Gyirong Port, the border crossing that was engulfed by the initial flood, and is at an elevation roughly 1,000 meters (3,280 feet) above it.

The country had mobilized an eight-member engineering team to survey the lake by air and build 3D models of the site. Engineer Chen Hanxiao described the difficulty of the terrain: "After the glacier collapse created the lake, many isolated cliffs and steep cliffs appeared along it," he told CCTV.

He said the team's general strategy was to dig a drainage channel at a lower point of the dam, though the channel's exact width and depth would depend on calculations of water flow and how quickly the lake continued to fill.

Their survey found the lake to be about 150 meters long and 40-50 meters deep. Continuing rain in the area, which is forecast to last through the coming week, has further destabilized the surrounding soil and rock.

What did Nepal say about search and rescue?

Nepal's Foreign Ministry said Friday it does not need foreign assistance for search-and-rescue operations, despite offers of help from several countries with nationals still missing.

Foreign Ministry spokesperson Lok Bahadur Chhetri said Nepal's security agencies were managing the response.

"The offer for help is natural. Our security agencies are doing the search and rescue operation. For now we don't require such help," he said.

Hundreds of foreign nationals remain unaccounted for, including from South Korea, which has already sent a response team and plans to dispatch a disaster relief unit. South Korea's Foreign Ministry confirmed that Nepal had indicated it was not yet ready to accept foreign rescue teams, adding, "South Korea will keep negotiating with Nepal over the matter."

Seoul has pledged $1 million (€860,000) in humanitarian aid through international organizations, after reporting nine of its nationals missing and 10 stranded after a hydropower plant they were working at was hit by the flood.

According to local media, India, China, the United States, Britain, Japan, South Korea, Sri Lanka and Bangladesh have all asked Nepal's government for permission to send their own search-and-rescue teams to assist.