Around 8:40 on the morning of August 26, a section of glacier collapsed on the north side of the Langtang range, near Nepal’s border with Tibet, three minutes after a magnitude 4.4 earthquake on the Chinese side. The impact registered as a magnitude 5.2 seismic event, which the U.S. Geological Survey initially logged as a separate earthquake before concluding it was the landslide itself. Scientists say warming likely helped trigger the glacier’s collapse. 

The debris entered the Lhende Khola, a small river that crosses into Nepal. It blocked the river roughly 20 kilometers upstream from the China-Nepal border crossing at Rasuwagadhi. When the blockage eventually broke, water levels in the Trishuli River surged by as much as nine meters in just 30 minutes. 

It is now the deadliest flood disaster on record in Nepal. The confirmed death toll stood at 987 in Nepal as of the morning of September 2, with 16 more dead in Tibet. Roughly 4,500 people remain missing on both sides of the border. Among them are hydropower workers, customs and immigration staff, security personnel, trekking guides, and some 700 foreign nationals, including pilgrims bound for Mount Kailash. 

According to UNICEF, 17,000 children are affected, 18 schools were destroyed, and 20 more damaged. The government’s preliminary damage estimate is 200 billion rupees ($1.3 billion). 

I was born in Nepal, and I study the economics of natural disasters, including floods in Nepal. All my experience and expertise suggests that these numbers – both deaths and damage – are going to keep going up.

But there is an aspect of the damage that isn’t being included in the counts: the opportunity cost of a broken trade connection.

On July 8, 2025, a supraglacial lake burst upstream in Tibet and sent a flood down the same river. It destroyed the Miteri Bridge linking Nepal and China, wrecked a dry port still under construction at Timure, and killed nine people. Before the flood, roughly a hundred container trucks crossed at Rasuwagadhi each day. Afterward, trade stopped entirely, and did not resume until the first day of 2026.

The closure from the flood lasted for almost six months, causing significant damage far beyond the cost of repairing the bridge. In the six months following the 2025 flood, trade through Rasuwagadhi fell 95 percent, from $302 million to $15 million, according to an analysis of Nepal’s own customs accounts by the Stimson Center. A fraction of that trade was redirected to Kora La, a crossing at roughly 4,650 meters of elevation in Upper Mustang that clears two or three cargo vehicles on a good day. Every dollar that arrived there came alongside roughly $3.30 lost at Rasuwa. The rest of Nepal’s trade went south, to India.

The bridge was eventually rebuilt, and the crossing reopened. But the trade was shut for half a year. Now it is destroyed again, along with the customs buildings on both sides, 19 road bridges and 40 kilometers of road. How long will take to resume trade this time?

Even worse, as of last month, before the August 26 flood, not one of Nepal’s three crossings with China was fully operational.

A trade route that shuts down for six months (or more) every year or two is not one an importer builds a business around, however good the bridge looks the day it reopens. And the cost of these repeated disruptions is being borne by the local community.

I saw this myself a few years ago. Studying a flood in Nepal’s southern plains, my co-authors and I found that the official damage assessment had missed most of what happened. Wages did not simply fall; they changed form, as employers with no cash began paying agricultural laborers in grain. Cash wages dropped 9 to 10 percent. Households borrowed more, taking on about 16,000 rupees each in new debt. All of this continued for roughly a year after the flood ended. 

Nepal is a landlocked country with two neighbors, China and India – and the latter closed its border on Nepal in 2015. Ever since, Kathmandu has been working to develop infrastructure links with China, to provide a second option for trade. 

The 2015 Gorkha earthquake effectively ended the old Tatopani route, and Rasuwagadhi became the main northern gateway almost by default. By 2024 the crossing at Gyirong – China’s side of the border with Rasuwa – was handling about $604 million in trade, close to a third of everything moving between Nepal and China.

Rasuwa was still rebuilding from that earthquake 11 years ago. Families it had displaced were resettled on the low banks of the Trishuli River; one such community of 250 households was swept away entirely last week. 

The flood also destroyed the 111-megawatt Rasuwagadhi hydropower project outright and knocked more than 430 megawatts off Nepal’s grid – over a tenth of national capacity. 

This doesn’t mean Nepal was wrong to build in the area. A landlocked country does not get to relocate its trade routes, and a country with Nepal’s rivers has every reason to build hydropower on them. But three of our assumptions need fixing

First, we can’t treat these recurring events as freak, one-off disasters. The same tributary has now produced a catastrophic flood twice in 14 months, and scientific evidence points out that 144 of 545 glacial lakes along the China-Nepal trade corridors are highly susceptible to outburst floods. Rebuilding to a hundred-year standard drawn from the old record is simply not good enough. The risks have changed. 

Second, Nepal needs to build flood warning systems that watch for more than rain. Nepal’s meteorological service reported no significant rainfall in the area before the flood, as was true last July. But a warning was possible: German geoscientists even recorded the glacial collapse roughly seven minutes before floodwater reached the border. Sirens will not stop an avalanche, but they do help move people off a valley floor in the interval between the slope failing and the water arriving. 

After the 2025 flood, Nepal and China agreed to share information on glacial lake risk across the Tibetan plateau. Clearly, there is work to be done linking upstream monitoring systems with warning mechanisms downstream.

Finally, Nepal keeps asking how to rebuild infrastructure when the question is how often it will close. The influx of aid in the wake of disasters like these is meant to rebuild a bridge, a customs building, a transmission line, or a school. While aid inflows can restore these assets, they do not instill confidence that they will stay open amid repeating disasters. 

Until traders can buy insurance that will cover lost income during the months a border stays shut – not just for the goods a flood destroys – Nepal risks losing the trade along this corridor. Nepal will rebuild the bridges. What it cannot rebuild is the confidence that the road will stay open – and that is what trade is really built on.