Nepal Lost a Tenth of Its Power Grid in Thirty Minutes

Here is the number that should have led every bulletin and mostly did not: 431 megawatts came off Nepal's grid on 26 August. The country has roughly 4,300 MW installed. So a single wave took out about a tenth of the national power supply in the time it takes to watch a sitcom.

Six facilities went down together — Rasuwagadhi, Chilime, Trishuli, Trishuli 3A, Trishuli 3B Hub and Devighat — because they are all strung along the same river. And another 470 MW still under construction was damaged too, which is next year's electricity, gone before it arrived.

Why six plants failed at once

They were not unlucky. They were adjacent.

Nepal builds hydropower where the water falls fastest, which means high, steep, glacier-fed rivers. The Bhote Koshi and Trishuli corridor is one of the best stretches in the country for it, so that is where the plants went, one after another down the same valley.

Which is fine, until the thing coming down the valley is not water.

The first two bars are shown against each other, not against the 4,300 MW total — at true scale they would be slivers, which hides the point rather than making it.

The debris was moving at about 180 km/h

A slab of glacier roughly 600 metres wide broke away and fell around 1,200 metres. Analysts put the debris speed at roughly 50 metres per second. That is 180 km/h, or motorway speed, made of ice and rock.

It dammed the Lhende Khola, held, and then let go. Downstream the Galchchi gauge rose nine metres in thirty minutes. Malekhu rose seven.

This exact thing happened in 1985

When Dig Tsho burst in the Khumbu in 1985, the flood destroyed a hydropower station at Thamo that had not yet been switched on. Fourteen bridges went with it.

Forty-one years later, a different lake, a different valley, and the same story: the power plants were on the glacier-fed river because that is where the power is, and the glacier-fed river is exactly where this happens.

Nobody has an easy answer to that. Nepal is not going to stop building hydropower — it is the one energy resource the country has in abundance, and it has spent a decade climbing out of the load-shedding years. But siting six plants down one glacial corridor turns a single upstream event into a national one.

So what does this mean for your trek? Genuinely, not much

We are a trekking company and we would rather tell you the boring truth than a scary one.

The power story is real and it is a national headache — expect some load-shedding pressure this winter while repairs run. But it is a grid story, not a trail story. Teahouses in the Annapurna and Everest regions run on local micro-hydro and solar, and were never on these lines.

Annapurna and Everest were untouched by the flood and are running normally this autumn. Langtang is the one to avoid for now, because its access road goes through the valley that got hit.

Open right now · Annapurna & Khumbu