Satellite Images Reveal Devastating Flood in Nepal’s Trishuli Valley

A glacier collapse on the rugged border between Nepal and Tibet sent a torrent of water and mud down the Trishuli River on Wednesday, leaving a path of destruction that stretched more than 45 kilometres downstream.

Satellite images from the U.S.‑based intelligence firm Vantor show villages, bridges and a hydroelectric power station washed away. The high‑resolution before‑and‑after shots reveal a valley that once hugged stone and tree, now dotted with mud‑filled holes and collapsed infrastructure.

According to Nepalese officials, the disaster killed more than 550 people and left thousands missing. One of the hardest‑hit sites was a Nepal–Tibet border crossing where the floodmates remained visible in CCTV footage as the rushing water swept through streets and buildings.

Satellite data also capture the glacier itself: a massive chunk has detached, creating a large cloud of rock and debris that redirected the flood velocity. The base of the landslide stretches up to 300 metres above the riverbed and has sliced through vegetation, leaving a stark canyon‑like scar.

Further downstream, the Trishuli River carried flooding debris past the village of Trishuli, covering the town in mud and leaving houses and bridges collapsed. A barrier lake formed at the landslide’s tail; Chinese authorities warn of a high risk of the lake breaching, which could trigger a second flood wave.

Glaciologist Dr. Argha Banerjee, who studied the images, said the lake’s surface area has not increased between Wednesday and Thursday, but the drainage channel was already visible, suggesting some water was escaping downstream. The volume of the lake is not alarmingly large but remains a concern for rescuers as they navigate the valley.

Because the Tibetan side of the border is heavily restricted, detailed damage there is still unclear. Nevertheless, the satellite images give aid authorities a clearer landscape for search and rescue operations and for locating missing survivors.

In the aftermath, the Vantor Open Data Program released these images to help local and international responders target the most affected areas and to accelerate recovery. Rescue teams are now huddling over waterlogged maps to plan routes to the villages of Timure, Trishuli and other downstream communities that were hit hardest.

For those who fled the border crossing the day before the flood, the videos show people trying to escape as water surged over bridges and streets, while survivors cling to houses that survived the onslaught. The images and footage serve as a sobering reminder of the accelerating threat of glacier‑melt induced disasters amid a warming climate.