How have Nepal’s floods impacted hydropower plants in Rasuwa?

In July 2025, a flood damaged or shut down all seven hydropower plants mapped below. All seven were running or under construction when a second flood hit them in August 2026.

Mitul IyengarLuke FioranteOct. 2, 2026 · 3 min read

On Aug. 26, 2026, a flood came down the Bhote Koshi (source: The Conversation, Sept. 1, 2026, opens in a new tab) in Nepal's Rasuwa district and washed away the Rasuwagadhi hydropower plant (source: The Kathmandu Post, Aug. 30, 2026, opens in a new tab). Nepal's disaster authority counted 1,451 dead and listed 5,745 people as missing (source: Nepal National Disaster Risk Reduction and Management Authority, Situation Report No. 20, Sept. 21, 2026, opens in a new tab) as of Sept. 21. It was the second flood to hit the plant in just over a year. Early on July 8, 2025, a lake on a glacier in Tibet drained into the same river (source: The Kathmandu Post, July 11, 2025, opens in a new tab) and severely damaged the plant's headworks (source: The Kathmandu Post, Dec. 7, 2025, opens in a new tab).

We wanted to understand what happened to the hydropower plants on this river between the two floods and the time it took to get each plant repaired and running again. We traced both floods down the river and followed the seven plants in their path. Use the arrows below, or click a date, to move through the timeline.

Before July 8, 2025 · 1 of 6

Five of the seven plants were running (source: Global Energy Monitor, Global Hydropower Tracker, March 2026, opens in a new tab): Rasuwagadhi, Chilime, Trishuli, Devighat and Upper Trishuli 3A. Upper Trishuli 1 and 3B were under construction.

Dec. 6, 2025 · 5 of 6

One of Rasuwagadhi's three units restarted (source: The Kathmandu Post, Dec. 7, 2025, opens in a new tab) at the repaired headworks, five months after the flood.

Aug. 26, 2026 · 6 of 6

Rock and ice broke loose (source: The Conversation, Sept. 1, 2026, opens in a new tab) near Langtang Lirung and sent a second flood down the same river. It hit all seven plants, as far down as Devighat, 77 kilometers from where it began. Rasuwagadhi was washed away and Chilime was buried (source: The Kathmandu Post, Aug. 30, 2026, opens in a new tab).

Before July 8, 2025 · 1 of 6

Five of the seven plants were running (source: Global Energy Monitor, Global Hydropower Tracker, March 2026, opens in a new tab): Rasuwagadhi, Chilime, Trishuli, Devighat and Upper Trishuli 3A. Upper Trishuli 1 and 3B were under construction.

  1. 1Rasuwagadhi 111 MW · running
  2. 2Chilime 22 MW · running
  3. 3Upper Trishuli 1 216 MW · under construction
  4. 4Upper Trishuli 3A 60 MW · running
  5. 5Upper Trishuli 3B 37 MW · under construction
  6. 6Trishuli 24 MW · running
  7. 7Devighat 14 MW · running
Plants the July 2025 flood hit: Rasuwagadhi, headworks severely damaged; Upper Trishuli 1, affected; construction suspended; Upper Trishuli 3A, dam gates damaged; Upper Trishuli 3B, affected; construction suspended; and Chilime, flooded through its tailrace. Shut down: Trishuli and Devighat. Plants the August 2026 flood damaged: Rasuwagadhi, completely washed away; Upper Trishuli 1, damaged; Upper Trishuli 3A, powerhouse and headworks lost; Upper Trishuli 3B, damaged; Trishuli, powerhouse and headworks lost; Devighat, powerhouse and headworks lost; and Chilime, buried.

A rapid hazard assessment of the Purepu lake, dated July 9, 2025, the day after the first flood, said the lake “still holds a lot of water” and that “recurring events are a possibility within 2025.” (source: Liu, Thapa and Steiner, Rapid Hazard Assessment Report CN1, July 9, 2025, opens in a new tab) It rated the likelihood of more outburst floods in the region, set off by heat, heavy rain, landslides or earthquakes, as relatively high, and called for closer monitoring and for China and Nepal to share information. It traced the flood to the border, but did not assess the hazard to the plants downriver.

We found no public assessment of the flood hazard at any of the seven plants before they restarted or construction resumed. We searched government, lender, company and court records, and news reports in English and Nepali, up to Sept. 29, 2026. The documents we did find describe damage and repairs. After the first flood, the Nepal Electricity Authority's executive director said Trishuli and Devighat had no significant damage and could restart after cleaning (source: Ratopati (Nepali), July 10, 2025, opens in a new tab). Upper Trishuli 1 has an independent panel of experts, which the Asian Development Bank requires. After a May 2025 site visit, two months before the first flood, the panel wrote that a climate resilience assessment it had recommended “was not launched yet.” (source: Asian Development Bank, Independent Panel of Experts report, May 2025, opens in a new tab)

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How we made this

Data

  • Global Hydropower Tracker, Global Energy Monitor, March 2026: each plant’s location, capacity and status. CC BY 4.0.
  • HydroRIVERS v1.0, Lehner & Grill 2013: the river network. Each flood line follows it downstream from where the flood’s sources say it began, to the farthest plant on this map that they report damaged. This product incorporates data from the HydroSHEDS version 1 database which is © World Wildlife Fund, Inc. (2006–2022) and has been used herein under license. WWF has not evaluated the data as altered and incorporated within this page, and therefore gives no warranty regarding its accuracy, completeness, currency or suitability for any particular purpose. Portions of the HydroSHEDS v1 database incorporate data which are the intellectual property rights of © USGS (2006–2008), NASA (2000–2005), ESRI (1992–1998), CIAT (2004–2006), UNEP-WCMC (1993), WWF (2004), Commonwealth of Australia (2007), and Her Royal Majesty and the British Crown and are used under license. The HydroSHEDS v1 database and more information are available at hydrosheds.org.
  • Terrain Tiles, AWS Open Data (Mapzen): the valley’s elevation, drawn with heights exaggerated 1.5 times. SRTM and GMTED2010 terrain data courtesy of the U.S. Geological Survey; ETOPO1, U.S. National Oceanic and Atmospheric Administration.
  • Damage, restarts and the record search: news reports in English and Nepali, the Nepal Electricity Authority, Nepal’s energy ministry, the Asian Development Bank and the Rasuwagadhi company, linked where they are cited above. Deaths and missing: Nepal’s disaster authority.

Tools

  • Processing: Python, openpyxl, pyshp, NumPy, Pillow, Matplotlib
  • Visualization: three.js, React