Where have hydropower plants been built along the rivers of the Ganges basin?
After the August 26, 2026 flood in Nepal’s Rasuwa district, experts are again questioning whether developers properly assessed the risks of building hydropower in the Himalayas (NPR). The concerns highlight the need to consider the cumulative impact of the construction of multiple plants on a river, rather than a single plant alone. Retired Indian ambassador Shyam Saran told NPR that developers usually assess the risks their project could cause and the risks it faces, and on those terms each project looks safe. “But if you do actually a cumulative environmental impact assessment of the whole river system,” he said, “then a different picture emerges.”
While there is no clear evidence that building the plants made the August flood worse, experts say the risks of building so many plants on the same river have not been properly studied. Parineeta Dandekar of the South Asia Network on Dams, Rivers and People told NPR that the World Bank’s risk assessment for the Upper Trishuli-1 project ignored “the cumulative disaster risk that can happen after having so many projects across the same river.” Geoscientist C.P. Rajendran warned that what happened in Nepal could happen in other parts of the range.
These warnings made us want to learn more. After we looked at how Nepal’s recent floods hit the hydropower plants of the Rasuwa valley (our previous Noodle), we zoomed out to the whole Ganges river basin, where 186 hydropower plants of 10 megawatts or more are running or under construction on 91 rivers. The timeline below shows the 20 rivers with the most plants, when they were built, which have been affected by hazards, and where more are planned.
Shown: 20 rivers of the Ganges basin with the most 10+ megawatt plants (built or under construction). Planned plants also shown but not counted in ranking. Positions of plants are approximate. Sources
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Data
Plant locations, capacities and statuses are from Global Energy Monitor’s Global Hydropower Tracker and the registers of Nepal’s Department of Electricity Development and India’s Central Electricity Authority. Rivers are from HydroRIVERS. Floods, earthquakes and landslides are from post-disaster assessments, official records and news reports. We merged these sources into one inventory of 1,752 hydropower plants across the Himalayas. Where the sources disagree on a plant’s capacity or status, we used the official register’s value.
- Global Hydropower Tracker, March 2026 (Global Energy Monitor, CC BY 4.0): projects of 30 megawatts or more, and a separate table of projects of 10 to 30 megawatts. Plants with incorrect coordinates, or coordinates shared by several projects, are ignored.
- Department of Electricity Development, Nepal: one register per stage of project. We assign a plant’s status according to the register on which it is found. The operating plants register gives each plant’s commercial operation date. The generation licence register lists projects licensed but not yet operating, and the application register lists projects that have applied for one. We also read the survey licence and cancelled licence registers, which are not shown as plants. Each register gives licence dates and the corners of each licence area. Dates are listed in the Bikram Sambat calendar, which we converted to the Gregorian calendar. Capacity and status for some operating plants are from the department’s royalty management system. Nepal Electricity Authority, A Year in Review FY2025/26: plants under construction, which the department does not list separately.
- Central Electricity Authority, India: station list, Hydro Performance Reviews (commissioning years, unit outages) and project-pipeline reports. WRI Global Power Plant Database v1.3 (CC BY 4.0) for some Indian plants’ capacity and status. Central Water Commission, National Register of Large Dams 2019 (archived copy), for one dam’s location.
- Hazards: post-disaster assessments (Nepal 2015, Uttarakhand 2013), Central Electricity Authority reports, the Glacier Lake Outburst Flood Database v3.1 (CC BY 4.0), news reports and research papers. The tooltips link the source for each event.
- HydroRIVERS v1.0 (Lehner and Grill, 2013): river network. Each river line follows the longest path upstream. One line may include two named rivers. If a river is labeled with multiple names across records, the most popular is used here. 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.
- Plant locations. Each plant is placed on the nearest river line within 3 kilometers of its coordinates, or within 8 km when the tracker marks the coordinates as approximate. In Nepal, if a plant’s licence names a river within 10 km, the plant is placed on that river. Most Nepal plants have no point coordinates, only a licence area, typically 2 to 9 km across. These plants are placed at the midpoint of the river stretch inside the licence area. Their positions may be off by several kilometers.
- Ranking. Rivers are ranked by their plants of 10+ megawatts that are running or under construction. Planned projects are not counted. A plant on a tributary counts toward the tributary only.
- Planned. A project counts as planned if it has a generation licence or a licence application in Nepal, a concurrence from India’s Central Electricity Authority, a state allotment in India, or an announced or pre-construction listing in the Global Hydropower Tracker. Survey licences are not counted. A planned project hit by a flood, earthquake or landslide is shown as under construction from the date of the hit.
Data as of 2026-10-14.
Tools
- Processing: Python, with Shapely, pyshp, openpyxl, nepali-datetime and Beautiful Soup
- Visualization: React