Mega-Dams: Clean Power or a Dangerous Bet?
On 19 July 2025, China's premier Li Qiang broke ground on the Medog hydropower project, on the Yarlung Tsangpo's Great Bend in Tibet - a machine designed to generate roughly three times as much power a year as the Three Gorges Dam, which is already the largest power station on Earth.
This video explains how a dam actually makes power - head, flow, the penstock, the turbine, the spillway - and why hydropower's dispatchable, fast-ramping, long-lived output makes it the plant a grid calls first. It follows the twentieth century's age of big dams (Hoover, Grand Coulee, the Tennessee Valley Authority), and the two disasters that rewrote how the world builds dams: Vajont, Italy, 1963 (close to 2,000 dead when a landslide sent a wave over a dam that itself never failed) and Banqiao, China, 1975 (as many as 230,000 dead when a typhoon overwhelmed a spillway and triggered a chain-reaction failure of 61 more dams).
It sets China's existing Three Gorges Dam - 22.5 gigawatts, a 600km reservoir, 1.3 million people relocated - against two other rivers that cross borders, the Nile and the Mekong, before returning to Medog itself: five cascade power stations, about 60 gigawatts, roughly 300 terawatt-hours a year, built in a gorge that produced the largest inland earthquake ever instrumentally recorded, in 1950, and a magnitude 6.9 earthquake in 2017 that triggered over 1,800 landslides on its own.
Downstream in India, the Siang Upper Multipurpose Project is India's answer - and, in the final days of September 2026, the site of clashes between villagers and security forces at Geku. The video closes by weighing hydropower's genuine case (still 14% of world electricity, not likely to shrink before 2030) against the specific, unresolved risk of building at Medog's scale on ground with Medog's history.
Educational documentary. Not financial or investment advice.
In these topics
Tags
Sources and credits
Photo credits (Wikimedia Commons)
- Li Qiang, Chinese Premier (with US Treasury Secretary Yellen, Jul 2023): Office of U.S. Treasury Secretary, Public domain - https://commons.wikimedia.org/wiki/File%3AChinese_Premier_Li_Qiang_with_Yellen_Jul_2023.jpg
- Hoover Dam under construction, intake towers, 27 Sep 1934: National Archives, Herbert Hoover Presidential Library and Museum, Public domain - https://commons.wikimedia.org/wiki/File%3AConstruction_Intake_Towers_Hoover_Dam_1934.jpg
- Grand Coulee Dam under construction, March 1938: U.S. Bureau of Reclamation, Public domain - https://commons.wikimedia.org/wiki/File%3AGrand_Coulee_Dam_construction.jpg
- Norris Dam powerhouse under construction, TVA, Clinch River, Tennessee, 1930s: Tennessee Valley Authority, Public domain - https://commons.wikimedia.org/wiki/File%3ANorris-dam-construction-tva3.jpg
- Longarone destroyed by the Vajont wave, 10 Oct 1963 (US Army): US Army, Public domain - https://commons.wikimedia.org/wiki/File%3ALongarone_1963.jpg
- Vajont Dam today, seen from Erto e Casso: Andre86, Public domain - https://commons.wikimedia.org/wiki/File%3AVajont_Dam.jpg
- Three Gorges Dam on the Yangtze, ASTER satellite image: NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team, Public domain - https://commons.wikimedia.org/wiki/File%3AThree_Gorges_Dam%2C_China_%28ASTER%29.jpg
- Grand Ethiopian Renaissance Dam, aerial view, Aug 2024: Prime Minister Office Ethiopia, Public domain - https://commons.wikimedia.org/wiki/File%3AGERD_Dam.jpg
- Yarlung Zangpo Grand Canyon and Namcha Barwa, Tibet, satellite image: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team, Public domain - https://commons.wikimedia.org/wiki/File%3AYarlung_Zangpo_Grand_Canyon%2C_Tibet.jpg
- Brahmaputra River in eastern India at the foot of the Himalayas, ISS photo: NASA Johnson Space Center, Public domain - https://commons.wikimedia.org/wiki/File%3AThe_Brahmaputra_River_in_eastern_India_at_the_foot_of_the_Himalayas_%28iss072e397228%29.jpg
Primary sources
- Xinhua, 19 July 2025, and Bloomberg, 'China Kicks Off Controversial Mega-Dam Project in Tibet,' 19 Jul 2025 - Medog groundbreaking, Li Qiang's role, cost figure and verbatim quote.
- Newsweek, 'China's project of the century,' Jul 2025; ABC News Australia, 22 Jul 2025 - 'project of the century' framing.
- Wikipedia, 'Medog Hydropower Station,' fetched 29 Sep 2026 - capacity, output, cost, timeline and Paizhen Fault cross-checks.
- The Diplomat, 'What's Driving China's Mega Medog Hydropower Project?,' Feb 2026; the 2033 completion date it is cited for is corroborated independently via Wikipedia and Newsweek.
- Tennessee Valley Authority - TVA founding and mission, 1933.
- ASDSO/damfailures.org, 'Vajont Dam (Italy, 1963)' and 'Banqiao Dam (China, 1975)' case studies, both fetched directly 29 Sep 2026.
- Human Rights Watch, 'The Three Gorges Dam in China,' 1995 - Banqiao's wider death-toll estimate.
- China Three Gorges Corporation, 'China's Three Gorges dam generates 1,600 TWh of power in 20 years,' 2023-24 - capacity, output, reservoir length, resettlement figure.
- International Hydropower Association, World Hydropower Outlook 2025 - hydropower's share of world electricity and dispatchable/ramping characteristics.
- IEA, Renewables 2025 - hydropower forecast share to 2030.
- Webuild GERD inauguration press release, 9 Sep 2025; Al Jazeera/France24, 9 Sep 2025 - GERD inauguration date and status.
- Stimson Center, 'Analysis of Hydropower Impacts in the Mekong's 3S Basin,' 2023 - Mekong dam counts and downstream impacts.
- GeoLog/EGU, 'The 1950 Assam-Tibet Earthquake: a singular Himalayan earthquake on its 75th anniversary,' Aug 2025.
- NHPC pre-feasibility reporting on the Siang Upper Multipurpose Project, via MyInd/vajiramandravi/Insights on India, 2022-2026.
- Arunachal Observer, 'Villagers & security forces clash at Geku over SUMP,' 30 Sep 2026; NE Now and Hub Network corroboration, 28-30 Sep 2026.
- Hub Network, 'Siang Project: Khandu assures community consultations amid Geku clashes,' 29-30 Sep 2026 - paraphrased, not quoted verbatim, per requirement 7.
Not regulated financial advice.