Upper Siang Hydroelectric Project
{{short description|Hydroelectric project in Upper Siang, Arunachal Pradesh, India}}
{{Use dmy dates|date=July 2018}}
{{Use Indian English|date=July 2018}}
{{Infobox dam
| name = Upper Siang Multipurpose Project
| image =
| image_caption =
| name_official =
| dam_crosses = Siang River
| location = Upper Siang district, Arunachal Pradesh
| country = India
| dam_type =
| dam_length =
| dam_height =
| dam_width_base =
| spillway_type =
| spillway_capacity =
| construction_began = 2028
| opening = 2032 (Expected)
| status = Pre-construction works
| owner = Government of Arunachal Pradesh
| operator = NHPC
| res_name =
| res_capacity_total = 320 tmcft
| res_capacity_active =
| res_capacity_inactive =
| res_catchment =
| res_surface =
| res_max_depth = 300 meters
| plant_operator = NHPC
| plant_turbines =
| plant_capacity = 11,000 MW (under construction){{cite web|url=https://www.natstrat.org/articledetail/publications/upper-siang-hydroelectric-project-key-to-prosperity-in-arunachal-pradesh-99.html|title=Upper Siang Hydroelectric Project – Key to Prosperity in Arunachal Pradesh |access-date=11 June 2025}}
| plant_annual_gen = 47 billion kWh
| plant_commission = 2032
| plant_decommission =
| purpose = Hydroelectric & Flood control
| coordinates = {{coord|28.6921|N|95.0443|E|type:landmark|display=inline,title}}{{cite web|url=https://www.gem.wiki/Siang_Upper_hydroelectric_plant|title=Siang Upper hydroelectric plant |access-date=11 June 2025}}
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The Upper Siang Hydroelectric Project, also known as the Upper Siang Multipurpose Project or Siang Upper Multipurpose Project (SUMP) is the biggest hydroelectric power project planned in the Upper Siang district of Arunachal Pradesh, India. Projects planning was commenced by the National Hydroelectric Power Corporation (NHPC) in April 2009 and various hydro dams will be constructed in phases over a span of 15–20 years.[http://www.expressbuzz.com/edition/story.aspx?Title=India+pre-empts+Chinese+design+in+Arunachal&artid=3CoV5eK0GKk=&SectionID=b7ziAYMenjw=&MainSectionID=b7ziAYMenjw=&SEO=DPR,+Siang+river&SectionName=pWehHe7IsSU= India pre-empts Chinese design in Arunachal]
The main dam is being constructed across the Siang river and upon completion, the dam reservoir will hold 9 billion cubic meters of water. The hydro power project at Siang will alone generate approximately 11,000 MW, making it the largest hydroelectric dam in the Indian Subcontinent.[https://web.archive.org/web/20110526054814/http://www.telegraphindia.com/1090402/jsp/northeast/story_10760784.jsp Dam shield against river threat - Arunachal nod to project]
Concerns
=Floods=
In 2006, Indian media reported that the NHPC was planning to relocate and scale down the project due to concerns on flooding upstream by Chinese government.[http://www.thehindubusinessline.com/2006/03/24/stories/2006032401830500.htm Upper Siang project likely to be relocated on Chinese concerns] However, the situation has reversed due to construction of many tall dams/massive storage reservoirs in the river basin area effecting river's natural flow regime in downstream India.
In 2025, NHPC is conducting pre-feasibility studies for site selection.{{Cite web |date=11 June 2025 |title=NHPC to fast-track site selection for Upper Siang hydropower project|url=https://www.projectstoday.com/News/NHPC-to-fast-track-site-selection-for-Upper-Siang-hydropower-project |access-date=11 June 2025|language=en}} The height of the dam is nearly 300 meters above the river bed level at dam location to store water up to 750 m MSL.{{Cite web |date=19 March 2025 |title=Part III: The Upper Siang Project|url=https://www.natstrat.org/articledetail/publications/the-upper-siang-project-189.html |access-date=11 June 2025|language=en}}{{Cite web |date=17 February 2025 |title=How data deficiency is hindering hydro-diplomacy between China and India |url=https://india.mongabay.com/2025/02/commentary-how-data-deficiency-is-hindering-hydro-diplomacy-between-china-and-india/ |access-date=11 June 2025|language=en}} The back waters of the reservoir would touch the foot of the Medog Hydropower Station (60,000 MW) being constructed on the upstream river in Tibet/China so that adequate flood buffer is maintained to safely discharge the peak floods arising out of upstream dam failures due to earthquakes, Glacial Lake Outburst Floods and massive land slides.{{cite web|url=https://www.projectstoday.com/News/NHPC-to-fast-track-site-selection-for-Upper-Siang-hydropower-project#:~:text=The%20proposed%20Rs%2011.2%20GW%20Siang%20Upper%20Multipurpose,a%20site%20amidst%20protests%20by%20villagers%20facing%20displacement.|title=NHPC to fast-track site selection for Upper Siang hydropower project |access-date=11 June 2025}} This reservoir acts as a regulating basin to release the continuous flows downstream according to the river flow regime when the water released from the upstream mega power station in China is regulated or intermittent as per the needs of power generation on daily and weekly basis.{{cite web|url=https://arunachalobserver.org/2025/01/13/china-to-come-to-its-knee-as-india-plans-siang-dam-mein/|title=China to come to its knee as India plans Siang Dam: Mein |access-date=11 June 2025}}
The state government of Arunachal Pradesh signed deals with various Indian power companies to develop hydro projects. A total of 42 schemes are planned to generate electricity in excess of 27,000 MW with the Upper Siang project being one of them.[http://www.indiatogether.org/2008/feb/env-arunachal.htm Massive dam plans for Arunachal]
=Environmental impact=
In 2010, a student body appealed to India's Environment Ministry to scrap various hydroelectric projects (including Siang project) in Assam and Arunachal Pradesh due to potential adverse environmental impact.[http://www.dnaindia.com/india/report_students-body-asks-jairam-ramesh-to-reconsider-setting-up-of-hydro-projects_1436827 Students body asks Jairam Ramesh to reconsider setting up of hydro projects] However, the Ministry remarked that though the projects will not be cancelled, necessary precautions will be undertaken to ensure minimal environmental impact.[https://web.archive.org/web/20121021222900/http://www.sify.com/news/assam-dam-project-may-continue-jairam-ramesh-news-national-kimpEcidiaa.html Assam dam project may continue: Jairam Rames]
References
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External links
{{stack|{{Portal|India|Water|Renewable energy}}}}
- [https://web.archive.org/web/20090904154449/http://www.arunachalbhawan.com/hydro.htm HYDRO POWER PROJECTS IN ARUNACHAL PRADESH]
{{Power Plants of North-east India}}
Category:Hydroelectric power stations in Arunachal Pradesh
Category:Dams in Arunachal Pradesh