Question: What river required for hydroelectric power is located in the country whose political system was based on hereditary monarchies , or dynasties for millennia ?

text: List of largest hydroelectric power stations
List -- Under construction
This table lists stations under construction with expected installed capacity at least 2,000 MW .
This article provides a list of the largest hydroelectric power stations by generating capacity. Only plants with capacity larger than 2,000 MW are listed. The Three Gorges Dam in Hubei, China, has the world's largest instantaneous generating capacity (22,500 MW), with the Itaipu Dam in Brazil/Paraguay in second place (14,000 MW). Despite the large difference in installed capacity these two power stations generate nearly equal amounts of electrical energy during the course of an entire year - Itaipu 103.1 TWh in 2016 and Three Gorges 98.8 TWh in 2014, because the Three Gorges experiences six months per year when there is very little water available to generate power, while the Paraná River that feeds the Itaipu has a much lower seasonal variance in flow. Energy output of the Three Gorges reaches 125 TWh in years of high feed availability. The Three Gorges (22,500 MW - 32 × 700 MW and 2 × 50 MW) is operated jointly with the much smaller Gezhouba Dam (2,715 MW), the total generating capacity of this two-dam complex is 25,215 MW. The Itaipu on the Brazil-Paraguay border has 20 generator units with overall 14,000 MW of installed capacity, however the maximum number of generating units allowed to operate simultaneously cannot exceed 18 (12,600 MW). The Jinsha River (the upper stream of Yangtze River) complex is the largest hydroelectric generating system currently under construction. It has three phases. Phase one includes four dams on the downstream of the Jinsha River. They are Wudongde Dam, Baihetan Dam, Xiluodu Dam, and Xiangjiaba Dam, with generating capacity of 10,200 MW, 16,000 MW, 13,860 MW, and 6,448 MW respectively. Phase two includes eight dams on the middle stream of the Jinsha River.
Name Country River Expected capacity ( MW ) Expected completion Location
Baihetan China Jinsha 16,000 2021-2022 28°15′06″N 103°39′34″E / 28.25167°N 103.65944°E / 28.25167 ; 103.65944 ( Baihetan Dam )
Wudongde China Jinsha 10,200 2020 -2021 26°20′02″N 102°37′48″E / 26.33389°N 102.63000°E / 26.33389 ; 102.63000 ( Wudongde Dam )
TaSang Myanmar Salween 7,110 ? ? ( on hold ) 20°27′23″N 98°39′0″E / 20.45639°N 98.65000°E / 20.45639 ; 98.65000
Ethiopian Renaissance Ethiopia Blue Nile 6,450 2020-2022 11°12′51″N 35°05′35″E / 11.21417°N 35.09306°E / 11.21417 ; 35.09306 ( Grand Ethiopian Renaissance Dam )
Diamer-Bhasha Dam Pakistan Indus River 4,500 2023 35°31′08″N 73°47′10″E / 35.51889°N 73.78611°E / 35.51889 ; 73.78611 ( Diamer-Bhasha Dam )
Dasu Dam Pakistan Indus River 4,320 2023 35°31′10″N 73°44′21″E / 35.51944°N 73.73917°E / 35.51944 ; 73.73917 ( Dasu Dam )
Rogun Tajikistan Vakhsh 3,600 2018-2029 38°41′03″N 69°46′26″E / 38.68417°N 69.77389°E / 38.68417 ; 69.77389 ( Rogun Dam )
Myitsone Myanmar Irrawaddy 3,600 ? ? ( on hold ) 25°41′23″N 97°31′04″E / 25.68972°N 97.51778°E / 25.68972 ; 97.51778
Mambilla Nigeria Donga 3,050 2024 07°09′44″N 10°34′17″E / 7.16222°N 10.57139°E / 7.16222 ; 10.57139 ( Mambilla Power Station )
Lianghekou China Yalong 3,000 2021-2023 30°09′46″N 101°00′49″E / 30.16278°N 101.01361°E / 30.16278 ; 101.01361 ( Lianghekou Dam )
Ituango Colombia Cauca 2,456 2021 ( ? ) 7°05′03.6″N 75°41′16.8″W / 7.084333°N 75.688000°W / 7.084333 ; -75.688000 ( Hidroituango )
Tocoma Venezuela Caroní 2,320 ? ? ( on hold ) 27°33′13″N 94°15′31″E / 27.55361°N 94.25861°E / 27.55361 ; 94.25861 ( Tocoma Dam )
Maerdang China Yellow 2,200 2020 ( ? ) 34°40′21″N 100°41′32″E / 34.67250°N 100.69222°E / 34.67250 ; 100.69222 ( Maerdang Dam )
Caculo Cabaça Angola Cuanza 2,172 2024 9°41′01″S 14°58′56″E / 9.68361°S 14.98222°E / -9.68361 ; 14.98222 ( Caculo Cabaça Dam )
Koysha Ethiopia Omo 2,160 2021 6°27′36″N 36°20′24″E / 6.46000°N 36.34000°E / 6.46000 ; 36.34000 ( Koysha Dam )
Lauca Angola Cuanza 2,069.5 2017-2020 9°44′34.9″S 15°07′32.2″E / 9.743028°S 15.125611°E / -9.743028 ; 15.125611 ( Lauca Dam )
Shuangjiangkou China Dadu 2,000 2020 ( ? ) 31°47′29″N 101°56′03″E / 31.79139°N 101.93417°E / 31.79139 ; 101.93417 ( Shuangjiangkou Dam )
Subansiri India Subansiri 2,000 ? ? ( on hold ) 27°33′13″N 94°15′31″E / 27.55361°N 94.25861°E / 27.55361 ; 94.25861 ( Subansiri Lower Dam )