Tuyamuyun Hydro Complex

THC Main Dam
Official name	Tuyamuyun Hydroengineering Complex
Country	Uzbekistan/Turkmenistan
Location	Turtkul District, Republic of Karakalpakstan/Dasoguz, Lebap Region
Coordinates
Purpose	Irrigation, power
Status	Operational
Construction began	1969
Opening date	1983 (1983)
Dam and spillways
Type of dam	Gravity
Impounds	Amu Darya River
Height	25 m (82 ft)
Length	141 m (463 ft)
Reservoir
Creates	Channel Reservoir
Total capacity	2,300,000,000 m3 (1,900,000 acre⋅ft)
Surface area	303 km2 (117 mi2)
Maximum length	102 km (63 mi)
Normal elevation	130 m (430 ft)
Power Station
Commission date	1983
Turbines	6 x 25 MW
Installed capacity	150 MW
Annual generation	571 GWh

The Tuyamuyun Hydro Complex (THC) is a system of four interconnected reservoirs and a series of canals on the lower Amu Darya River, bordering Uzbekistan and Turkmenistan. Its primary purpose is to provide water for irrigation in Xorazm, Karakalpakstan and Daşoguz regions of Uzbekistan, Turkmenistan and as far north as Kazakhstan. The complex is located about 74 km (46 mi) southeast of Urgench in Xorazm Region, Uzbekistan and about 2 km (1.2 mi) north of Gazojak in Lebap Region, Turkmenistan. It was constructed between 1969 and 1983. Aside from irrigation, the complex also provides water for industrial and municipal uses. A 150 MW power station on the main dam contains six 25 MW hydroelectric turbine-generators.

The main dam (THC Main Dam) is located on the Amu Darya, straddling the border of Uzbekistan and Turkmenistan. It is the center-piece of the complex. The main dam is a 141 m (463 ft) long and 25 m (82 ft) high gravity dam. It creates the Channel Reservoir which has a storage capacity of about 2,300,000,000 m³ (1,900,000 acre⋅ft) and length of 102 km (63 mi). Water from the Channel Reservoir can be fed into the adjacent Kaparas and Sultansanjar Reservoirs for later use. The Sultansanjar Reservoir is connected via a canal to the Koshbulak Reservoir which lies just east. When first completed, all four reservoirs had a capacity of about 7,800,000,000 m³ (6,300,000 acre⋅ft) but due to silt build-up, this had been reduced to about 6,700,000,000 m³ (5,400,000 acre⋅ft) by 2001.

A system of canals off the main dam supply a network of irrigation canals to the various regions for irrigation. Diversion of river water into these canals, along with similar diversions of water from the nearby Syr Darya River, has greatly contributed to the desiccation of most of the Aral Sea, an endorrheic lake basin. Prior to damming and diversion, the two rivers were the main sources of surface water that replenished the lake.