Jiangya Dam

The Jiangya Dam is a concrete gravity dam on the Loushui River, located 50 km northeast of Zhangjiajie in Hunan Province, China. The primary purpose of the multi-purpose dam is flood control but it also generates hydroelectricity, supplies water for irrigation and municipal use and improves navigation.

Background
The dam's power plant has a 300 MW capacity and generates on average 756 GWh annually. It provides for the irrigation of 5570 ha and water storage for about 50,000 people. The dam also reserves 740000000 m3 for flood storage and supports a 20-ton ship lift. Construction on the dam began in 1995, the first generator was operational in 1998 and the project complete in 1999. The dam was constructed with roller-compacted concrete (RCC) and is noteworthy because it was the first dam to use the slope/inclined laying process as opposed to horizontal. This technique was used from the dam's midsection upward and reduced both the cost and time of construction. The dam was constructed at a cost of about US$400 million, of which $97 million was provided by the World Bank.

Design
The dam is a 131 m tall and 368 m long concrete gravity dam with a structural volume of 1370000 m3. The base of the dam is 107 m wide and the crest is at an elevation of 245 m while the reservoir has a normal elevation of 236 m. The dam sits at the head of a 3711 km2 catchment area and creates a reservoir with a capacity of 1740000000 m3. The dam's spillway is controlled by four gates and at the base of the chutes, flip buckets dissipate the water's energy. Within the three center spillway piers are three intermediate outlets. These outlets and the spillway can discharge up to 11700 m3/s. The dam's power house is located underground on the dam's right bank and contains three 100 MW Francis turbine-generators. The dam's 20-ton ship lift is located on the left bank and is 935 m long. The irrigation intake is located on the left bank of the reservoir.

VLF-transmitter
Over the eastern part of Jiangya reservoir at 29°35'21"N   110°44'23"E multiple wires of a VLF-transmitter used for transmitting orders to submarines are spun. The facility is similar to Jim Creek Naval Radio Station, but much larger,