Daguangba Dam

The Daguangba Dam is a multi-purpose dam on the Changhua River in Hainan Province, China. It is located 35 km east of Dongfang. As the primary component of the Daguangba Multipurpose Project, the dam was constructed between 1990 and 1995. It serves to provide water for both hydroelectric power generation and agriculture. It supports a 240 MW power station and supplies water for the irrigation of 12700 ha. It is also the largest dam and hydroelectric power station in Hainan.

Background
Preliminary construction (roads, bridges, river diversion) on the project began in March 1990. On 29 December 1993, the first generator was commissioned, with the second and third in 1994. On 29 March 1995, the fourth and last generator was commissioned. In June 1995, the concrete portion of the dam was poured to its design height. In December of that year, the entire power station was placed into commercial operation. In November 1996, the reservoir was full. The project also includes the 16 km long Head Main Canal which connects to a designed network of 154 km of branch and lateral canals. Approximately 23,800 people were relocated because of either the reservoir or irrigation works. Of the project's US$197.5 million cost, US$67 million was funded by the World Bank.

Design
The Daguangba Dam consists of a concrete gravity section flanked by two homogeneous earth-fill embankment dam sections. The gravity dam lies over the river and is 57 m high with a length of 719 m. The embankments have a maximum height of 44 m and combined length of 5123 m. The total length of the entire dam is 5842 m, making it one of the longest in China. The volume of concrete (including roller-compacted concrete) in the gravity dam is 860000 m3 while the embankments have a fill of 7800000 m3. It is the largest dam in Hainan Province. The reservoir withheld by the dam has a storage volume of 1710000000 m3. Of that volume, 1315000000 m3 is active (or "useful") volume. The spillway is located on the gravity section and is controlled by 16 radial gates. Its maximum discharge is 35564 m3/s. The dam's power station is located on the right side of the gravity section and contains four 60 MW Francis turbine-generators for a total installed capacity of 240 MW. It is the largest hydroelectric power station in Hainan.