Xinfengjiang Dam


The Xinfengjiang Dam is a gravity dam on the Xinfeng River, upstream of its confluence with the Dong River, and just west of Heyuan City in Guangdong Province, China. The dam's power station has a 292.5 MW installed capacity and its reservoir supplies water for farming along with drinking water to Guangzhou, Shenzhen and Hong Kong. Construction on the dam began in 1958, the first generator was operational in 1960 and the dam complete in 1962. The dam's reservoir-filling is attributed to several earthquakes within the project area including a 6.1-magnitude on March 19, 1962.

Background

Construction on the dam began in 1958, a total of of earth was excavated at the construction site. On October 20, 1959 the reservoir behind the dam began to fill and in November there were several small earthquakes within the reservoir zone. When the water level reached above sea level in May 1960, there were three to four earthquakes at a 3.1- and on July 18, when the water level ASL, a 4.3- earthquake occurred. On March 19, 1962 when the reservoir reached ASL there was a 6.1- earthquake with an epicenter downstream from the dam which destroyed several houses in the area. After the earthquake and as a precaution, cavities within the foundation were reinforced with concrete. This and other upgrades brought the dam to a 9.5--rated resistant design.

Design

The dam is a tall, wide gravity dam. Its crest width is and it has a structural volume of of concrete. Above the dam is a drainage area and it withholds a reservoir of. The dam contains a surface controlled spillway with three floodgates, each with a maximum discharge capacity for a total of. The discharge tunnel on the dam's left bank has a diameter, is long and has a capacity. The dam's reservoir has a flood storage capacity, rated for a once in a hundred-year flood. The dam's power station is located at its base and contains four Francis turbine generators. Three are rated at 72.5 MW and the fourth at 75 MW for a total design capacity of 292.5 MW but the power plant can operate at a maximum 315 MW after later upgrades.