“Yala” is a province among 3 southern border provinces which has a diversity of races, languages, and cultures. However, they have been combined together, bringing about social and community development, including the power system to be secure and stable. The construction of “Bang Lang Dam” is the development of water source according to Pattani River Basin Development Plan. Bang Lang Dam is the first multipurpose dam of the South providing many benefits to people in the region ranging from electricity generation, irrigation for cultivation, flood mitigation at the lower Tapi River basin, freshwater fishery, and tourism. The dam is one of tourist attractions in Yala Province which is beautiful, safe, and worthwhile for a visit.

The construction of Bang Lang Dam began in July 1976 and completed in June 1981. Their Majesties King Bhumibol Adulyadej The Great and Queen Sirikit The Queen Mother accompanied by Her Royal Highness Princess Maha Chakri Sirindhorn performed the opening ceremony of the dam on September 27, 1981. At present, the power plant of the dam has contractual generating capacity of 84 MW.

On the occasion of the royal visit to the construction site of Bang Lang Dam in 1978, His Majesty King Bhumibol Adulyadej The Great had an idea of making use of the overflow water from the weir to the dam reservoir by generating electricity from a small power plant in order to develop the local water source for the optimum benefit. 

Thus, in 1981, EGAT constructed the first underground power plant at Moo Ban Sunti 1, Cho Sub-district, Bannang Sata District, Yala Province. A generator of 1.275 MW was installed at the power plant. The power plant could supply electricity in October 1981.

Ban Sunti Hydropower Plant has an automatic control which can be operated from Bang Lang Dam Power Plant. It is a small power plant which uses high technology.