Prior to the construction of Pak Mun Dam, the Northeast had the power sources totaling 138.50 MW which was insufficient to meet the rising demand for electricity in the region causing instability of the power system and a risk of blackout. It was necessary to receive additional power supply from the Central part and the Northern part including power purchase from Lao PDR. Therefore, “Pak Mun Dam” was planned to construct at Baan Hua Haew, Khong Chiam District, Ubon Ratchathani Province.

Pak Mun Dam was designed to be a diversion dam (Run-off River) to regulate water in the river to be higher. It is beneficial for irrigation, fishery promotion and agriculture. EGAT had made the fish ladder for fish from the Mekong River can swim to lay eggs in the Mun River. The Fishery Center was established to be aquaculture for fish breeding and aquatic species conservation for their abundance. The fisher occupation has increased income to villagers.

 The construction of Pak Mun Dam began in June 1990 and was completed in November 1984. Benefits from the dam is worthwhile to the public. In addition, it serves as a source of clean and cheap energy to help enhance security of the power system in the Northeast. At present, the power plant has contractual generating capacity of 136 MW.