The Kwai Noi River is one of the important rivers of the country originated from Ta Nao Sri mountain range flowing pass Kanchanaburi Province with the total length of 390 kilometers. According to the Mae Klong River Basin Development Plan, the Electricity Generating Authority of Thailand (EGAT) has developed the plan to generate electricity which gives several benefits to the people such as agriculture, irrigation in lower Mae Klong River basin. The reservoir above the dam serves as the aquaculture source of freshwater fish for fishery.

Vajiralongkorn Dam or formerly known as “Khao Laem Dam” is the first rock fill dam covered with reinforced concrete situated on the Kwai Noi River in Tha Kha Nun Sub-district, Thong Pha Phum District, Kanchanaburi Province. The construction began in 1977 and was completed in 1984. The power plant is installed with 3 generators each of 100,000 kW having the annual generated electricity averagely of 460 million kWh. On 15 December 1984, the generator Unit 3 was operated for the first time to supply electricity to the power system. Later, on 24 December 1984 and on 13 February 1985, the generators Unit 2 and Unit 1 were operated to supply electricity to the system respectively.

Vajiralongkorn Dam can store a large amount of water during the rainy season to alleviate the flood problem whereas in the dry season it can discharge water to prevent the saltwater from intrusion and the pollution of industrial wastewater from factories on both banks of Mae Klong River to maintain the water quality.              

The opening of the dam was performed by His Majesty King Bhumibol accompanied by Her Royal Highness Princess Maha Chakri Sirindhorn and Her Royal Highness Princess Chulabhorn on 9 January 1986. On 13 July 2001, His Majesty King Bhumibol graciously bestowed the name “Vajiralongkorn Dam” after the name of the Crown Prince (Presently King Rama X).