The Queen Sirikit Dam is an embankment dam on the Nan River, a tributary of the Chao Phraya River, in Uttaradit Province, Thailand. The dam was built for the purpose of irrigation, flood control and hydroelectric power production. It is named after Queen Sirikit of Thailand.The Sirikit Dam among others in the Chao Phraya basin were constructed beginning in the 1950s to exploit the agricultural and hydroelectric potential of the basin. Preliminary construction on the dam began in 1968 and it was finished in 1972. The power plant and first three units were commissioned in 1974, the fourth in 1995.Previously in 1964, the Bhumibol Dam was completed on the Ping River, one of two major tributaries of the Chao Phraya including the Nan.