Constructed during 1963- 1972 across the Nan River at Tha Pla District
of Uttaradit Province, this is the first earth dam of the country with the dam
height of 113.6 m, crest length of 810 m and retention capacity of 9,510
million m3. The water released from the dam not only causes benefits in
hydro power generation of 375,000 kW capacity but also used in irrigating
the areas of 96,000 ha under the Phitsanulok Irrigation Project and
1,200,000 ha in the wet season and 480,000 ha in the dry season under
the Greater Chao Phraya Project in collaboration with the Bhumibol Dam.
Similar to the Bhumibol Dam, the dam also helps lessen flood problem of
the Chao Phraya river basin and facilitate inland navigation of the country.