For the betterment of the Mekong River Basin Development various Thai Government Agencies and The United Nations Lower Mekong River Survey Committee agreed after the survey of the major branches of the Mekong River that it was necessary to constructed a dam across the Lam Nam Pong, which is major tributary of the Mekong River in order to store rain waters and prevent flooding over the lower area and utilize the stored water for power generation, irrigation etc. There fore the National Energy Authority was assigned to construct the Pong Nip Dam in 1964(B.E.2507) which is later called the “Ubonratana Dan” in the Lam Nam Pong and the Royal Irrigation Department(RID) to construct the irrigation system to distribute water released from the power plant for cultivation on both bank of the Lam Nam Pong
In 1965 (B.E. 2508) RID undertook the construction Headworks of the Nong Wai in Nam Pong District Khon Kean Province. The OGEE reinforced concrete weir with 5.90 m. height, 125.24 m. crest length and max. crest length 162.500 m. Maximum flow 1,500 cubic m./sec. The weir construced across the river bend 35 km. south of Ubonratana dam or 33 km. north of the city of Khon Kean Province along Khon Kean-Udornthani Friendship Highway,
followed by the construction of the irrigation system as below,
-Water spillway of the Right (2 Bending spillway 3.0x2.0 m.) and Left (2 Bending spillway 3.0x2.0 m.) operated water distribution into both bank of Lam Nam Pong.
-Sand drainage spillway of the Right (2 Bending spillway 4.0x2.25 m.) and the left (3 Bending spillway 4.0x2.25 m.) drained sediment to for sufficient water distribution.
-Emergency spillway 3.5 high by 240 m. long, weir head 166.000 m. drainage capacity 1,000 cubic m./sec.
Distribution System of both banks of Lam Nam Pong were:
* 1964-1972 Construction of the Right main canal and all supports canal systems
* 1972-1975 Construction of the Left main canal and all supports canal systems
Including the improvement of Irrigation system in form of irrigated agriculture over the existing areas and extension as scheduled for higher efficiency in water distribution at the farm level. The development phases were as followed:-
* 1975-1979 Improvement of Irrigation system over the upper left bank of the Project in Nam Pong District, Sumsoong District and Muang District of Khon Kean Province over an area of 58,500 rais. Under the Nam Pong Irrigation Project Phase I, with financial supported from the International Development Agency (IDA)
* 1976-1983 Undertaking land consolidation works and improvement of irrigation system on the right bank of the Project in Nam Pong and Muang Khon Kean District Khon Kean Province over and irrigated area of 68,800 rais. Under the Nong Wai Pioneer Agriculture Project-Right Bank with financial supported from Asian Development Bank (ADB).
* 1979-1985 Construction and Improvement of the main and on-farm irrigation system on the left bank of the lower part of the Project in Chiang Yeun District, Khon Kean Province and Kosumpisai District, Mahasarakham Porvince. Over an area of 127,500 rais. Under the Nam Pong Irrigation Project-Phase II with financial supported from the Kreditanstalt für Wiederaufbau (KFW)
*1985 Construction Rubber Weir with air pump extended from regular weir at 0.60 x125.24 m.