The Lam Takhong Dam is an embankment dam

Embankment dam

An embankment dam is a massive artificial water barrier. It is typically created by the emplacement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay and/or rock. It has a semi-permanent waterproof natural covering for its surface, and a dense, waterproof...

 on the Lam Takhong River

Lam Takhong River

The Lam Takhong River is a river in Thailand and a tributary of the Mun River in eastern Thailand. It is impounded by the Lam Takhong Dam....

 in between Pak Chona and Si Khiu

Amphoe Sikhio

Sikhio is a district in the western part of Nakhon Ratchasima Province, Thailand.-History:Originally known as Mueang Nakhon Chantuek, Sikhio is an ancient frontier city between the Thai dominated Chao Phraya valley and the Lao dominated Khorat Plateau. There is not record of the time of its...

 districts in Nakhon Ratchasima province

Nakhon Ratchasima Province

Nakhon Ratchasima or , often shortened to Korat or Khorat , is one of the north-eastern provinces of Thailand...

, Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

. The dam was originally constructed in 1974 for the purposes of irrigation and water supply but after 2002, its water storage also serves as the lower reservoir for the Lam Takhong Pumped Storage Power Plant, Thailand's first power plant of that type.

Background

Construction on the Lam Takhong Dam began in 1969 and was completed in 1974 while the pumped storage project was initially proposed in 1975. From 1989-1991, the Japan International Cooperation Agency funded a feasibility study. Khon Kaen University carried out an Environmental Impact Assessment beginning in 1991 and by 1994, the project was approved for construction. The project was to be constructed in two 500 MW phases. The first phase began in December 1995 and was completed in 2001, with the first two 250 MW generators operational in August 2002. After the 1997 Asian financial crisis, Phase 2 never began. The power plant and its components were constructed underground to preserve the nature and scenery of the area. During construction, various complaints were raised about the blasting of the upper reservoir. The dust from blasting reportedly had negative effects on locals and their farms.

Design and operation

The Lam Takhong Dam is a 251 m (823 ft) long and 40.3 m (132 ft) high earth-fill embankment dam. It creates a reservoir with a capacity of 310000000 cubic metre. The upper reservoir 17°14′31"N 99°00′58"E is located 6.8 km (4 mi) southwest of the main dam on top of a hill. The upper reservoir is created by an asphalt lining 2170 m (7,119 ft) long and 50 m (164 ft) high. It has a capacity of 10300000 cubic metre and surface area of 0.34 km² (0.131274733921462 sq mi). The power station is a pumped-storage type and contains two 250 MW reversible pump-generators. Water is a first pumped to the upper reservoir and then during peak-demand hours, it is sent back down to the power station for power production. This process repeats itself. The power station is connected to the upper reservoir via two 650 m (2,133 ft) long, 6 m (20 ft) diameter penstock

Penstock

A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....

s. Water returning from the power station does so via two 1430 m (4,692 ft) long, 6.8 m (22 ft) diameter tailrace tunnels.