Background

Tha Thung Na Dam is a project in the Lower Kwai Yai Development Plan of EGAT. Formerly known as the Lower Kwai Yai Project, the dam was constructed across Kwai Yai River downstream of Srinagarind Dam.

Tha Thung Na Dam is a multipurpose supporting dam of Srinagarind Dam which enables the reuse of water which has passed the turbine in power generation of Sinagarind Dam. During the period of low demand, the water is pumped to be stored at the reservoir of Srinagarind Dam for power generation. Thus, the special feature of Tha Thung Na Dam is to increase the efficiency of power generation of Srinagarind Dam which ultimately saves foreign currency in importing fuel oil. 

The government approved the implementation of EGAT’s Tha Thung Na Dam Project in September 1977. The construction of facilities such as accommodation, storage building, bridges, electricity, and waterworks began in December 1977.

In January 1978, the initial work at the dam site started by preparing construction ground and water diversion followed by civil work such as construction of spillway, intake structure, power plant, river outlet, and switchyard which was completed gradually. The overall completion was in December 1981. 

For the installation of the generators, the water turbines were installed in August 1980 followed by other equipment. With the completion of the installation of generators of units 1 and 2, the electricity distribution started in December 1981 and February 1982 respectively. The opening of Tha Thung Na Dam was officiated on April 16, 1982.