Lower Se San 2 Dam was first envisioned in a 1990 study funded by the Asian Development Bank and the project was approved on 2 November 2012.
The Lower Sesan 2 (LSS2) was first envisaged in a 1999 study funded by the Asian Development Bank, and in which it was deemed an unattractive investment due to its marginal financial viability and its large potential environmental impact. The Cambodian government approved the project on 2 November 2012. 
