Kaptai Lake is the biggest lake in Bangladesh. It is situated in the Kaptai Upazila under Rangamati District of Chittagong Division. The lake was made because of building the Kaptai Dam on the Karnaphuli River, as a feature of the Karnaphuli Hydro-electric venture. Kaptai Lake's typical profundity is 100 feet (30 m) and greatest profundity is 490 feet (150 m).
Development of the supply for the hydro-electric plant started in 1956 by the Government of East Pakistan. Thus, 54,000 sections of land (220 km2) of farmland in the Rangamati District went submerged and made the lake. The hydro-electric undertaking was supported by the United States. The undertaking was done in 1962. Worldwide Engineering Company and Utah International Inc. gotten the agreement for development of the dam. The dam is 670.8 meters long, and 54.7 meters high. The dam has a 745 feet (227 m) long spillway containing 16 entryways. Through the spillway 5,250,000 cu ft/s (149,000 m3/s) of water can pass.
The land that went submerged because of the dam development, was 40% of the absolute arable land nearby. Alongside that, 29 square miles (75 km2) of the Government-claimed timberland, and 234 square miles (610 km2) of other woodland land went submerged. Around 18,000 families with a sum of very nearly 100 thousand individuals were likewise dislodged. The royal residence of the lord of the Chakmas was likewise overflowed and is currently submerged.