Kaptai Lake (কাপ্তাই লেক)

Kaptai Lake lies in Rangamati Hill District in the Chittagong Hill Tracts of southeast Bangladesh, with the town of Rangamati built on its shores. It was formed when the government of East Pakistan built the Kaptai Dam across the Karnaphuli River for the Karnafuli Hydropower Station. Work on the reservoir began in 1956 and was finished in the early 1960s.

The lake flooded valleys that had been home to many people of the hill tracts, especially the Chakma. About 100,000 people were displaced, and farmland and the old palace of the Chakma Raja were submerged. The dam remains the only hydroelectric power station in Bangladesh.

At full monsoon level the reservoir covers about 688 square kilometres. Because it filled a hilly landscape, it has a very long, winding shoreline with hundreds of small islands and narrow arms reaching into the forest. Fishing is an important source of income for communities around it.

Most visitors take a hired boat from Rangamati. Common stops include the hanging bridge, a pedestrian bridge that is a symbol of Rangamati town, the Rajban Vihara Buddhist monastery, island restaurants run by local communities, and Shuvolong, where a waterfall flows into the lake after rain. Local Chakma, Marma and other communities sell handwoven textiles in Rangamati's markets.

There is no fee to see the lake, but boats are hired by the hour or for the day, and the price is agreed with the boat owner. Foreign visitors to the Chittagong Hill Tracts may need to follow entry rules set by the authorities, so check current requirements before travelling. The months from October to March are the most comfortable, and after the monsoon the lake is at its fullest.

Kaptai Lake is the largest man-made lake in Bangladesh. The dam that holds it back is 670.8 metres long and 54.7 metres high, built under a contract held by the International Engineering Company and Utah International Inc. The reservoir drains a catchment of about 11,122 square kilometres. Its average depth is about 30 metres and the deepest point about 53 metres.

The human cost is still part of local memory. Around 40 per cent of the arable land in the area went under water, and the palace of the Chakma Raja now lies beneath the surface. Water levels are managed closely during the monsoon: in September 2024, when the lake approached its maximum level of 109 feet above mean sea level, the authorities opened all 16 sluice gates of the dam.

The level rises and falls through the year, so the lake looks fullest after the monsoon, which is also when the hills around it are greenest. Boat trips from Rangamati usually last a few hours; agree the route, the stops and the price with the boat owner before setting off, and carry drinking water and a hat, as there is little shade on the open water. Because the reservoir also supports fishing communities and a power station, some areas near the dam are restricted, so follow local instructions about where boats may go.