Posted on October 27, 2025
The government’s plan for a Tk 6.89 billion project to dredge Kaptai Lake and its surrounding rivers is a massive engineering challenge born from an even greater necessity. For decades, silt accumulation in the Chattogram Hill Tracts’ waterways has severely hampered transport and disrupted livelihoods, necessitating an immediate and comprehensive response. To address this, the Bangladesh Water Development Board (BWDB) is set to start a four-year project in 2025, encompassing the dredging of 65.7 km of river routes, fortification of 11.75 km of eroding riverbanks and re-excavation of 25.85 km of canals.
The origins of this crisis trace back to the construction of the Kaptai dam for hydroelectric power in the 1960s. While the dam successfully fulfilled its primary goal of supplying electricity to the national grid, it simultaneously triggered an ecological chain reaction. Heavy siltation gradually choked the life from tributaries and linked rivers. The lake bed’s continuous filling with sediment has reduced Kaptai Lake’s water-holding capacity by 25 per cent in the last 30 years, forming obstructive submerged and visible chars. Consequently, sediment build-up and reduced inflows have impaired boat transport in remote Rangamati upazilas, cutting off communities from vital markets and services.
The long-term silt build-up in Kaptai Lake is taking a severe toll on environment as well. It devastates fish populations by depleting oxygen and smothering critical breeding grounds, leading to a sharp loss of biodiversity. Pollution from diesel boats worsens these impacts. Furthermore, the altered water flow from the dam has intensified flash floods and monsoon landslides, accelerating erosion and environmental damage. The project, therefore, holds the promise of protecting the region’s unique environmental heritage while easing communication for local communities and boosting local economies, making its urgency and benefits undeniable.
However, its success hinges critically on correcting the flawed dredging and management practices that plagued previous dredging efforts in other rivers. A persistent problem, widely reported and condemned, is the dumping of excavated sediment in close proximity to the riverbanks. Whether this is due to poor oversight or is a deliberate way to create need for future dredging contracts, this negligence defeats the entire goal of the restoration.
The piled-up material is simply washed back into the river during the next monsoon rains, wasting the investment and leaving the channel as clogged as before. Such mismanagement of public funds and ecological resources cannot be tolerated in a project of this magnitude, which is directly tied to the infrastructure and livelihood of a historically marginalised region. Success should not be measured by how much is initially dredged, but by how long the channels stay clear. This demands a total break from these failed and costly past methods. It is imperative that all dredging contracts include a scientifically sound sediment disposal plan, one that explicitly prohibits dredged material from being dumped on riverbanks that invites wash-back.
Crucially, Kaptai Lake’s problems are exacerbated by intense land use in its upstream catchment area. Unchecked deforestation and harmful jhum cultivation technique accelerate soil erosion, dramatically increasing the silt that enters the river system. Any solution must therefore address the root cause through an integrated river basin management approach that rehabilitates the surrounding hills and promotes sustainable agriculture. Just as critically, the project must operate with strong, independent oversight. This requires actively involving local communities, environmental scientists and civil society groups in the monitoring process. Their continuous engagement is the best guarantee that transparency and accountability will prevail over the potential for corruption, securing a true and lasting restoration for Kaptai Lake and its surrounding rivers.
