Dhaka’s dying rivers and the urgent way forward

Dhaka did not grow out of concrete. It grew out of water.

For generations, the rivers Buriganga, Turag, Balu and Shitalakshya shaped the city’s economy, culture, and daily life. Boats carried goods and people across a thriving delta network. Markets rose along riverbanks. Agriculture depended on seasonal flows. Water was not a backdrop—it was the foundation.

That foundation is now eroding.

The rivers still exist, but they are no longer what they were. In many stretches, the water runs black, thick with waste, carrying a smell that signals distress long before it is seen. What is unfolding is not a temporary environmental problem. It is the slow unmaking of a river system that once sustained one of South Asia’s great cities.

The numbers tell a story that is difficult to ignore.
Each day, approximately 80,000 cubic meters of untreated liquid waste are released directly into Dhaka’s surrounding rivers. When considering broader hydrological systems, including industrial zones and peri-urban areas, that number increases significantly. When the wider metropolitan and industrial zones are accounted for, estimates suggest that up to 1.5 million cubic meters of wastewater may be entering the river system daily.
This is not just water. It is a complex mix of untreated sewage, industrial chemicals, dyes, heavy metals, oils, and solid waste.

A significant portion originates from industrial discharges—particularly from textile dyeing, chemical processing, and tannery operations. These sectors use large quantities of water mixed with dyes, acids, alkalis, and heavy metals. Chromium, widely used in leather processing, and PFAS, Lead, and Mercury are used in the textile sector, which is of particular concern due to its toxicity and persistence in the environment.
Domestic waste adds another layer. Untreated sewage, food waste, detergents and plastics flow through open drains into canals which eventually connect to the rivers. Oil spills and fuel residues from river transport further compound the problem.

Together, these sources have turned the rivers into open conduits for waste disposal.

The decline of Dhaka’s rivers did not happen overnight, and it did not happen by accident. It is the result of a long chain of decisions—some taken, many avoided—that together created a system where pollution is not the exception, but the norm.

To understand why the rivers are failing, one has to look beyond individual polluters and examine how governance, planning, and economic priorities have interacted over time. What emerges is not a single point of failure, but a structural pattern.

Bangladesh has environmental laws that, on paper, are robust. Industries are required to treat wastewater. Discharge standards are defined. Environmental clearance is mandatory. Yet enforcement remains uneven.
Monitoring thousands of industries requires technical capacity, consistent oversight, and institutional independence. In reality, inspections are often irregular, penalties are limited, and compliance is inconsistent.
This creates a simple economic calculation: for many operators, it is cheaper to pollute than to comply.

Bangladesh is not short of environmental laws. Regulations governing water quality, industrial discharge, and environmental protection have been in place for decades. On paper, industries are required to treat wastewater, protect water bodies, and comply with environmental standards.

But here’s the uncomfortable reality: enforcement has not kept pace with growth.

Regulatory agencies are often under-resourced, both technically and institutionally. Monitoring thousands of industries across a rapidly expanding metropolitan region requires manpower, technology, and independence—three things that are often limited.

As a result, compliance becomes selective. Some industries follow the rules, many partially comply, and others bypass them altogether. Inspections may be irregular, penalties insufficient, and legal processes slow.

Responsibility for water, drainage, environment, and urban development is spread across multiple agencies. Each operates within its own mandate, often with limited coordination. The result is a patchwork approach.
Drainage systems are expanded without parallel investment in treatment facilities. Industrial zones grow without adequate environmental infrastructure. Encroachment continues in areas where jurisdiction is unclear.

No single authority sees the full picture, and without that, the system falters.

Dhaka’s water and environmental management is divided among multiple institutions—each with its own mandate, jurisdiction, and limitations.
One agency oversees water supply, another handles sewerage, another manages inland waterways, while environmental regulation sits elsewhere. Urban planning authorities operate on a different track altogether.
In theory, this division allows specialization. In practice, it creates gaps.
For example:
• Drainage systems may be designed without considering wastewater treatment capacity
• Industrial zones may expand without adequate environmental infrastructure
• River encroachment may fall between legal jurisdictions

Without strong coordination, each institution addresses part of the problem, while the system as a whole continues to fail.

Dhaka is one of the fastest-growing megacities in the world. But growth has come at the cost of natural systems. Wetlands have been filled. Canals have narrowed or disappeared. Floodplains have been converted into real estate.

These natural features once acted as buffers—absorbing excess water, filtering pollutants, and maintaining ecological balance. Their loss has accelerated the flow of untreated waste into rivers while reducing the rivers’ capacity to cope.

In effect, the city has dismantled its own protective infrastructure.

Industrial pollution is visible and often blamed. Less visible—but equally damaging—is domestic wastewater.
A significant share of Dhaka’s population lacks access to proper sewerage. Wastewater from households flows through open drains into canals and rivers without treatment.

This creates a continuous stream of contamination—rich in organic matter, pathogens, and household chemicals. Because it is diffuse and constant, it is harder to regulate. But its cumulative impact is enormous.

Dhaka’s economic engine—particularly textiles and manufacturing—depends heavily on water.

These sectors generate employment and export earnings. But the environmental costs of their operations are rarely reflected in production.
The result is a distorted system: industries benefit from growth, rivers absorb the waste, and society bears the long-term consequences.

Climate change is intensifying an already fragile situation.
Heavier rainfall increases runoff, carrying more waste into rivers. Reduced dry-season flows limit dilution capacity. Changes in delta hydrology complicate water management further.

These pressures amplify existing weaknesses, making recovery more difficult.

Scientific indicators reveal just how severe the situation has become.
Dissolved Oxygen (DO) is essential for aquatic life. Under healthy conditions, river water should contain at least 5 milligrams of oxygen per liter. In parts of the Buriganga, however, DO levels have dropped to as low as 0.24 mg/L.

At such levels, fish and other aquatic organisms cannot survive.
At the same time, Biological Oxygen Demand (BOD)—a measure of organic pollution—has surged to around 100 mg/L in certain stretches, far exceeding acceptable limits.

These two indicators together tell a clear story: the rivers are overloaded with organic and chemical waste, and the natural processes that would normally restore balance are no longer functioning.

In practical terms, this means sections of these rivers are biologically dead.
Ecological consequences: The collapse of a living system

Rivers are ecosystems, not just channels of water. When pollution reaches critical levels, the entire system begins to unravel.

Fish populations decline sharply, either dying from lack of oxygen or migrating to less polluted waters. This disrupts the food chain, affecting birds, amphibians, and other species that depend on aquatic life.
Microbial imbalance increases, often leading to the proliferation of harmful bacteria. Sediment builds up as waste accumulates, reducing water depth and flow capacity.

During the monsoon, this reduced capacity contributes to urban flooding. Water that once flowed freely now struggles to move, turning seasonal rains into disasters.

The loss is not only ecological—it is structural.

The health implications of river pollution are profound and far-reaching.
Communities living near the rivers—often among the most economically vulnerable—face the greatest risks. In areas where access to clean water is limited, river water is still used for washing, cleaning, and sometimes even cooking.

This exposure leads to a range of health problems:
• Waterborne diseases such as diarrhea, cholera, and typhoid
• Skin infections and respiratory issues
• Long-term exposure to heavy metals leading to kidney damage, neurological disorders, and increased cancer risk

There is also an indirect pathway. Polluted river water used in agriculture leads to contamination of soil and crops. Heavy metals accumulate in vegetables and grains, entering the human body through food.

This process—bioaccumulation—is slow but dangerous. It turns everyday meals into potential sources of toxicity.

Environmental degradation is already reshaping Dhaka’s economy and society.

Fishing communities, once dependent on river ecosystems, are losing their livelihoods as fish stocks decline—by as much as 50 to 80 per cent in severely polluted stretches. Many are forced into low-income informal work, marking a clear downward shift in economic security.

Households are paying more for clean water and healthcare. In informal settlements, families often pay significantly higher prices for safe water than those with municipal connections. Illness linked to pollution adds further financial strain.

Transport systems are also affected. Rivers once provided a cost-effective alternative to road transport, often 30 to 50 per cent cheaper per unit of cargo. As pollution and sedimentation reduce navigability, more goods shift to roads, worsening congestion and increasing fuel use.

Urban value is declining as well. Polluted riverfronts deter investment, limit tourism, and reduce the potential for public space development. Cities around the world have built thriving economies around clean waterways. Dhaka is moving in the opposite direction.

These impacts are interconnected. Loss of income, rising costs, and declining urban quality reinforce each other, creating a cycle that is difficult to break.

Polluted rivers are forcing households to pay more for what used to be freely available—safe water and a healthy environment.

Dhaka already faces a growing gap between water demand and supply. As river water becomes increasingly contaminated, the cost of treatment rises significantly. Utilities must invest more in purification, and in many low-income settlements where piped water is unreliable, families turn to private vendors.

In informal settlements, households often pay 5–10 times more per liter of water than those connected to municipal supply.

Healthcare costs are rising in parallel. Studies on water pollution exposure in urban Bangladesh indicate that waterborne diseases remain a major burden, particularly in low-income communities. Diarrheal diseases alone account for significant out-of-pocket expenditure, while chronic exposure to heavy metals adds long-term health risks that are harder to quantify but far more expensive to treat.

For a low-income family, even a single illness episode can consume a substantial share of monthly income. When such exposure is continuous, poverty deepens.

Rivers were once Dhaka’s most efficient transport corridors. Moving goods by water is significantly cheaper than by road—often costing 30–50% less per tonne-kilometer.

But pollution and sedimentation are undermining this advantage.
Industrial waste and solid dumping have accelerated siltation, reducing navigability in key channels of the Turag River and Balu River. In some stretches, vessels can no longer operate year-round without dredging. As a result, cargo shifts to road transport, adding pressure to an already congested urban system. Dhaka is consistently ranked among the most traffic-congested cities in the world, and reduced reliance on waterways only intensifies fuel consumption, travel time, and economic inefficiency.

There is also a hidden cost: increased air pollution from additional road traffic—creating a feedback loop between environmental degradation and public health.

A city’s environmental quality directly influences its economic competitiveness. Clean rivers enhance livability, attract investment, and create opportunities for tourism and recreation. Dhaka is moving in the opposite direction. Riverfront areas that could have been hubs of economic and cultural activity are instead associated with odor, waste, and visual degradation. Property values in heavily polluted river-adjacent zones tend to stagnate or decline compared to cleaner urban areas.

Global urban studies consistently show that proximity to clean water bodies increases real estate value by 10–20 per cent or more. Dhaka is effectively losing that premium.

Tourism potential is also undercut. River cruises, waterfront development, and public spaces—common in cities like those along the Thames River—remain largely unrealized.

The loss is not abstract. It is a direct forfeiture of economic opportunity.
Rebuilding what has been lost

The path forward is neither simple nor quick, but it is clear.

Pollution control begins with enforcement. Industries must operate functional treatment systems, and compliance must be monitored in real time.

Penalties need to be strong enough to change behavior. Without that, regulation remains symbolic.

Dhaka cannot address river pollution without addressing wastewater.
The city generates vast volumes of sewage, yet only a small portion is treated. Expanding sewer networks, building new treatment plants, and introducing decentralized systems in dense areas are essential steps.
Separating stormwater from sewage is equally important, particularly in a city prone to flooding.

This is not just an environmental investment—it is a public health and economic necessity.

Encroachment must be reversed. Restoring riverbanks will improve flow, reduce flooding risk, and create opportunities for public use. This requires legal enforcement, supported by fair rehabilitation measures for affected communities.

Effective environmental management depends on capable institutions.
Coordination between agencies must improve. Monitoring systems need modernization. Public access to environmental data can strengthen accountability.

Recovery will take time, but it is possible.
Targeted dredging, habitat restoration, and biodiversity conservation can gradually revive river systems. Examples from abroad show that even severely polluted rivers can recover with sustained effort.

The Thames River and the Cuyahoga River stand as reminders that restoration is achievable.

No solution will succeed without public participation.
Reducing waste, preventing plastic dumping, and maintaining local drainage systems require behavioral change. Awareness, education, and community engagement must be part of any long-term strategy.

Dhaka’s rivers are not beyond saving. But they are approaching a point where recovery will become far more difficult and costly.

This is not just an environmental issue. It is about health, livelihoods, and the future of the city itself.

The rivers once sustained Dhaka without question. Today, they are asking for deliberate care in return.

The choice is clear: continue on the current path and accept gradual collapse, or act decisively to restore what remains.

Time, however, is no longer on the city’s side.

* Shahriar Hossain is an environmental scientist, journalist, and activist, globally recognized for pioneering Bangladesh’s plastic bag ban and championing action against toxic pollution.
Contact: [email protected]