The rivers in the lower part of the southwest coastal region under Satkhira, Khulna and Jessore districts are tidal rivers. Tidal water comes from the sea and returns at low tide. Due to this phenomenon, the entire area is a tidal floodplain, often mistaken for a swamp.
In the lower part of this floodplain lies the Sundarbans mangrove forest. Every year, millions of tons of tree leaves from the Sundarbans fall into the region's deep tidal rivers and slowly convert into food particles for aquatic animals. Hence, the biological productivity of this region is much higher than any other region of the world.
Prior to the formation of coastal embankments, large volumes of water overflowed the riverbanks into the floodplain through tides, and sediment carried by the tides was deposited on the floodplain and returned to the strong currents. Through this process, the navigability of tidal rivers was maintained naturally. The land formation process was also going on at the same rate. Moreover, the farmers in the region erected temporary embankments around the flood plains in the months of Jaishthya-Ashar (May-June) and planted Aman paddy. Then, in the month of Poush (December-January), they broke the dikes and allowed the tide-borne sediment to settle in the flood plains. As a result, the rivers also remained navigable.
Because of this, the rivers, nature, environment and agricultural system in the region have a unique feature, different from other coasts of the country.
Some of the well-known rivers in the region are the Shibsa, Pesa, Boleshwar, Pasur, Arpangasiya, Kholpetua, Agunmukha, Bhadra, Atharobaki, Alaipur, Gasiakhali, Daratana, Ichhamati, Raimangal, Namud Samudra, Sonagang, Bhangrakud, Malanch, Satkhira, Sutarkhali, Marjati, Harinbhanga, Mahaganga, Galangi, Haripur, Sonai, Budhhatar Ganga, Dhaki, Golaghemia, Wazirpur, Katakhan, Guchiakhali, Akra Khal, Mongla Khal, Solpayara Agurmukh Mohuri, Modlam, Hariyabhanga, Panguchi, Meyar Gang, Kazibachha, Kakshiali, Maravola, Shoulmari, Morapshur, Nalua, Khoria, Jhopjhopia, and Manga.
Destroying the synchronization
In 1861, while establishing the Assam-Bengal railway line, the existing river structure was disturbed due to the construction of a narrow railway bridge at the source of Kumar, Navaganga, Chitra and lower Bhairab branches of the Mathabhanga river between Chuadanga and Kushtia districts at that time.
After 1950, the Krug Mission was appointed at the request of the then United Front government due to crop losses and floods in the south. During that time, 4,000 kilometres of embankments or dikes, 782 sluice gates and 92 polders were constructed in erstwhile East Pakistan.
In that project, a 1,556km embankment, 92 sluice gates and 37 polders were constructed in the southwestern region alone. This policy resulted in the separation of floodplains from rivers. As a result, most of the rivers in this region began to fill with silt.
This led to flooding in the 1980s and gradually became catastrophic and destructive. When the government projects failed to alleviate flooding and stagnation, the people gradually organized themselves and presented their own plans to the government to solve the problem and demanded its implementation.
Due to the implementation of irrigation projects in Kushtia, Chuadanga, Jhenaidah and Magura in 1993, many rivers in the region became fragmented.
In this context, in the 90’s, the government completed the EIA-I SIA survey in the Khulna-Jessore Drainage Rehabilitation Project (KJDRP) project area through CEGIS, a research organization of the Ministry of Water Resources. At the end of the study, CEGIS recommended the adoption of the Tidal River Management (TRM) approach to alleviate flooding by saving the rivers. The CEGIS EIA Report (1998) states that the TRM systems are technically feasible, financially viable, environmentally friendly and socially acceptable.
Following this, the government implemented this method in the Hari Basin, especially in the Khukshia Beel. As a result, five to six upazilas remained flood-free for a long time. But the process stopped after conflicts related to compensation of acquired land arose. As a result, the Hari, Sri and Bhadra rivers have again filled up and the intensity of flooding is increasing.
In 13 of the 38 bolder areas, at least 129 rivers small and large rivers have completely dried up over the years. Of these rivers, 109 inside the polder area have dried out completely.
On the other hand, nine of the 20 rivers outside the polders have dried up and the rest have partially dried up and lost navigability.
Locals have long been demanding the implementation of the TRM system in the zones to protect the rivers. They allege that a huge amount of money has already been looted by officials in the name of dredging these rivers, but the benefit has not reached the locals. If the TRM method is implemented, there will be no need for any digging or dredging.
Name-only rivers
According to sources, 80% of the region’s rivers—other than those in the Sundarbans—are now practically in existential crisis. As a result, along with fisheries, the environment is under threat. Due to man-made crises and erosion, these rivers have gradually dried up. There is also no current in the rivers that have water. Meanwhile, salinity is also eating away at the greenery of the region.
At least 50 rivers are already dead in greater Khulna alone. The depth of these rivers is endangered due to the embankments around the region and the hasty implementation of different projects.
A study on the geomorphology, ecology and fish production status of 189 small and large rivers in Khulna region showed that the depth of hundreds of rivers has decreased. In 180 of the rivers, fish species have declined significantly, fish passageways have been destroyed in 168 rivers, 42 rivers have died, and 177 rivers are facing severe river erosion.
Again, 170 rivers have been filled up and 189 are facing increased salinity. As the current of 182 rivers has weakened, the waters have receded too. Moreover, the mouths of 34 rivers have been filled with silt.
Beginning and end of TRM
In 2015, the TRM program was launched in Pakhimara Beel to alleviate waterlogging in the Kapotaksha River Basin of Satkhira district. Since the introduction of this system, there has been no further flooding in the Kapotaksha basin. However, the navigability of the river is decreasing day by day due to the suspension of the TRM activities.
Instead, the then government implemented many projects to prevent flooding in the southwest region, but none of them are compatible with nature, rivers and the environment. For this reason, these projects failed to eliminate flooding and protect the navigability of the rivers.
At present, the work on removing the silt accumulated on Betna and Barichcha riverbeds in Satkhira is going on through the excavation at a cost of Tk475 crore.
Initially, there was a proposal to implement the TRM method to protect the freshness of the two rivers in this project. However, the TRM portion was omitted during the final approval of the project.
In the “Bangladesh Delta Plan-2100”, the government instructed regarding the phased implementation of TRM in 39 beels of seven river basins. Again, in the National Adaptation Plan (2023-2050), a localized TRM method was suggested for proper drainage and sediment management in the inner and outer parts of a polder.
Meanwhile, problems such as flooding and river filling, one-sided land subsidence, and climate change impacts have emerged as serious problems in the area and many rivers in the region have died due to sedimentation in the riverbed.
Activists push for effective steps
Green activists believe that if proper measures are not taken now to protect the rivers, these will soon be filled with silt. Since the rivers will soon be filled with silt, the tidal rivers within the mangrove forest will die.
The population and civilization of this region will face destruction, experts fear.
They say in order to protect the population and civilization of the south-west coast region, measures should be taken to keep the rivers alive or ensure navigability by implementing the TRM method.
Recently, experts, academicians and activists took part in a discussion on river conservation organized by the Bangladesh Environmental Lawyers Association (BELA) in Khulna.
Mahfuzur Rahman Mukul, Khulna divisional coordinator of BELA, presented the main article at the meeting. Several recommendations were made in the discussion to protect the rivers of Khulna Division. He said the number of rivers in the division is said to be 138. But the existence of 36 rivers is currently in critical condition.
The threatened rivers are the Sholmari, Chunkuri, Rupsa, Honta, Moyur, Hamkura, Pasur, Mukteswari, Horihar, Kapotaksha, Ichhamati, Gorai, Kaliganga, Bhairab, Monumati, Navaganga, Chitra, Kumar, Atarobanki, Betna, Mathabhanga, Boleshwar, Bhola, Morichap, Kakshial, Mongla-Khadiyakhali Channel, Kholpetua, Thangrai, Shirshah, Teligati, Wachapa, Hariyabhanga, Guakhali, Salta, Lavanyavati and Chuna rivers.
Out of 37 rivers that are in crisis of existence, there is no water flow in 20. the Hamkura River is almost non-existent, he added.
Mahfuzur Rahman said these rivers are now under threat due to the construction of unplanned bridges, dams, silt filling, industrial waste pollution and encroachment.
Mentioning the historical reasons for the crisis in some rivers, he said: “In 1938, Carew & Co sugar mill was established by filling up a bend of the Bhairab River. Because of this, the connection between the Mathabhanga River and the Bhairab River was severed. As a result, the Bhairab River is in an existential crisis.”
Shahidul Islam, director of a non-governmental organization named Uttaran, said out of the 103 coastal polders, the land formation system of 38 polders in Khulna region is different from the others. Out of the Khulna polders, 13 were surveyed and revealed a dire picture.
Prabhat Debnath, a resident of Paikgasa said: “I see the river while going out every morning. I observe it even when returning home. There is no flow.”
Laila Parveen Sejuti from Satkhira said commercial shrimp farming is destroying the rivers. Farmers take control of the canals and cultivate shrimp. As a result, the natural flow of the rivers is disturbed, she said.
Rahima Akhter Shampa, president of Anirban Library in Paikgasa, said the drought-resistant Kapotaksha River is disappearing. Effective measures should be taken to save this river.
Mustafa Sarwar, the former chairman of Dumuria's Gutudia Union Parishad, said if one lets nature move at its own pace, it moves in the right direction. Even if it changes its course, it maintains balance. Public representatives have to play an important role in saving these rivers and evicting illegal occupants. No agricultural land shall be used for other purposes than just agriculture as well, he opined.
Mir Mohammad Ali, assistant professor of Sher-e-Bangla Agricultural University, said only 12 types of fish were seen in Paikgasa market recently. But 10 years ago, the scenario was different. Local fish species are disappearing. It is imperative to take action now, he added.
Sharif Jamil, the coordinator of Watakeepers Bangladesh, said the Kapotaksha River is gradually dying. The Shibsa River has now become a drain filled with silt. The rivers of the southwestern region are facing a crisis also for various other reasons like climate change and man-made troubles.
Recommendations for policymakers
During the discussion, experts called for protecting the rivers of Khulna Division by allowing flood water to enter the vast plains during the monsoon season, removing unnecessary sluice gates and dikes to open up the habitat for all aquatic animals, including fish, removing all illegal dikes obstructing the flow of water, de-encroaching all Char lands, cancelling lease of all canals and freeing from encroachment and connecting with the rivers and provision should be made for sedimentation in beels through the canals along with the flow.
They also suggested that small culverts be removed, and big and high bridges be constructed, research be launched to determine the number of rivers in the country and a database be prepared based on the findings.