Rivers on a devouring binge

Land being lost continuously
Wali Newaz . Faridpur
The unusually scanty monsoon rain this year has not stopped the major rivers from swallowing habitats, croplands, embankments and even a railway ghat in places from Bogra to Bhola in the last two months.

Thousands of people have lost homes and lands, and thousands more are at risk as the Jamuna, Meghna and Padma rivers, along with many of their tributaries, indulge in a devouring binge, overwhelming all the stopgap arrangements of the Bangladesh Water Development Board to tame their uncontrollable torrents.

While the victims are blaming the BWDB for its failure to protect them from unabated erosion, water engineers believe that dumping sandbags in strong currents is just a drain on public money in the name of maintenance of protective structures.

A portion of the Sirajganj town protection embankment collapsed on July 10, triggering panic among the town people and worrying experts, including BWDB chairman Abul Kalam Azad, about the fate of the Jamuna Bridge. The embankment collapsed for a second time in a week, frustrating the delayed move by the BWDB to check further erosion by the Jamuna.

The merciless Jamuna devoured the Bahadurabad railway station ghat, including other valuable establishments, in Jamalpur on July 25. The railway station ghat, marine and passenger yard, security forces’ barrack, railway staff quarters and the nearby Harindhara village became part of the river bed.

The Jamuna was joined in its depredations by Bangali River, threatening the embankment that protects Sariakandi and Dhunot in Bogra.

The Sahrabari spur was damaged, so the BWDB is trying the save it by dumping concrete cement blocks and sand bags on it.

At least 40 metres’ of the embankment built to protect Faridpur town and Padma’s bank at Munshidangi under Decreerchar union of Sadar upazila collapsed in July.

M Rafiqullah, executive engineer of the BWDB in Faridpur, blamed the torrential current in the Padma for the collapse. The construction work of the 6-kilometre town and river bank protection embankment was completed in the dry season of 2008 at a cost of Tk 119 crore. In the same year about 500 metres of the concrete embankment caved in!

The small district of Bhola is losing lands almost everyday from mid-July to the insatiable Meghna. Renewed fears have gripped the people of Haimchar of Chandpur, which has been on the decline for decades because it is losing lands to the Meghna.

The old Louhajang town in Munshiganj was devoured by the Padma, while its tributary Garai swallowed the old part of Kushtia years ago.

In every case the BWDB responded lamely by dumping sandbags and concrete blocks on the rivers’ banks to stop erosion. Locals say that the water agency only appears when the damage is already done and almost goes into hiding in the dry season. All its efforts in the monsoon go in vain as strong currents wash away almost all the materials that have been dumped, they opined.

Studies of various protective measures taken for control of major rivers like the Jamuna, Padma and Meghna, and the recent collapse of two portions of the hard point of Sirajganj town protection embankment on the Jamuna, raise questions about protective measures like dumping of sand filled geo-textile bags and concrete blocks along the areas being eroded.

Water engineers at the River Research Institute in Faridpur say the type of soil along most of the banks of the country’s major rivers is different from the soils beside other major rivers of the world. Absorbing additional moisture from rain water, the local soil gains extra weight and becomes vulnerable to large-scale erosion and collapse of banks due to huge scouring holes or gaps developed under the soil’s layer close to the banks.

As revetment (facing) of banks by concrete boulders is still used as a quick and effective measure to resist erosion, some experts suggest the ‘bundling method’, which is less expensive. But in both the cases, regular monitoring and maintenance is essential to keep the rivers in check.

The bundling technique has recently been applied to the Sirajganj town protection embankment, where bundles made of bamboo are used to minimize the current’s force and attract silt to the river bank to save it from further collapse.

Lutfar Rahman, principal scientific officer of the River Research Institute who is now working at the eroded site of the Jamuna in Sirajganj district, said that dumping of geo-textile bags and CC-blocks is not the only solution. Placing of bundles of rocks, concretes, timber or bamboo could help to save vulnerable river banks.

He recommended biological protection of the river banks by the planting of deep-rooted trees as long-term precaution, stating that it would be very effective.

‘Capital dredging’ is a term which is being heard frequently with erosion taking a serious turn in all the major river basins. Even before the Sirajganj town protection embankment saw its first breach on July 10 and rang the alarm bell for the Bangabandhu Jamuna Bridge, built only 12 years ago by Korean company Hyundai, Prime Minister Sheikh Hasina talked about an ambitious capital dredging plan involving Tk 30,000 crore. She envisaged an average annual spending of Tk 3,000 crore for at least 10 years to bring river flows under control.

Citing an example, she said that the Jamuna reaches a width of 11km in the monsoon. If the river’s width could be limited to 4km by dredging and erecting dams on both sides, thousands of acres of land could be reclaimed, she said while seeking finance from global lenders and bilateral donors, including the Netherlands, for the mega-plan.

While the source of the huge fund has still not been found, water experts have reservations about the practicality of the capital dredging plan apart from the huge expenditure it entails.

Lutfar says that capital dredging is not a solution for mighty rivers — it can be effective for only the small ones.

A BWDB reports in 1984 found that 1,200km stretch of rivers was in a state of erosion, of which 565km faced severe erosion. About 100 square kilometres of highly productive land, including homesteads and establishments, have been lost to erosion. The extent of damage will be actually much bigger as the rivers have continued swallowing lands and homes for the last 25 years.

Another current report on the same issue by the Centre for Environmental and Geographic Information Service showed that at least 535 metres of effective embankments have been in a vulnerable state. The total length of concrete embankments along the major river banks may be around 20 kilometres, situated close to Rajshahi, Sirajganj and Faridpur towns.

The River Research Institute has identified about 35 places on the banks of the Jamuna and Padma — Kurigram, Jamalpur, Gaibandha, Bogra, Sirajganj, Tangail, Pabna, Manikganj, Nawabganj, Rajshahi, Kushtia, Pabna, Rajbari, Faridpur, Shariatpur and Munshiganj districts — where erosion claims large tracts of land every year.

Besides Barisal, Madaripur, Chandpur, Bhola, Shatkhira, Potuakhali and Pirojpur have been under constant threat of erosion by the Meghna and some smaller rivers as well as the Bay of Bengal.

Pintu Kanungoe, principal scientific officer of the River Research Institute, told New Age that there should be a long-term master-plan for mitigating river erosion. But due to resources constraint it is not possible to implement such a plan in the near future, so bank protection work is being implemented on a priority basis.
He suggested an ‘adaptive’ approach to the threat of river erosion: maintaining harmony between the new constructions and the structures which are already in place.

‘Proper monitoring of the rivers’ condition and maintenance of constructed works should be given the outmost importance,’ he said.