Poor navigability leaves Karnaphuli in lurch

Shoals emerges along the right bank of the river Karnaphuli stretching from Shah Amanat Bridge to Sadarghat. PHOTO: Zobaer Hossain Sikder

Lack of river training (Nadi Shashan) poses a serious threat to the navigability of the river, which provides the only dependable outlet for the export and import of the country, they said.

None of the technical reports of the surveys on the 20km stretch of the river Karnaphuli under the Chittagong Port Authority (CPA) in the last 50 years were followed properly.

The experts said this at a seminar titled "Flowing Karnaphuli and Chittagong" at the Institute of Engineers Bangladesh (IEB), Chittagong auditorium on Tuesday.

The Forum for Planned Chittagong, a voluntary organisation of professionals and members of the civil society, organised the seminar.

They said that CPA had taken measures to maintain the navigability and stop erosion of the river stretching from the estuary to Sadarghat. But, the authorities concerned have yet to take any technical step for the training of the river in the upstream up to the river Halda, they added.

The absence of river training in the upstream is forcing a slow but irreversible change in the river course and flow, threatening the navigability of the river at the port channel, they said.

The speakers emphasised executing the Master Alignment Plan, permanent embankment alignment, construction of training walls, retaining walls and revetment for permanent resistance of the river erosion.

They also suggested the closure of the Bakalia left channel, dredging of the river and removal of the sunken vessels from the channel and keeping the outlets of different canals falling into the Karnaphuli.

FPC General Secretary Architect QS Tauhid presented the keynote paper at the seminar with its president scientist Prof Dr Jamal Nazrul Islam in the chair.

Former CPA Chairman Mahmud-Ul-Islam, Chittagong University Museum Curator Shamsul Hossain, The Suprabhat Bangladesh Joint Editor Muhammad Idris, FPC Secretary Engineer Subhas Barua, Dr. Shafique Haider Chowdhury, Engineer Ali Ashraf, Architect Zarina Hossain and Professor Dr. Md. Shahidul Islam also spoke.

Major protection work started in the river when revetment of its 4.8km stretch near the port was done in1912, sources said. Then a series of training, including the extension of the cutting bend revetment, training wall, were executed during the 1929-40.

It brought about a steady improvement and the river required no dredging after the completion of the river training.

In view of the rapidly deteriorating condition of the river due to heavy erosion at Chaktai and the accompanying downstream shifting of shoal along Chittagong foreshore causing instability of jetty reach, work for a 3000-ft Upper Training Spur (Chaktai to the upstream) was completed in 1947.

Following the rapid development of the Chittagong port in the late forties, Sir Claude Inglis, director of the London based Hydraulic Research Station (HRS) was called in to conduct a survey in 1948. According to Inglis' suggestions a model investigation was carried out at the Hydraulics Research Station during 1956-59. The model investigation recommended executing three works, immediate closure of the channel between Haldachar and the right bank of the Karnaphuli, closure of the upstream and downstream entrances to the Nazirchar right channel and filling in the embayment upstream of the jetties on the suggested alignment.

Of them, the first two works were completed in 1960 resulting in substantial improvement in the channel at the jetties as well as in the approaches to the jetties.

But the third work was not executed. In the upper reaches between Mazhirghat to Bakalia, the gradual shifting of the deepwater channel to the left bank on the other side of Chittagong remained an increasing concern.

Besides, a number of studies were done by Bangladesh University of Engineering and Technology, DHI and other agencies to improve the condition of the river, but nothing remarkable was done to train the river after the 1960s.

The BUET experts in their latest survey found construction of Shah Amanat Bridge as the main reason behind the massive siltation at some two-kilometre stretch of the river upto Sadarghat BIWTC terminal. They also blamed the bridge for chocking the Karnaphuli at the Bandar channel alarmingly.

But, no steps were yet to be taken to train the river as per the suggestions.