The Khowai embankment project could not be completed in about four decades due to frequent design changes and half-hearted attempt at implementation.
And gushing rainwater rolling down from across the border often breaks through the completed portion of the dam during the monsoon.
Besides sand collectors cut road through the embankment to make way for truck movement during the dry season when the river becomes a narrow stream. The ravaged points never get repair work, locals said.
The sinuous Khowai snakes through Chunarughat, Habiganj sadar, Baniachang and Lakhai upazilas of Habiganj.
The government took up the Khowai project in 1969 to keep vast farmlands on its banks from yearly flooding, facilitate irrigation and save the Habiganj town, Water Development Board (WDB) officials said.
Later in 1973, the government sanctioned Tk 39.41 crore for the project that aimed at erecting 73-mile earthen embankment on both banks, concrete walls at six points, loop cutting, reconstructing a railway bridge at Shaistaganj, installing two pump stations, digging up canals and 65-mile drainage.
The project could not be completed in time after spending 29.13 crore. A revised project was taken up in the 1995-96 fiscal plan at an estimated cost of Tk 72 crore. Only Tk 18 crore was sanctioned at the time. Later in 1999, the government raised the amount to Tk 33.12 crore.
The government changed the design and readjusted costs in 2002-2003 to complete the project by 2006.
WDB sources said work on 93-km embankment, 36-km submersible embankment, loop cutting at 8 points, two sluice gates, 28 irrigation infrastructures and a few other things have so far been completed at an accumulated cost of Tk 68.5 crore.
Yet the completed portion has several breaches from Ballah to Habiganj town. In addition, a 7.5-km stretch between Ballah and Rajarbazaar has no protection wall.
The WDB last year asked the government for Tk 12 crore to buttress the weak points on an emergency basis.
Tk 3.27 crore was sanctioned. Officials now claim the repair work was done well and monsoon rains would no more pose any threat to the embankment.
But locals say the repair work did not follow the river's course. Besides, they allege the contractor used poor quality blocks and boulders in the knowledge of WBD officials.
The swollen river now threatens the dam at Govindapur, Eralia, Masulia, Bhadoi, Moshajan and Shaistaganj points. People fear that a few days' rain may lead to the busting of the riverbank.