Photo : Belal Uddin
Within a year of its construction, the coastal embankment in Banshkhali suffered a catastrophic collapse into the sea, triggering a dispute between locals and the Bangladesh Water Development Board (BWDB).
The community placed blame on the embankment's design flaws and the use of subpar building materials, particularly in the Kadam Rasul area of Khankhanabad Union.
Locals vehemently asserted that a one-kilometer section of the embankment succumbed to the pressures of shoddy construction and an inadequate design, rendering it unsustainable as low-quality materials were utilized in its construction. Consequently, a staggering Tk 293 crore of investment was washed away in less than a year.
On the other hand, BWDB authorities contended that the erosion was primarily a result of a change in the course of the Sangu River, dismissing allegations of poor construction quality.
The project, originally budgeted at Tk 251 crore and initiated seven and a half years ago, experienced significant delays and cost overruns, ultimately escalating to Tk 293.6 million. The project's completion was scheduled for June 2022 and encompassed various components, including 6.2 km of embankment conservation, erosion prevention, and rehabilitation, 3.8 km of river bank conservation, and 5.6 km of embankment rehabilitation. By 2022, nearly 90 percent of the project had been completed.
Superficially, it is evident that a substantial portion of the one-kilometer embankment surrounding the CC block, constructed in the Kadmarsul area of Khankhanabad Union, has succumbed to the relentless onslaught of the Bay of Bengal's waters.
A segment of the dam has vanished altogether, with the severity of erosion increasing daily. The perilous situation places five villages at imminent risk, as the dam's potential failure could lead to their submersion. Blocks intended to thwart embankment erosion have disintegrated, with hardly any of them remaining intact. BWDB resorted to using geobags to fortify the sinking dam, but these measures proved futile, as the geobags sank swiftly into the sea, leaving the embankment even more vulnerable.
Remarkably, the process of obtaining sand for the geobags, aimed at preventing dam erosion, involved the use of dredger machines stationed 300 meters from the dam's location in the sea. Geobags were filled directly from the dredger via a pipeline. Even these geobags, when placed in the submerged portion, suffered a similar fate, exacerbating the embankment's precarious state. Strikingly, there was a conspicuous absence of large-scale response or activities in the town despite the calamity.
Mohammad Shahedul Alam, a resident of the Khankhanabad Kadmarsul area, expressed his concerns, highlighting the region's vulnerability to annual monsoons and cyclones. He also raised allegations of corruption, suggesting that political leaders, contractors, and local officials had siphoned funds meant for the dam by compromising on construction quality.
Jasim Haider, Chairman of Khankhanabad Union Parishad, acknowledged that the BWDB was actively installing geobags on the deteriorating dam. He underscored the critical role played by the shifting mouth of the Sangu River in the embankment's degradation and emphasized the need for long-term planning to avert the potential disappearance of the Kadmarsul area.
Sagar Dey, the sub-divisional engineer for Chattogram at the Water Development Board, clarified that the erosion stemmed from the Sangu River meeting the Bay of Bengal at that specific location, causing a shift in the river's course that ultimately impacted the embankment. Approximately 700 meters of the embankment in that area had been breached, prompting the placement of geobags as a mitigation measure.
TDM/SD
