The century-old Beradoma canal and Shyamababur khal in Tangail municipality have been turned into concrete drains, exacerbating environmental pollution.

Once vital waterways, the canals had long been on the brink of extinction due to rampant encroachment. Instead of reclaiming them, the municipality authorities allegedly collaborated with vested groups to convert them into drains, locals claimed.

The canal-turned-drains are now clogged, obstructing water flow and becoming breeding grounds for mosquitoes.

Originating from the Louhajang river, Beradoma canal flows through the Kagmara area before reconnecting with the river in Anayetpur. In 2016, the district administration, along with environmentalists, recovered encroached portions and demarcated its boundaries. However, the then municipality mayor, now absconding, allegedly worked with influential groups to shrink the 30-foot-wide canal to a mere five-foot drain, ignoring opposition from environmentalists, said Ratan Ahmed Siddique, general secretary of the River, Canal, and Waterbodies Protection Movement Committee in Tangail.

He said land on one side of the canal has been merged with the road, while locals have occupied the other side, setting up sewage lines to discharge household waste directly into the drain.

The other waterway, Shyamababur Khal, was excavated in 1905 by Shyamacharan Gupta, a teacher at Bindubasini High School and vice-chairman of the then municipal council. The canal once served as a vital drainage and transport route, with people using boats to cross its 35-40-foot width even in the 1970s.

In the 1990s, the Water Development Board constructed a sluice gate on the Louhajang river in Jugani under a development project. As part of the same initiative, a 1.5-kilometre stretch of the canal -- from Paradisepara to Godown Bridge -- was turned into a drain. Subsequently, the municipality authorities built commercial high-rise markets beside the drain and rented them out, further disrupting the town's drainage system.

More recently, under an infrastructure development project, the remaining portion of the canal in Biswas Betka was also targeted for drain construction. However, following the Awami League government's exit last year, the work was left incomplete, leaving the canal clogged. Stagnant water in the unfinished drain now emits a foul odour, adding to environmental concerns.

Local resident Suvas Sheel said the drain was meant to discharge water into the Burai Beel, but much of the beel has already been lost to encroachment and waste dumping. As a result, the drain remains blocked, accumulating waste and producing an unbearable stench.

According to cadastral survey records, most of the 74 canals in Sadar upazila have already disappeared due to encroachment and pollution, with the remaining ones facing a similar fate, said Gautam Chandra Chanda, divisional coordinator of Bangladesh Environmental Lawyers Association (BELA).

Echoing his concerns, local environmental activist Noor Mohammad Rajjo stated that there is no legal provision allowing canals to be converted into drains. He alleged that corrupt individuals implemented these environmentally destructive projects for financial gain, stressing the need for restoration.

Contacted, Shihab Raihan, administrator of Tangail Municipality and deputy director of the Local Government Department in Tangail, said an investigation would be conducted, and necessary steps would be taken accordingly.