Bangladesh fears that failure to renew a 30-year Ganges water-sharing treaty with India before it expires in December could deepen water shortages, threatening tens of millions of livelihoods.
In Bangladesh's parched Barind region, 72-year-old Bikash Soren remembers when the Ganges River flowing in from neighboring India carried large boats past his village year-round.
"For almost three months a year, you hardly see the river flowing," the Protestant priest said.
Two farmers killed themselves last season, he added, after dwindling water levels devastated their rice and wheat crops.
Shrinking flows in the Ganges have also slashed fish catches in the river, known in Bangladesh as the Padma.
"Where will we find fish now?" said Abu Bakar Siddique, 55, who has switched to fish farming in ponds.
"I used to catch many kinds."
The 2,525-kilometer (1,569-mile) Ganges flows through the world's most populous river basin, home to 655 million people, including more than 50 million in Bangladesh, according to the World Bank.
The 1996 treaty, which expires on Dec. 12, governs dry-season water sharing at India's Farakka Barrage, 20 kilometers upstream of Bangladesh.
But Bangladesh needs a new deal based on "mutual benefit and respect," Rashed al Mahmud Titumir, a prime ministerial adviser who heads a technical committee on water sharing, told AFP.
Disputes over water from 54 cross-border rivers between India and Bangladesh stretch back decades and the Ganges is among the most important.
Malik Fida A. Khan, a former Bangladeshi member of the Joint Rivers Commission, the body overseeing water sharing, said India had built "additional dams" upstream.
"This time, the agreement must include provisions on climate change – and take the entire river basin into account," he said.
Bangladesh said India had not responded to its request to negotiate a treaty renewal.
New Delhi's Foreign Ministry said that "discussions regarding river-related matters" are a matter for the Joint Rivers Commission, which held its last technical talks in May.
The last officially confirmed ministerial-level commission meeting was in 2022 – after a 12-year gap.
And a proposed water-sharing deal for the cross-border Teesta River has been stalled since 2011.
Relations between New Delhi and Dhaka have soured since Bangladesh's former Prime Minister Sheikh Hasina fled to old ally India, where she remains, following a 2024 uprising.
Hasina, sentenced to death in absentia for crimes against humanity, has vowed to return to Bangladesh from India in December, the month the treaty she signed expires.
Prime Minister Tarique Rahman may also visit India before the treaty expires, according to reports, but no visit has been confirmed.
Disputes date back to 1975, when India opened the 2.2-kilometer-long Farakka Barrage. Bangladesh accused India of diverting most of the water.
The United Nations intervened in the dispute and the countries reached a deal in 1977.
But water-sharing arrangements lapsed a decade later, bringing severe consequences, said Sheikh Rokon of Dhaka-based environmental group Riverine People.
"The Ganges suffered during the years without a treaty, and at least three rivers almost dried up," Rokon said.
One was the Gorai, which carries freshwater into the Sundarbans, the world's largest mangrove forest and a World Heritage site, helping limit saltwater intrusion as sea levels rise.
Bangladesh's largest irrigation project, the Ganges-Kobadak Irrigation Project, designed to water 955 square kilometers of farmland, "became inoperative because of water scarcity," Rokon said.
In May, Dhaka approved the Padma Barrage, a $2.8 billion project intended to ease shortages and include a 113-megawatt hydropower plant.
The 1996 treaty has no automatic extension clause.
"If we fail to reach a deal, I fear the situation will be worse than what we experienced during the years without a treaty," Rokon added.
"Demand for freshwater on both sides has increased significantly."
Even with the treaty in place, the Ganges-Kobadak project has shrunk to 550 square kilometers, according to Bangladeshi state news agency BSS.
"If the river does not carry enough water, the consequences could be disastrous," said Chowdhury Sarwar Jahan, a geology professor at Bangladesh's University of Rajshahi.
Bangladesh's agriculture-dependent economy is already reeling from climate change, which compounds changes in river flows, bringing alternating dry-season shortages and intense monsoon floods that wash away farmland and villages.
In Chapainawabganj district, the river has widened by 3 kilometers in recent years – nearly doubling its size – according to Bangladesh's Water Development Board.
Rehana Khatun, 50, described the "howling sound" as floods destroyed her home in Fielder Bazar village.
"The river turned wild and started swallowing everything along the bank," said Khatun, who now lives in a bamboo shelter.
"And the trauma stays with children long after the waters recede."