Dhaka’s new Padma barrage will reshape South Asia’s water power map

Bangladesh recently approved the operation of the Padma barrage. The barrage is intended to power the Padma river, which is the sanction of the Ganga successful Bangladesh, and abate the country’s seasonal h2o scarcity.

The 2.1-km-long operation volition store 2,900 cardinal cu. m of h2o to service 6.5 crore radical crossed southwestern and bluish Bangladesh. It is estimated to outgo Tk 50,443 crore (Rs 39,170 crore) implicit 7 years.

The Padma barrage volition prevarication conscionable 180 km downstream of the Farakka barrage successful West Bengal — and what Bangladesh has progressively viewed arsenic an impediment. The Farakka barrage is 1 of India’s largest with a feeder canal and was built to divert h2o from the Ganga to the Bhagirathi-Hoogly and frankincense flush the Kolkata Port.

Under the 1996 Ganges Water Treaty, Bangladesh volition person fractional the h2o from the Farakka barrage erstwhile the travel is nether 70,000 cusecs. But during the adust play betwixt March and May, each state has to person astatine slightest 35,000 cusecs of h2o successful 3 alternating 10-day periods.

Treaties past and future

A 2019 reappraisal by an planetary squad of experts successful Water Policy recovered that determination were “repeated occurrences of debased travel astatine Farakka during the drier years successful the post-Treaty period,” including successful 1997, 2008, 2010 and 2016. They concluded that the 1996 Treaty couldn’t relationship for rising unpredictability successful the flows.

The statement is acceptable to expire successful December 2026. Both New Delhi and Dhaka person said negotiations to widen it are underway.

But Dhaka has besides said the Farakka barrage is liable for the country’s periodic h2o scarcity. To adhd to the resulting anxiety, respective river-sharing agreements betwixt India and Bangladesh stay unsigned, including the Teesta River Treaty.

According to S. Janakarajan, president of the South Asia Consortium for Interdisciplinary Water Resources Studies, “All transboundary h2o issues centre astir the deficiency of timely travel of water,” implying that the barrage volition beryllium a mode for the little riparian authorities to exert immoderate power implicit its h2o resources.

But this equity volition travel astatine a sizeable biology cost. Bangladesh is already precise drought-prone, ranking 3rd successful the World Resources Institute Aqueduct drought-risk ranking.

Effects of Farakka barrage

Dhaka’s concerns implicit the Farakka barrage are not unfounded. Diverting the Ganga’s waters altered the river’s quality and ecology successful Bangladesh. About a 3rd of Bangladesh relies connected the Ganga basin, mostly to irrigate crops. By redirecting the stream and reducing downward flow, the Farakka has dried up respective of Bangladesh’s rivers. The effect is reduced groundwater levels, less waterways for navigation, accrued salinity, riverbank erosion and reduced freshwater flows to the Sundarbans. 

“A important portion of Bangladesh is nether a debased elevation coastal zone,” Mr. Janakarajan said, meaning the onshore is little than 10 m supra oversea level.

“In the adjacent future, sea-level emergence volition pb to the disappearance of 17% of the territory of Bangladesh,” researchers wrote successful the Journal of Marine Science and Engineering successful 2022. This, they added, volition “create 20 cardinal refugees, and 220,000 km² of onshore volition beryllium submerged pursuing a projected sea-level emergence of 1500 mm to instrumentality spot wrong 150 years.”

Groundwater overextraction isn’t helping. Bangladesh drew astir 520 litres of groundwater per idiosyncratic per time successful 2008 (the latest twelvemonth for which the U.N. FAO Aquastat database provides nationalist figures for withdrawals by source), which is not peculiarly precocious — but the country’s dependence connected groundwater is simply a substance of concern.

Because the Farakka barrage besides reduces the travel successful the Padma, the Padma is little capable to transport silt, which sinks to the riverbed and piles up. When the monsoons arrive, then, the stream overflows rapidly and floods.

Keeping the sediment flowing is besides important to support the ecosystems and the livelihoods that beryllium connected it.

For example, the Sundarbans portion hosts the world’s largest contiguous mangrove wood and relies connected h2o from the Ganga, Brahmaputra, and Meghna rivers. Mr. Janakarajan said little sediment and freshwater flowing from these barrages volition origin the h2o successful the Sundarbans to go saline whereas the ecosystem requires the h2o to beryllium brackish, which is little salty.

These changes volition pb to less fish, affecting the lives and livelihoods of fisherfolk successful the area.

Fondness for concrete

South Asia is presently connected a dam-building spree. There are much than 160 hydroelectric powerfulness projects underway successful South Asia and much than 700 planned hydropower plants person been georeferenced successful the Indus-Ganga-Brahmaputra region, per a 2023 review successful Water. China is besides gathering what volition beryllium the world’s largest dam implicit the precocious people of the Brahmaputra, conscionable earlier the stream enters India. In response, India initiated a Rs 6.4 lakh crore hydroelectric powerfulness project, including gathering implicit 200 dams successful its Northeast.

Dams — of which barrages are a benignant — are mostly designed to run for a century. Climate alteration is breaking this guarantee.

To guarantee barrages don’t overflow nether dense bursts of rain, for instance, engineers person to drain h2o from down a barrage via canals to different areas, Omair Ahmad, erstwhile South Asia managing exertion astatine Dialogue Earth. However, this volition necessitate gathering extended h2o diversion infrastructure, which would apt beryllium made of cement.

“Creating greater pondage present successful a cement happening means h2o is not going into your groundwater. It cannot. It is robbing a overmuch larger country astir that barrage of the regular travel of h2o that would seep successful from a stream basin,” Mr. Ahmad said.

Given the bevy of adverse biology consequences, experts accidental gathering different barrage is not the astir rational choice. In fact, they person already said overmuch of South Asia’s obsession with gathering large dams is thing of a assemblage hangover.

“We deliberation large projects volition really negociate [water] contempt humanities grounds that they bash not,” Mr. Ahmad said. “It is uncommon for large projects to beryllium capable to negociate this due to the fact that ecosystems are a spot excessively complex.”

Mr. Ahmad and Mr. Janakarajan besides suggested that alternatively of 1 ample barrage, Bangladesh should see gathering a bid of smaller check-dams, which don’t dramatically change a river’s flow.

But this has the downside of requiring cross-country readying and maintenance. The Padma barrage connected the different manus volition beryllium ‘confined’ to 1 circumstantial area.

Water and neighbourhood

“Water sharing is ever going to beryllium a governmental issue,” Sreeradha Datta, an planetary affairs prof astatine O.P. Jindal Global University, said. “The much we effort to tame the river, the much we autumn into different issues [with] semipermanent consequences which we cannot spot now. But successful the contiguous context, it looks beneficial, and we are ever pandering to the constituency.”

The semipermanent consequences besides evolve. After the Pahalgam onslaught successful 2025, India suspended the Indus Water Treaty with Pakistan. Experts person said India engages successful one-on-one diplomacy with its neighbours, successful portion to task a ascendant stance but besides to support relations separate. Still, India’s absorption whitethorn beryllium connected Dhaka’s caput arsenic it heads into the 1996 Treaty talks portion New Delhi steps up its rhetoric connected “illegal” migrants.

China looms arsenic well. According to a study successful The Daily Star, Bangladeshi officials person said the authorities volition physique the Padma barrage with its ain money. Experts, however, accidental the state lacks the engineering resources for a task of this standard and apt has assistance from China, which is already progressive successful different infrastructure projects successful the area.

“China is simply a non-resident South Asian,” Prof. Datta said. Working connected a task truthful adjacent to the borderline on with India’s scepticism towards Bangladesh’s caller Tarique Rahman medication could marque India uncomfortable, she added.

During his 2016 travel to Dhaka, China President Xi Jinping said the Chinese and the Bangladeshi radical “drink h2o from the aforesaid river”.

“China gets to beryllium seen much and much arsenic a ascendant h2o manager successful South Asia, arsenic it has already go successful the Mekong,” Mr. Ahmad said. “India becomes a little applicable histrion wrong its ain neighbourhood.”

For each these concerns, however, India has not straight commented connected the Padma Barrage. Bangladesh has said its narration with India depends connected what they hold astir sharing the Ganga’s waters. Delhi has said each river-sharing issues volition beryllium handled wrong the existing bilateral framework. The treaty’s renewal process is underway.

sonikka.l@thehindu.co.in