West Bengal’s 2026 election delivered a major political shift, with the Bharatiya Janata Party (BJP) winning a two-thirds majority (207 seats) and ending 15 years of Trinamool Congress rule. This matters far beyond state politics because West Bengal shares over 2,000 km of India’s border with Bangladesh and 54 transboundary rivers, including the Ganga and Teesta.

For more than a decade, the Teesta water-sharing agreement has remained stalled. In 2011, India and Bangladesh came close to signing a deal, but it stalled after objections from the West Bengal government led by Mamata Banerjee. Unresolved transboundary river issues have continued to breed mistrust in both Bangladesh and India.

Now, with the same party in power both at the Centre and in West Bengal, political alignment will lead to improved administrative coordination, and the Centre will face fewer overt obstacles to Teesta water-sharing. However, a deal is still not guaranteed and rests on agrarian and technocratic interests in both riparian nations, as they seek a mutually acceptable path forward. To assure long-term binational water security, any agreement must balance irrigation needs under highly seasonal river flows, early flood warning, and coordinated disaster mitigation with the ecological health of the Teesta itself. The key question now is whether Centre-State alignment will reduce political hurdles and help move Teesta negotiations from promise to delivery.

The Teesta Water-sharing Struggle

In India, water is largely a State subject (Entry 17), although the Central Government has powers over inter‑State rivers (Entry 56). This federal setup means the Central government negotiates international river agreements, but States must be consulted, primarily because implementation rests in their hands, including clearances and decisions that affect local water allocation. As a result, Centre–State coordination is essential for India to sign the Teesta deal.

Over the past 15 years, West Bengal’s former Chief Minister Mamata Banerjee engaged in Teesta discussions with both the Congress‑led United Progressive Alliance (UPA) and the BJP‑led National Democratic Alliance (NDA). Yet she repeatedly raised concerns about water needs in North Bengal (Jalpaiguri, Cooch Behar, Darjeeling, Uttar Dinajpur, Dakshin Dinajpur, and Malda districts), pointing to rising irrigation demand and shrinking dry‑season flows, and sounding the alarm that a simple 50–50 allocation would hurt the region’s agriculture. Teesta water-sharing had not been a major electoral issue in North Bengal, but her government broadened the debate to include arrangements on smaller rivers like Torsa, Jaldhaka, and Raidak, making a Teesta‑specific agreement all but impossible.

The outcome has been a familiar pattern of hope followed by delay, reinforcing a cautious view in Dhaka: West Bengal’s participation matters, but it does not guarantee delivery. Political messaging has remained cordial—after Banerjee’s 2021 win, Bangladesh’s then-Prime Minister Sheikh Hasina spoke warmly about ties with West Bengal and hoped for deeper cooperation—but this did not translate into progress on the core Teesta issue. Critics describe this recurring reliance on sub‑national “veto points” as a form of institutional hydro‑coercion, where domestic politics of the upstream riparian can be used—often intentionally, though not always—to stall or dilute agreements with downstream nations.

What Fueled BJP’s Win: Water or Border Security?

The 2026 election outcomes in West Bengal and Assam are closely watched in Bangladesh because these border states shape everyday realities—migration control, trade routes, and shared rivers. Assam, where the BJP-led alliance secured a third consecutive term, sits upstream on the Brahmaputra (Jamuna) that supports millions downstream in Bangladesh.

Yet in both West Bengal and Assam, the 2026 campaign spotlight focused far more on border security and “illegal migration” than on water security. BJP leaders repeatedly framed the election around “infiltration,” stronger border enforcement, and citizenship and identity politics, often portraying the ruling Trinamool Congress as an obstacle to tougher border measures. In this framing, Bangladesh clearly did not feature as a foreign policy partner. By contrast, transboundary water-sharing barely registered as a vote-driving theme in West Bengal or Assam.

Meanwhile, in Bangladesh, Teesta is frequently described as an urgent public and political issue. So, the key question remains: if border politics helped power the West Bengal election shift, will the BJP-led Centre and state governments still move forward on water-sharing with Bangladesh?

“Double Engine Sarkar” and Promise

Irrespective of domestic political rhetoric, India’s national strategic calculus has long viewed Bangladesh as a key partner for regional cooperation, given its geographical contiguity and deep cultural and historical ties. India’s broader regional frameworks—often articulated through “Neighbourhood First” and its eastward-oriented regional engagement—provide an enduring policy foundation that extends beyond short-term political cycles. During multiple visits and bilateral discussions with Bangladesh, India’s Prime Minister Narendra Modi has consistently reaffirmed India’s commitment to resolving the Teesta impasse.

The Teesta issue, in particular, has repeatedly illustrated how state politics can shape the pace and scope of binational negotiations. From the standpoint of cooperative federalism, sustained high-level engagement has emphasised the need for a fair and workable Teesta arrangement acceptable to both countries and to key stakeholders within each – India and Bangladesh.

The Teesta impasse is often reduced to “equitable” sharing, commonly interpreted as a 50–50 water division. But that framing obscures deeper geopolitical and ecological realities.

This strategy also hinges on the prospect of stronger Centre–state alignment within India—often described as a “double-engine ki sarkar” (two-engined government)—which is meant to enhance coordination and speed up the delivery of development by politically aligned governments. We call for the same framing to be applied to transboundary river-basin cooperation: better Centre–state coordination can ease sub-national political constraints and help build a domestic consensus that supports broader India–Bangladesh cooperation. For instance, with the BJP in power at the Centre and in Assam and Tripura, India signed MoUs with Bangladesh on the Kushiyara and Feni rivers.

Likewise, the 2015 Land Boundary Agreement between India and Bangladesh, brokered by the BJP-led central government, marked a historic settlement of a decades-old border issue and demonstrated that politically complex bilateral issues can be resolved when sufficient political will, institutional coordination, and sustained diplomacy converge.

India’s immediate diplomatic challenge is to recalibrate its engagement with the newly elected Bangladesh National Party (BNP)-led government, which can help mitigate persistent anti-India sentiment within Bangladesh. In this context, Teesta water-sharing offers a strategic opening to reset bilateral trust and cooperation. A credible breakthrough on Teesta can help reshape perceptions of India’s governing BJP in Bangladesh while enabling the BNP to deliver on a long-standing public commitment—resolving a tension that has remained politically salient and deeply consequential for Bangladeshi citizens, and crucially, the rural economic backbone.

Challenges ahead

While Teesta water politics have been amplified over the last 15 years, the roots of water-sharing tensions stretch back to partition and border delineation. The Teesta impasse is often reduced to “equitable” sharing, commonly interpreted as a 50–50 water division. But that framing obscures deeper geopolitical and ecological realities. Climate-driven flow variability is becoming more evident, water demand has surged, and the river’s ecology has degraded due to dams, barrages and embankments. Under these conditions, can a narrow focus on dry-season flow volume allocation alone realistically build trust and enable sustained cooperation?

Dry-season flow in the Teesta has fallen sharply over the last three decades—by more than half, even upstream in India. The Gajaldoba Barrage has irrigated less than half of its planned command area, and the 67 MW link-canal hydropower plant can run for only about one-quarter of the dry season. At the same time, climate-induced risks are rising. The October 4, 2023, flood—triggered by a large glacial outburst from South Lhonak Lake in the Teesta headwaters in Sikkim—caused major damage to roads, buildings, dams, and riverbanks, with heavy sediment deposition and loss of life in Bangladesh and India.

In Bangladesh, the Teesta flows through the drought-prone northern region, where irrigation water is critical. The Teesta Barrage was built to irrigate about 750,000 hectares, but during the dry season—when farmers need water most for Boro rice—it delivers far less, reaching at best half of its irrigation target. As the riverbed appears dry, many people assume that upstream structures are taking Bangladesh’s “fair share”, although both countries divert the reduced dry-season flow. In such low-flow conditions, a simple 50–50 split is unlikely to meet dry-season needs in either country.

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Another challenge is the proposed Teesta mega project with growing strategic competition from China and India. Plans that try to narrow the river’s wide, braided channel into a single, confined corridor can damage river ecology and may increase flood risk over time, especially as sediment continues to accumulate and raise the riverbed. The Teesta is a sediment-heavy river, carrying around 10 million tons of sediment each year that helps build floodplains and islands and supports farming and livelihoods far downstream. And while infrastructure is important, it should be designed around the river’s natural processes, not against them.

What does this mean for cooperation?

Domestic political messaging and sensitive issues such as illegal cross-border migration can inflame public opinion and erode trust. India and Bangladesh both want a stable relationship, so, with the support of the newly elected West Bengal government, they must pursue a pragmatic cooperation approach that people can see and feel, especially for livelihoods directly supported by irrigation, water supply, flood mitigation, and hydropower, and the infrastructure these require.

Expanding energy trade, improving dry-season water cooperation, and sharing broader river benefits will strengthen agriculture, support industry, reduce poverty, and lower the economic drivers that tend to push migration over time.

In the long run, cooperation across the wider Brahmaputra–Teesta River system, including transparent data-sharing, basin-wide planning, and robust benefit-sharing, could also help manage risks in India and better navigate broader geopolitical drivers. Ultimately, lasting river cooperation depends on building trust among riparian partners—not just signing a flow-sharing number on paper.

Kausik Ghosh, PhD, is an Assistant Professor at the Department of Geography, Vidyasagar University, West Bengal, India.

Christopher Scott, PhD, is the Goddard Chair and Professor at the Department of Ecosystem Science and Management, Pennsylvania State University, USA.

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