What Is The Sone River Dispute And Why Are Bihar, Jharkhand Settling It Now?

A water-sharing dispute between Bihar and Jharkhand that has run for a quarter of a century is finally being put on paper. The signing will close a long and largely technical standoff — but one that has held up a major irrigation project and left farmers across both states waiting on a settlement that outlived the very accord that created the dispute in the first place.

According to The Hindustan Times, the two states will formally sign the Sone river water-sharing pact on Monday, 25 years after Jharkhand's creation first triggered the disagreement over how much of the river's water each state was entitled to draw.

What is the Sone River, and why does it matter?

The Sone is a perennial river that originates in the Amarkantak hills of Madhya Pradesh and flows for roughly 784 km through Madhya Pradesh, Chhattisgarh, Uttar Pradesh, Jharkhand and Bihar before joining the Ganga at Koilwar, near Patna. It is a critical source of irrigation for large parts of Bihar through the Sone canal system, making the river central to farming livelihoods across several districts in the state's southern and central belt.

What is the Bansagar Accord, and how did the dispute begin?

The sharing of Sone waters has been governed since 1973 by the tripartite Bansagar Accord between Madhya Pradesh, Uttar Pradesh and undivided Bihar, which fixed undivided Bihar's entitlement at 7.75 million-acre-feet (MAF) of water.

The dispute traces back to November 2000, when Jharkhand was carved out of Bihar, taking with it a stretch of the Sone basin. The Bansagar Accord's allocation to "Bihar" was never formally divided between the two successor states, and Jharkhand began pressing for a clearly defined share of that entitlement almost as soon as it was formed.

What exactly were the two states disputing, and what did it hold up?

At the heart of the dispute was a straightforward but unresolved question: how much of undivided Bihar's fixed 7.75 MAF entitlement should now belong to Jharkhand. The absence of an agreed formula had practical consequences — it reportedly stalled central clearance for the long-planned Indrapuri reservoir, to be built on the Sone between Kadwan in Jharkhand's Garhwa district and Matiwan in Bihar's Rohtas district. The project was designed to stabilise irrigation supply through the Sone canal system, but could not move forward without both states first agreeing on their respective shares of the river's water.

How was the 25-year deadlock finally broken?

The breakthrough came at a meeting of the Eastern Zonal Council in Ranchi on July 10, 2025, chaired by Union Home Minister Amit Shah, which brought representatives of both state governments to the table. Following that meeting, the Centre constituted a technical committee with representatives from both states, which unanimously recommended a specific water-sharing formula.

The Central Water Commission (CWC) subsequently vetted and cleared the draft agreement built around that formula, paving the way for both states' cabinets to approve it.

What does the new agreement say?

Under the finalised formula, Bihar will retain 5.75 MAF of the 7.75 MAF originally allotted to undivided Bihar, while Jharkhand receives the remaining 2 MAF. Jharkhand's cabinet approved the draft agreement in January 2026, and Bihar's cabinet, then headed by Chief Minister Nitish Kumar, cleared it on January 13, 2026, based on the CWC-vetted memorandum of understanding.

The Union Ministry of Jal Shakti subsequently worked to fix a date and venue for a formal signing ceremony, to be held in the presence of the Union Jal Shakti Minister and the chief ministers of both states.

What changes on the ground now?

With the water-sharing question resolved, the path is now clear for construction of the Indrapuri reservoir between Kadwan in Jharkhand and Matiwan in Bihar.

The project is expected to strengthen irrigation via the Sone canal system across eight Bihar districts — Bhojpur, Buxar, Rohtas, Kaimur, Aurangabad, Patna, Gaya Ji and Arwal. The settlement also gives Jharkhand, for the first time, a formally recognised entitlement to draw a defined quantity of Sone water for its own use, ending 25 years of ambiguity over its claim.

Why is this being settled now, after 25 years?

The immediate trigger was direct, high-level intervention from the Centre — Amit Shah personally chairing the July 2025 Eastern Zonal Council meeting achieved a breakthrough that years of lower-level, inter-state technical talks had failed to produce.

The timing also fits a broader pattern of the Centre working through India's backlog of long-pending interstate river disputes; reports on the Sone settlement note that the Centre is expected to next turn its attention to the more contentious Mahanadi river dispute between Odisha and Chhattisgarh.

Notably, the agreement's momentum has survived a change in Bihar's own political leadership, moving from cabinet approval under then-Chief Minister Nitish Kumar in January 2026 to the formal signing that is now taking place. What finally unlocked the deal, in short, was political will at the Centre translating a technically simple division of numbers into an agreement that a quarter-century of state-to-state negotiation alone could not deliver.