The Ganges Water Treaty is a bilateral international agreement between India and Bangladesh, officially titled the "Treaty on the Sharing of the Ganga Waters at Farakka". It was signed on December 12, 1996, by Indian Prime Minister H. D. Deve Gowda and Bangladeshi Prime Minister Sheikh Hasina Wajed.
The treaty was created to resolve a long-standing dispute over the sharing of the Ganges River's water, which intensified after India commissioned the Farakka Barrage in 1975. The barrage was built to divert water into the Hooghly River to maintain the navigability of the Calcutta Port, which significantly reduced the dry season flow downstream into Bangladesh. The treaty replaced a series of temporary arrangements, including a five-year agreement signed in 1977.
The core mechanism of the treaty is a formula for sharing the water at the Farakka Barrage during the lean season, which runs from January 1 to May 31 every year, based on 10-day periods. The formula is based on the flow recorded at Farakka, using 40 years of average flow data from 1949–1988. The key provisions are:
- If the flow is 70,000 cusecs or less, the water is shared 50:50.
- If the flow is between 70,000 and 75,000 cusecs, Bangladesh receives a guaranteed 35,000 cusecs, and India receives the remainder.
- If the flow is 75,000 cusecs or more, India receives 40,000 cusecs (or 75,000 cusecs, depending on the source), and Bangladesh receives the balance. The treaty also includes an emergency clause, Article II(iii), which mandates immediate consultations if the flow falls below 50,000 cusecs in any 10-day period.
The treaty is valid for 30 years and is set to expire in December 2026. It connects to the broader framework of transboundary river management, particularly through the Joint Rivers Commission (JRC), which was established in 1972 and is tasked with monitoring the treaty's implementation. The treaty has not been replaced or amended, but both countries have begun technical-level talks for its renewal or the drafting of a new agreement, with discussions focusing on the formula and the inclusion of upstream withdrawals.