The Teesta River is a major transboundary Himalayan river, approximately 414 km long, that flows through India and Bangladesh. It originates from the Tso Lhamo Lake (or Teesta Khangtse Glacier) at an elevation of about 5,280 meters in North Sikkim, India. The river flows southward through the Indian states of Sikkim and West Bengal, carving a deep gorge through the Siwalik Hills, before entering Bangladesh. In Bangladesh, it merges with the Jamuna River (the name for the Brahmaputra River in Bangladesh). The river is vital for irrigation and hydroelectric power generation, with projects like the Teesta Barrage Project in India and the Teesta-III Dam in Sikkim.
The river's significance is deeply connected to the unresolved Teesta Water Dispute between India and Bangladesh, which dates back to the partition of India in 1947. The problem it seeks to solve is the equitable allocation of water, especially during the dry season (December to March), when the flow significantly decreases. An ad hoc water-sharing agreement was reached in 1983, which temporarily allocated 39% of the water to India and 36% to Bangladesh.
The mechanism for a permanent solution has been stalled; a draft treaty in 2011 proposed allocating 37.5% of the water to Bangladesh and 42.5% to India, but it was not signed. The agreement was stalled due to opposition from the Chief Minister of West Bengal, citing concerns about water scarcity in the state. The issue connects to the broader diplomatic relations between the two countries and the management of other shared rivers, such as the Ganges, for which a treaty was signed in 1996. Recently, the dispute has resurfaced, with Bangladesh prioritizing the resumption of talks with India on the water-sharing issue.