By the time the Ganga winds its way across the north Indian plains and enters Bangladesh in the dry season, there isn't much water left in it. In future there will be even less water.
This is not just an international problem between India, Bangaldesh and Nepal. Increasingly, Delhi will have to deal with the conflicting water needs of Uttar Pradesh, Bihar and West Bengal.
Since India achieved independence from British rule in 1947, the Ganga and its tributaries in North Bihar have seen a surge in embankment building for flood control and irrigation. Far from controlling floods, these interventions have made drainage congestion and water logging worse. The resulting floods have spread human misery, and seriously affected the ecology of the plains. Social and environmental activists in Bihar have been left to pick up the pieces.
North Bihar's human and environmental crisis is a result of bad governance, promoted by inflexible technological choices. And it affects almost all aspects of public life, not just river management. But this is not acknowledged in discussions between Patna and the federal government in New Delhi. Both have tried to sidestep the issue by looking for a politically easier technical solution that will divert attention from their own past failings—a high dam upstream in the mountains of Nepal. But delays in building such a dam could widen the contradictions between New Delhi and Bihar, and bring their dispute into the open.