In the last two weeks that it has been flooded, Bihar received well below normal rainfall. In the last one week, it had a rainfall deficiency of 40 per cent while the week before that, between August 11 and August 17, it received almost 30 per cent below normal rainfall. And yet, it has seen widespread flooding, in and around Patna, and some other areas.
The flooding happened for two main reasons. There was widespread rainfall in the foothills of the Himalayas during this period and the rivers flowing from those areas like Rapti, Sarada or Ghagra, were carrying excess water by the time they reached Bihar. The other reason was the sudden release of large amounts of water from the Bansagar dam MP, into the Sone river that travels through south Bihar before meeting the Ganga.
While little could have been done about the excess flow of the Himalayan rivers, the release of water from the Bansagar dam could have been managed better. Data from the Madhya Pradesh water resources department website shows large volumes of water were discharged from the dam over a three-day period starting August 18, once the reservoir got very full. Very little water was released before that, even though the reservoir level was swelling and there were forecasts of more rains in central India.
Water officials in the central government say that had the water been released phase-wise, ignoring the tendency to hoard water in the reservoirs, the situation would have been much better.
The tragedy has once again highlighted the need to have more consultative decision-making process on operations of large and medium dams that have an impact across state boundaries. It has also brought back the focus the way Bansagar is being managed.
A big inter-state project like Bansagar usually has a reservoir regulatory committee with representation from all the concerned states. This committee decides on operational issues, including the time and quantity of water to be discharged. The Sardar Sarovar project or the Damodar Valley project have such committees. Officials say that in the case of Bansagar, however, this regulatory committee has not been constituted because of objections from the Madhya Pradesh government which apparently claims the project as its own. Bihar and Uttar Pradesh, therefore, have no say on when or how much water is released from the reservoir.
The two states do have a representation on the Bansagar Control Board that was constituted when the project was initiated in the early 1970s, but this board’s mandate is restricted towards the construction and expansion of the project. It does not deal with operational issues, officials say.