Dams are temples of doom, not development
by Kanti Kumar
31 July 2001
India’s east coast state of Orissa has kept its date with being in disaster news every year. After being hit by a heat wave in 1998, super cyclone in 1999 and severe drought in the following year that forced unparalleled migration from western Orissa, it had to be washed away in worst of the floods in independent India’s history. More than 8.5 million people in 24 districts have been affected and 89 lives have been lost. Crops standing on 5.25 million acres worth Rs. 451.7 million have been damaged.
At the time of writing, 400,000 people were still marooned without food or shelter. It is as if nature is following a calendar of one major calamity every year for Orissa. While such natural mishaps have been the norm for decades, the human factor behind the current devastation is not insignificant.
Most ironically, it’s the “multi-purpose” Hirakud dam, built across the Mahanadi in 1956 to control floods, which has a major role in floods that have become frequent and worse. The frequency of floods has increased from once in 9.75 years before the dam’s construction to once in every 3.75 years. The reasons are not only environmental degradation, but also unsound development policies and vested political, caste and business interests.
The primary objective of the Hirakud dam was to control floods in coastal districts. But for political considerations power generation and irrigation took precedence over flood control. The politically correct targets need high water storage in the reservoir throughout the year. But heavy siltation caused by deforestation and soil erosion in the Mahanadi’s catchment has substantially reduced the reservoir’s storage capacity.
In the event of an active monsoon, the reservoir is soon filled to the brim and it becomes essential to release vast amounts of floodwater to save the dam, which has developed cracks. Because of scanty release of water from the dam most of the year, the Mahanadi and its distributaries downstream are perpetually short of flowing water. The beds thus have considerably risen over the years.
When floodwater is suddenly released in bulk, these rivers which are by now swollen with rainwater cannot release it to the sea. The swollen Mahanadi and its distributaries then erode their banks and inundate the low-lying coastal areas.
Not only the dam has worsened floods, it has also had negative impact on Orissa’s overall environment: The distributaries’ courses in the delta have changed. Tidal batterings are fast eroding the coastline as the Mahanadi’s mouth is deprived of the protective sand, and threatening the state’s only major port at Paradip. The tidal forest area is also declining and floods are becoming more frequent and cyclones more devastating.
The salt water carried in by tides cannot completely flush out during the ebb. The soil and water table in the lower reaches of the delta have become saline, affecting the crop yield. The water has become brackish even in deep tube wells, threatening a major drinking water problem in the area.
