Large Dams Blamed for Floods
By Bharat Dogra
NEW DELHI, Sep 4, 2006 (IPS) - While floods are a perennial feature of the Indian sub-continent, this year's inundations have left
leading environmental activists pointing fingers at the many large dams built precisely with the idea of controlling natural water systems.
''There is much to learn from the experience of floods this monsoon. Contrary to the case made out for large dams for controlling floods, the flood situation has actually been worsened by the dams,'' said Medha Patkar, internationally-known anti-big dam campaigner.
This year, with several downstream states accusing those upstream with improperly timed water releases, it has become particularly hard for the champions of big dams to hit back at people like Patkar. Even
officials in Nepal have accused India of not opening sluice channels in time, aggravating floods in that Himalayan country.
'Mismanagement and negligent operations of the large reservoirs on the Tapti, Narmada, Krishna, Godavari, Mahi and Sabarmati rivers have created man-made disaster in the states of Gujarat, Maharashtra, Madhya Pradesh, Karnataka and Andhra Pradesh,'' said Himanshu Thakkar, hydrologist and coordinator for the South Asia Network on Dams, Rivers and People (SANDRP). 'The worst affected states are also the ones with the biggest dams''.
Thakkar has been demanding a '
credible, independent enquiry as to why such a situation arose when they it could have been avoided with more optimal operation of projects.'' The true extent of the damage cause by the floods is yet to be estimated but hundreds of thousands of people are reported to have been affected.
Some experts believe that this year's deluge, affecting large parts of the country, resulted from a failure to balance properly flood control with the others major uses of big dams -irrigation and hydro-power generation.
Ramaswamy Iyer, former chief secretary in the water resources ministry, told IPS that many of the dams were specifically designed for flood control. 'But there is an inherent conflict of this objective with the other objective of trying to maximize hydro-power and irrigation,'' he said.
Iyer said while flood control demands that dams allow adequate space to receive flood flows, the objective of maximizing hydro-power potential means that
water level in dams is kept as high as possible. 'As there is greater pressure to increase power generation, the objective of flood control gets lesser attention.
This can lead to a situation when water has to be released suddenly on a large scale leading to disastrous flash floods,'' he said.
Dinesh Mishra, an engineer and convenor of the Barh Mukti Abhiyan (Campaign for Freedom from Foods) says: 'It has been widely acknowledged in official documents that the siltation rate of an overwhelming number of dams has been much higher than original estimates. The real problem is silt, not water. Silt eats up the storage capacity of reservoirs. Hence, their capacity to absorb flood flow is reduced."
But
Thakkar attributes this year's devastation to sheer mismanagement. In particular, he says, the floods which ravaged Surat city in the western state of Gujarat were preventable. Known for its diamond cutting industry, the city saw three-fourths of its area submerged with the army having to be called out to rescue thousands of marooned people.
An estimated three million people had to do without basic needs such as food and clean water on the evening of Aug. 6, when the irrigation department suddenly released 800,000 cusecs of water from the Ukai dam.
According to Thakkar enough information on rainfall was available to suggest that water release in manageable quantities should have started from Aug. 1. But this was neglected so that when water was finally released it was about double the drainage capacity of the Tapti river. Worse, water was released around high tide.
In the Marathawada region of western Maharashtra state, where hundreds of farmers were reported to have committed suicide this year following drought-related distress, the situation changed to one of worse distress from floods.
Vijay Diwan, an activist with Nisarg Mitra Mandal, has monitored the situation carefully. He says: "
A comparison with the rainfall for the earlier five years shows that rain has not been significantly higher this year in districts like Jalna, Parbani and Nanded, so people are asking whether these floods were related to the mismanagement of projects like Jayakwadi and Issaper dams and Vishnupuri Lift Irrigation Project."
People in these parts were caught between large volumes of water released from upper dams and no water release from lower dams, said Diwan. There was considerable water already stored in the dams when the rain started.
Thakkar points out that data available for several dams show that they had substantial water just before the onset of monsoon and therefore, had much less capacity to absorb monsoon flows.
'Of course reservoirs need to store water as protection against the possible failure of monsoon, but there have to be some norms about what is adequate protection.
In the case of Ukai, the water in storage before monsoon was much greater than the needs of Surat,'' said Thakkar. 'Clearly there are several aspects of dam management that can be debated, but this year's floods have led to serious doubts about the usefulness of dams for flood-protection.''
Ravindranath, an activist closely involved with flood-warning in northeastern Assam state, said: "
Our past experience has been that even relatively small dams have been able to unleash destructive flash floods, but now nearly 160 dams are being planned in the northeast and some of these are very massive projects''.
Moreover, the north-east has been witness to large-scale ecological destruction in the catchment areas due to illegal lumbering, quarrying and mining. 'With ruined catchments and large-scale dam building, the future is hazardous,'' said Ravindranath who works with River Basin Friends', a well-known environmental organization.
An important aspect of this year's floods was that while floods were reported from what were regarded as water-deficit areas (there was a highly destructive flood in one of India's most drought-prone districts - Barmer in Rajasthan), some of the surplus basins experienced drought-like conditions, said Iyer.
Activists say
this year's apparent mismanagement is the best argument yet against India's ambitious but controversial plan to link together its major rivers to offset floods against droughts that occur simultaneously in widely-separated parts of the vast country. (END)
