Floods in south India: A man-made disaster

Both the state governments have requested the Centre for flood relief to the tune of a whopping Rs 32,000 crore. The debate has begun to find the causes that led to such a horrible situation.

Intergovernmental Panel on Climate Change (IPCC) had categorically stated that heavy rainfall in such a short period of time is linked to the global warming and climate change. The traditionally water deficit regions of Deccan plains in these two states have suddenly become water surplus within a few days. It is very unnatural to get rainfall that is 10 times the normal average rainfall for the entire year in a matter of just few days.
However, the blame game has already started between the state governments, in which the downstream Andhra Pradesh is accusing the upstream Karnataka government that it started releasing the dam waters from Almatti without giving adequate notice. This has resulted in a large inflow of 22 lakh cusecs of water into Srisailam dam, whereas the dam was built to handle only 10 lakh cusecs. The situation was grim as the water level rose to 890 ft, whereas the capacity was only 885 ft.

Why did the dam authorities wait for such an eventuality, which led to unimaginable destruction? Well, to find an answer, we need to understand the water politics in the Krishna Basin involving the upstream states of Maharashtra and Karnataka and the downstream state of Andhra Pradesh.

In their respective greed to conquer River Krishna, the Maharashtra government built the Koyna dam, while Karnataka built Almatti and Narayanpur dams on the same river. Andhra built Srisailam and the Nagarjuna Sagar, the 124 meter-high dam, the tallest in India. Both Andhra and Karnataka joined hands to built Tungabhadra dam across the Tungabhadra river, which is a tributary of Krishna.

These major dams were built in the Krishna basin with an objective to exploit the water resources both for irrigation and hydro-electric power generation. Srisailam is one of the biggest hydro electric projects in south India with an installed capacity of 1760 MW. The dam authorities have to meet the dual objectives of generating power and to meet the demands of irrigation. In order to maximise the output, they store water to the brim, instead of releasing it periodically and gradually reducing the load.

Accepting the fact that the irrigation authorities mismanaged the flood waters, the question remains as to why the river basins were not able to drain out the water and reduce the impact of flood fury? Prof Jayanta Bandopadhyaya of IIM, Calcutta says: “We have mucked up the drainage system of our rivers. We have cut off the lifeline of rivers; the natural water flow has ceased due to construction of dams and the riverbed has risen due to silting (leading to floods).”

Is silting a major problem that is causing floods in south India? The catchment area of Krishna is in the hills of Western Ghats from where it originates. Extensive deforestation in these hills and accompanying soil erosion have resulted in the silting of major dams. “It is more difficult and expensive to remove the silt than to build new dams,” said Karnataka’s water resources minister in the Assembly some time ago.

D K Mishra, an expert on flood management says the official documents have acknowledged that the siltation rates of the major dams in the country are higher than what was estimated. The real problem is silt and not the water. Silt eats up the storage capacity of the reservoirs. Hence their capacity to absorb flood flow is reduced.
A disturbing phenomenon is that in most of the cases, the dams that were built to control floods have turned the major causes of floods in the downstream.

We have built huge dams, but we have not devised mechanisms to co-ordinate the release of surplus waters from these dams. Obviously, this is a human and technical failure. The Central Water Commission has all the technical inputs and remote sensing data to predict the water flow in the river basins. The dam managers and  political leaders could have used this to reduce the destructive impact of the flood fury in the downstream regions.

There is some truth in the statement of the Telengana Rashtra Samiti that the flood havoc is a human failure rather than nature’s fury. TRS has alleged that the irrigation projects were illegal and politically motivated to benefit the contractors’ lobby.
The irony is that thousands of crores of rupees of public money is spent on construction of these dams and now the governments are seeking several thousand crores more to mend the damage caused by these structures. While the ordinary people struggle to recover from the impact of the deluge, the politicians see a great opportunity in the present situation. The political breed always loves a good flood relief package!
(The writer is a noted environmentalist)