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Drowned Out Despite massive amounts of money spent on dams, embankments and canals, the floods in India just keep on increasing in frequency and destrucive capacity? Why? Hundred years have passed since ‘Article 1’ was published in the December 21, 1907 issue of the India Mirror. Still, ‘Article 2’ from one of today’s leading newspapers Business Standard (published on September 5, 2008) expresses the same helplessness. And the same concerns. The only thing that has changed is the frequency and magnitude of floods in India. Obviously, we have not learnt a lesson from the mistakes in the past. What went wrong? To answer this, let us go back to Article 1. India was visited by floods every year. Still, the people who lived here used ingenious, home-spun techniques to manage the floodwaters. Like in Bengal. BENGAL’S GENIUS Bengal once had an extraordinary system of inundation canals. Floodwater entered the fields through these canals, and irrigated the fields. The water carried rich silt, which fertilised the fields, and fish, which swam through these canals into the lakes and tanks to feed on the larva of mosquitoes. This helped to check malaria in this region. Clever, isn’t it? But, unlike Bengal, there are some regions that do not have a tradition to battle floods. Like North Bihar. Wondering why? The reason is not that it was not capable of controlling floods; it did not want to. The local cultivators welcomed the floods.
Floods in the North Bihar plains date back to antiquity. However, they were never considered as a bad phenomenon, rather they were deemed as nature’s bounty. Farmers extensively used floodwaters for irrigation. The waters refilled the tanks and wells, and the silt deposits of inundating rivers replenished the natural fertility of the soil and ensured a good winter harvest. Eklavya Prasad of Megh Pyne Abhiyan explains, “The floodwater used to spread across a large area. Thus, its height was low. It would also recede quickly, as there were no obstructions. And there was no need for flood control because floods were never as devastating as today.” However, with growing population the British rulers began to pressurise the locals to move into the fertile areas around the rivers – the floodplains – to occupy and cultivate these rich tracts. As they settled closer and closer to the rivers, the floodwaters that could earlier spread across a larger area, now exploded on human habitat, causing havoc. This changed the entire perception about floods. Floods now became a destructive force for the people living in the floodplains. Post-independence, the government decided to control this menace by constructing dams and embankments. Did that help? Let’s delve into the history of embankments and dams and find out. Hey! But aren’t we talking about floods in this issue? Yes we are. So, we must begin here… HISTORY: PROPHET OF THE FUTURE During the British raj, the colonial rulers did not pay enough attention to flood control measures besides constructing embankments. When they left, there were some 5,280 km of embankments along different rivers, of which 3,500 km were in the Sundarbans in West Bengal and 1,209 km along the Mahanadi in Orissa. In independent India, the First Five Year Plan, which began in 1951, decided to shift from embankments and focus on building dams. Dams were deemed as the ‘most effective way of preventing flood damage’ (the Plan document). Because embankments contain or restrict floodwater within rivers, but dams hold floodwater in the rivers’ upstream and later release it slowly to prevent any flooding downstream. But before the country could begin any of these plans, there came a spate of severe floods in 1954. All northern rivers flooded simultaneously and caused enormous devastation across Uttar Pradesh, Bihar, West Bengal and Assam. The floods attracted public attention to the inadequacy of control measures. To counter this, the government immediately claimed that it was possible to get rid of this menace. How? It started a massive upsurge to construct structural measures like embankments and dams. So, embankments changed the character of floods in Bihar for the worse. But how is that possible when embankments are supposed to protect people from floods? Here’s how...
• Build-up of floodwaters Embankments act like walls and limit the river’s natural flood plains, the lands adjacent to rivers. So, a dangerous amount of water builds-up within the embanked area. • Drainage congestion They cut off the natural drainage of water from flood-protected areas into the rivers. • Water logging If the bed of a river rises rapidly after embanking, say due to excessive silt deposition, the water level may reach a point where it would always remain higher than the surrounding area. Thus, the flood-protected area will get waterlogged. • Sediment load The sediments, which would have earlier deposited over a wider area of the flood plains, get deposited within the embanked area. This raises the floodwater levels. To stop this, the height of embankments is constantly increased. • Reduced natural fertility Embankments also deprive the floodplains of the rich silt deposits left behind by receding floodwaters. • River attacks Shifting rivers can erode embankments. • Breach blow The main problem is that embankments encourage human occupation of flood plains by installing a false sense of security. So when they break, the floodwaters literally cascade upon the surrounding area. What makes these “protectors” tumble down? According to Professor Vishwanath of National Institute of Disaster Management, Ministry of Home Affairs, “Too much water often forces rivers to change their course, as in the case of River Kosi. The water hits the embankments directly. If there is even a slight fault in their engineering, they break.” This is not all. Embankments often dig up their own graves. The silt that gets deposited in the embanked area puts pressure on the structure and erodes it. The Rashtriya Barh Ayog, Ministry of Water Resources, 1980 report states, “embankments are not a feasible measure of flood protection in cases where the country run-off draining into the river is so large as to inundate appreciatively the area protected by the embankments from river spills...” The Report of the Government of India’s National Commission on Floods (NCF) mentions that “…construction of embankments in certain areas can lead to increase in flood levels upstream and downstream.”
Even dams, which are expected to provide flood moderation, are often the cause of massive floods. Before monsoon, huge quantities of water are stored in them. When they are nearly full, a lot of water is suddenly released into the river to lower the water levels. If the water is more than the river can take, it overflows in the downstream. “Dams are actually the cause of many of the floods that visited India in July-August 2006, particularly those in Mahi, Sabarmati, Narmada Tapi, Chambal, Krishna and Godavari basins”, writes Himanshu Thakkar of South Asian Network of Dams, Rivers and People (SANDRP) in ‘A Dam-made Disaster’. Many of these disasters could have been avoided if the dams had been operated properly. For instance, the 2006 Gujarat floods. The catastrophe, which killed more than 120 people and rendered 25,000 people homeless, occurred because of the mismanagement of the Ukai Dam on Tapi River. First, the “dam managers” allowed the reservoir to fill past the allotted ‘flood storage’ point, and then they delayed the release of water. Not only was Tapi River’s carrying capacity not taken into account, it’s reduced storage capacity due to siltation was also overlooked. All these factors led to the destructive floods in the cities located downstream. This was not a unique case. Dams, including the Bhakhra, Hirakud, Tawa-Bargi, and Damodar, have led to major flood disasters. OTHER FACTORS Apart from embankments and dams, snowmelt, tropical storms, hurricanes, tsunamis, and undersea earthquakes are the other common causes of floods in India. But the main culprit is, of course, the monsoons. India gets an annual rainfall of 400 million hectare metres. Seventy-five per cent of this is received during the four monsoon months of June to September. As a result, almost all the rivers swell up with water and flood due to:
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