The ‘rainbow waters’ of the Brahmaputra4 min read . Updated: 22 Jul 2018, 08:25 AM IST
The annual monsoon floods of the great river destroy everything in their path, but they also nurture life
In most of the North-East, when it rains, it pours. Water comes down from the grey sky in torrents. Drops gather into trickles on the ground. The trickles join together until they become little streams, into which countless other trickles and numerous streams merge. This network of arteries either becomes a river, or meets one. The rivers rush down through the green hills, gathering yet more streams along the way. Eventually, down in the floodplains of Assam and Bangladesh, they join the great river formed by many rivers: the Brahmaputra.
Every monsoon, the Brahmaputra floods, as it has for millennia. Its waters have ceaselessly carved the earth around it, destroying a river bank here, creating an island there. The cycle of life in the valley that bears the river’s name has evolved to take advantage of this annual flooding. The floods used to spread water and silt on the floodplains. They used to fill up the water bodies—ponds, lakes and wetlands. The fertile soil and fish from the water bodies used to provide livelihood to people round the year, says Himanshu Thakkar, coordinator of the South Asia Network on Dams, Rivers and People.
An estimated 95% of the people in Assam eat fish, according to a senior official of the state’s fisheries department. Demand now outstrips local production by thousands of metric tonnes a year. Artificial methods of breeding are in vogue as the natural processes by which fish used to breed and spread are now hampered and inadequate. Before the artificial methods became popular in the 1950s, there was only nature’s system. During the monsoon floods, the rising waters would inundate the floodplain wetlands that lie along the Brahmaputra. Monsoon is the breeding season for fish. Several fish species would move into the safety of the wetlands with the rising waters, where the young would be born and grow big, before moving out with the receding waters.
There are now only a few such safe places left. The Kaziranga National Park, which lies on the banks of the Brahmaputra, is one of them. It is a floodplain ecosystem, says Rathin Barman, joint director of the non-profit Wildlife Trust of India. The monsoon floods provide major “energy" for the ecosystem, he says. Since it is a protected area, the park serves as a breeding ground for many kinds of fish that replenish the river. The fish are not the only creatures that benefit from the floods; the park as a whole depends on its creative destruction for sustenance. “If there is no flood, Kaziranga will die," says Barman.
The floods, a boon for the park’s grasslands, wetlands and fish, take a toll on the animals, however. Barman says the problem is not floods per se, but flash floods. In a normal flood, the animals migrate to higher ground as the waters rise gradually. The Karbi Hills adjoin the park, and that is where the rhinos, elephants, tigers, deer, all make their way. “The present boundary of Kaziranga is given by us, not the animals," Barman points out. Rhinos don’t read maps.
Flash floods give animals and humans no time to migrate. With every passing year, it is this kind of flooding, rather than the natural and gradual rise of waters, that is becoming common. Thakkar, a graduate of the Indian Institute of Technology in Mumbai, blames engineers for this. The government saw natural flooding as a problem. Engineers offered embankments as a solution. “Every honest engineer will tell you it’s not possible to flood-proof the whole Brahmaputra valley," says Thakkar.
Embankments constrain the river’s expansion during the rainy season at particular points; the waters eventually find an outlet somewhere further downstream. The silt that would have been deposited on the floodplains is now deposited on the riverbed. The riverbed starts rising. Eventually, somewhere or the other, sooner or later, the embankment breaches. It is like a dam bursting. The flood waters come rushing in. There is a whole new character to the flood, which is now a disaster.
This image of flood as disaster is what the world now knows. It plays out every year, the same old headlines, of so many killed, so many thousands rendered homeless, hundreds of thousands affected.
This year, the monsoon has come late to Assam. The rains have so far been deficient. There are, however, reports already of flooding from three districts.
Life in the Brahmaputra valley continues to revolve around the floods. Preferred livelihoods, these days , no longer come from farming the fertile silt or fishing the bountiful wetlands and rivers. They come from fishing for government funds, which pour in every monsoon. The flood remains a harbinger of both misery and bounty...it’s just that the misery goes largely to one lot, and the bounty to another.
The floodplains and river islands have been colonized into permanent human habitats. The ebb and flow of water with the monsoon rains is now a problem. Many water channels have disappeared. Wetlands have been cut off from rivers. The arteries of water that formed an organic system are now viewed as individual canals. The image of the braided Brahmaputra has absurdly turned into one channel of water flowing between two banks.
The many streams and rivers, the forests around them, and the rains that nourish them, all form one interconnected whole. Experts call the water in rivers, streams, lakes and groundwater “blue water", and that held in the vegetation, “green water". The water held as vapour in the “rivers in the sky", what they call “rainbow water", closes the hydrological cycle. Much of the landscape of the Brahmaputra valley has been shaped by the stars of this cycle—the torrential monsoon rains and the river. Forever destroying and creating, they are the primary movers, in these parts, of the cycle of life.