The recent high floods in the Mahanadi river system as well as in Brahmani, Baitarani and Subarnarekha rivers have underscored the need for a fundamental review of the flood management and mitigation measures. The state being home to many rivers is hit at regular intervals by high floods which defy all predictions resulting in a miserable situation for millions. At least a million people have been affected by the devastating floods in the densely populated deltaic regions.
Let us have a quick relook at the past. Not so long ago (in 2008) when the Mundali peak flow crossed 15.60 lakh cusecs, more than 4 million people were affected, the worst-affected districts being Kendrapara, Cuttack, Jagatgsinghpur and Puri where 240 breaches had occurred.
Over a period of six decades, people have been misled to believe that engineering solutions were the only answer to control floods. However, the experiences of large floods in 1955, 1982, 2001, 2008 and 2012 have demonstrated their inadequacy and ineffectiveness beyond a point.
CHANGES OVER THE DECADE
A well-entrenched engineer, politician and contractors lobby has been successful in mobilizing gargantuan amount of public funds to construct yet more bunds, embankments, etc. There is always pressure from the voters to build more and more embankments as people want to avoid the inconvenience of living with gentle floods. Nobody wants the muddy flood water in their village as it disrupts daily life. Roads got cut off and mobility was affected which was not a great issue 50 years ago.
Everyone knows how much of our budget is swallowed by the Water Resources Department for river flood control embankments, dams, etc. However, this has failed to prevent the recurrent high floods in Mahanadi and its distributaries.
A few years ago, Mahanadi River brought down huge quantities of silt and the large fan-like network of distributaries were useful in depositing silt over thousands of hectares of fertile agriculture land in the coastal delta districts. In fact, for farmers in the delta, the annual floods were a boon as it enriched the soil with rich silt leading to rich harvests.
When the state embarked on an embankment building spree since 1970s with generous doses of World Bank loans, the natural silt depositing process which had been going on for thousands of years was abruptly arrested since the embankments became artificial impediment to free spillage. This resulted in accumulation of silt in the river bed leading to increase in bed height over the last four decades which decreased the water carrying capacity of the river.
When the embankments breached, the intensity and duration of flooding increased. The water could not flow back back to the river due to obstruction posed by embankments. The flood plains which had hitherto open access to the river bed are now isolated and they turn into giant stagnant water pools increasing the misery of the victims. Therefore, we now see waterlogging inspite of a rapid decline in river level. Road communications collapse and crops rot. Mud houses collapse killing the inhabitants and cattle. The single most important cause of death for flood victims is mud house collapse.
There are many ox bow lakes and dead river channels beside the course of the river Mahanadi and its distributaries which are now illegally drained for agriculture and whose exits and inlets are blocked. Ansupa lake, for example, is less than half of its orignal spread. They used to absorb floodwaters and were effective natural sinks for floods. They have disappeared now and that volume of water which was retained upstream is now simply gushing down the river.
For thousands of years, the dwellers of Mahanadi delta had learnt to live with floods and had accordingly constructed houses only on high plinths which survived the worst of floods even though they were mud houses. The water used to drain out within 3-4 days after depositing rich silt which enriched the soil and lead to bumper crops. No longer this is happening. The silt and sand load is not being spread over the flood plain due the high embankments. It ends up on the river bed raising it every year with successive monsoon floods. More the bed rises more is the danger of flooding of the surroundings.
SOME FLOOD CONTROL/MITIGATION MEASURES:
Can we think beyond embankments and dams? In the era of climate change that is now playing out in full force, rainfall can be abrupt, unpredictable and incessant at times bringing down a deluge that cannot be managed for the simple reason because it never occurred historically in recorded memory.
Instead of embarking on high cost solutions by building another dam in downstream of Hirakud reservoir, government has to allow nature to play its role. Mitigation for flood damage would be more appropriate to manage floods rather than attempts to stop the river from flooding into the historical flood plains which nature has developed over centuries.
Satellite technology and GIS mapping should be used to study the flood patterns. We can get valuable data to identify the historical flood plains and natural drainage channels through which the flood waters entered and escaped.
The government's disaster management plans need a drastic change in the approach. Instead of trying to stop floods, we should now think of allowing soft flooding! Everyone knows the enormous power of the floodwaters that gush out of a breach in the embankment. We should think what could be done to decrease the chance of a breach! The force of the water gushing out of the breach which is usually 20-30 ft high from the ground level of surrounding paddy fields or villages causes enormous damage to infrastructure and human lives and cattle. Can we address this?
(1) While rebuilding the embankments, there should be reinforced concrete spillways on the banks at strategic points where breaches have been noticed historically to allow flood waters to escape after a certain level so that the high water pressure does not force the river to breach embankments and cause utter devastation. Most of the damage to houses, roads and installations is caused by the ferocity of the high currents which were created by the pressure build up due to extra high embankments. This was further aggravated by increased height of river levels due to unreleased silt load.
(2) The government should ensure that the extensive metal road network in the Mahanadi and other major rivers delta has sufficient number of causeways to allow free and quick flow of floodwater. Over the last 4 decades, these causeways have been built up to the level of the road to make it easy for driving. The design should not be altered as most roads laid during the British period had adequate causeways to allow excess water to flow.
(3) The Forest Department foolishly embarked upon the Green Mahanadi mission and planted up the flood plains and the river bed at many locations including Cuttack city. Creating obstructions on river beds lead to trapping of silt and sand and changes the natural topography of the river bed. This again leads to a rising river bed thereby creating a flooding potential. Shockingly, the W.R. Department never stepped in to halt such disastrous activity of the forest department. Even now there is time to cut down all such plantations in river beds and riverine islands and keep them free of trees to stop sand and silt trapping.
(4) People living in the flood vulnerable zones should be given special grants for building pucca houses on a war footing. All villages within a radius of 5 km of the river or distributary in the delta should be covered under this scheme. The state government can easily divert money from non-emergency purposes like Sports Stadium, Temple renovation and carry out such life saving work if money is an issue.
A trusted contractor should be engaged with a slightly higher cost, wherein he can complete the work using BIS standard materials within 3-4 months in every village. Such houses will be strong and can withstand flood fury. Moreover, a high platform for protecting cattle/goats should be built on stilts in each village. The money spent on such protective measures would be a fraction of that required to repair high embankments which do not guarantee that floods would not recur and the compensation payment for house damage.
(5) Let’s not recount the normal relief measures which need to be in place since the state government is well aware of SOP to be followed for this given the fact that Odisha regularly faces floods. There is a need for sufficient number of power boats and relief material to be stationed at vantage points. There is lack of a motivated volunteer group, which is why there is a necessity of building up an army of village-level trained volunteers of college students with regular training sessions and orientation at the local college who can assist the administration in carring out rescue and relief operations.
It is hard to fight nature and there is a limit to this too despite providing enormous budgets to do so. A better sustainable and low-cost strategy is to allow nature to play its course and also simultaneously make attempts to decrease the hard impacts on people of the delta.
(DISCLAIMER: This is an opinion piece. The views expressed are the author’s own and have nothing to do with OTV’s charter or views. OTV does not assume any responsibility or liability for the same. The author is a conservationist and a former member of the National Board for Wildlife. He can be reached at firstname.lastname@example.org)
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