In Hindu mythology, Rain God Indra provides water to protect life forms but becomes Purandar to destroy cities and habitations when humans violate the laws of nature. The destructive flooding of cities is thus explained. Indra pours water as per requirement of every particular region. Meteorologically, there was no devastating upward or downward trend of rainfall in 200 years. But in the last 20 years, rainfall diminished alarmingly with a peculiarly contrast record of increasing floods in most Indian cities. So, the oft-cited reason by expert administrators that ‘heavy rainfall in a few hours’ does not hold good. It is obviously an excuse for bad town planning. Real researchers know the root cause of the problem: Cities have become less dependent on their own water sources. They look for water from rivers away from the habitation. No wonder, the number of water bodies in all major cities has drastically come down in the last three decades. The builder-politician-bureaucrat nexus has knowingly suffocated the city open spaces for commercial purposes, causing permanent havoc. Water, which over the ages seeped into the soil, has nowhere to go now. As insane craving to live in cities kept growing big, property business became highly lucrative. Unscrupulous politicians and builders began making easy money by selling off floodplains to create prime residential locations. So, as monsoon comes, disasters happen. The floodplains and lakes in the low-lying parts of age-old cities have been filled up with garbage-debris to become reclaimed land. These divine water bodies not only provided water to all forms of life but also drained off excess rainwater. Indiscriminate construction has blocked the path of water leading to dangerous flooding on the city roads. Even then, the ancient storm water drains are blamed by so-called experts. It is important to know most modern drains designed recently are not capable of containing the excess water that has no seepage ground. Mumbai's drainage system was designed in the early 20th century for a maximum rainfall of 25 mm per hour, assuming that half the rain would be absorbed by the soil and only half would flow into the drainage system. But mindless rampant urbanisation with concrete or asphalt pavements does not permit water to go underneath. Today, even one inch per hour rain throws the drainage systems out of gear. Water, finding no natural path, stays on ground in flood form.
Natural drainage by using slopes of a city is now a forgotten technique. Half-baked town planners and engineers keep focusing on artificial beautification by high-level roads and parks across all places without considering the nature-made contours. Ring roads in most riverside cities have no culverts to discharge excess water even when the cities have the base above the riverbed. And the great flyovers look great but cause excessive flooding! Bhubaneswar, a Smart City candidate with the highest scoring in competition, is now experiencing the beauty of Venetian waterways. Venice has fun gondolas; Bhubaneswar has stranded people with submerged vehicles without any hope of relief for days. Most hubs across cities, particularly bus-stands, markets and housing complexes have been brought up on buried water bodies and wetlands. Many streams with natural slopes feeding the rivers have been levelled to make room for concrete jungle. The CDA human habitation in Cuttack has come up in the heart of Kathjodi riverbed. When brainless human experts tamper with surfaces where rainwater is supposed to rest or flow, people have to live with the wrath of floods.
The Governments start cleaning drains in May instead of February when monsoon is right in the face and the garbage debris collected from the drains is waiting on the banks of nullahs to be washed by rainwater back into the heavily silted nullahs and drains.
Interestingly, the central Europe does not have monsoon torrential rains. Yet, it now witnesses rivers diverting up to three km from their designated channels after only a little rainfall. The very idea of channelisation which the Western world had introduced is now being considered terrible bane. They are compelled to remove manmade embankments at a great cost now.
A report on the ‘State of India's environment due to floods’ shows that all the money spent on flood mitigation has only resulted in more floods because the government focussed only on constructing more and more embankments.
Water harvesting in lakes and ponds is no traditional wisdom. It is a tested contemporary solution, not just to mitigate floods but also to fulfil the local water requirements. Rainwater is meant to become groundwater; so, every citizen has to take the initiative to recharge it. When somebody constructs a house, it is their responsibility to take care of the excess water from that plot of land, which would otherwise go into a storm water drain. Or else, waterlogging would happen around the plot. A proper rainwater harvesting system in the house would not just replenish groundwater but also improve its quality and mitigate flooding. Five per cent of any built-up area, be it an apartment complex or an individual house, if used for rainwater harvesting, can mitigate floods and also reduce water bills. Some towns in Germany have made it mandatory for construction projects to take responsibility for their excess runoff or pay more for putting pressure on storm water drains. Administration must ensure water drains are utilised as water harvesting bodies. The federal government is now toying with the idea of providing technical and logistical support to people keen to implement rainwater harvesting structures. Recharge wells can be constructed in open spaces around storm water drains. Drain water then can be intercepted and directed to these wells. In areas where open spaces are not available, recharge wells can be dug in the drain itself beneath the manhole so that it can be cleaned from time to time without difficulty. Relaying of roads as per the natural drainage patterns should be done as soon as possible, no matter if it costs for long-term benefits. All new construction projects must follow this model to remain safe from flooding.
Every drop of rainwater contributes to floods; so permeable gravel or stone-lined parking spaces and footpaths that can absorb water have to replace concrete floors. And there is no substitute to planting trees in whatever area is available with the sole view to promoting water absorption and preventing soil erosion.
*The Mahanadi is lifeline of both Chhattisgarh and Odisha. It drains an area of around 1,41,600 sqkm across a total course of 858 kim with an average annual surface water potential of 66.9 km³ in its basin. But only 50.0 km³ out of this is utilisable
water. 80,000 sqkm are irrigated by this river.
During the peak monsoon, the Mahanadi discharges 20,00,000 cubic feet per second, nearly the same as river Ganga does. But the Ganga is perennial and the Mahanadi is dry for eight months.
The Mahanadi dispute between Chhattisgarh and Odisha has been in news for quite some time. Chhattisgarh has 54 per cent of the Mahanadi drainage area and Odisha only 46 per cent. Chhattisgarh says its projects under progress have been sanctioned by the Central Water Commission which ensures individual States are not deprived of their legitimate shares. A Joint Control Board proposed in 1983 to resolve water sharing disputes has not come in place until now. lately, the Chhattisgarh Chief Minister has nearly proved that Odisha was aware of the projects at all times. The people of both the regions have a right to know what’s happening. The Central Water Commission is duty-bound to clarify the rights of the individual States and if there has been any violation of the guidelines for sharing the water. But if eventually Chhattisgarh is exposed as thieving Odisha’s shares and rights, the Odia people to whom the Mahanadi means so much, will agitate fiercely.
(The writer is a core member of Transparency International, Odisha)