Development has to take place. However, it certainly cannot happen at the cost of fragile ecosystems which provide food and water security to us. Our blind pursuit of development has allowed massive encroachments of forest land, which can lead only to more floods and conversely more water scarcity, Dr T.V. Ramachandra, Head Scientist, IISc, tells Aksheev Thakur
The floods in Kerala and Kodagu are the tragic indication of mismanagement of the riverine ecosystem. This includes our land and water resources. The watershed or catchment area of a water body retains the flow of water and mitigates floods and droughts, these are either areas covered by natural vegetation or monoculture plantations. Our studies in the area indicate higher levels of infiltration, between 40 and 50 percent, in the catchments covered by native vegetation, while that dominated by monoculture plantations allows infiltration to an extent of between 15 and 24 percent. Degraded catchment areas, where extensive deforestation or devegetation has taken place, has very little infiltration capacity. This is also evident with the existence of perennial streams in the catchment dominated by native vegetation.
However, catchments in which native vegetation has been degraded, has seasonal streams that dry out in about four months, while those with monoculture plantations do so in between six and eight months.
The area has seen a massive decline of forests, without about 24 to 30 percent giving way to senseless, large-scale land use. Deforestation and the infestation of monoculture plantations are the prime cause of floods, for they have resulted in a sharp decline in water retention capability of the respective waterbody catchment.
The coastal areas are more vulnerable compared to inland areas like Bengaluru. Kerala has faced ecological destruction since 1970's and Bengaluru city too is same. We have infrastructural projects at places where it is not required. Our city planning should include climate resilience which would incorporate on how the city contributes to climate change and how one can make it more adaptive.
Kshitij Urs
— country head, Greenpeace India
Yes, the region needs to develop. However, it certainly cannot happen at the cost of already fragile ecosystems which also provide food and water security to peninsular India. Our blind pursuit of development has allowed massive encroachments of forest land, which can lead only to more floods and more water scarcity. Forest deparment officials of the respective states should be held accountable for these encroachments.
The mismanagement of watershed and catchment areas, as well as the lack of accountability amongst our decision makers, are the prime causes of the floods in these regions. Irresponsible, large-scale land cover changes in ecologically sensitive river basins, combined with unplanned development activities. Linear road projects, road widening, railway lines, river diversion projects in the name of drinking water schemes have succeeded in fooling the judiciary, managed to bypass environment protocol and social impact assessments have invited nature's wrath.
The implantation of unscientific, consultant-driven projects, with a nexus of corrupt bureaucrats, engineers and contractors all united by the sole aim of looting our natural resources, have impeded nature's flow and left us with deadly consequences.
Bengaluru if witnesses the rain what Kodagu is facing, we will be in worse state since canals are in a bad shape. Due to vast projects, top soil is eroded and SWDs' are encroached. Unless people realise the importance of SWD and lakes as flood mitigation area the situation will be precarious
Ram Prasad — Convener and co-founder of Friends of Lakes
Temporal Rainfall data analyses highlights a seven to eight year cycle of above average rainfall, followed by a seven year cycle of below average rainfall. Times of high rainfall, when floods are likely, can be mitigated by the integrated, ecologically sensible management of the precious catchments. Narrowing and concretising natural drains will only enhance the instances of floods as drains lose their natural hydrological functions, including infiltration, groundwater recharge and remediation. The federal government must intervene, identify ecologically sensitive regions in the country and ensure that they are protecte from the clutches of this mafia. The nation will develop better with a healthy ecosystem.
URBAN FLOODING
We also concluded in our study that the frequent flooding in Bengaluru is the result of an increase in impervious area, combined with high-density urban development in catchments and the loss of wetlands and vegetation. The increment in the paved surface will be a whopping 94% by 2020, along with the resultant reduction in wetlands, vegetation and pervious area. Urban flooding creates huge economic losses and there have been instances when even eight cm to 10 cm of rainfall in a short span have resulted in flooding. The low lying areas can be flooded in 30 minutes with 30 mm of rainfall, all due to unplanned and intense urbanisation.According to CDP 2005, 2015, buffer zones should be declared as No Development Zones. the time has also come to decongest the city. Encroachment of lakes and Storm Water Drains (SWD) leads to the depletion in groundwater which further increases the chance of flooding. Moreover, the encroachment of water bodies has led to a loss of interconnectivity in the lakes.
Koramangala Floods in 2017
During a field visit, made with the officials of the Karnataka Lake Conservation and Development Authority (KLCDA), we found that the storm water drain connecting Bellandur lake with City Market, had been narrowed down to 28.5 m from its orignal width of 60 m. This was in complete violation of NGT guidelines. The concretisation and narrowing of drains only worsened the impact of the flood in Koramangala last year. This also affected the hydrological functional ability of the storm. Moreover, with concretisation of drains, the velocity of water in the drain increases and there is a chance of us losing the city if things are not brought to control. One of the major points to highlight is that the continuous flooding of low-lying areas has a catalyzing effect should solid waste and building debris accumulate in the drains.
(As told to Aksheev Thakur)
