Rejuvenation of Lakes in Indian Cities: A Case Study for the Betterment of Wetlands in Bangalore

Pollution is defined as “to make something impure”. Water bodies, natural or man-made, are susceptible to pollution ranging from plastic waste disposals to urban and industrial sewage discharge. Until 1960, records show that there were 262 water bodies in Bangalore dotting its topography to impound runoff water so that citizens would always have an abundance of water to drink, irrigate their lands and for fishing. In recent times, the number of lakes in the city has dropped drastically and even the ones present are subjected to illegal encroachment, sewage, toxic waste apart from dumping of domestic waste, human and animal defecation. Few of the lakes now have a permanent froth, consisting of harmful bubbles on the surface that occasionally catch fire due to the presence of oils and chemicals (e.g. Bellandur Lake). Samples from five lakes were tested for pH value, TDS and EC values. Further, the afore- mentioned lakes were assayed for change in area over a span of seventeen years (2000 to 2017). Based on the sources of pollution, a TRIZ-based ‘Morphological Analysis’ was carried out to propose various technological and bio-inspired solutions for the betterment of these lakes and its ecosystem. It was interpreted from the study that lakes near industrial areas (i.e. Varthur and Bellandur lake) were more polluted than the other lakes (i.e. Hebbal lake and Sankey Tank). This study infers that city sewer lines and industrial waste are the broad sources of water pollution. Moreover, illegal encroachment of lakes due to increasing urbanization has taken a heavy toll on these dying water-bodies. Various preliminary conceptual models based on technological and bio-inspired approach were proposed, which needs to be comprehensively developed and further tested in the future.