flooding in Bengaluru, particularly the encroachments of wetlands that acted as
natural drainage channels for the city. The second case study of Mumbai looks at
the July 2005 floods when the entire metropolis was marooned due to unprecedented heavy rainfall. It puts in perspective various scientific studies that show
impacts of climate change in Mumbai and the associated risks; and argues that
unless environmental planning is made an integral part of the city planning exercise,
Mumbai will witness more flooding and huge loss of property. It also talks about
adaptation measures being undertaken by the civic administration and if these are
good enough.
2 Bengaluru’s Flooding Woes
Bengaluru, known to be the hi-tech city with the IT boom, is one of the fastest
growing cities in the world. Bengaluru meteoric growth into a globally integrated
network of trade besides highly competitive framework has aggravated profound
changes in the settlement patterns impacting strain on the infrastructure. City’s built
up area has increased by almost 600 % in the last forty years. Increased migration
from rural areas have increased the number of slums portraying urban poverty, the
official data indicates 597 slums in Bengaluru, which may be much more, since the
data is based on the survey conducted more than three decades ago. The city did not
witness obvious instances of urban flooding until the recent past. Given the topographical conditions of being above 3000 ft the sea level, well planned wetland
system and no rivers close by, floods did not affect the city for decades. Study by T.
V. Ramachandra et al. have reiterated that urban heat island phenomenon is evident
across localities with higher local temperatures showing that pattern of growth and
its implications on local climate, besides, decline in natural resources—loss of
vegetation by 76 % and decline in water bodies by 79 %), poor drainage network
and encroachment of flood plains have added to the problems, which have caused
urban flooding problems.
The urbanization process and the hydraulic insufficiency of drainage systems are
seen as the two most major causes of urban flooding in Bengaluru. Ad hoc
urbanization has altered the drainage characteristics of natural catchments resulting
in increase in the volume and rate of surface run-off. The current drainage systems
do not have the capacity to cope with the increased volume of water, further
blocked with solid waste and debris. Encroachment of wetlands, floodplains have
obstructed floodway’s causing loss of natural flood storage. Studies have indicated
the gravity of the situation highlighting the fact that the city has lost more than half
of its water bodies and two thirds of its green space in the past four decades (Sridhar
et al. 2012). Bengaluru does not have water resources of its own other than its
aquifers and ground water reservoirs. These tanks were gravity-fed and excess
water was redirected through canals located at a lower gradient, as it has a natural
Lack of Environmental Planning Exacerbating Climate Change Risks …
451
natural drainage channels for the city. The second case study of Mumbai looks at
the July 2005 floods when the entire metropolis was marooned due to unprecedented heavy rainfall. It puts in perspective various scientific studies that show
impacts of climate change in Mumbai and the associated risks; and argues that
unless environmental planning is made an integral part of the city planning exercise,
Mumbai will witness more flooding and huge loss of property. It also talks about
adaptation measures being undertaken by the civic administration and if these are
good enough.
2 Bengaluru’s Flooding Woes
Bengaluru, known to be the hi-tech city with the IT boom, is one of the fastest
growing cities in the world. Bengaluru meteoric growth into a globally integrated
network of trade besides highly competitive framework has aggravated profound
changes in the settlement patterns impacting strain on the infrastructure. City’s built
up area has increased by almost 600 % in the last forty years. Increased migration
from rural areas have increased the number of slums portraying urban poverty, the
official data indicates 597 slums in Bengaluru, which may be much more, since the
data is based on the survey conducted more than three decades ago. The city did not
witness obvious instances of urban flooding until the recent past. Given the topographical conditions of being above 3000 ft the sea level, well planned wetland
system and no rivers close by, floods did not affect the city for decades. Study by T.
V. Ramachandra et al. have reiterated that urban heat island phenomenon is evident
across localities with higher local temperatures showing that pattern of growth and
its implications on local climate, besides, decline in natural resources—loss of
vegetation by 76 % and decline in water bodies by 79 %), poor drainage network
and encroachment of flood plains have added to the problems, which have caused
urban flooding problems.
The urbanization process and the hydraulic insufficiency of drainage systems are
seen as the two most major causes of urban flooding in Bengaluru. Ad hoc
urbanization has altered the drainage characteristics of natural catchments resulting
in increase in the volume and rate of surface run-off. The current drainage systems
do not have the capacity to cope with the increased volume of water, further
blocked with solid waste and debris. Encroachment of wetlands, floodplains have
obstructed floodway’s causing loss of natural flood storage. Studies have indicated
the gravity of the situation highlighting the fact that the city has lost more than half
of its water bodies and two thirds of its green space in the past four decades (Sridhar
et al. 2012). Bengaluru does not have water resources of its own other than its
aquifers and ground water reservoirs. These tanks were gravity-fed and excess
water was redirected through canals located at a lower gradient, as it has a natural
Lack of Environmental Planning Exacerbating Climate Change Risks …
451