Thursday 27 June 2013

The first flooding of Bangalore

A sharp spell of rain is all that it takes for Bangalore to turn into a nightmare, leaving road flooded, drains overflowing, houses and apartments water logged and traffic piled up for hours on end.
In the previous post on urban flooding, we had spoken of  how the first recorded flooding of Bangalore took place more than a century ago.
Since then, little has changed. Every rain brings forth the same age old problems, the same assurances and of course the same result. The only thing that seems to have changed is the name of the civic body. It was Bangalore Municipality when it was started in the id 1900s. It then became the City Corporation of Bangalore and now the Bruhat Bangalore Mahanagara Palike (BBMP).
Though the BBMP has identified five main areas in the city as flood prone, there seems to be a clear lack of focus and commitment in taking remedial action.
The Ejipura-Koramangala area comprising also of National Games village, BTM Layout Ist and 2nd Stages, parts of Bannerghatta road and Jayanagar-JP Nagar: Shankarappa Garden which embraces Magadi Road and surrounding areas: Brindavan Nagar and Mathikere areas and finally Ambedkar College that straddles across Airport Road area.
Apart from this, the BBMP has identified 134 low lying and flood prone areas. Such areas have been identified in each zone, including zones under Greater Bangalore like Byatarayanapura, Bommanahalli, Dasarahalli, Mahadevapura and Rajarajeshwarinagar.
BBMP says the east, west and south of Bangalore are more prone to flooding than the other parts.  It has identified Koramangala, Austin Town, Domlur and Jayamahal in the east zone; Rajkumar Road, RMV Layout, and Mahalakshmi Layout in west Zone;  Bhuvaneshwari Nagar, Maruthi Nagar, Bapuji Nagar and Tavarekere in the south zone as regular flood prone.
The east zone was found to be the most vulnerable to urban flooding with 108 areas, while the west zone had 31 such points.
Residential layouts situated within and in the periphery of these areas virtually turn into a sea of water and this is mainly because of the inability of the Koramangala valley to pump out excess rain and drain water.
The Koramangala valley has a fall of just thirty metres for a length of 13 kilometers that it traverses across the city.  Other natural valleys in the city such as Chellaghatta and Hebbal have a fall of 120 metres for 11 kms. Moreover, all the valleys are chocked with debris and encroached and heavily silted. These natural outflows needed to be fully cleared for smooth flow of rain and waste water away from Bangalore. This is the key to prevent flooding and water logging of drains and roads, inundation of low-lying areas and overflow of sewage onto to the streets.
The mean annual rainfall in Bangalore is about 880 millimetres (mm) spread over 60 rainy days in an year. The city has a network of a 180-km- long primary and secondary
storm-water drainage system. The network needs to be harnessed in its entirety and suitably remodelled  to take the monsoon load of the rains. Despite the remodeling taken up under the Jawaharlal Nehru scheme and spent hundreds of crores, nothing seems to have worked and a permanent solution continues to evade Bangalore.
Bangalore has a natural elevation of 920 metres and this means that the water can percolate on its own down the slopes. But why is this not happening. The answer is simple. Encroachment, illegal construction, blockage of storm water drains, breaching of tanks and lakes and deliberately blocking the natural flow of water.
Poor and often short sighted urban planning has resulted in Bangalore rapidly losing its green cover and water bodies, so much so that they have become the prime reason for almost all of the City’s ills. Bangalore is the only city among the big four metropolis of India-Mumbai, Kolkata, Delhi ad Chennai-not to be located in or near a water source. If Mumbai has the Arabian Sea, Kolkata the Ganges and Madras the Bay of Bengal, Delhi has the Yamuna but Bangalore has no such water body. The Cauvery, which supplies a major portion of the City’s water is 100 kilometres away.
Yet, Bangalore has seen a massive urban influx over the last five decades and there has been a 637 per cent increase in urban areas in Greater Bangalore area from 1973 to 2009 and it is still growing. The rise in built up area from 16 per cent in 2000 to around 24 in 2009 and almost 30 per cent today has seen a corresponding decrease in wet lands, breaching of lakes and tanks and decrease in green cover, leaving water with no natural course to flow off. This has been exacerbated by the presence of 542
slums with many of the lacking basic facilities in sanitation and hygine and straining the natural resources.
The wetlands in and around Bangalore decreased from 51 in 973 to just 17 now and even the water bodies have fallen sharply from 159 to 93. Besides, a staggering  66 per cent of lakes are sewage-fed, 14 per cent surrounded by slums and 72 per cent showed
loss of catchment areas. More alarmingly, catchment areas were used as dumping yards by all people and organizations ,including the civic agencies.
Between 2002 and 2009, water bodies decreased by almost 60 per cent and on an average 10,000 trees were cut every year. Thus, man interfered with the natural drainage system: destroying natural water channels, blocking natural flow of water, encroaching on water bodies and filling up drains and channels with debris. The  result: flooding and only one example of  how difficult it is to cope up with such events is enough to boggle one’s imagination. In August 2000,  torrential rains wrecked havoc on most parts of Bangalore and the BBMP had to pump out one crore litres of water from City Market area. This operation went on for three weeks. Where did this water go. To the drain and how. What the BBMP failed to ensure naturally, it had to do manually.
(This is the second part of a series of articles on urban flooding.)  

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