Abutting a large wetland where lake inter-linkages have been broken by buildings and debris, floods were but inevitable at Doddanagamangala where PESIT is located, say local residents and researchers who have studied lakes in this area.
While PESIT may not be situated within a wetland, it is certainly located very close to one, said a research associate with Azim Premiji University. Just a week ago, PESIT had witnessed flooding though not of the same magnitude.
The network of rajakaluves or connecting channels between two lakes here — Doddanagamangala and Konnapana Agrahara — have been encroached by houses and institutes and are also blocked by construction debris being illegally dumped here, said M. Krishnappa, MLA, Bangalore South.
Satellite imagery shows an increase in the number of buildings around Doddanagamangala Lake and wetland over the years, says T.V. Ramachandra of Energy & Wetlands Research Group, Indian Institute of Science. “In fact, most wetlands in Bangalore are being encroached. We see this in Bellandur and Varthur too.”
In a study on urban flooding in Bangalore, Dr. Ramachandra had found that construction on wetlands and rajakaluves dramatically reduced their capacity to cope with rain. With a lowered natural flood storage capacity “even 30 mm rainfall in 30 minutes could cause flooding, especially in low-lying areas” the report said.
The consistent encroachment of feeder canals and wetland in the area has destroyed the topography, said a local resident. “The natural water flow gradient has also been disturbed. The piece of land next to the campus was a paddy field earlier and has now turned into a marshy land with water all year round.”
M.R. Doreyswamy, chairman, PES group, who owns the land and the building where Azim Premji University is located, denied that the building was either built on a wetland or on rajakaluves.
