This is one example of human encroachment to build infrastructure for the needs of increasing population. However, it ends up disturbing the ecological balance , making the region prone to disasters - deemed "natural" , but in reality, are "man-made".
In Chennai, such encroachment of canals, marshlands , along with inadequate storm water drainage system for the increasingly expanding Metropolis, is a major reason for waterlogging and floods during north East monsoons.