After all, in India when the government cannot ensure good quality road construction, something that is visible, who is going to ensure high quality construction underground. Even worse, who is going to ensure that they are kept well-maintained and desilted. This can be repeated adnauseum for most cities. The biggest reason for urban floods is the total lack of attention to the nature of India's hydrological system. This is something our ancestors knew but our current urban planners and politicians don't worry about such mundane things.
Urban land is valuable.
So illegal filling of urban waterbodies is rampant. Every deluge brings with it immediately a complaint against the meteorological department for inadequate warning. The CPM did this in Calcutta last year and Chandrababu Naidu in Hyderabad this year. At least Hyderabad's environmentalists like K L Vyas and K Purushotam Reddy have forced the chief minister to acknowledge that the major cause was blockage of drainage channels by buildings and improper maintenance of tanks. Built in 1562, the storage capacity of Hussainsagar tank, the city's biggest waterbody, is now half.