Reason for floods in rivers and heavy destruction on account of floods
1. Heavy siltation of rivers reduces their carrying capacity
2. Weak embankments break on rise in water level
3. The low efficacy of the flood forecasts issued by nearly 180 specialised stations now in operation
4. The lack of preparedness by flood vulnerable regions namely 19 States and Union Territories.

Reasons for floods in Urban Areas
The scenes of gridlock and frustration in Gurgaon, Bengaluru and Delhi last week travelled around the world, just months after the disaster in Chennai. 
1. Severely encroached upon or polluted Wetlands, Lakes and Open spaces reduces seepage on ground water. 
2. Siltation of lakes and other water bodies
3. Haphazard development which ignores the gradient of the city