No lessons were learnt. This year, when the city went underwater again, some 22 slum dwellers died in another landslide, the army was called out for help and some 300 people had to be evacuated. And as water mixed with filth like rat and dog urine, the city faced a dirty disease called leptospirosis. The mixing of floodwaters with sewage gives the urban flood a particularly unhealthy character. Hyderabad has suffered an estimated damage of Rs. 700 crore this year.
Mindless urbanisation is the key cause.
The problem will continue to grow till there is proper urban management. But inadequate infrastructure is often cited because everybody wants to make money creating these systems whose quality is very poor. 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.