Why it's not a river but a dirty drain, back home?

We were at the Jim Corbett National Park in Uttarakhand and as usual, the visuals of the river were a pleasant surprise for our eyes, with neat and clean water and no pollutants at all.

My daughter had a very simple question that how this neat and clean water gets that much stinking and polluted that it resembles a drain? Why it's not a river but a dirty drain, back home? 





Truly, it's no more a river, no more a lifeline of Delhi as we have converted it into a dirty and a stinking drain. No doubt earlier, it was the lifeline of Delhi, but today you cannot go even nearer to it as it has the dirty and stinking water, the surroundings are covered with filth and garbage and you won't even get a feel of a river as now it resembles a dirty drain.



Hope you have viewed all the vids embedded above depicting the present status of the river Yamuna in Delhi. Don't you think that it's the right time to come forward to save the river Yamuna in order to save our Delhi?