The River, it is rotten, or sometimes to throw down a canal clogged by debris, according to pipe heavy fall it causes phifon cataclysm. Finally finding a human intellectual it loop back ourselves.
The river is polluted Or sometimes dumped into the canal Debris to clog the pipe was pitch was heavy rain caused flooding. Finally, a problem that the man had come back to ourselves.
The river will rot, or sometimes left on the right track. Trash can clog pipes according to special heavy rain is caused by flood. Finally, the problem of man-made is back to ourselves.