Watch: Why the people of Kerala need to wake up and save the Periyar
When the gates at the bridge open, you can witness the moment the colour of the water changes. From a greenish blue, the water suddenly becomes pitch black - but that's just one day. On other days, at other points in the rive, the water turns red, or blue. Sometimes, the fishermen say, it has all the colours of the rainbow. And if you come in contact with it, the rashes and other diseases are unbearable.
This is the reality of the Periyar river in Kerala. The 244 km long Periyar is the state's longest river. Originating in the Shivagiri Hills in Sundaramala in Tamil Nadu, the river flows through the districts of Idukki and Ernakulam before it joins the Arabian Sea at Cochin.
There are 280 industries that function on its banks, and many of them let out untreated chemicals into the water, affecting the livelihood and health of the communities that depend on the river.
So how do we save the Periyar from dying? Watch: