Two years back, if anybody had come across the Narayanapuram Lake located in Sunnambu Kolathur on the 200 ft Thoraipakkam- Pallavaram Radial Road and Puducherry Keni near Sholinganallur, then they would have said that these two lakes were useless and dead. This situation has changed completely now and these two lakes mentioned above are brimming with water.
It must be noted that eco-restoration was carried out at these two lakes in Chennai. In the initial step the water hyacinth was removed and then the inflow of sewage was plugged. The information collected is the water level in these 2 lakes started recharging the groundwater table in the localities.
According to Vasantha Raja, an activist, invasive water hyacinth spreads like a mat on the surface of the water body and hence it must be cleared. It blocks the sunlight from penetrating and hence there would be depletion of the oxygen levels. Finally the organism inside get destroyed and water body also gets destroyed in the end.
It should be noted that untreated raw sewage results in water contamination and water hyacinth thrives well in this scenario. One important piece of information gathered is after the Narayanapuram Lake was restored, typha reed started growing in a portion of the lake. This typha reed is present in the Pallikaranai marshland is known. It is now revealed that typha reed has brought out the improvement in the ecology of the lake. The superb information is this reed would not allow water hyacinth to reappear on the water body.
Bio-remediation work was carried out on the Puducherry Keni near Sholinganallur and it produced superb results now. Information got is both these water bodies in Chennai are free from water hyacinth and sewage does not enter them. The role played by the activists is tremendous in restoration of these 2 lakes or water bodies. It took six months for them to clear the water hyacinth and strengthen the bunds and de-silt the water bodies.
It is now proved that if other water bodies are also cleaned and maintained in a similar manner then these water bodies could even become an alternative source of water during drought.