“The stench was unbearable. It was like a dumping ground – its water a sickly green, and swarms of mosquitoes thronging around the garbage which line its shores,” this is how Madhulika Choudhary remembers the Hyderabad’s Neknampur lake from July last year, when she and her green NGO Dhruvansh, started work on reviving it.
Dhruvansh adopted the lake last year and planned to clean and restore it to some semblance of its earlier clean self. And now, they plan to do so with what Madhulika calls a “sustainable, minimal budget solution” – floating islands.
A ‘floating island’ unit, Madhulika explains, is essentially a plant which is introduced on floating surface into the water. “Sewage water has high content of phosphorous and nitrogen, which are also fertilisers. Once the plant grows and its roots reach the water, they will start absorbing these nutrients, reducing their content in the lake,” she says.
The dirty Neknampur lake before Dhruvansh began the clean up
The structure
Madhulika got the idea of floating islands when she read about it online, and realised it was low-cost and easily imitable.
The base of the ‘island’ is made out of thermocol and plastic bottles – light, buoyant material which will not react with water. This is then covered with yarn and some soil is added to the top. Then, saplings of plants like Kelly’s Lilly and Fishbone Water Fern are planted in the soil. There are holes beneath the structure so that once the plant grows, the roots can reach the water.
The floating islands on Neknampur lake
“We also have to remove and replace these plants every six months to a year because they would have become saturated with the pollutants they are absorbing,” she explains. The base is also a sturdy 10x10 feet to give a stable foundation to the plants, she adds.
The larger picture
Madhulika says that the idea is not just to rid the water of the pollutants, but also to restore the biodiversity which disappeared because of incessant dumping.
Apart from the floating islands, Madhulika and her team also planted local species along the entire shoreline of Nakempur lake, like peepal and gulmohar.
She also hopes to attract birds, butterflies and other fauna through the plantations. “A lake is not merely a water body, it is an entire ecosystem where every organism plays a part. If you just give it some breathing space, it will thrive,” Madhulika says.
Tree saplings planted along the shoreline of the lake
They also hope to cover about 30%-40% surface of the 10-acre lake with the floating islands, so as to reduce the algae. Algal blooms, or excess algae, are found in water bodies with excess nutrients. Too much algae can block sunlight from reaching aquatic plants underwater.
The floating islands, Madhulika hopes, will also become popular because of the beautification. “Many people may not care much about the tech behind it if it does not look good. It’s a lake after all. But we hope their blooming flowers, greenery and subsequently the birds and butterflies it will attract, will serve the twin purpose of beautification and sustainability,” she says.
Conservation is an ongoing process
Madhulika and her team are receiving funding from the Hyderabad Metropolitan Development Authority (HMDA). Presently, each floating island unit costs about Rs 3,000. Two units have been introduced to the lake a fortnight ago.
She does concede that at some point, we are going to have to stop polluting the lakes incessantly. “According to the regulations, you need to have one sewage treatment plant for every 20 apartments. But that’s not being followed. A water body can only take so much. Somewhere people have to move ahead of merely raising a hue and cry, and take responsibility,” she asserts.
(All photos courtesy Madhulika Choudhary)