Hyderabad: The Neknampur Lake is seeing better days in terms of its water quality and biodiversity now, thanks to the ‘floating island’ self-purification project taken up by city-based NGO Dhruvansh. Commemorating World Wetland Day, on February 2, a unique island made up of 27 rafts, each measuring 10 feet x 10 feet and carrying a total of 3,500 saplings over 2,500 sq ft of styrofoam, bamboo, gunny bags and coir was floated at the centre of Neknampur Lake.
The concept was based on hydroponics technology under a phytoremediation project, and took about a year to materialise. The conservation and management of the lake is being done by the NGO with supervision and support of the State Irrigation Department, Rangareddy District Collector, Hyderabad Metropolitan Development Authority, Telangana State Pollution Control Board, Telangana Fisheries Department and the Telangana State Biodiversity Board.
According to the latest data collected by the Telangana State Pollution Control Board and shared with Telangana Today by the NGO, the Biological Oxygen Demand (BOD) at the outlet of the lake has come down from 27 mg/L to 3.8 mg/L, a stupendous fall, in these five months.
The BOD at the inlet of the lake is 76 mg/L, which was is above the 3 mg/L standard required for water to be used for drinking after disinfection and conventional treatment. Similarly, the Chemical Oxygen Demand (COD) has come down to 56 mg/L at the outlet of the lake from a high of 253 mg/L at the inlet of the lake.
On the other hand, biodiversity was noted to be on the rise as the conservationists found five bird nests with one of them containing six eggs in it. The nests and eggs belong to Whistling Ducks, Herons, and Geese, managing trustee of Dhruvansh Madhulika Choudhary said. “The floating Styrofoam island has led to an increase in the aquatic and bird life. It has even cleaned up the lake and we have numbers to prove that the self-purification is proceeding at a good pace. This indicates that bio-remediation, self-purification and self-rejuvenation projects like this are important to allow nature to take care of itself,” said Choudhary.
Python spotted on floating island
Dhruvansh volunteers met a sly predator recently when they brought the floating Styrofoam island to shore for maintenance. A 12-ft-long python peeked out of the plants as they were clicking pictures of bird nests and eggs, Dhruvansh founder Neeraj Singh said. “Spotting a healthy young python, although is a scary experience, showed us the rejuvenation of the biodiversity at the Neknampur Lake was going very well. A food chain has been boosted as can be seen by the numerous new turtles, birds, seasonal plants and sparrows we spotted.
The fact that a python slithered onto the floating island shows that there is enough biodiversity for all aquatic life from small fishes to large snakes,” said Singh. No fish deaths were recorded after the restoration process began, Singh added, with the lake now home to 132 species of flora, 178 species of birds, 12 species of mammals, 21 species of reptiles, several species of insects and 20,000 fishes.