Artificial 'floating islands' clean Madiwala Lake

The Karnataka Forest Department has set up 10 artificial 'floating islands' in Madiwala Lake, one of the oldest lakes in Bengaluru's southern section.

A report by the Bangalore Mirror describes these islands as raft-like structures that are built with PVC and PET bottles as the frame and mesh and coir as the actual body. The 'islands' are fitted with plants that absorb chemicals like nitrates from the water, reducing their concentration.

The KFD decided to adopt this technique after seeing several examples of it being used to clean waterbodies around the world. The benefits of these 'islands' includes helping control algae bloom by means of absorbing the nutrients that come into waterbodies through sewage. In addition, these can act as resting grounds for birds, low-cost and are easy to maintain.

In Bengaluru, Puttenahalli and Hebbagodi lakes have been exposed to this form of treatment and have responded well to it, the report states, quoting Harshavardhan, Additional Conservator of Forest, Bengaluru Urban Division.

The WWF is also part of the initiative and they have conducted extensive research on the quality of water in the lake and the birds that frequent it.

The report says the plants used in the 'islands' are Typha and Canna, two genera of flowering plants, to absorb the nutrients. The KFD is responsible for maintaining the islands and is planning on extending this program to other lakes.